provisional description of italian observation balloon usa 1919

8/8/2019 Provisional Description of Italian Observation Balloon USA 1919

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THE GENERAL SERVICE SCHOOLS

LIBRARY

H QUO3-815.Class Number

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I|3JB6UAccession Number- WAR DEPARTMENT,

"Washington, January 24, 1919.

"Provisional Description of Italian

— the information of all concerned.XWO2.X a. G. 0.)

order of the Secretary of War:\

PEYTON C. MARCH,

General,

Chief of Staff.Official:

P. C. HARRIS;4

The Adjutant General.

\



TABLE OF CONTENTS.

Page.—Description of Italian observation balloon Part 1 3

Gas bag 4

Figure 1 4

Figure 2 5

Maximum pressure 6

Cone and stabilizers 6

Figure 3 7Suspension 8

Regulating the valve 8

Construction of the gas valve 9

Figure 4 10

Electric —onnections — 11

Rigging Maneuvering Mooring 11

Summary of the advantages of the Italian observation balloon 12

The Italian observation balloon in its various operations 13

Gas valve 13

Figure 5 14

Inflation and adjustment of the valve 15

Figure 6 15

Figure 7 16

Figure 8 17

Figure 9 18

Figure 10 19

Inflation of the cone and upper stabilizers 20

Figure 11 20

Figure 12 21Figure 13 22

Figure 14 23

Rigging of the basket 24Figure 15 24

Figure 16 25

Transportation 26

Figure 17 \ 26#



Page.Warning 31

Data on Italian observation balloons 3.2Highest altitude attainable with, one observer,, using a cable of 160 grams

per meter. Breaking strength 3,500 kg >... 32

PART lI—PLATES.

Plate I. Plate IV. Plate VII.Plate 11. Plate V. Plate VIII.Plate 111. Plate VI. Plate IX,



DESCRIPTION

OF

ITALIANOBSERVATION BALLOON.PART I.

The new type of balloon conceived by Dr. Eng. Prassone, Director of the

establishment of Aeronautical Construction, and by Major del Genio Avorio,

head of the Aeronautical Division, can be considered as a stabilized spherical

balloon, since the shape of the gas chamber is only slightly ellipsoidal, orovoidal; it

hastherefore all the advantages inherent in the spherical balloon.

On the other hand, with reference to stability, it can be considered as adirigible (due to the fixed suspension and the weight which is concentrated

in only one point, and also to its better penetrating shape when the rear

air chamber is in operation), in which, instead of the thrust given by the

engine, there is the action of the wind resulting from its retention by the

cable and in place of the tail planes there are the bag stabilizers, which

are more practical considering the special use of the observation balloon.

Its form offers minimum resistance permitting it to be used in strong winds,

even at -25 meters per second, while its small moment of inertia makes itimmediately take its position of equilibrium, even under the action of strong

squalls, with minimum movement of the basket.The balloon consists of a gas bag "I," either of ellipsoidal or ovoidal

form (Plates Iand II),provided with a cone shaped appendage "C" which

has the two-fold function of diminishing the resistance and giving stability

to the balloon, as well as that of acting in conjunction with the ballonet toinsure in the descent the maintenance of the shape of the gas bag. The

appendage carries three stabilizing bags "S" (fig. 3) 120° apart.

The gas bag of ellipsoidal form has the basket attached near the cable

and can be used not only as an observation but also as a defense balloon,being able to liftto very high altitudes considerable loads and descend with

out in the least varying its shape and, therefore, its stability. Naturally,

for this purpose the various parts of the balloon are made lighter.The gas bag of ovoidal form has precisely the same external appearance

as the one of ellipsoidal form, from which it has been derived by filling a

part of the air cone with gas. This has been done with the object of aug

menting the ascensional force at the stern in order to separate the basket



The basket is suspended and held by means of eight ropes, of which the

four side ones "c" and the two rear ones "f" are secured to the terminal

rings of the catenaries; the two front ones "f," if the basket is near the main

cable, are secured to the two rings holding the suspension ropes (Plate III);

if the basket is farther from the cable, the two ropes are attached to the

second suspension points of the gas bag (fig. 14). These ropes are assembled

on rings in two groups, all suspension ropes on each side being on one ring

and the two rings connected by a strap of steel cable to which the main

cable is attached.

The cone and stabilizers (Plates Iand II) are designed solely to hold

the air which enters from the special inlet "2" and from the opening of

communication "4" between the ballonet and the lower stabilizer. The cone

and stabilizers are intercommunicating, freely in the case of the two upper

stabilizers, but the lower one only communicates with the cone by means

of inlet "17" supplied with a cloth valve, which permits the passage of air

from the stabilizer to the cone and not vice versa. Thus it is possible to have

the cone and upper stabilizers inflated, in the beginning, by using a small

pump worked by hand or motor.

The gas is all contained in the ellipsoidal, or ovoidal, gas bag, which

has in the lower part a diaphragm "D" designed to give place to an air

chamber "A" when the balloon is not full of gas. The air reaches the

air chamber from the special inlet "1" and moreover the air chamber communicates with the lower stabilizer by means of opening "4."

The system is completed by gas valve "13," located near the equator, and

which is opened by means of small non-elastic metallic cables controlled by

the cloth of the diaphragm "D" and regulated by a simple and convenient

device on the lower part of the balloon; also a cloth valve "3" situated on

the upper part of the cone adjusted in such a way as not to permit the

pressure of air to exceed a certainpreestablished

limit.Lastly, the gas bag has several transversal bands (15) with the two-

fold purpose of reinforcing the canvas and of constituting, with the terminal

rings "T," firm attachments for the mooring and maneuvering ropes.

GAS BAG.

As before stated, the gas bag is of ellipsoidal or ovoidal form.



It is fusiform (like dirigibles), while the zone formation is made secureby strong and large reinforcement bands placed transversely and which end

at the vertices of the suspension catenaries "P," serving thus also as rein

forcements to the vertices themselves.

Directly above the catenaries and parallel to the line of vertices, or knots,

there is the attachment of the ballonet, placed in such a way that all the

outside covering underneath the balloon, which in mooring touches the

ground, contains only air and is subjected only to the pressure due to thewind; whereas the tensions due to the ascensional force and the action of

the wind are all concentrated in the knots and transmitted to the cable by

means of the suspension ropes.

The catenaries are made of small steel cable, while the suspension ropes

are of hemp.

Fig. 2.



MAXIMUM,PRESSURE.

In order that the balloon may retain its shape, it is not necessary to

inflate it to an excessive pressure 1,but it is sufficient to fillto the point where

the ballonet is entirely distended against the outside covering, when the valve

may be opened.

When the balloon is up, no matter how little wind there may be, the air

penetrates the air chamber, insuring the perfect form of the gas bag.Having adjusted the gas bag for this purpose, the maximum pressure

which can be attained in the upper part of the gas bag, supposing the balloonto be entirely filled with gas and in a wind of 20 m. per second, is nearly

that of 12 mm., plus the pressure due to the wind, which in this instance is

24 mm. In all, therefore, there would result a maximum pressure of about

36 mm. in the upper part, which, is, however, only attainable with a wind of

20 m. per second and when the balloon is completely filled with gas (initially).This, at sea level; at higher altitudes the pressures diminish by reasonof the diminished density of air and hydrogen.

Notwithstanding the fact that there is a large margin of safety in the

cloth, its inevitable deterioration must be borne in mind, and therefore amaximum pressure of 30 mm. of water has been set for the upper part, corresponding to that of about 15 mm. of water in the basket.

On the glass tube of the manometer there has been placed a mark at 15

mm. The gas valve is operated by hand when the liquid reaches this mark.

(For gauge liquid it is best to use colored alcohol instead of colored water,

in order to avoid freezing at high altitudes. However, in this case, owing to

the different density, the mark should be made at 18 mm.)

CONE AND STABILIZERS.

The cone and upper stabilizers form a single air chamber independent of

the one formed by the ballonet inside.

This air chamber is closed by means of a cap-shaped cloth valve, its

weight balanced in such a manner as to adjust the opening to a lower pressure

than that for which the gas valve is adjusted, and to open wide under apressure of about 6 mm., so that the gas expanding before the gas valve is in

operation causes the surplus air to be expelled from the cone and stabilizerssimultaneously with the air in the ballonet, which assures the shape of the

balloon, and of the ballonet, and with the latter keeps the nose inflated.

For the "balloons which are used as aerial defense, it is advisable to

increase by a few millimeters the tension of the gas valve, in order to have

consequently



coefficient of safety the noticeably increased pressure due to the high velocityof the wind.

The cone and upper stabilizers may be inflated from the beginning even

when the balloon is moored, whereas the lower stabilizer becomes inflated

while ascending, as with the stabilizers of the discarded "Drachen."

For the initial inflation!, a hand air pump, with a capacity of inflating

50 to 60 cv. m. the first minute, is used. (The capacity of the air chamber,

consisting of the cone and upper stabilizers, is less than 200 cv. m. when thegas bag is entirely inflated.

A decided advantage results in having the balloon in shape from the

beginning, since the swaying is entirely prevented, both in transportation and

in ascending.

Fig. 3.

The air inflation can be continued as long as the cloth valve "3," located



On mooring, everything may be flattened in a few minutes by openingthe proper inlets.

The cloth of the cone and stabilizers must be filled only with air and

made as light as possible. It is advisable that they be of 2-ply rubberized

cloth fabric which must be of very fine texture. This 2-ply fabric may be

employed only for the upper portions of the cone and of the two lateral

stabilizers which are more exposed to atmospheric influences, fabric of single

thickness being used for the remaining parts.The form of the stabilizers is well reinforced by means of light dia

phragms of rough texture, perforated to allow the rapid passage of air.

SUSPENSION.

The suspension of the cable consists of (Plates V, VI, VII) 12 ropes,

which start from the vertices of the catenaries of the gas bag andcome

together in two groups, right and left, each terminating with a metallic ring.

The two rings (Plate V) are secured by means of a thimble bearing a

steel strap, to which the main cable is directly attached.

In addition, they are joined by two other rings; the first of these bears

a steel cable for the central ballast; this cable has on one end a snap hook

which secures it to the ring, and on the opposite end a releasing-hook for the

simultaneous removal of all thesmall

sandbags, which

release is made afterattaching the main cable ; while on descending, before removing the cable,

it is necessary to reattach the central ballast.

The second ring carries the attachments for the maneuvering ropes,

when it is necessary that these ropes be in the center, as is the case when

maneuvering over obstacles.

Also these loops, which are made of ropes of hemp; are attached to the

ring by means of snap hooks, the purpose of which is to allow, before the

ascension, the prompt release of all the ropes from the two rings whenever

this is thought necessary in order to render a freer field of vision.

The suspension, as well as the staying of the basket, consist of eight

ropes also attached to the vertices of the catenaries of the gas bag (Plates VI,

VII) ,except when the basket is placed near the cable, in which case the two

front ones go to the two rings of the suspension group.

Both the suspension ropes of the cable and the basket ropes are pro

vided with adjustment thimbles to correct the possible difference in the length

of the ropes. It is to be noticed that the last two ropes in the rear of the

cable suspension must remain less tight than the others and that the gas

bag, as well as the basket, must incline slightly toward the front, to counter

balance, ascending, wind, tip



cone until the valve opens. This is located below in the center of the balloon.It is well that the regulating be verified with the balloon placed under the

same conditions as when itwill ascend, as willbe stated later.

Once regulated, the ropes on the inside, being metallic, should never be

made to stretch so as to cause a failure in the functioning because the valve

has a long course. Moreover, being situated on a parallel with the greatest

pressure, the ropes are more stretched because the balloon tends to enlarge

itself,whereas the

consequentand simultaneous

shorteningof the

longi

tudinal axis of the balloon, which occurs also under the effect of this samegreat pressure and which would tend to loosen the ropes, cannot have any

influence upon the ropes.

Inany case, it would be advisable to verify from time to time the regula

tion by means of the small closed sleeve, which operation (as before

described) takes just a very few minutes, while it guarantees good automaticfunctioning.

Having regulated the valve, the pilot must take scrupulous care to roll

up the small sleeve and replace it in the proper pocket in the ballonet, with

which the small sleeve must rise when inflating the air chamber.Any short-circuiting of the balloon with the basket is avoided by the new

plan on which the electric connections are based, which is that of leaving

the gas bag at the potential of the surrounding air, while the basket and

main cable are placed at the earth potential.

For the same reason, in the rip cord and valve ropes, which end in the

basket, has been inserted a silk cord with the object of still better insuring

the insulation.

CONSTRUCTION OF THE GAS VALVE.

The balloon, during the ascension, carried the terrestrial potential into

a surrounding medium of quite a different potential, and therefore a high

difference of potential is established between the balloon and the surrounding

air. Under such conditions occur electric discharges (phenomenon of the

"corona") emanating from the surfaces of the bodies and especially from

projecting parts, such as thin wires, sharp points, etc. The electricity

escaping from the surfaces of the bodies to the surrounding atmosphere of

different potentiality gives rise to discharges, which, though silent, arecapable of producing the ignition of a mixture of hydrogen and air.

It has therefore been found necessary to take, together with other pre

cautions, which will later be enumerated, that Of adopting a gas valve with

no metal parts. The valve used in the Italian balloon is a wooden one of



its place, being prevented by the greater bulk of the rubber at the end of thehole on the opposite side of the wooden plug.

Ifit is desired to adjust the cord, it is enough to pull the rubber at the

same time on either side of the hole in the wooden plug, and then the rubber

slides gently.

By this plan has been obtained the greatest simplicity for regulating,

with the greatest security.



Before attaching the valve to the gas bag, when the inflation is beingmade, it is necessary to see if it begins to open at about 13 kgs.

With this tension one is sure of obtaining a good seating when the insideropes are slack and a sure functioning when the aforesaid ropes begin to be

under tension, provided that during inflation they have been suitably

regulated by shifting the regulating knot.

The valve is attached to the hole in the gas bag by means of a lacing

with small hemp cords of from 3 to 4 mm., which is then covered with water-proof cloth.

When the balloon is being moored, it is necessary that the pilot see to

the proper covering of the valve.

ELECTRIC CONNECTIONS.

In order that the observation balloon may work, as regards electricity,under the best of conditions, the advisability has been demonstrated, by exper-

iment, of keeping the gas bag insulated, allowing it to take, without inter-ference, the potential of the surrounding air in which it may be at high

altitudes and to put the basket at the potential of the earth.The realization of this condition has been obtained in the Italian balloon

in the following ways:

1.Eliminating

all metallic connections between the gasbag

and thebasket and between the gas bag and the main cable.

2. Insuring the insulation of the gas bag by inserting silk cords in the

valve ropes and rip cord which end in the basket.

3. Adopting the wooden gas valve with elastic cords.4. Suspending an "aigrette" to the valve in front and fraying the upper

extremity of the main cable.

The basket is attached to the main cable and therefore to theearth

by thetelephone cable.

RIGGING—MANEUVERING—MOORING.

The rigging of the Italian balloon is reduced to the greatest simplicity,

since the operations to be performed are reduced to that of attaching thebasket to. its ropes and attaching the main cable to the one with which

the suspension ropes terminate.

The maneuvering, owing to the fact that all the weight is centered, is

based on the same plan used for dirigibles by ballasting the balloon in

order to overcome a great portion of its lifting force; the men, therefore,



It is, however, necessary to keep in mind that the mooring and maneu-

vering ropes fixed to the aforesaid attachments are normally held in the

direction of the bands themselves, which is the direction of maximum

resistance.

SUMMARY OF THE ADVANTAGES OF THE ITALIAN

OBSERVATION BALLOON.

1. Great stability of the balloon, making possible efficient observations

even with wind at 25 meters per second.

2. The basket has no noticeable motion, not only on account of the

stability of the balloon, but also because of its method of suspension.

3. Little resistance to the wind and therefore less tension on the cable

and thepossibility

ofbeing

able toemploy lighter

cables.4. Slight deviation from the vertical with the resulting gain in altitude.

5. The small number of suspension ropes diminishes greatly the wind

resistance and the dead weight, and due to the fact that they are fixed instead

of movable, there results a very compact arrangement.

6. In case of the breaking of the main cable, it will act like a free

spherical balloon.

7. On account of the spherical form of the balloon, the simple method of

attachment of the suspensions, the compactness of the whole and the arrange

ment of the air chamber, the retention of the shape of the gas bag is assured,

and therefore great speed in descending is made possible; also a smaller

static current and the more even surface.

8. On account of this same spherical form, the maneuvering, the trans

portation and mooring are easily made, and the pit to be dug for the mooring

in the open can be very shallow; if necessary to build balloon hangars, they

can be built shorter, about half the length of the present ones and only afew meters wider.

9. There has been adopted a 3-ply fabric, in order to better assure its

wearing well, notwithstanding the continual stay in the open air. The 3-ply

fabric in question, though nearly of the same weight as the 2-ply, guarantees

quite a long life for the observation balloon, as regards both its resistance and

tightness.

10. In comparison with existing types, there is a noticeable saving ingas, both because, at the same altitude and for useful load lifted, the volume

is less, and because it is possible under any circumstances to have the balloon

rise not completely filled with gas, its form being assured by means of an air

chamber (similar to the one used in dirigibles of the semi-rigid type) closed



14. The swaying of the balloon under the action of squalls at the

beginning of the ascent and at the end of the descent is not noticeable, on

account of the small moment of inertia, which permits it to immediately

regain its equilibrium.

15. Consequently the maneuvering field can be small.

16. In descent there is no noticeable caving in of the nose.

17. The possibility, due to the ropes being fixed and to the greater

stability, of putting a manometer in the basket.

18. Simple valve regulation, which is within reach of the hand.

19. Long life of the suspension ropes, which are not worn out by friction

on rings.

20. The shape of the balloon, together with its stability, make possible

the placing of a platform on top, on which could be installed a machine gun,

or other similar means of defense, thus providing the observation balloon with

an active defense, in addition to its passive one of rapid descent in case ofattacks by enemy airplanes.

21. Due to the similar behavior of this balloon to a spherical balloon,

there is the possibility, whenever the surrounding field permits, of escaping

enemy attacks by rapid descent.

InPlate IX is shown the static calculation of the 1,100 cv. m. balloon.

In it are indicated the respective positions of the center of volume of the

gas bag and of the center of gravity of everything carried.Assuming the balloon to be full of hydrogen, on the ground at the tem-

perature of 10° C, with an ascensional force of 1.15 Kg. per cv. m., it is

seen that the balloon at sea level is slightly tipped forward, whereas it is

perfectly horizontal at 1,000 meters, and is tipped slightly backward at

greater heights.

THE ITALIANOBSERVATION BALLOON IN ITS VARIOUSOPERATIONS.

In order to facilitate the task of the commander of the Aeronautic Sec-

tion, the principal operations which are to be carried out for the perfect

adjustment of the balloon are described below.

GAS VALVE.



together the two hems instead of superposing them, in order to obtain (fig.7)

a sure sealing when the fabric is cemented on later.



The inflation (fig. 8) is made according to the rules already indicated in

the expressly prepared instructions of the Balloon Battalion, keeping well



the suspension group are to be placed the sand bags constituting the centralballast.

Fig. 7.



completely filled (itmust then be at about 1meter from the ground with the

gauge sleeve distended), he must then direct his attention to the cloth of the

inside diaphragm which separates the gas chamber from that of the air

Fig. 8

(ballonet), in order to slow up, in time, the emission of gas whenever the

cloth of the diaphragm is about to come into contact with the outside cover-in g of the balloon, and to completely stop it when the gauge sleeve begins

to swell.

Ifup to this moment the gas valve has not been functioning, the regu-

lating knot is shortened and more gas le t in .

The operation is repeated until the gas valve functions regularly.

In case, however, the valve should function a long time before the small

sleeve begins to swell, it is best to lengthen the knot, repeating the operationuntil regular functioning is obtained.

Moreover, it will be well to again verify the adjustment of the valve in

the ascending position of the balloon, and in order to do this, all the other

restraining



The balloon being placed as in figure 10, with the maneuvering ropesslack, gas continues to be given and the adjustment of the valve controlled,

keeping well in mind that, if it has not functioned until the moment in

which the little gauge sleeve begins to swell, that the gas must be stopped,

the balloon lowered, the regulating knot corrected and the balloon permitted

to rise again in order to repeat the operation described.

INFLATIONOF

THECONE

AND UPPER STABILIZERS.

Having performed the above operations the balloon is again lowered

without touching the sand bags of the central ballast, and then is begun the

inflation (fig. 11) of the cone and upper stabilizers by inlet 7, having,

however, taken the precaution of first closing sleeves (5-12-10-6-7-8) andplacing the rolled up, small gauge sleeve in the proper pocket of the

diaphragm.



The inflation of the cone and upper stabilizers is continued until the

opening of the valve located on the cone (fig. 12).

RIGGING OF THE BASKET.With wind-sleeve 7 closed, the balloon is again raised to the position it

was in for the valve adjustment, where it is held down by the central ballast

(fig. 13), with the maneuvering ropes slack, the same as when ascending. In

this manner one proceeds to the rigging of the basket, in which there must

be placed the weight of two persons.The basket placed, the ropes cross one another in the way designated in

detail in Plates VI and VII, so as to hold it securely and therefore give

it the necessary stability.

The suspension ropes of the balloon which go to the two rings of the

suspension group are of such length as to cause the balloon to remain alittle tipped forward; besides they must be all stretched approximately alike,

but a little less tension on the two rear ones. This can be verified by touching them with the hand. Should there be any difference, they are regulated,

first lowering the balloon by means of the maneuvering ropes.

Seen from the side, the basket with the required weight must be hori

zontal, or, better still,inclined slightly forward (fig. 14) by tightening, a little

more, all the four rear ropes. In any case, itmust never tip backward. Other

wise, should the balloon not be completely filled, it could not maintain its

stability, especially in descending.

Seen from the front, the vertical plane containing the longitudinal axis

of the balloon must pass through the contact of the two rings, to which are

attached the suspension ropes, and must also bisect the basket and be at

right angles to it .



TRANSPORTATION.

The balloon is transported as indicated by figure 15, overcoming a part

of the ascensional force with central ballast, for maneuvering with greater

security, both on account of requiring less effort by the balloon squad and

because the balloon maintains its shape and horizontal position better.

When there are obstacles to be passed over there must be attached to the

center the long central maneuvering ropes held by all the men who first held

the lateral maneuvering ropes; having, however, surmounted the obstacles

Fig. 17.



ACCEPTANCE TEST.

In figures 19-20 is shown the balloon in ascension during acceptance test.

It is best to make it rise to the highest altitude attainable, after having

placed in the basket the weight corresponding to one or two observers.

*•

t

Fig. 19.

Having started completely filled, itwill naturally lose through the valve

a volume of gas corresponding to the expansion for the altitude reached,

Thus, for example, in case of a balloon of 1,110 cv. m., rising to 2,000

meters, the volume of hydrogen lost is about 250 cv . m.

While descending, with balloon horizontal, one can see through the inspec-tion holes the volume of air contained in the air chamber, by comparing,

for convenience, the height of the cloth of the inside diaphragm with its

attachment to the balloon.



In

this way, one is sure to have the volume necessary to reach altitudes,without considerable loss of hydrogen.

Moreover, it will be best never to reach the acceptance height, which is

the highest possible, but to remain a little under it , in order to give the

balloon the necessary reserve ascensional force.

Fig. 20.

MOORING.

In figure 21 is represented the mooring made by means of the special

ropes, always fixed to the balloon and attached to the rings of the strong

transversal bands which are united to one another both by means of the

longitudinal band placed on the upper part and by the curved lateral bandsof hemp ropes, the whole constituting a net. The transversal bands and the

curved bands are only cemented to the gas bag and therefore (whatever

deterioration of the cement might take place, especially during very hot



The fabric of the lower part of the balloon should not form foldswhich

might endanger, by greater air resistance, the security of the mooring, nor

should itbe so greatly squashed down as to strain the attachments.

The mooring ropes are held in the direction of the transversal bands,

which is the one of greatest resistance, and should all be under equal tension.

Due to the small surface of the balloon, if the mooring is carriedout

as indicated and continually watched by one of the balloon guards, it is

capable of withstanding all winds.

Naturally, however, providing the ground so permits, it will be well to

dig a small pit, even if not very deep.

Fig. 21

the protection of the cloth of the lower part of the balloon and the

eFor ropes from water, friction, etc., the ground cloth provided servesension

the purpose very well. Also a trench placed laterally to the balloon prevents



It is therefore best, each timethe

balloon is moored, to cover the upper

part (which wears out the most rapidly) with a protecting cover of a color

that willbest disguise it .

As is seen from figure 22, it consists of an elliptical cap, lengthened at

the stern, of such dimensions as to cover the upper part of the balloon,

including the curved mooring bands and the upper part of the cone and

Pig. 22.

stabilizers; it is of single thickness, to which is glued transversal reinforcing

bands at the upper axis. The border is finished in points, from each of which

branch off the mooring ropes.

The putting on of the cover is simple; the pulling rope is thrown over

the balloon by means of the special ladder, which is carefully placed against

the moored balloon.Ifa pit has been dug the placing of the cover is much more rapid.

Inany case it is best never to neglect putting it on whenever possible,

since it is very beneficial to the cloth, straps and attachments. Nor is it to



The tipping forward, when there is little or no wind, results, during thedescent, in a spiral motion of the balloon around the cable, which sometimes

causes the basket to be almost perpendicular to the cable itself.

For this reason, it is wise, above all, to make use of the parachute before

the balloon starts to come down, or else when it is being dragged by the

winch; for, when it is absolutely essential to leave the basket during the

descent, the commander of the section must stop the balloon before giving

the order to the observer to jump.

7j.1j.1

Capacityapacity 1,100 cv.,100 m.v. m. 900 cv.00 m.v. m. 800 cv.00 m.v. m.(38,840 cv.38,840 ft.)cv. ft.) (31,780 cv.31,780 ft.)cv. ft.) (28,250 cv.28,250 ft.)cv. ft.)

Diameteriameter 11.44 m.1.44 m. 10.65 m.0.65 m. 10.28 m.0.28 m.(37' 6)37' 6) (3411")3411") (33' 8y2")33' 8y2")

Length 18 m.8ength m. 16.75 m.6.75 m. 16.20 m.6.20 m.(59' 0")59 '0") (54' iiy2")54' iiy2") (53' 1")53' 1")

Total weight of bag, including suspenotal weight of bag, including suspen-sion catenaries and transversal moorion catenaries and transversal moor-

" "" " " lbs.bs.ng bandsng bands 390 Kg. 858 lbs.90 Kg. 858 lbs. 340 Kg. 748 lbs.40 Kg. 748 lbs. 320 Kg. 704 "20 Kg. 704 "Mooring ropes attached to balloonooring ropes attached to balloon 13 28.63 28.6 13 28.63 28.6 13 28.63 28.6Suspension ropes of cable withrings foruspension ropes of cable withrings for

attachment to cable and attachmentsttachment to cable and attachmentsfor ballast and central maneuveringor ballast and central maneuvering " " " "" " ""ropesopes 21 "1 " 46.2 " 19 "96.2 " 41.8 "1.8 " 18 "8 " 39.6 "9.6 "

Suspension ropes of basketuspension ropes of basket 7 "" 15.4 " 7 "5.4 " 15.4 "5.4 " 7 "" 15.4 "5.4 "Cotton mooringCotton ropesooring ropes 30 "0 " 66.0 " 30 "06.0 " 66.0 "6.0 " 30 "0 " 66.0 "6.0 "Gas valveas valve 5 "" 11.0 " 5 "1.0 " 11.0 "1.0 " 5 "" 11.0 "1.0 "Basketasket 32 70.4 32 70.422 70.40.4 32 70.42 70.4

498 Kg.1,095.6 lbs.98 Kg.1,095.6 lbs. " 425 Kg. 935.0 lbs.25 Kg. 935.0 lbs.otal.otal. " 446 Kg. 981.2 lbs."46 Kg. 981.2 lbs."Total ascensional force at0°and 760 mm.otal ascensional force at0°and 760 mm. 1,298 ",298 " 2,855.6 ",855.6 " 1,062 ",062 " 2,336.4 ",336.4 " 944 "44 " 2,076.8 ",076.8 "Reserveeserve 800 1,760.0800 1,760.0 616 3,355.216 3,355.2 519 1,141.819 1,141.8

IGHESTGHEST ALTITUDE ALTITUDE A CAINABLE \AINABLE \ VITH. ONEITH. ONE OBB ERVER,RVER,•»us:s: NG AG CABLECABLE >F 160F GRAi)160 GRAi) IS PERS MlER Ml ;tete

BREAKINGREAKING STRENGTHTRENGTH 3,500 KG.,500 KG.

Capacityapacity Starting Altitudetarting Altitude Highest Altitudeighest Altitude

Cu. m.u. m. m.. m..1,100,100 0 2,175,175

50000 2,525,5251,000,000 2,850,8501,500,500 3,150,150

90000 0 1.650.65050000 2,000,000

1,000,000 2,300,300

80000 0 1,350,35050000 1,700,700



ITALIANOBSERVATION BALLOON.

Plate I.DETAILS OF THE GA S BAG.

1. Air inlet to ballonet.2. Air inlet to lower /stabilizer, hence to cone and upper stabilizers.3. Outlet valve.




Plate 11.DETAILS OF THE GAS BAG.

1. Air inlet to ballonet.2. Air inlet to lower stabilizer, hence to cone and upper stabilizers.'3. Outlet valve.



ITALIANOBSERVATION BALLOON. PLA.TE 111.RIGGING.



ITALIANOBSERVATION BALLOON. Plate IV.RIGGING.

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Plate VIII.


Regulating of Gas Valve.

Valve

Cone of cloth.

provisional description of italian observation balloon usa 1919

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