Document text
UNCLASSIF1EL
FM 4-184
WAR DEPARTMENT
ANTIAIRCRAFT ARTILLERY
FIELD MANUAL
BARRAGE BALLOON SITE
INSTALLATIONS
April 13, 1943
REGRAOED UNCLASSIFIED
AUTHpaovoF DOD DIR. 5200. 1 R
FM 4-184
ANTIAIRCRAFT ARTILLERY
FIELD MANUAL
j*
BARRAGE BALLOON SITE
INSTALLATIONS
UNITED STATES
GOVERNMENT PRINTING OFFICE
WASHINGTON : 1943
WAR DEPARTMENT,
Washington, April 13, 1943.
FM 4-184, Antiaircraft Artillery Field Manual, Barrage
Balloon Site Installations, is published for the information
and guidance of all concerned.
[A. G. 062.11 (2-25-43) .]
By order of the Secretary of War :
. G. C. MARSHALL,
Chief of Staff-
Official :
J. A. ULIO,
Major General,
The Adjutant General.
Distribution :
IBn and H 44 (5) ; IC 44 (25).
(For explanation of symbols see FM 21-6.)
ir
TABLE OF CONTENTS
Chapter 1. General. Paragraph Page
Section I. General 1-6 1
II. Classes of sites 7-9 6
• III. Occupation of sites 10-11 7
Chapter 2. Basic construction of site.
Section I. Access road 12-16 9
II. Earthwork 17-21 9
III. Steel and concrete 22-24 11
Chapter 3. Construction of bed and winch instal-
lations.
Section I. Anchorages 25-36 12
II. Winch installations 37-43 21
Chapter 4. Use of bed.
Section I. Bedding down 44-57 26
II. Tail-line mooring 58-68 38
III. Mooring-circle close-haul 69-72 48
IV. Midship mooring 73-76 50
Chapter 5. Other site installations and site main-
tenance.
Section I. Buildings, gas cylinder stacks, and
local defenses - 77-98 57
n. Maintenance of site 99-116 65
Appendix I. Dummy sites 69
II. List of references 72
Index 73
III
FM 4-184
ANTIAIRCRAFT ARTILLERY FIELD
MANUAL
BARRAGE BALLOON SITE INSTALLATIONS
CHAPTER 1
GENERAL
Section I. General
II. Classes of sites
III. Occupation of sites
Paragraphs
1-6
7-9
10-11
Section I
GENERAL
■ 1. Scope. — This manual presents the details of construc-
tion, use, and maintenance of land sites for low altitude
barrage balloons. Rigging of the bed is described for securing
low altitude barrage balloons by bedding down, tail-line moor-
ing, mooring-circle close-haul, and midship mooring. Ap-
pendix I discusses dummy sites. For information on water-
borne sites see PM 4-187.
■ 2. Site. — A barrage balloon site is the area that contains
the balloon bed and auxiliary installations necessary for in-
flating, mooring, and flying the balloon. The winch position,
balloon maneuvering space, local defenses, gas cylinder stacks,
motor parking space, operations hut, and frequently the crew
quarters are all part of the site. (See fig. 1.)
■ 3. Bed. — A balloon bed is that part of the site on which the
balloon is moored when it is not flying.
■ 4. Grounding. — a. The primary function of barrage bal-
loons is to fly, but circumstances often require that they be
brought down to the bed for varying lengths of time. Bal-
loons often must be grounded to prevent their loss due to
adverse weather. They must be grounded for inspection
and servicing. They must be grounded if demanded by
tactical operational controls.
1
2
BARRAGE BALLOON SITE INSTALLATIONS
4-5
b. Basic considerations in grounding the balloon are:
(1) The balloon must be secured so that it can be put into
the air with a minimum of delay when orders to fly the
balloon are received.
(2) Danger of damage or destruction to the balloon due to
adverse wind conditions must be reduced to a minimum.
c. Mk. VII, Mk. X, D-7, and D-8 balloons are of the low pres-
sure ballonet type. The low pressure ballonet type balloon is
designed to operate with very little or no internal gas pressure,
and is dependent on the wind to obtain and maintain a
streamlined shape. A streamlined shape is not necessary in
still air, but it is very important in a high "wind, because a
flabby balloon is liable to damage, is hard to control, and
causes excessive tension on the flying cable. A streamlined
shape is obtained in the low pressure ballonet type of balloon
by wind blowing through the air-scoop into the ballonet and
forcing the ballonet diaphragm upward; the upward move-
ment of the diaphragm compresses the inflation gas and
tightens the balloon envelope. Since the air-scoop cannot
scoop up air unless the balloon is headed into the wind, it is
important that the balloon be headed into the wind at all
times. During flight, this position is assumed automatically
by the balloon; when the balloon is grounded, it is moored so
that its nose points into the wind.
■ 5. Methods. — a. When the inflated balloon is not flying,
there are four methods of securing the balloon on land
sites: bedding down, tail-line mooring, mooring-circle close-
haul, and midship mooring.
~ /SX) Bedding down is securing the balloon close to the
ground by means of ballast so that the air-scoop is just
above the ground. (See fig. 9.) It is stressed that the bal-
loon, when secured by this method, does not actually rest on
the ground.
(2) Tail-line mooring is securing the balloon by the junc-
tion assembly and tail-line, the balloon being permitted to
turn with the wind. (See fig. 15.)
(3) Mooring-circle close-haul is securing the balloon by
the junction assembly and four handling lines, allowing
restricted movement with the wind. (See fig. 20.)
3
5-6
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
(4) Midship mooring is securing the balloon by the junc-
tion assembly and a wire running line, allowing restricted
movement with the wind. (See fig. 21.)
b. The situations in which the four methods of securing
a balloon are used are as follows :
(1) Bedding down is used to secure the balloon in strong
winds, for inspection, and for minor repairs. The balloon
may be bedded down or partially bedded down for topping-up.
(2) Tail-line" mooring is used to secure the balloon in
readiness for quick flying. In this method of mooring, the
balloon can be handled with the least number of men and
ride light gusty winds with a minimum of attention. If
the tactical situation requires readiness for immediate flight,
the balloon may be held at tail-line mooring even in high
winds. Under ordinary circumstances, however, tail-line
mooring is not used in high winds or storms.
(3) Mooring-circle close-haul is used for the same reason
as tail-line mooring on sites that do not have sufficient
space for tail-line mooring.
(4) Midship mooring is an improved alternative for moor-
ing-circle close-haul.
■ 6. General Features of Handling Equipment. — a. Bedding
down. — The standard equipment for bedding down the low
pressure ballonet balloon is designed so that —
(1) The balloon may be hauled onto, the bed by hauling
on the handling lines, either manually with block and tackle
or mechanically by using the gipsy-head on the winch.
(2) The balloon remains attached to the flying cable while
bedded down, and actually flies close to the ground. The lift
is counteracted by ballast attached in such a manner that the
pull is exerted on the rigging patches in the same direction
as when the balloon is aloft.
(3) No part of the balloon gets too great a load because
the maximum load on any patch is determined by the amount
of ballast that patch must lift.
(4) The balloon may be turned to keep its nose into the
wind without removing the balloon from the bed.
b. Tail-line mooring. — The standard equipment for moor-
ing the balloon at tail-line mooring, which should be pro-
4
BARRAGE BALLOON SITE INSTALLATIONS
6
vided on all sites where sufficient space is available, is de-
signed so that —
(1) The balloon may be moored at the junction assembly
by a wire cable pyramid, and connected at the tail to a
snatch block which rides on a circular cable track.
(2) The snatch block riding on the cable track permits
the balloon to swing with the wind. If the space does not
permit the construction of a complete circular cable track,
a fractional circle should be built in order to take advantage
of this efficient method of mooring. Special effort should be
Blade to locate a segment of the tail-line mooring circle on
the down wind side of the bed.
c. Mooring -circle close-haul. — The standard equipment for
mooring the balloon at mooring-circle close-haul is designed
so that —
(1) The balloon may be moored at the junction assembly
by a safety strop which takes the tension off the flying cable
when the balloon is moored.
(2) The front handling lines are fastened to a cluster of
sandbags on each side of the balloon.
(3) The rear handling lines on each side are reeved through
bed blocks attached to mooring-circle anchorages on the
37-foot circle and are connected by means of a transverse
strop. This arrangement enables the tail of the balloon to
swing with the wind, to a more limited extent that in tail-line
mooring.
d. Midship mooring. — The equipment for mooring the bal-
loon at midship mooring is designed so that —
(1) The balloon may be moored at the junction assembly
by a wire cable pyramid, as in tail-line mooring, and by a
wire running line.
(2) The wire running line, which hangs under the balloon
and just ahead of the rudder, is suspended from two wire
bridles, rigged approximately amidships on opposite sides of
the balloon.
(3) The running line is attached by a trolley assembly to
a cable track around the 37-foot mooring circle.
(4) In this position the balloon is secured at only two points
and is free to swing with the wind, its nose always pointing
into the wind.
518084° — 43 2
5
7-8 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
Section II
CLASSES OP SITES
■ 7. Locations. — In a balloon barrage it may be necessary
to fly balloons from different types of sites. Some sites will
contain ample space for installing all equipment needed for
safe and speedy handling of the balloon, other sites may be
in restricted areas, and still other sites may be over water.
(For information on selection of sites, see FM 4-181 (when
published).) As a rule, exact site locations will have been
designated before those in charge of making installations
arrive.
■ 8. Types. — a. General. — (1) Wherever possible a complete
tail-line mooring system should be installed on a site. The
next best site is one combining a partial tail-line mooring
system and a mooring-circle close-haul or midship mooring
system. When room for complete tail-line mooring is not
available, the site should be made to yield as much tail-line
mooring space on the down wind side as is possible.
(2) On sites lacking room for a tail-line mooring system or
portion thereof, a mooring-circle close-haul or midship
mooring system is necessary. If sufficient space is not avail-
able for at least mooring-circle close-haul or midship moor-
ing, it normally is recommended that a different site be
selected.
b. Urban sites. — Tactical situations will often require the
siting of balloons in urban districts. These urban sites may
be divided into three general classes: residential, industrial,
and business.
y^tl-) In residential districts, sites may be located in vacant
lotsT public parks and playgrounds, golf courses, athletic
fields, school grounds, street intersections, and other open
spaces.
(2) In industrial and business areas, buildings may be
sufficiently scattered to permit selection of ground sites.
When space is not available, it may be necessary to take over
street intersections for sites, moving power lines and other
obstructions. In emergencies, balloons sometimes may be
6
BARRAGE BALLOON SITE INSTALLATIONS 8-10
flown from alleys, courtyards, flat roofs of buildings, and
other similar places too small for the usual bed installations.
c. Waterborne sites. — For information on waterborne
sites, see FM 4-187.
d. Airport sites. — Balloons may be flown from airport run-
ways by use of mobile winches. In such cases, beds for moor-
ing the balloons when they are not. flying should be along
the outside of the runways.
■ 9. Ratio. — It is difficult to predetermine the average num-
ber of the different kinds of sites that will be established in
future balloon barrages. Liaison officers from Great Britain
estimate that less than one-tenth of the Mk. VII balloons
in Britain are flown from water-borne sites and that about
75 percent of the land sites have either complete tail-line
mooring systems or partial tail-line mooring plus mooring-
circle close-haul.
Section III
OCCUPATION OF SITES
■ 10. Fully Prepared Site. — a. An organization moving onto
a completed site should And the following:
(1) Bed leveled.
(2) Anchorages for all ground rigging installed.
(3) Anchorage for winch installed.
(4) Crew quarters and operations hut complete, when
needed, including sanitary and messing facilities where
specified.
(5) Access road constructed, when necessary.
b. In this situation, an occupying unit will usually perform
the following tasks:
(1) Move into the barrage area, with battalion, battery,
and platoon commanders reconnoitering the prepared posi-
tions, and with troops and materiel being sent to the sites.
(2) Go into housekeeping at each site, see that communi-
cation is established, check equipment on hand, install
ground rigging on the bed, install the winch, select the gas
7
10-11 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
cylinder dump and motor parking space, prepare and inflate
the balloon for flying, and construct local defenses.
■ 11. Partially Prepared Site. — An organization arriving at
a site which has been only partly completed should go into
housekeeping, see that communication is established, com-
plete the site, and then continue as in paragraph 10.
8
CHAPTER 2
BASIC CONSTRUCTION OP SITE
Paragraphs
Section I. Access road
II. Earthwork
III. Steel and concrete
12-16
17-21
22-24
Section I
ACCESS ROAD
■ 12. Construction. — If no road leads to the location selected
for a site, an access road should be built immediately, so that
materials and equipment can be trucked to the site.
■ *13. Quality. — The access road should be of a quality suffi-
cient to hold up a 2y 2 -ton truck fully loaded. For techniques
in road-building, refer to FM 5-10.
B 14. Turn-outs. — If the road is a one-way road and is fairly
long, one or more turn-outs should be provided to allow for
passage of vehicles.
■ 15. Maintenance. — If the access road is not a public road,
maintenance will be the responsibility of the using organiza-
tion. Particular attention should be paid to drainage, so that
the road will be passable during prolonged periods of inclem-
ent weather.
■ 16. Parking Space. — Wherever possible, it is desirable to
have available space at or near the site for parking of motor
vehicles. This may be in the form of a loop in the access
road.
■ 17. Plans. — This manual showing lay-out of beds should
always be on hand or readily available to those immediately
directing the construction of the site.
Section II
EARTHWORK
9
18-19 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 18. Clearing the Area. — In preparing the site, it is neces-
sary to clear the area of all ground obstructions which would
impede efficient and safe handling of the balloon. The bed
area should be cleared of all trees and stumps, but the site
area should not necessarily be cleared to the ground. Small
trees are valuable as a windbreak, and natural vegetation
serves to camouflage and to reduce both erosion and the prob-
lem of site maintenance. However, the safety of the balloon
should be the chief factor in determining how much of a site
>s should be stripped of ground obstructions.
Yf~\
\U) 19. Grading. — After the area is sufficiently cleared, any
necessary excavating, filling, and compacting will follow. If
the site is on a hillside, it may be necessary to shore up or
revet the edge of the fill or excavation. (See FM 5-15.) The
slope of the bed proper should not be over 5 percent. Great
IN LEVEL BED CROWN ENTIRE BED:
I TO 2% SLOPE
MAIN POINTS MUST BE IN SAME
PLANE. PLANE AND BEO MAY
SLOPE UP TO 5i;FR0M HORIZONTAL.
Figure 2. — Drainage of site.
care should be taken to assure proper bed drainage by obtain-
ing a crowning (or watch crystal) effect; that is, completely
around the bed there should be a gentle slope from the
central anchorage. (See fig. 2.)
10
BARRAGE BALLOON SITE INSTALLATIONS 20-24
■ 20. High Water Marks. — When sites are to be in low areas,
the high water marks should be ascertained to make sure the
bed is above such marks. Sources in the community in which
the site is to be established probably will be able to furnish
this information. If the site is in an unpopulated area, trees
may be studied for water marks.
■ 21. Safeguarding Property. — In constructing a site, great
care is necessary to avoid damage to property adjacent to the
site. Crops should not be trampled or other damage done.
Section III
STEEL AND CONCRETE
■ 22. Steel. — o. Normally, all steel equipment except cable
needed for the balloon bed — anchorage rods, flop rings, and
other like equipment — will arrive at the site already fabri-
cated to the proper dimensions.
b. When, in an emergency, it is necessary to fashion equip-
ment on the site from scrap steel, care should be taken to
see that the steel is free of rust or grease.
■ 23. Concrete Anchorages. — To insure long life of the bed
and to avoid the difficulties that must eventually develop
from the use of deadman anchorages and screw pickets, all
anchorages should be made of concrete. For safe anchor-
age in every type of soil, a standard anchorage should con-
tain a sufficient weight of concrete to hold the load imposed
on that anchorage. No attempt should be made to design
anchorages so that their shape will give a deadman effect,
and no dependence should be placed on the weight of the
soil to be disturbed before failure.
■ 24. Mix. — The 1-3-5 concrete mix (1 part of cement to 3
parts of sand to 5 parts of gravel ) is suggested for use on the
bed. For other mixes, which may be required for special
conditions, and for rules of thumb for mixing and curing,
see tables in FM 4-198 (when published). For further de-
tails on concrete see FM 5-35.
11
CHAPTER 3
CONSTRUCTION OF BED AND WINCH INSTALLATIONS
Section I. Anchorages
II. Winch installations
Paragraphs
25-36
37-43
Section I
ANCHORAGES
■ 25. Bed Space. — Operations in the field require a cleared
space upon which a balloon may be inflated and inspected,
with equipment for mooring a balloon. In most instances
it is desirable to fly the balloon from this cleared space. The
area and the anchorages required for these operations con-
stitute the balloon bed. (See fig. 3.)
■ 26. Laying Out Balloon Bed. — In laying out the bed, the
steps listed below should be followed in order.
a. Select central point of bed.
b. Determine direction of prevailing wind.
c. Establish one main point exactly in the direction from
which the prevailing wind blows.
d. Select fair-lead anchorage 22%° to right or left of the
main point established in c above.
e. Establish winch anchorage so that its right edge is in
line with fair-lead anchorage and center of bed.
/. Establish first tail-line mooring-circle anchorage di-
rectly in front of center of winch anchorage.
g. Establish curb of central anchorage so that one side is
perpendicular to line from bed center to winch anchorage.
h. Establish positions for the remaining main points, moor-
ing-circle anchorages, hauling anchorages, and tail-line
mooring-circle anchorages.
■ 27. Central Anchoragk. — -a. The central anchorage con-
sists of a steel anchorage rod fixed in a concrete block, a
12
28
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
metallic grounding mat, a concrete curb, and a grounding
plate with proper electrical connections. (See fig. 4.)
i>. The central anchorage is placed in the center of the
balloon bed, and, from its center, measurements to all points
of the bed are made. The block of the central anchorage is
made of concrete and is formed to the dimensions shown in
figure 4. The purpose of the crown of the block is to catch
the shank of the snatch block and hold the sheave clear
14
BARRAGE BALLOON SITE INSTALLATIONS 27-29
when the wind forces the flying cable off at an unusual angle.
The anchorage rod is placed accurately in the block so that
it is in the same vertical plane as the left edge of the winch
and the center of the central arfchorage block. The curb
extending around the center block is constructed of concrete
according to the dimensions shown in figure 4.
c. The grounding mat, grounding plate, and the central
anchorage rod are of the type and dimensions shown in
figure 4. The grounding mat is secured in position by having
the crown of the concrete block formed over its center and
by having its edges embedded in the curb. This embedding
prevents curling of the mat and consequent cutting of the
balloon. Gravel or crushed stone is placed under the mat
within the curb to provide drainage and to prevent the for-
mation of mud. The grounding plate is electrically con-
nected with the central anchorage rod and the grounding
mat. The grounding plate and connections must have a
conductivity of at least No. 4 copper wire.
■ 28. Temporary Central Anchorage. — When a concrete an-
chorage is not immediately available for the central anchor-
age, a temporary deadman anchorage of logs or timbers
can be used (see fig. 5) . Size of the deadmen and the depth
to which they are buried naturally will vary with the kind of
soil. For holding powers of various types of earth, see tables
in FM 4-198 (when published) . Dimensions suggested below
are approximate.
■ 29. Construction. — A trench is dug about 2 feet wide, 5
feet 8 inches deep, and 8 feet long at right angles to the cable
coming from the winch to the snatch block. On the side of
this trench toward the winch an undercut big enough to
receive the deadman is made about 5 feet below the surface.
The next step is to dig two small trenches, of shovel width, in
the form of an inverted V, from about 18 inches below the
surface to a point about 2 feet in from each end of the large
trench. See figure 5 for proper slope and other details.
Two deadmen, one about 8 inches by 8 inches by 8 feet and
the other about 4 inches by 4 inches by 4 feet, are cut.
15
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
UPPER t05 : 4"X4»X4'
• •>. ■ * :SURF«CE)
GALVANIZED RODS
(OR EQUIVALENT) :
CABLE
LOWER LOG 8"X8*X8' :
CLOVE HITCH
. SIDE ViEW
CABLE
SMALL tREHGH
■ . L WIDTH)
JPPER
LOS
-CLIPS
LOWER LOS
TOP VIEW
Figure 5. — Temporary central anchorage.
16
BARRAGE BALLOON SITE INSTALLATIONS 29-31
Balloon cable is fastened to the larger deadman with a clove
hitch, with the crossing of the cable being on the underside
of the deadman, and the deadman is placed in the large
trench. Cable is then fastened to the smaller deadman,
interlocking with the cable on the larger deadman via the
two small trenches, and the smaller deadman is placed just
below ground surface at the convergence of the two small
trenches. The snatch block at the central anchorage is
attached to the anchorage cable on the small deadman, and
is ready for use as soon as the trenches are filled and tamped.
■ 30. Grounding. — Grounding the snatch block and balloon
cable is accomplished, where a grounding plate and connec-
tions are not available, by driving a 10-foot, %-inch galvan-
ized rod or its equivalent into the ground close to the upper
deadman and connecting it to the block by No. 4 copper wire,
or by burying approximately 16 feet of grounding wire in the
trench and connecting the end to the block.
■ 31. Eight Main Points. — a. Eight anchorages are evenly
distributed on a radius of 16 feet 4 inches from the center
of the central anchorage, the distance between centers of
adjacent anchorages being 12 feet 4 J /2 inches. When the
prevailing wind can be accurately located, one main point
should be placed so that it points directly into the prevailing
wind. Two bent rods with flop rings are embedded in each
main point anchorage. Flop rings are placed so that when
held vertically, they are in line with the center of the bed.
(See figs. 3, 4, and 6.)
b. The eight main points should be in one plane so that
one set of markings on the handling lines will be sufficient
for hauling the balloon onto the bed. Any inclination of
the plane of the main points induces difficulty in bedding
down the balloon, and an inclination of 5 percent or greater
in the plane of the main points may peel the handling-line
patches.
c. A wire cable called the "octagon" is reeved through the
outermost flop rings of the main point anchorages and
17
31
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
BARRAGE BALLOON SITE INSTALLATIONS 31-34
fastened taut. The octagon should be made from salvaged
flying cable. (See figs. 4 and 12.)
■ 32. Mooring-Circle Anchorages. — A mooring circle of 37-
foot radius is laid out from the center of the bed. On this
circle 24 concrete anchorages equipped with bent rods and
equally spaced 15° apart (9 feet 8 inches between bent rods
of anchorages) are placed. Eight of the mooring-circle
anchorages are placed so as to be radially in line with the
8 main points and the center of the bed. (See fig. 3.) Each
anchorage has a number distinctly painted on it, with No. 24
on the anchorage most nearly north, and Nos. 1, 2, 3, through
to No. 23 proceeding clockwise. For details of the anchor-
age, see figure 6. The cradle bed embraces everything up to
and including the 37-foot circle. It does not include the
tail-line mooring circle.
■ 33. Hauling Anchorages. — There are four hauling anchor-
ages and a fair-lead anchorage on a radius of 62 feet from
the center of the bed. Each of the five anchorages con-
sists of a concrete block with a bent rod; each bent rod
holds a flop ring. The four hauling anchorages are located
directly in line with the center of the bed and with the four
consecutive main points on the side of the bed toward the
winch. (See fig. 3.) Midway between the second and third
of these hauling anchorages, the fair-lead anchorage is
located. By the use of these anchorages, the balloon can
always be hauled down with its nose within 22y 2 ° of the
wind direction. When the balloon is hauled down mechan-
ically, the hauling cable passes through a block attached to
whichever hauling anchorage will most nearly cause the nose
to be brought down into the wind. The hauling cable is then
led through a block on the fair-lead anchorage to the gipsy-
head of the winch. For details of the hauling anchorage,
see figure 6.
■ 34. Tail-Line Mooring-Circle Anchorages. — On a circle
of 90-foot radius, 24 concrete anchorages of the same design
and dimensions as the mooring-circle anchorages are placed.
The first tail-line mooring-circle anchorage is located on a
line between the center of the bed and the center of the
19
34^35 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
winch anchorage. The remaining 23 anchorages are equally
spaced around the tail-line mooring circle at intervals of
approximately 23 Vz feet. (See figs. 3 and 6.) If a 90-foot
radius is not possible, any radius between 80 and 90 feet may
be used.
■ 35. Substitute Anchorages. — a. When concrete anchor-
ages are not immediately available for the eight main points
and the hauling anchorages, the deadman type of anchorage
should be used. For installing the deadman anchorage, fol-
low the general procedure outlined in this manual for emer-
gency central anchorages and winch anchorages.
Figure 7. — Screw picket.
20
BARRAGE BALLOON SITE INSTALLATIONS 35-37
b. For the 37-foot mooring circle and the tail-line mooring
circle, screw pickets may be used, either alone or lashed to
deadmen.
c. If screw pickets are used, they should be about 3 feet
long, with a %-inch solid steel shank, or equivalent, a screw
4 to 6 inches in diameter, and a 3-inch eye on top for fasten-
ing rope or cable. Figure 7 shows one of several types. In
installing a picket, it sometimes is advisable to dig a small
hole 6 inches deep, insert the picket, cover it with dirt, pack
the dirt, and then screw the picket into the ground for the
rest of the way. In extremely hard ground, it may be neces-
sary to dig a hole to the depth of the picket. When this is
done and the picket has been placed, about 3 inches of dirt
should be put into the hole and tamped. Then 3 more inches
of dirt shoulder be put in and tamped, and this repeated until
the surface is reached.
■ 36. Surfacing the Bed. — a. If material is available, the
bed should be paved from the central anchorage to the main
points, paved or graveled to the 37-foot circle, and grassed
from there to the tail-line mooring circle. The paving may
be either concrete, asphalt, brick, or plank. The soil of the
bed may also be consolidated by chemical treatment. Sur-
facing the bed is advantageous for several reasons: it prevents
the formation of mud; it enables the crew to work at night
with more certainty and speed; and it allows the ballast to
be moved easily.
b. A gravel walk should lead toward the central anchorage
from the operations hut to that point on the bed at which
hard surfacing begins.
at 6- .// / ; " '
Section II
WINCH INSTALLATIONS
■ 37. Purpose. — The winch anchorage is to provide an
anchor to which a barrage balloon winch may be securely
fastened.
518084" — 43 4
21
38-41 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 38. Types of Plying. — Balloons are flown by either indi-
rect or direct flying, in the following manner:
a. In indirect flying, which is the usual flying method, the
winch is anchored just outside the tail-line mooring circle
or about 100 feet from the central anchorage, which is the
ascension point. The winch should be on the up wind side
of the bed to minimize the frequency with which the tail-line
snatch block will interfere with the flying cable.
b. In locating the winch anchorage, a line from the central
anchorage rod, running along the right edge of the winch
anchorage (the edge of the winch anchorage nearest the
bed being considered as the front of the anchorage) , should
run midway between two main points. The center of the
winch anchorage should be set radially with the central
anchorage rod. (See fig. 3.)
c. In direct flying the balloon flies directly from the winch,
with the lead-off gear as the ascension point. The winch
should be on the ap wind side of the ascension point, with
the lead-off gear facing down wind.
■ 39. Concrete Anchorage. — a. The standard winch anchor-
age is of concrete. For dimensions see figure 8.
Y 1 1>.\ Imbedded in the anchorage are four anchor rods, bent
into the shape shown in figure 8. The anchorage should be
capable of sustaining a vertical lift of 3,000 pounds and should
be grounded electrically. Like that of the central anchorage,
this electrical grounding is done with a ground plate and
connecting straps, the straps of the winch anchorage extend-
ing 8 inches above the ground level so that they can be
connected to the winch.
■ 40. Temporary Anchorage. — In emergencies, occupying
troops may use a deadman anchorage made of logs or tim-
bers, with the standard concrete type anchorage being in-
stalled to replace it as soon as feasible.
■ 41. Method of Temporary Anchoring. — In both direct and
indirect flying, the winch is anchored by three deadmen, two
being placed in front of the winch (that is, in front of the
22
BARRAGE BALLOON SITE INSTALLATIONS
41
41
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
two corners nearest the lead-off gear) , and one being placed
in rear of the winch. (See fig. 8.) Size of the deadmen and
the depth to which they are buried naturally will vary with
the kind of soil. For holding powers of various types of
earth, see tables in FM 4-198 (when published). The two
corners of the winch nearest the lead-off gear are anchored
to resist the vertical pull in case the snatch block breaks
loose. Experience has shown that in many cases the dead-
men on these corners will be of sufficient strength if they
are timbers 6 inches by 6 inches by 8 feet or 8 inches by 8
inches by 6 feet, or logs of equal size, and are located 4 feet
from the winch and buried 4 feet below the ground. In plac-
ing each of these front deadmen, a trench is dug at an angle
to the cable coming from the winch to the snatch block. The
trench should be 2 feet wide, Ay 2 feet deep, and long enough
to accommodate the deadman. On the side of this trench
toward the winch, an undercut big enough to receive the
deadman is made at about 4 feet below the surface. At the
midpoint of the trench, a small trench of shovel width is dug
toward the winch. The bottom of this trench will slope at
about 45°. Balloon cable is fastened to the deadman by a
clove hitch, with the crossing of the cable being on the under-
side of the deadman, which is placed in the trench. The log
should not be notched, since pull alone will cause the cable
to bite into the wood and hold. Several stakes may be
driven into the side of the trench just over the deadman to
prevent slippage. The ends of the cable then are passed up
the inclined trench to the ring on the corner of the winch,
are passed through the ring from opposite directions, and
clamped with U -clips 6 or 8 inches below the ring. The
U-part of the clip should be placed on the running end of the
cable. The two rear corners of the winch are anchored to
resist a horizontal pull toward the central anchorage. Usu-
ally, a deadman 8 inches by 8 inches by 8 feet is of sufficient
size, if buried 8 feet in rear of the winch and at a depth of 4
feet. The deadmen are anchored to the winch by means of
cable and U-clips, as described above.
24
BARRAGE BALLOON SITE INSTALLATIONS 42-43
■ 42. Grounding. — The winch frame is electrically connected
to the ground, and electricity dissipated, by one of the follow-
ing or equivalent: a %-inch 10-foot pipe, a zinc-coated iron
plate, or a 15-foot No. 4 copper wire buried in the ground,
which is kept wet.
■ 43. Truck Winch Anchorage. — a. A truck-mounted winch
should be anchored on each of the four corners, following
the general principles outlined for anchoring the winch on
the ground. The truck's weight is not to be considered in
determining anchorage strength, since this weight should be
allowed as a safety factor.
b. The truck frame is electrically connected to the ground
by a wire capable of carrying 2,500 amperes. This is a copper
cable similar in size to an automobile battery cable. If no
large wire is available, smaller wire can be wrapped together
to form a larger cable. In no case should a wire smaller than
y 4 inch be used.
25
CHAPTER 4
USE OF BED
Paragraphs
Section I. Bedding down.
44-57
58-68
69-72
73-76
II. Tail-line mooring
III. Mooring-circle close-haul.
IV. Midship mooring
Section I
BEDDING DOWN
■ 44. Necessity. — The safest and most effective method of
securing the balloon is bedding down (see fig. 9). If the
tactical situation permits, the balloon is bedded down for
inspection, for minor repairs, and for securing the balloon
in winds unsafe for a close-haul mooring system. Since even
a well-drilled crew takes about 4 minutes to fly the balloon
from a bedded-down position, certain tactical situations may
make it inadvisable to bed down. The balloon should be
bedded down when grounded for extended periods.
■ 45. Point of Attachment. — The balloon is hauled down by
winch until it is at point of attachment, that is, the junction
assembly is within 3 to 6 feet of the central anchorage
snatch block.
■ 46. Bed Blocks. — Eight bed blocks are attached to wire
grommets on the outer flop rings of the main points (see
fig. 6) . The eight main points permit the balloon to be
hauled onto the bed with its nose pointing in any of eight
directions.
■ 47. Wire Spider. — Attached to the end of the hauling cable
or hauling rope is a wire spider, to which the handling lines
are tied when the balloon is to be hauled onto the bed. The
26
27
47-48
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
spider consists of six legs, each terminating in an eye. For
design and dimensions, see figure 10.
■ 48. Attaching Handling Lines to Wire Spider. — a. The
free ends of the handling lines on each side of the balloon
are reeved through three consecutive bed blocks. That is,
six bed blocks are used, leaving the bed block under the nose
and the bed block under the tail free. Each handling line
is then attached to an eye of the wire spider with a swab
hitch, the closest handling lines to the shortest legs of the
spider, the farthest handling lines to the longest legs of the
spider.
b. (1) The handling lines are marked at the point where
they are to be tied onto the spider. Front and rear lines
are marked at two points. These markings are necessary
since the balloon may be hauled down with either its nose or
tail in the direction of the spider. Obviously if the tail of
the balloon is in the direction of the spider, the rear handling
lines will be closest to the spider. In this event, they will
be pulled through the eyes of the spider and tied to it at
the second marking from the end of the line; if, on the other
hand, the nose of the balloon is pointing in the direction
of the spider, the rear handling lines are then the farthest
ones from the spider and are consequenty tied into it at the
first marking from the free end of the line. The same pro-
cedure, of course, is followed with the front handling lines.
All measurements are made from the upper ends of the lines.
The following approximate measurements are used:
Hauling Hauling
from tail from nose
Front handling lines (D-7) 62 feet 51 feet
(D-8) 67 feet 54 feet
Center handling lines (D-7) 61 feet 61 feet
(D-8) 64 feet 64 feet
Rear handling lines (D-7) 51 feet 62 feet
(D-8)__ 54 feet 67 feet
(2) The handling lines may be marked by passing a short
length of balloon fabric through one lay of the rope at the
prescribed distance. It is important that these distances
28
518084° — 43 5
29
48-51 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
be checked frequently, since even manila rope will stretch
or shrink and substandard rope will vary even more. Varia-
tion of handling-line markings makes bedding down more
difficult.
■ 49. Hauling Down. — After the handling lines are reeved
through the bed blocks and attached to the spider, the bal-
loon is hauled down onto the bed by power applied to the
hauling cable. Power may be applied to the spider either
mechanically by use of the gipsy-head of the winch, or
manually by block and tackle. (See FM 4-187.)
■ 50. Equipment for Manual Haul-Down. — For manually
hauling the balloon from point of attachment, a tackle con-
sisting of two double blocks and 200 feet of %-inch manila
rope (or equivalent) is connected to the shackle of the wire
spider and to the hauling anchorage, and is tied off with a
picketing hitch. (See fig. 10.)
■ 51. Cradle. — a. Cradle legs. — (1) The cradle of the bed',
which remains rigged at all times, consists of 12 legs of wire
cable or 1-inch manila rope (or equivalent). Each cradle
leg is constructed with a small eye-splice at the inner end
and a 5-inch eye-splice at the outer end (see fig. 11). The
lengths of the cradle legs used for the D-7 balloon are as
follows:
Legs Nos. 1 and 6 (4 legs) 12 feet 6 inches over-all.
Legs Nos. 2 and 5 (4 legs) 11 feet over-all; straight
cut splices 1 foot 6
inches from external
eye.
Legs Nos. 3 and 4 (4 legs) 8 feet over-all.
(2) A wire strop 1 foot 2 inches long is reef -bent onto the
inner eye of each of the long legs of the cradle (12 feet 6
inches) when the D-8 balloon is to be bedded down. Pour
strops are used.
b. Attachment to central anchorage. — The small eyes of
each set of legs are reeved onto a shackle, and each shackle
is attached to the rod of the central anchorage by an 18-inch
wire strop (see fig. 11).
30
BARRAGE BALLOON SITE INSTALLATIONS
51
c. Cradle ballast. — Cradle ballast is attached to the outer
eye of each cradle leg (see figs. 11 and 12) . Ballast may be
31
51-52 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
in the form of clusters of three sandbags, weighing approxi-
mately 120 pounds, or concrete blocks. Concrete blocks are
superior to sandbags in that they do not deteriorate through
friction with the bed. The ballast blocks should be covered
to prevent wear of the balloon on rough edges. The blocks
do not normally require lifting and are easily dragged along
the ground by the slips to which they are attached or with
a grapple. For details of a concrete ballast block and block
cover, see figure 11. Each sandbag should weigh 40 pounds
and should be rigged as shown in figure 13.
■ 52. Cradle Slips and Lines. — a. General. — Twenty slips
(ropes rigged with adjusting blocks) and four lines are used
on the cradle. These cradle slips (9 feet long) and lines (6
feet long) are constructed of %-inch manila rope (or equiva-
lent). Two grommets are lark's-headed onto the octagon
between each two main points (total 16) .
b. Lower cradle slips and lines. — The legs of the cradle are
held to the wire octagon by eight lower cradle slips and four
cradle lines. The cradle lines are used where space is so
limited as to prohibit the proper use of the adjusting blocks
on slips. The cradle slips are attached to the eyes holding
the ballast of Nos. 2, 3, 4, and 5 cradle legs by a single sheet-
bend if sandbag ballast is used, or to the concrete ballast
blocks by means of a rope bridle (see fig. 11) . The hooks in
the bights of the lower cradle slips are hooked to grommets
on the octagon. The four cradle lines are attached by a
single sheet-bend to the eyes holding the ballast of Nos. 1
and 6 cradle legs if sandbag ballast is used, or to the concrete
ballast blocks by means of a rope bridle. The cradle lines
are attached to grommets on the octagon by means of a
single bowknot. All lower cradle slips and lines are firmly
tensioned. Their purpose is to keep the cradle legs fully
extended in the direction of the balloon rigging patches, and
to prevent the cradle ballast from shifting.
c. Upper cradle slips. — The balloon is held to the cradle
ballast by 12 upper cradle slips. The free end of each upper
cradle slip is fixed to a straight toggle and attached to the
cradle leg ballast (see figs. 9 and 11). All upper cradle slips
are hooked to bedding strops.
32
33
ANTIAIRCRAFT- ARTILLERY FIELD MANUAL
BARRAGE BALLOON SITE INSTALLATIONS 52-55
A
(dj Bedding strops. — Plying with the balloon from each rig-
ging patch is a bedding strop. These strops are made of
%-inch manila rope (or equivalent) with a soft eye in each
end, and are lark's-headed to the rigging patches. The
overall lengths of the strops are as follows:
D-7 Or Mk. VII D-8
No. 1 rigging patch 1-foot strop 1-foot strop
No. 2 rigging patch 2-foot strop 2-foot strop
No. 3 rigging patch 3-foot strop 3-foot strop
No. 4 rigging patch 4-foot strop 4-foot strop
No. 5 rigging patch 5-foot strop 5-foot strop
No. 6 rigging patch 6-foot strop 8-foot strop
■ 53. Rigging-Line Sandbags. — a. General. — Part of the bal-
last of the balloon consists of sandbags attached to the rigging
lines on each side of the balloon envelope (see figs. 9 and 13).
b. Sandbag lines. — Twelve sandbag lines of %-inch manila
rope (or equivalent) , 7 feet long, are used in bedding the
balloon. At their upper ends, ten of these lines are attached
by a single bowknot to grommets on the rigging line. At the
lower ends, each of the lines is toggled to two sandbags. Each
of the two other lines is tied, one on each side of the balloon,
to the bedding strop of the first rigging patch and toggled to
a single sandbag. These two sandbags prevent the hooks of
the cradle slips at the nose of the balloon from pressing into
the balloon envelope.
■ 54. Mooring Slips. — Ten mooring slips are used to moor
the balloon to the mooring-circle anchorages. These, slips
are constructed of %-inch manila rope (or equivalent) , 25 feet
long. The slips are constructed with a large hook eye-spliced
into the free ends. The small hook (in the bight) of each
mooring slip is hooked into a grommet reef -bent onto the
cut-splice in each handling and mooring line. The large
hooks of the mooring slips are hooked into the rods of the
mooring-circle anchorages. (See fig. 9.)
■ 55. Tensioning Slips. — Ten tensioning slips are used to
maintain tension on the mooring and handling lines. These
35
55-57 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
slips are constructed of %-inch manila rope (or equivalent) ,
12 feet long. Each slip is hooked at the same point at which
the mooring slips are attached, that is, to the grommet on the
handling and mooring lines. When properly adjusted, the
slips tension the handling and mooring lines so that they are
tangent to the envelope of the balloon. Three sandbags are
attached to the lower end of each tensioning slip at 2^4 -inch
intervals, arranged so as to have a shock absorber action.
(See figs. 9 and 13.) _ ,-• I
■ 56. Purling the Rudder and PiNs.-^a, General. — When the
balloon is bedded down for a period of time, the rudder and
fins must be furled. Furling is necessary to prevent the wind
from tossing the fins and rudder around and damaging them.
It is particularly important in keeping the rudder deflated
and thus preventing it from rubbing on the ground. Standard
equipment for furling consists of a rudder protection sheet
7 by 26 feet and two fin-furling lines 32 feet long for the D-7,
and 38 feet long for the D-8.
b. Furling the rudder. — The rudder is deflated and drawn
up close to the envelope of the balloon by means of the rudder
protection sheet held in place by cords and hooks.
c. Furling the fins. — In furling the fins, it is necessary to
use a 20-foot stepladder, which is placed with the steps facing
the balloon. Setting the ladder up in this way is highly
important in order to prevent injury to personnel and damage
to the balloon. In this position the ladder is braced to the
maximum; consequently, surges of the balloon are unlikely
to turn it over. Furthermore, a man on the ladder can work
more efficiently from this position and can keep the balloon
from rubbing against the ladder and being damaged.
■ 57. Additional Equipment for Storm Precautions. — In
high winds or when a storm warning has been issued and the
balloon is to be bedded down, the following additional equip-
ment is necessary (see fig. 14) :
For the D-7 balloon, four mooring -line extensions
of !/2-inch manila rope (or equivalent), 25 feet long, eye-
spliced at one end.
36
57-59 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
(2) For the D-8 balloon, four mooring-line extensions of
%-inch manila rope (or equivalent), 30 feet long, eye-spliced
at one end.
b. (1) Extra sandbags or ballast blocks to provide addi-
tional ballast for Nos. 2 and 5 cradle legs.
(2) For the D-8 balloon, it may also be necessary to attach
a ballast block or three additional sandbags to the large eye
of each cradle leg.
c. An extra set of bedding strops.
d. An extra set of upper cradle slips.
e. One extra sandbag for each sandbag line.
Section II
TAIL-LINE MOORING
■ 58. General. — a. When the balloon must be ready for quick
flying, the most efficient and desirable method of securing it
in all but severe weather is tail-line mooring. At tail -line
mooring the balloon is secured at only two points: at the
junction assembly by the safety strop and wire pyramid; and
at the tail by the tail-line assembly and tail-line bungee
assembly. (See par. 6b and fig. 15.) The flying cable
remains attached to the balloon.
b. Equipment necessary for tail-line mooring includes: tail-
line mooring-circle anchorages; tail-line mooring-circle
cable, posts, and wire-cable strops; a handy-billy; a pyramid;
a handling-line bag; and a tail-line bungee assembly.
■ 59. Tail-Line Mooring-Circle Cable. — The cable which
forms the tail-line mooring circle is held in place by wire
strops reeved through the rods of the tail-line mooring-circle
anchorages and passed over the tops of wooden posts. The
cable must be taut when held by the strops of 23 anchorages.
On the tail-line mooring-circle cable runs the block attached
to the lower end of the bungee assembly, the upper end of
which is attached to the tail of the balloon by a toggle. The
balloon is thus allowed to turn with the wind, its nose, in the
manner of a weathercock, always pointing into the wind.
38
39
60-61 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 60. Tail-Line Mooring-Circle Posts. — a. About 2 feet in-
ward from the rods of the tail-line mooring-circle anchor-
ages (see par. 34) are the tail-line mooring-circle posts, which
are of wood (2- by 4-inch minimum) with a triangular groove
cut in the top. On a level bed the posts are driven into the
ground until about 18 inches remain above the surface. If
the ground along the tail-line mooring circle is uneven, the
posts are left at varying heights above the ground, so that
their tops compensate for the unevenness of the ground and
keep the tail-line mooring-circle cable in an approximate
plane. (See fig. 16.)
b. Twenty-five tail-line mooring-circle posts are used. Two
posts are placed 2 feet apart, one on each side of the tail-line
mooring-circle anchorage in front of the winch anchorage,
with a spacer brace in between (see fig. 16). Directly in
front of these two posts the tail-line mooring-circle is joined
by means of clips or nicopress sleeves. The other 23 posts
are placed around the tail-line mooring circle on a line be-
tween the bent rods of the other tail-line mooring-circle
anchorages and the center of the bed.
■ 61. Strops. — a. Twenty-five strops made of wire cable, nor-
mally 6 feet long, with a hook spliced in each end, are used
to support the tail-line mooring-circle cable.
b. Two strops are used at the junction of the cable, one on
each side of the cable clips or nicopress sleeves. These
strops are reeved through the bent rod in the tail-line
mooring-circle anchorage opposite the winch anchorage, and
each of them is passed through the notch on one of the posts
on each side of the anchorage. The hooks are then fastened
over the cable. (See fig. 16.)
c. Each of the remaining 23 strops is reeved through the
bent rod of one of the tail-line mooring-circle anchorages,
passed through the notch of the corresponding post, and en-
gaged by means of the hooks to the cable. Since the notch
in the top of the post is approximately 18 inches above the
ground, the strop passing over it keeps the cable also about
18 inches above ground. That is, the strop, being reeved
through the rod of the anchorage and passed over the post,
40
61-63 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
creates enough tension to hold the cable at about the same
height as the notch in the post.
d. The hooks are placed in opposite directions when sup-
porting the tail-line mooring-circle cable.
■ 62. Adjusting the Mooring Circle. — a. When the balloon
is at tail-line mooring, one strop is always detached from the
tail-line mooring-circle cable. The block to which the tail
line is attached is thus free to ride two sections of the cable.
When the wind shifts sufficiently to bring the block into prox-
imity with one of the supporting strops, it is necessary to
open a new section of the cable and to close the one no
longer required by the movement of the block. This switch
is made by releasing one of the supporting strops and by reen-
gaging the one previously released.
b. To engage and release the strops, a tackle arrangement
(sheave and pulley) called a handy-billy is used (see fig. 16) .
The handy-billy enables one man to make the switch. The
hook on the double block is placed over the cable, the hook
on the single block is attached to a mooring-circle anchorage
rod, and pull is exerted away from the cable.
■ 63. Pyramid. — a. General. — The balloon is moored at the
junction assembly by a junction strop and safety strop. Four
pyramid legs are used to restrict movement of the safety
strop.
b. Safety strop. — The safety strop is used to take the lift of
the balloon off the flying cable. The safety strop is 5 feet
10 inches long, made of wire cable, eye-spliced at each end
around thimbles. The strop is shackled at its lower end to
the central anchorage rod and at its upper end by a quick
release shackle to the lower end of the junction strop. (See
fig. 17.)
c. Rip cord strop. — A rip cord strop, made of %-inch manila
rope (or equivalent), 5 feet 6 inches long and eye-spliced at
each end, has its lower end on the shackle with the safety
strop. The rip cord strop is seized to the safety strop at
intervals of about 18' inches, leaving the upper eye seized by
its throat to the safety strop (see fig. 17) . When the balloon
42
BARRAGE BALLOON SITE INSTALLATIONS
63-66
is tail-line moored, the rip cord is transferred from the flying
cable to the upper eye of the rip cord strop.
d. Pyramid legs. — The pyramid legs are attached at their
lower ends to the inner flop rings of four main points, and
at their upper ends to the quick release shackle (see fig. 17).
On a level site the pyramid legs are 15 feet 9 inches long.
It is necessary to vary this length on sloping sites so that
the quick release shackle will be vertical above the central
anchorage rod.
■ 64. Handling-Line Bag. — The ends of the handling lines
are coiled and placed in a bag, which is perforated at the
bottom to prevent the accumulation of rain water and con-
sequent rotting of ropes. The handling-line bag hangs free
when the balloon is flying but is attached to the junction
assembly by a small rope when the balloon is close-hauled.
Bagging the handling lines prevents them from fouling on
the ground rigging when the balloon is moored. When the
balloon is flying, bagging also keeps the lines from tangling
around the parachute or otherwise fouling the lethal device.
Note. — Two handling line bags may be necessary for the D-8
balloon.
■ 65. Tail -Line Rigging. — The tail of the balloon is con-
nected by means of a tail-line assembly and a tail-line bungee
assembly to the tail-line mooring-circle cable (see fig. 18) .
■ 66. Tail-Line Assembly.— Components. — The tail-line
assembly includes all parts of the tail-line rigging which fly
with the balloon. It consists of a tail-line bridle, a tail line,
and a tail-line extension.
b. Tail-line extension. — The tail-line extension, which must
be made by the using troops, is 25 feet long, of y 2 -inch cotton
rope. When used with a double strop tail line, the tail-line
extension has a 6-inch eye in one end and is lark's-headed
just above the 8-inch eye in the tail line. When used with
the single strop tail line, the tail-line extension is short-
spliced into the tail line 1 foot above the 8-inch eye, with
the splice toward the center of the tail line.
43
44
45
67-68 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 67. Tail-Line Bungee Assembly. — a. General. — The tail-
line bungee assembly includes all parts of the tail-line rigging
which do not fly with the balloon. It consists of a tail-line
strop with toggle, a bungee strop, a check strop, and a
^snatch block. (See fig. 18.)
V; 6; Tail-line strop. — The tail-line strop is made of %-inch
ma'hila rope (or equivalent) , 15 feet long, with a soft eye in
the upper end. The eye is connected to the tail line by a
14-inch toggle. The lower end of the strop is reeved through
the upper eye of the bungee strop and tied to its standing part
with a picketing hitch. The 14-inch toggle is secured to the
tail-line strop by a retaining cord.
c. Bungee strop. — The bungee strop is 4 feet long, made of
rubber cords, %6-inch in diameter, and constructed as shown
in figure 18. The upper eye of the bungee strop is attached
to the tail-line strop, and the lower eye is shackled to a block
which runs on the tail-line mooring-circle cable. Retract-
ing and stretching with the pull of the balloon, the bungee
strop tends to keep the tail of the balloon under tension at
all times.
d. Check strop. — A check strop made of J /2-inch manila
rope (or equivalent) , 6 feet long, with a soft eye in each end,
is seized to the bungee strop at the center, as shown in figure
18, and is secured with the bungee strop at either end. The
check strop prevents the bungee strop from going beyond
its elastic limit and being broken.
e. Tail-line snatch block. — The tail-line snatch block con-
tains a 9-inch sheave and runs on the tail-line mooring-circle
cable.
■ 68. Tail-Line Bypass.— When the wind is blowing from
directly opposite the front of the winch anchorage, the move-
ment of the tail-line snatch block will be blocked by the
clips or nicopress sleeves on the tail-line mooring-circle cable,
in front of the winch. To remedy this a cable bypass may be
constructed and installed as shown in figure 19. To use the
bypass, the tail-line snatch block is transferred from the tail-
line mooring-circle cable to the bypass cable. When not in
46
68-71 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
use the bypass is unshackled and coiled at the anchorage to
which one end of the bypass is clamped.
Section III
MOORING-CIRCLE CLOSE-HAUL
■ 69. General. — a. Mooring-circle close-haul is one of two
substitutes for tail-line mooring when a sufficient area for
tail-line mooring is not available. (The other substitute is
midship mooring, discussed in section IV, ch. 4.) Mooring-
circle close-haul is neither as safe nor as satisfactory as tail-
line mooring; it requires a larger crew and more time.
Furthermore, the balloon will not stand as much wind at
mooring-circle close-haul as it will at tail-line mooring.
b. When the balloon is at mooring-circle close-haul, the
lift is principally overcome by a safety strop attached to the
central anchorage and to the junction strop. The flying
cable remains attached to the balloon. To restrain the bal-
loon in gusty winds, each front handling line is anchored
to clusters of sandbags. Each rear handling line is reeved
through a bed block attached to a mooring-circle anchorage
and then tied to a transverse strop. The transverse strop is
tensioned by a running tensioning slip which is attached to
straight cut-splices in the transverse strop and which runs
through a small block attached to the junction assembly.
(See fig. 20.)
c. Equipment necessary for mooring-circle close-haul in-
cludes the following: a safety strop, a rip cord strop, sandbag
spiders and sandbags, snubbers, bed blocks, a transverse strop,
and a running tensioning slip.
■ 70. Attachment at Central Anchorage. — a. Safety strop. —
The safety strop is used to take the lift of the balloon off the
flying cable. (See par. 63 and figs. 17 and 20.)
b. Rip cord strop. — When the balloon is mooring-circle
close-hauled, the rip cord is transferred from the flying cable
to the upper eye of the rip cord strop (see par. 63) .
■ 71. Rear Handling Lines. — a. HSd blocks. — Two bed blocks
are attached to the mooring-circle anchorages slightly in the
48
49
71-73 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
rear of each of the rear handling patches of the balloon.
When the blocks are properly located, seven vacant mooring-
circle anchorages remain between the anchorages to which
the blocks are attached. The rear handling lines are reeved
through these two bed blocks and are attached by a swab
hitch to the ends of the transverse strop. (See fig. 20.)
b. Transverse strop. — The transverse strop, generally made
of flying cable, is 25 feet long, and eye-spliced at each end
with an eye the same size as the large eye on the wire spider.
The transverse strop also has straight cut-splices 5 feet from
each end.
c. Running tensioning slip. — A running tensioning slip of
14 -inch rope, 36 feet long, with a hook on the running end as
well as in the bight, is used to tension the transverse strop.
The hooks of the tensioning slip are hooked to the transverse
strop at the cut-splices. The slip runs through a block at-
tached to the quick release shackle (see fig. 20) . When the
close-haul has been completed, tension will be applied to draw
the transverse strop about 5 feet nearer the junction assembly.
■ 72. Front Handling Lines and Snubbers. — a. Attachment
of lines. — Each front handling line is extended out from the
balloon at the normal angle to its respective patch and is
tied with a picketing hitch to the eye of a rope spider that
holds a cluster of sandbags. For details of the sandbag
spider see figure 20. About 5 feet of line should be allowed
to make the picketing hitch, and the line should be almost
taut when tied.
b. Snubbers. — Looped cut-splices are made in each of the
front handling lines at 15 feet and 25 feet from the lower end
of the line. Two sandbags are attached to the outer cut-
splice of each line and a single bag to the inner splice, as
shown in figure 20. These snubbers give a shock absorber
action.
Section IV
MIDSHIP MOORING
■ 73. General. — a. In the past, when lack of space pre-
vented the use of tail-line mooring, mooring-circle close-
50
BARRAGE BALLOON SITE INSTALLATIONS 73-74
haul was recommended. Though this method has been par-
tially satisfactory, the need for a speedier, less complicated
method requiring fewer men has been recognized. As a
result, midship mooring has been evolved.
b. It is suggested that as new balloons arrive in the field
for use on sites currently equipped for mooring-circle close-
haul, both balloons and sites be rigged for midship mooring,
since midship mooring has the following advantages over
mooring-circle close-haul:
(1) It requires less time for mooring and flying the bal-
loon.
(2) It permits the balloon to swing with the wind over a
wider arc, to ride more satisfactorily in gusty winds, and to
be turned more easily in event of a sudden shift in wind
direction.
(3) It reduces the size of the crew required by two men.
c. In midship mooring, as in tail-line mooring, the junc-
tion assembly of the balloon is attached to the pyramid and
safety strop, and the rip cord is transferred from the flying
cable to the rip cord strop. The tail of the balloon is moored
at the 37-foot circle by a running line, trolley assembly, and
a cable track, which function in a manner similar to the
tail-line assembly, tail-line bungee assembly, and tail-line
mooring-circle cable of tail -line mooring. (See fig. 21.)
d. Site equipment required for midship mooring includes
the pyramid with safety and rip cord strops, a mooring-circle
cable track and track strops, a trolley assembly, a handy-
billy, and two handling-line bags. Special rigging on the
balloon is also required.
■ 74. Rigging on Balloon. — On each side of the balloon the
rigging consists of a front midship patch, a rear midship
patch, a wire bridle grommet, and a wire bridle. A wire run-
ning line connects the bridles.
a. Patches. — (1) Front midship patches. — Each front mid-
ship patch on the balloon is placed 16 inches in front of and
5 inches below No. 3 rigging patch. It is placed with the
center axis of the patch parallel to a line drawn through
the bottom of the rigging patches (see fig. 22) . Each front
midship patch carries a sector ring.
51
52
53
74
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
(2) Rear midship patches. — Each rear midship patch is
placed with the center of the bottom of the patch 6 inches
ahead of the center of the bottom of No. 5 rigging patch, so
that the new patch appears to be a rotation forward of
No. 5 rigging patch (see fig. 22). Instead, of a sector ring,
a %-inch iron pipe, 6 inches long and bent to an angle of
60°, is placed in the junction of the midship patch ropes
and seized into place. The ends of the pipe are turned
toward the No. 5 patch.
b. Bridle grommets. — (1) Definition. — The bridle grom-
met is a short piece of cable made into a 9 -inch loop by-
passing it through the eye of the sector ring of No. 4 rigging
patch and clamping the ends together (see fig. 22) .
(2) Installation. — The bridle grommet is installed, one on
each side of the balloon, by looping 1 foot 8 inches of wire
rope through the eye of the sector ring of No. 4 rigging
patch and clamping the ends together with a nicopress
sleeve. A second nicopress sleeve is slipped onto the grom-
met and left loose when the ends of the grommet are
clamped. For details of nicopress sleeve (see PM 4-196
(when published)).
c. Bridles. — (1) Location. — A wire cable bridle is rigged
from the front midship patch to the rear midship patch on
each side of the balloon.
(2) Installation. — Each bridle is started at the forward
midship patch, carried around the sector ring, and clamped
to itself by a nicopress sleeve. It is then run through the
loose nicopress sleeve on the bridle grommet (see fig. 22) ,
through a thimble on the end of the running line, through
the bent pipe on the rear midship patch, and finally through
the eye of the sector ring on No. 5 rigging patch. The run-
ning end then is clamped to its standing part 12 inches below
the sector ring of No. 5 patch by two nicopress sleeves 4 inches
apart. The bridle is tensioned by pulling on the cable until
the distance between the forward midship patch and the
bridle grommet (points A and B, fig. 22) is 9 feet 2 inches.
After this adjustment, the nicopress sleeve attaching the
bridle to the bridle grommet is clamped tight.
Note. — The installation and adjustment of the bridle should be
made after the balloon is inflated.
54
BARRAGE BALLOON SITE INSTALLATIONS 74-75
d. Running line. — (1) Definition.— The running line is a
wire cable (41 feet 5 inches long for the D-8 balloon, 39 feet
5 inches for the D-7) passing under the balloon and con-
necting the two bridles (see fig. 21) .
(2) Installation. — The running line passes under the bal-
loon in front of the rudder air-scoop and hangs loosely when
the balloon is flying. Each end of the line terminates
in an eye formed with a nicopress sleeve around a V2-inch
thimble. The bridle passes through the eye of the thimble
so that the bridle supports the running line behind No. 4
rigging patch.
■ 75. Rigging on Bed. — The balloon bed used for midship
mooring is the standard bed without the tail-line mooring
circle.
a. Pyramid. — The pyramid is shackled onto the junction
strop of the balloon, as described in tail-line mooring (see
par. 63) .
b. Mooring circle. — (1) Cable track. — A cable track is fas-
■~ tened onto the 37-foot mooring circle anchorages by track
3 strops.
\ . >(2) Track strops. — Track strops are 1-foot 10-inch wire
strops with a small ground rigging hook in each end. Eyes
are formed in the ends of each strop with nicopress sleeves.
(3) Securing cable track. — A track strop is reeved through
the bent rod of each 37-foot mooring-circle anchorage. Both
ends of 21 consecutive track strops are hooked onto the
cable that is to become the track. The cable is pulled hand
tight and secured with a wire rope clip. Then, with the use
of the handy-billy, the twenty-second track strop is secured
to the track, the cable being allowed to slip in the wire rope
clip if necessary, but still being kept taut. The junction of
the cable is secured with 2 nicopress sleeves 4 inches apart
and the ends of the cable are trimmed back to the sleeves.
The wire rope clip is removed and the cable is allowed to
lie on the ground with 2 points always unhooked. The junc-
tion in the cable track lies under the flying cable.
c. Trolley assembly. — (1) Definition. — The trolley assembly
consists of the blocks, strops, and shock absorbing devices
used to attach the running line to the cable track. The com-
55
75-76 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
ponent parts are the running-line snatch block and shackle,
the rubber strop and the check strop, the midship tensioning
strop, and the trolley block and shackle. (See fig. 22.)
(2) Running -line snatch block. — A 6-inch, drop-link snatch
block rides on the running line when the balloon is moored.
It is attached to the rubber strop and check strop by a
shackle. It is removed from the running line when the
balloon is to be flown.
(3) Rubber strop. — The rubber strop is made of 10 strands
of %6-inch rubber cord constructed in the same manner as
the tall-line bungee strop described in FM 4-196 (when pub-
lished) . A 1-inch thimble is served into an eye at each
end of the rubber strop and the finished, contracted length,
from crown to crown of thimbles, is 24 inches.
(4) Check strop. — The check strop is 3 feet 4 inches long
with a soft eye in each end, and is made of >/2-inch manila
rope or equivalent.
(5) Midship tensioning strop. — The midship tensioning
strop is 7 feet long with a soft eye in one end and with the
other end served. It is made of %-inch manila rope, or
equivalent.
(6) Trolley block. — The 6-inch trolley block rides on the
-cable track.
^yS^Fitting trolley assembly. — To fit the trolley assembly,
a shackle is first attached to the running-line snatch block.
One eye of the rubber strop is put on the shackle; then one
eye of the check strop is slipped on beside the rubber strop
eye and served into place. The soft eye of the tensioning
strop next is lark's-headed on the lower eyes of the rubber
and check strops. The other end of the tensioning strop is
passed through the shackle on the trolley block and tied
with a picketing hitch.
■ 76. Adjusting the Cable Track. — To permit the trolley
block to ride back and forth, thereby allowing the balloon
to shift with the wind, the cable track remains detached from
two down wind points on the 37-foot mooring circle. When
a shift in wind warrants it, the trolley block is switched
by opening one or more points in the direction of the wind
shift and closing an equal number of points.
56
CHAPTER 5
OTHER SITE INSTALLATIONS AND SITE MAINTENANCE
Paragraphs
Section I. Buildings, gas cylinder stacks, and local defenses. 77-98
BUILDINGS, GAS CYLINDER STACKS, AND LOCAL
77. Crew Quarters. — The nature of barrage balloon op-
erations requires that the crew be housed on or near the
site. Whenever facilities are not available close by, quarters
must be constructed for sleeping, messing, and recreation.
They preferably should be not less than 75 feet nor more than
150 feet from the tail-line mooring circle.
■ 78. Construction. — It is suggested that the crew quarters
be 48 feet long and 20 feet wide and made of prefabricated
material to facilitate dismantling and relocating if the site
is moved.
■ 79. Equipment. — a. Equipment will include double bunks
or steel cots, clothes shelves and poles, a space heater, a coal
box where needed, a stove for cooking, food storage shelves,
a food preparation counter, two mess tables, a sink, a dish
storage, a rifle rack, and sanitary facilities.
b. If connections with public water and sewer lines are pos-
sible, the quarters should include a faucet for drinking
water, two lavatories, a toilet, a urinal, a shower, and a
hot water heater. If public water and sewer connections
are not available, a latrine will have to be built outside the
quarters, but it still is advisable for the quarters to contain
personal washing and drinking facilities and a shower at-
tached to a barrel water supply on a platform. Drinking
water should be stored in a barrel or other large container;
and it may be well for the men to keep canteens filled for
II. Maintenance of site.
99-116
Section I
DEFENSES
57
79-86
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
emergencies, the water in the canteens being changed every
day. Electricity should be used for lighting wherever pos-
sible; otherwise, lanterns or lamps will be required.
■ 80. Latrine. — If a toilet is not at hand, it is imperative
that a latrine be constructed immediately on the crew's
arrival. For construction details see FM 4-198 (when pub-
lished) or FM 8-40.
«|f)81. Garbage Disposal. — If garbage is not collected by a
public or private agency, it may be necessary to dispose of
refuse on the site. For details on incinerators,, see FM 8-40.
■ 82. Operations Hut. — On each barrage balloon site it is
necessary to have a building where the telephone is manned
24 hours a day, where all logs and records are maintained
by the balloon chief, and storage space is provided for extra
equipment. This building is known as the operations hut. '
■ 83. Location. — The hut must be within a few feet of the
90-foot mooring-circle and placed so as to allow a full view
of the bed through a window facing the central anchorage.
When site space is at a premium, the hut may be constructed
in combination with the winch shelter.
■ 84. Construction. — The hut should be at least 12 by 16 feet
and, if possible, constructed of prefabricated material to
facilitate relocation if the site is moved (see figs. 23 and 24) .
■ 85. Equipment. — The hut should contain a desk placed just
inside a window facing the central anchorage, a large bulletin
board, a work bench, a space heater, a fire extinguisher, a
tool chest, a rifle rack, lighting fixtures, tackle brackets, and
shelves and pegs for the storage of extra equipment.
■ 86. Storage. — It is important that all extra equipment
needed on the site be properly labeled and kept in a definite
place in the operations hut. Equipment to be stored will
include inflation apparatus, lethal devices, mooring slips,
tensioning slips, upper cradle slips, lower cradle slips, han-
dling lines, sandbag lines, extra sandbags, grommets, toggles,
running nose line, bedding strops, central anchorage cushion,
rudder protection sheet, fin-furling lines, block and tackle,
58
59
BARRAGE BALLOON SITE INSTALLATIONS 86-92
~ v weigh-off stand, topping-up tube, extra ground cloths, tools,
^ and other bed and site equipment.
y 87. Wind Sml. — The wind sail should be placed on the
site so as w jjive an accurate indication of the wind direc-
tion. In ^inej^a^es^./^y.-4re^d^ble to place the wind
sail on top oi^the'operations^hijt,— —
■ 88. Location op Gas Cylinder Stacks. — The gas cylinder
stacks should be accessible by truck, and preferably located
on the side of the inflation appendix of the balloon, as the
balloon nose faces the prevailing wind. The stacks should
be about 10 feet outside the 90-foot mooring circle.
■ 89. Preparation. — The lower row of cylinders should be
placed on 2- by 6-inch wooden runners or prepared concrete
dunnage, with each cylinder chocked with wooden blocks to
prevent sidewise motion. The cylinders should be stacked
13 on the bottom row, with the stack not over 6 tiers high
and containing a total of not more than 63 cylinders (see
fig. 25). When two or more stacks are made, they should
be at least 10 feet apart.
■ 90. Grounding. — The bottom row of cylinders should be
grounded with copper tape 1 inch by Ya inch by 15 feet (or
equivalent) attached to a zinc-coated iron grounding rod
% inch by 6 feet (or equivalent) driven at least 4 feet into
the ground.
■ 91. Cylinder Care. — Cylinders should be stacked with valve
outlets turned down. The stacks should be covered with
tarpaulin, removable wooden sheds, or other suitable material
to offer protection from direct rays of the sun. All safety
precautions relating to hydrogen should be observed. (See
FM. 4-187.)
■ 92. Local Defenses. — Combat efficiency of a unit is de-
pendent on its morale almost as much as on its technical
proficiency. In combat zones, morale tends to drop as casu-
alties rise. Consequently, in construction of balloon sites.
61
92-95 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
it is necessary to establish some form of shelter for the men
in event of air or ground attack. The building of such
shelters is a function of the occupying troops and should be
carried out at the earliest opportunity.
■ 93. L-Shaped Fox Holes. — a. Reports from combat areas
indicate that several L-shaped fox holes scattered around the
site afford the most satisfactory protection against bombing
or strafing attacks. The resulting dispersion of manpower
is extremely desirable since a single bomb hit is less likely
to effect the entire site personnel. The L-shape prevents
enfilading during a strafing attack if crewmen take shelter
in the leg of the L perpendicular to the line of attack.
b. The size and terrain of the individual sites naturally
will govern the exact location of the defenses. It is suggested,
. however, that at least three fox holes be placed about the bed
approximately as an equilateral triangle, in order to obtain
dispersion of the crew. They should be located so that the
men can reach them quickly and still be in position to operate
the winch, if necessary, and guard against attack from
paratroops or ground troops.
c. One fox hole should be within 15 feet of the winch and
in line with the opening in the winch barricade, if a barricade
is present, or with the operator's seat if there is no barricade.
A second fox hole should be near the operations hut and
within easy access of the door. A third should be across the
bed from the winch. If crew quarters are on the site, a
fourth should be close to the quarters. Any of these fox holes
could be used in conjunction with a machine-gun emplace-
ment, if one is located on the site.
■ 94. Assignment. — To avoid confusion, each squad member
should be definitely assigned to a fox hole.
■ 95. Fox Hole Construction. — The fox holes should be
about 18 inches wide, about 4y 2 to 6 feet deep, and with each
leg of the L at least 8 feet long (see fig. 26) . Steps should
be dug on each end to facilitate entering and leaving. If
the fox holes are in soft ground, it may be well to brace them.
The dug-out earth should be used as a parapet, which will
afford extra protection and at the same time help keep out
62
63
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
64
BARRAGE BALLOON SITE INSTALLATIONS 95-99
surface water. To drain off water which may fall directly
into the fox hole, use either of the following methods: On the
low side of the fox hole place a wooden flume, carrying into a
ditch or hollow; or slope the bottom of the fox hole and on
the low side dig a deep sump, filling it with loose rock, gravel,
or similar material.
■ 96. Individual Fox Holes. — On some sites, individual fox
holes may be advisable for use against ground attack. For
construction details, see FM 21-45.
■ 97. Winch Protection. — Damage to the winch will immo-
bilize the balloon and therefore it is essential that some type
of protection be provided. One suggested shelter for the
winch consists of a plank wall about 9 by 16 by 5 feet, sur-
rounded on three sides by an earth embankment sloping up
from a point about 10 feet out from the wall (see fig. 26) . On
the fourth side, facing the bed, is a removable wooden panel,
fronted by sandbags sloping up to the top of the wall. Rec-
tangular wooden tunnels provide passage for the flying cable
and for the hauling cable leading to the gipsy-head. A
narrow entrance for the winch operator is on one side of
the shelter. The winch anchorage should be installed before
the shelter is built.
■ 98. Camouflage. — The fox holes and the winch barricade
should be camouflaged whenever possible. Either natural or
artificial materials or combinations of both may be used, but
the results should blend with the appearance of the imme-
diate vicinity. Chicken wire, nets, burlap or burlap substi-
tute, paints, and lumber are some of the artificial materials
which may be used on occasion to supplement natural mate-
rials. For more detailed information on camouflage see
FM 21-45 and FM 5-20.
Section n
MAINTENANCE OF SITE
■ 99. Care. — Site equipment at all times should be kept in the
best of condition, since faulty equipment means faulty
operations.
65
100-106 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 100. Cable. — All cable used on the bed must be kept free
from dirt and rust by frequent inspection, cleaning, and
application of new engine oil. For further information on
cable repair, treatment, and storage, see FM 4-187.
■ 101. Rope, Slips, and Grommets. — All equipment made of
rope should be inspected frequently and kept clean and dry.
If wet, it should be hung up and allowed to dry naturally,
avoiding the application of artificial heat. Care should be
taken to prevent the freezing of wet ropes. Wet rope equip-
ment should never be stored until dried. To test rope, it
should be twisted open, and loose fibers, dampness, or flaki-
ness noted. Markings on handling lines should be checked
after each rainy spell and, if necessary, moved. Worn rope
naturally should be replaced at once. For detailed informa-
tion on rope, see FM 4-196 (when published).
■ 102. Adjusting Blocks and Toggles. — All equipment made
of wood should be checked frequently for splits or other
defects.
■ 103. Hooks on Slips. — Hooks should be maintained clean
and free from rust and kept either painted or oiled.
■ 104. Ground Cloths. — When ground cloths are not needed,
they should be dried, if necessary, folded, and placed in the
operations hut.
■ 105. Anchorages. — All metal work on anchorages should be
oiled or painted and kept free from rust or dirt. Frequent
anchorage inspections should be made for damage or under-
mining by erosion.
■ 106. Metal Blocks. — Metal blocks should be cleaned fre-
quently to prevent accumulation of rust or dirt, and the
moving parts should be kept oiled. Frames should be painted.
When the blocks are not in use, it is best to protect them with
fabric covers.
66
BARRAGE BALLOON SITE INSTALLATIONS 107-115
■ 107. Spiders. — Frequent inspections should be made to see
^ that eyes of the spiders are well served, since worn serving
y v makes for unnecessary wear on the handling lines.
' i
Hg)l08. Sandbags. — Sandbags should be frequently weighed to
insure the correct quantity of sand. They should be checked
for rips and for dampness and when wet should be dried.
Care should be taken to avoid dropping the bags, since this
shortens their life.
■ 109'. Handy-Billy. — When not in use the handy-billy
should be placed on top of a tail-line mooring-circle post. It
should be kept clean and oiled. The blocks should be painted,
and the rope frequently checked for wear.
■ 110. Tail-Line Block. — The tail-line block should be sub-
ject to the care applied to all metal blocks (see par. 106) , but
in addition, should have a fabric cover on at all times.
■ 111. Shackles. — Shackles should be kept free from dirt and
rust and should be oiled to facilitate freedom of movement.
A check should be made for bent pins.
■ 112. Grounding Mat. — The grounding mat should be in-
spected for general condition and should be kept free from
mud.
■ 113. Grass. — Grass is desirable on that part of the bed
which is not paved or graveled, but it should be kept free from
weeds and brush that would impede handling of the balloon.
■ 114. Drainage. — Care must be taken to keep the bed and site
well drained at all times.
■ 115. Deadmen. — Deadmen once installed will not last in-
definitely and frequent inspections should be made for
deterioration of wood and corrosion of cable.
a. Care of wood. — Creosote or some other protective mate-
rial will help prolong the life of the deadmen.
b. Care of cable. — For protection of cable several commer-
cial products are available. They are usually applied by
67
115-116 ANTIAIRCRAFT ARTILLERY FIELD MANUAL
painting, dipping, or spraying, and are reported highly re-
sistant to acid, alkaline, or sea water. The length of time
cable will last depends upon the type of soil and atmospheric
conditions. Experience indicates that in salty soil it is neces-
sary to replace all nontreated cable by the end of the third
or fourth month.
■ 116. Storage. — Adequate storage space is needed on the
site for all extra site equipment. (See par. 86.)
68
Appendix I
DUMMY SITES
■ 1. Purpose. — a. Dummy installations are intended prima-
rily to confuse the enemy as to the location of the target
or targets and the strength of the barrage, but also may
give some protection to personnel by distracting strafing
airplanes.
b. A dummy should be made to look exactly like a real bed
from the air, so far as this is possible. If the roof of a
building is used, it may be possible to paint the bed in, but
on the ground much of the earthwork necessary for a real
site will be required. Painted boards for anchorages, scat-
tered blocks, and a winch faked from boards may be em-
ployed. Whenever possible, experts on camouflage should
be consulted before dummy sites are constructed.
■ 2. Using Old Balloons. — The illusory value of dummy sites,
particularly in open areas, will be increased considerably
if old balloons, no longer fit for actual flying but suitable for
air inflation, are placed on the beds, inflated, and moored.
Dummy beds holding such balloons naturally will have to be
constructed with this function in view.
■ 3. Mooring Old Balloons. — a. The balloons, minus rudder
and fins or with rudder and fins furled, should be air inflated,
bedded down in the direction of the prevailing wind, and left
pointing that way regardless of subsequent shifts in wind.
One suggested method for bedding down is to lay out a 37-foot
circle of 24 screw pickets and secure the balloon with han-
dling, mooring, and nose mooring lines (see fig. 27). No
octagon or cradle bed is required.
6. The procedure is as follows:
(1) The 37-foot circle should be laid out.
(2) Ground cloths should be placed in the middle of the
bed and four 50 -foot lengths of %-inch rope laid out.
69
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
BARRAGE BALLOON SITE INSTALLATIONS
(3) The balloon then should be laid out, with nose to the
prevailing wind, and a cradle formed by running the Mi-inch
rope from the Nos. 2 and 5 rigging patches on the left side
underneath the balloon to the pickets on the 37-foot circle
on the right side, and similarly from the Nos. 2 and 5 rigging
patches on the right side to the pickets on the left side.
(4) Air inflation should begin, with the gas valve line
buckle being moved about 20 inches in from the gas setting,
toward the gas valve.
(5) The handling, mooring, and nose mooring lines mean-
while should be rigged to the 37-foot circle.
(6) Then, to prevent the balloon from moving forward, a
length of Vi-inch rope on each side of the balloon should be
rigged to the No. 1 rigging patch, run outward and toward
the tail, and made fast to screw pickets placed 3 feet out
from the No. 3 rigging patch.
(7) Four sandbags should be tied together by the loops and
hung across the rigging line between rigging line patches.
(8) Inflation should continue with the handling, mooring,
and nose mooring lines and sandbags being adjusted until all
are subjected to a light strain with the gas valve blowing off.
(9) All knots should be secured, with no subsequent cord-
age adjustments made except when topping-up with the air
blower or when the valve is blowing off. Slack cordage indi-
cates topping-up is needed. When deemed advisable, extra
sandbags may be hung on rigging lines and bedding strops.
■ 4. Maintenance. — Adequate personnel should be assigned
to dummy balloons, both to protect materiel and to top-up or
perform other servicing as needed.
71
Appendix n
IJST OF REFERENCES
Organization and Tactics FM 4-181 (to be published)
Service of the Balloon and Bal- FM 4-187
loon Equipment, Low Altitude.
Rigging and Fabric Repair FM 4-196 (to be published)
Reference Data FM 4-198 (to be published)
Communications, Construction, FM 5-10
and Utilities.
Field Fortifications FM 5-15
Camouflage _ — - FM 5-20
Reference Data FM 5-35
Field Sanitation - FM 8-40
Protective Measures, Individuals, FM 21-45
and Small Units.
72
INDEX
Access road: Paragraph Page
Construction 12 9
Maintenance 15 9
Parking space near 16 9
Quality 13 9
Turn-outs 14 9
Airport sites 8 6
Anchorages :
Permanent :
Central 27 12
Pair-lead 33 19
General requirements 23 11
Hauling 33 19
Main point 31 17
Mooring-circle 32 19
Tail-line mooring-circle 34 19
Winch 39 22
Temporary :
Central 28-30 15
Hauling 35 20
Main point 35 20
Mooring-circle 35 20
Tail-line mooring-circle 35 20
Winch 40-42 22
Assembly, trolley 75 55
Bag, handling line 64, 73 43, 50
Ballast blocks, extra 57 36
Ballast, cradle 51 30
Ballonet type balloon, characteristics 4 1
Balloon:
Ballonet type 4 1
Old App.I ' 69
Securing 5 3
Bed:
Definition of 3 1
Steps in laying out 26 12
Surfacing 36 21
Bed blocks:
Attachment of in bedding down 46 26
Use in mooring-circle close-haul 71 48
Bedding down 44-57. 26
Characteristics of equipment 6 4
Necessity 44 26
Bedding strops 52 32
Extra 57 36
Block, central anchorage 27 12
Block, trolley 75 55
73
INDEX
Blocks : Paragraph Page
Bed:
Attachment of in bedding down 46 26
Use in mooring-circle close-haul 71 48
Ballast 51 30
Bridle grommet 74 51
Bridle, wire 74 51
Bungee assembly, tail-line 67 46
Bungee strop 67 46
Bypass, tail-line mooring-circle 68 46
Cable :
Hauling 33 19
Tail-line mooring-circle 59 38
Track for midship mooring 75 55
Camouflage, site 93 65
Central anchorage:
Construction of concrete type 27 12
Construction of temporary type 28, 29 15
Grounding equipment 27 12
Rod 27 12
Check strop : "
For tail-line mooring 67 46
For midship mooring 75 55
Close-haul, mooring-circle 5, 6, 69-72 3, 4, 48
Concrete :
Suggested mix of 24 11
Use for anchorages 23 11
Cradle :
Ballast 51 30
Extension strop 51 30
Legs 51 30
Lines 52 32
Slips •
Extra upper 57 36
Lower 52 32
Upper 52 32
Cradle bed, definition 32 19
Crew quarters:
Construction 78 57
EJquipment 79 57
Garbage disposal equipment 81 58
Latrine 80 58
Curb, central anchorage 27 12
Deadman central anchorage:
Construction 29 15
Grounding 30 17
Deadman winch anchorage:
Construction 41 22
Grounding 42 25
Defenses, local 92-98 61
Dummy sites:
Construction App. I 69
Mooring old balloons App. I 69
Purpose App. I 69
Use of old balloons App. I 69
74
INDEX
Earthwork: Paragraph Page
Clearing site 18 10
Grading site 19 10
High water marks 20 11
Equipment :
Additional for storm precautions 57 36
Features of handling 6 4
Manual haul-down 50 30
Pins, furling 56 36
Flying, types 38 22
Fox holes 93-96 62
Assignment of men 94 62
Construction 95 62
Location 93 62
Front midship patch 74 51
Furling rudder and fins 56 36
Garbage disposal equipment for site 81 58
Gas cylinder stacks:
Care 91 61
Grounding 90 61
Location 88 61
Preparation 89 61
Gipsy-head • 33 19
Grading of site 19 10
Grommet, bridle 74 51
Grommets, wire 46 26
Grounding mat, central anchorage 27 12
Grounding plate:
Central anchorage 27 12
Winch anchorage 39 22
Handling equipment, general features 6 4
Handling-line bag 64,73 43,50
Handling lines:
Attaching front in mooring-circle close-haul- _ 72 50
Attaching to wire spider 48 28
Marking 48 28
Reeving and tying rear in mooring-circle close -
haul 71 48
Handy-billy 62,73 42,50
Haul-down:
Manual 49.50 30
Mechanical 49 30
Hauling anchorage, construction 33 19
Latrine 80 58
Laying out bed, steps 26 1Z
Line, running 74 51
Lines:
Cradle 52 3<!
Sandbag 53 35
Local defences:
Camouflaging 98 65
Fox holes 93-96 62
Winch barricade 07 65
75
INDEX
Main points: Paragraph Page
Construction 31 ^
Plane 31 ™
Maintenance of site equipment 99-116 65
Manual haul-down 49 30
Kquipment 50 30
Mechanical haul-down 49 30
Midship mooring 5, 6, i3-76 3,4 'fl;
Advantages-
73 50
19
19
4, 48
Characteristics of equipment 6 4
Midship tensioning strop 75 55
Mooring circle, radius 32
Mooring-circle anchorages, construction 32
Mooring-circle close-haul 5, 6, 69—72
Characteristics of equipment 6 4
Mooring-line extensions 57 36
Mooring, midship 5,6,73-76 3,4,50
Mooring slips 54 35
Occupation of site:
Procedure for when site fully prepared 10 7
Procedure for when site partially prepared- — . 11 8
Octagon 3 1 17
Old balloons:
Maintenance App. I 69
Mooring App. I 69
Tactical use App. I 69
Operations hut:
Construction 84 58
Equipment stored 86 58
Location 83 58
Parking space 16 9
Patches, midship 74 51
Pickets, screw 35 20
Point of attachment 45 36
Post, tail-line mooring-circle 60 40
Pyramid 63 42
Quarters, crew 77-81 57
Quick release shackle 63 42
Rear midship patch 74 51
Rigging, tail-line 66, 67 43, 46
Rigging-line sandbags 53 35
Rip cord strop 63 42
Rods, anchorage 27, 31-34, 39 12, 17, 22
Rubber strop 75 55
Rudder, furling 56 36
Running line, wire 74 51
Running-line snatch block 75 55
Running tensioning slip ' 71 48
Safeguarding property 21 11
Safety strop 63 42
Sale, wind 87 61
76
INDEX
Sandbag— Paragraph Page
Lines 53 35
Spider 72 50
Weight 51 30
Sandbags :
Extra 57 36
Rigging-line 53 35
Securing balloon:
Basic considerations 4 1
Methods 5 3
Shackle, quick release 63 42
Shelter for —
Crew 92-96 61
Winch 97 65
Site:
Airport 8 8
Auxiliary installations 2 1
Definition 2 1
Dummy App. I 69
Earthwork 17-19 9
Grading 19 10
High water marks 20 11
Occupation • 10,11 7,8
Sites:
Ratio 9 7
Types 8 6
Urban 8 6
Site equipment, maintenance 99-116 65
Slip, running tensioning 71 48
Slips :
Extra upper cradle 57 36
Lower cradle 52 32
Mooring 54 35
Tensioning 55 35
Upper cradle 52 32
Snatch block :
Running-line 75 55
Tail-line 67 46
Snubbers 72 50
Space, parking 16 9
Spider, sandbag 72 50
Spider, wire 47 26
, Attaching handling lines 48 28
Steel equipment 22 11
Stepladder for fin furling 56 36
Storm precautions, extra equipment 57 36
Strop :
Bedding 52 32
Bungee 67 46
Check 67 46
Rip cord 63 42
Rubber 75 55
Safety ; 63 42
Tail -line 67 46
Tail-line mooring-circle 61 40
Tensioning, midship 75 55
77
INDEX
Strop-Continued. Paragraph Page
Track 75 55
Transverse 71 48
Surfacing bed 36 21
Tail-line — ■
Assembly 66 43
Bungee assembly 67 46
Rigging 65 43
Snatch block 67 46
Strop 67 46
Tail-line mooring 5, 6, 58-68 3, 4, 38
Characteristics of equipment 6 4
Tail-line mooring-circle 34 19
Anchorages, construction 34 19
Bypass 68 46
Cable , 59 38
Posts 60 40
Strops 61 40
Temporary anchorages, (see Anchorages, tempro-
ary.)
Tensioning slips 55 35
Tensioning strop, midship 75 55
Track, cable 75 55
Adjusting 76 56
Track strops 75 55
Transverse strop 71 48
Trolly assembly 75 55
Pitting 75 55
Trolley block 75 55
Types of flying 1 38 22
Urban sites 8 6
General classes 8 6
Winch anchorage:
Construction of —
Concrete type 39 22
Deadman type 41-42 22
Truck type 43 25
Location for —
Direct flying 38 22
Indirect flying 38 22
Wind, prevailing:
Relation to main point 26, 31 12,«17
Relation to winch anchorage 38 22
Wind sail 87 61
Wire bridle 74 51
Wire running line 74 51
Wire spider 47 26
o
78
c 1
ANTIAIRCRAFT ARTILLERY
FIELD i MANUAL *
EAKRAGKE BALLOON SITE INSTALLATIONS
pHANGESV WAR DEPARTMENT,
No. 1 J Washington 25, D. C, 27 March 1944.
J ffiM 4-184, 13 April 1943, is changed as follows : .
, 5. Meehqbs. — a. When the inflated * * » and midship
: : ling.
»:<1) Bedding down is securing the balloon close to the ground
y means of ballast so that the air-scoop is just above the
._id, the lowest point of the ballonet clears the ground by
jout 18 inches, and the junction of the rudder and ballonet
3 to 5 feet above the ground. (See fig. 9.) It is stressed
* * on the, ground.
* * » * *
8. Types.
* * * * *
b. Urban sites. — Tactical situations will * * » industrial,
id business
(1) In resMtential districts, sites may he located in vacant
' j, public parbs, .golf courses, street intersections, and other
>en spaces. If it is necessary to locate balloon sites in school
1 : or pMai|||ptiids, the civilian population should be ex-
d from aw occupied areas.
* * * *
19. Gkadijto.— After the area * * * the central anchor-
e. (See fig. 2.) i It may be necessary to camouflage the
.inage ditch and the outline of the bed in order to fit into
;al camouflage plans.
36. Suepacins the Bed.
* » * * *
}. ! (Added.) It may be necessary tp camouflage the surface of
j bed in ordw to fit into loj;al camouflage -pjais. 1
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 39. Concrete Anchorage. ■
*****
6. Imbedded In the anchorage are four anchor rods, bent into
the shape shown In figure 6. The anchorage should * » *
to the winch.
■ 52. Cradle Slips and Lines.
*****
d. Bedding strops (Superseded). — Bedding strops are made
of %-inch manila rope (Or equivalent) with a soft eye in each
end. On balloons with delta type rigging patches, the bedding
strops are lark's-headed to the foot ropes. On balloons with
finger type rigging patches, the bedding strops are lark's-headec*
into the suspension rings. Two bedding strops are attached at
each No. 5 rigging patch, and one strop is normally attached at
each of the remaining patches. For storm precautions, an extra
bedding strop is attached at every rigging patch except No. 5.
The overall lengths of the strops are as follows :
Rigging patch D-t or Mk. VII DS
Nos. 1 through 4 2 feet 6 inches 2 feet 6 inches
No. 5 3 feet 9 inches 5 feet
No. 6 6 feet 8 feet
■ 56. Fueling the Euddeb and Fins. — a. General. — When the
balloon * * * on the ground. Standard equipment for furl
ing consists of a rudder protection sheet 7 by 26 feet and tr.
fin-furling lines 38 feet long.
*****
■ 57. Additional Equipment fob Stoem Precautions. — In hlg
winds » * * (see fig. 14) :
a. (1) For the D-7 balloon, four mooring-line extensions c
%-inch manila rope (or equivalent), 25 feet long, eye-splice
at one end.
* * * * *
■ 66. Tail-Line Assembly. — a. Components. — The tail-line a
sembly * * * tail-line extension. The tail-line bridle
tail line are furnished with, the balloon. For dimensions,
FM 4r-196 or FM 4r-198.
* * * * *
2
BARRAGE BALLOON SITE INSTALLATIONS
■ 67. Tail-Line Bungee Assembly.
* * * • •
o. Tail-line strop.— The tail-line » * * the upper end.
The eye is connected to the tail line by a 14-inch toggle, which
is secured to the tail-line strop by a retaining cord. The
lower end * * * a picketing hitch. The tail-line strop is
tensioned so that the balloon rides at an angle of trim «f
about 12°.
*****
■ 71. Reab Handling Lines. — a. Bed blocks.
*****
■ 75. Rigging On Bed.
*****
&. Mooring circle.
*****
(2) Track strops. — Track strops are 1-foot 6-inch wire strops
with a small ground rigging hook in each end. Byes are formed
in the ends of each strop with nicopress sleeves.
*****
d. Fitting trolley assembly. — To fit the * * * a picketing
hitch. The tensioning strop is tensioned so that the balloon
rides at an angle of trim of about 12°.
*****
I 77. Ceew Quabtebs. — The nature of * * * messing, and
recreation. They preferably should be not less than 75 feet nor
more than 150 feet up prevailing wind from the tail-line moor-
ing circle, and doors on the side of the quarters facing the
balloon bed should be avoided.
*****
■ 81. Gabbage Disposal (Superseded).— Garbage from the sites
should be collected and disposed of at a central location by the
platoon, battery, or battalion. Incineration of garbage at the
site should not be attempted because of the Are hazard.
■ 81.1. (Added) Steeilization of Mess Kits. — Open fires
should not be used at balloon sites to heat water for the steriliza-
tion of mess kits. A closed brick or stone fireplace may be con-
structed on the site to heat water, provided such a fireplace is
located not less than 150 feet from the balloon.
3
ANTIAIRCRAFT ARTILLERY FIELD MANUAL
■ 87. Wind Sail.— Rescinded.
■ 108. Sandbags. — Sandbags should be * * * shortens
their life. The use of clean pea gravel, if available, instead
of sand for filling' sandbags will help to increase the life of
the bags. Capillary dampness does not occur in gravel-filled
bags, and these bags dry more quickly after becoming wet.
[A. G. 300.7 (7 Mar 44).]
Py order of the Secretary of Wab :
G. O. MARSHALL,
Chief of Staff.
Official :
J. A. ULIO,
Major General,
The Adjutant General.