The balloon naturally works under the same difficulties as all lighter-than-air craft, that is, there is a constant leakage of the hydrogen through the fabric in addition to that lost by the expansion of the gas on warm days when the summer sun beats down directly on the gas bag. Where a field generating plant is employed, quick inflation of a new balloon or replacement of loss is accomplished by the used of several "nurses", Fig. 27. These are simply large gas bags which are kept replenished by the gas plant working constantly, in other words, they are storage tanks, and when it is necessary to inflate the balloon quickly, their contents are simply transferred to it.
Fig. 27. Landing Big Kite Balloon at Training Station "Somewhere in England." "Nurse" in Background
Copyright by Underwood and Underwood, New York
Balloon Company. Though aeronautical in character, the kite balloon service is actually a branch of the artillery, to which it is directly attached. A balloon company accordingly consists of twelve to twenty artillery officers of varying ranks and about 120 to 130 men. Of the officers, six to eight are artillery lieutenants or captains and go aloft as observers, this number being necessary because the strain of watching constantly is very great and the observers must be relieved at frequent intervals, the balloon otherwise being kept up continuously, both day and night. There are also a number of sergeants, each of whom is in charge of a different branch of the work, such as the inflation, transport, telephone service, and winding machine. No less than fifteen 3-ton to 5-ton motor trucks are necessary for each balloon company besides two or more motorcycle messengers, the care of the machines usually being entrusted to the corporals of the company. The remainder of the company are practically laborers, whose chief duties are to attach the ballast bags to the ropes when it is intended to hold the balloon on the ground for any length of time and to utilize their own weight for the same purpose when the balloon is about to go aloft or is only on the ground temporarily. In addition, every company has its surgeon and assistants, quartermaster, cooks, company clerk, and other attaches necessary to complete its organization, since a balloon company serves as an independent unit.
Equipment. The paraphernalia required is quite as elaborate as that necessary to keep several aeroplanes aloft, though naturally of a different nature. It must all be readily portable, for a balloon company has to change camp more or less frequently, or as often as the enemy artillery happens to discover its range. To secure mobility is the purpose of the great number of motor trucks employed. One of these is equipped with a hoisting winch and a large drum capable of holding 3,000 or 4,000 feet of about 3/8-inch steel cable. The winch is driven by the same engine that propels the truck, and in case of emergency the engine may be applied to the two purposes alternately within a short space of time. For instance, in case of attack either by shrapnel from an enemy battery or by a hostile aviator, it may be used to quickly haul in or let out cable to change the altitude of the balloon, or it may be employed to drive the truck to another and more favorable location with the balloon in tow.
Another truck houses a complete telephone exchange, since the observers in the balloon may wish to communicate with any one of a number of batteries which they are serving. Telephone communication is established by means of an insulated wire which forms the core of the cable, while the steel cable itself acts as the return wire to complete the circuit. In some cases, a separate copper cable is employed, using the steel cable as the return half of the circuit. In addition there is a truck for transporting the balloons, for the company must always have duplicate equipment at hand in case of the destruction of the balloon it is using or, as more frequently happens, damage of a nature that requires hours or days to repair. In addition to the balloon itself, there are covers and the ground cloth, as in inflating a balloon no part of its fabric must be allowed to touch the ground because of the danger of stones or sticks tearing rents in it. The balloon proper and its immediate accessories utilize at least one and sometimes two motor trucks.
To hold the balloon on the ground when out of service, there are eighty sacks of sand weighing 25 pounds each, or an aggregate of 1 ton of ballast, in addition to which there are necessary a large number of steel screw stakes, spare ropes and parts, ladders and the like, besides the basket and its equipment. The stakes are employed to hold the balloon down in a heavy wind by "pegging" it in the same manner as a tent. Three or four trucks are required to carry the large supply of hydrogen necessary, which entails the transportation of 130 to 150 containers. Each container holds several thousand cubic feet of gas under high pressure, which is released through a reducing valve. Some of the other transportation units required are the "cook wagon," quartermaster’s stores truck, truck for carrying tents, blankets, and other impediments for the men, and the "doctor’s wagon" (ambulance).
Advantages of Kite Balloon. It became a necessity to resurrect the captive balloon and bring it up to date, not simply because the Germans were employing it in numbers, but because experience demonstrated that it possessed numerous advantages over the aeroplane for artillery observation. The observer in an aeroplane is carried back and forth over and around the location he wishes to watch, at high speed and at a constantly varying altitude. He must communicate by means of either signals or wireless, and it is not always possible for him in either case to know whether his signals have been received and understood, since it is possible to transmit messages by wireless from an aeroplane but a very difficult matter to receive. The observers in a kite balloon, on the other hand, have the advantage of being able to scrutinize a certain sector constantly with the aid of powerful glasses. With a few weeks of experience in observing a given terrain they become so familiar with it that any changes or the movements of troops or supplies are quickly distinguished. The greatest advantage, however, is that the information thus acquired may be instantly transmitted not merely to one but to any one or all of a group of batteries extending over a mile or two of front in either direction, the balloons being stationed 4 to 6 miles apart. The observers are fitted with portable head sets so that they speak directly into their telephones without the necessity of removing the glasses from their eyes, which enables them to watch the fall of the shells and tell the battery attendant in the dugout alongside the gun whether a shell fell "short", "over," "left," or "right," and the amount of correction needed before the smoke from the explosion has cleared away. With the aid of close corrections of this nature the battery commander is in a position to get the range exactly without the great expenditure of ammunition that firing entirely by map or with the assistance of aeroplane observers entails. Instances are recorded in which a 9.5-inch shell has been landed right in a concrete "pill-box" not over 15 feet square from a distance of 3 miles after six trial shots had been fired to obtain the range. Such a shot is reported back to the battery by the balloon observer as a "direct hit," and it is only necessary to fire the gun at the same range and direction to score as often as necessary.
Duties of Balloon Crew. Each kite balloon carries aloft two observers, Fig. 28, both of whom can concentrate their entire attention on the work of "spotting," since they have nothing to do with the control of the balloon itself, except to give orders. Their chief duties consist of "counter-battery" observation, that is, spotting the location of enemy batteries, and being constantly alert to detect any suspicious movements back of the enemy’s lines, such as movements of troops, ammunition, or supplies. The batteries controlled from observation balloons are the "heavies," which are located 1 mile or more back of the front line trenches and to the gunners of which the objects they are firing at are never visible. Some of the heaviest guns mounted on specially constructed railway trucks are often fired from points 5 miles or more back of the lines. In fact, when balked in their attempt to take Calais, the Germans bombarded the town with the aid of long-range naval guns from a distance of over 15 miles and every shot dropped into either some part of the city or its outskirts. Buildings, hills, or specially constructed and concealed observation towers are frequently utilized in conjunction with captive balloons to serve as auxiliary observation posts, so that the base line connecting the two may be used to triangulate distances and thus calculate them more accurately than is possible by direct observation from a single point.
