Power Plant. No less than nine large motors were employed to drive the huge gas bag, the maximum horsepower probably aggregating 1,600 to 2,000. The motors were distributed in five different locations, the largest being suspended just abaft the wireless room. The remainder were placed in self-contained units in the form of gondolas suspended from the sides of the frame, as shown in Fig. 24, the outline being that of a blunt-nosed fish. Each of these gondolas carried two motors placed side by side and coupled up so that either one or both could be employed to drive the single propeller. For cruising speeds one motor in each gondola supplied sufficient power or in some gondolas both motors could remain idle. No accommodation was provided for attendants in the gondolas, any of which could easily be reached by light ladders from the inclosed gangway.
To insure greater safety, the fuel supply was divided among sixteen tanks, all of which were interconnected with each other and the engines so that gasoline from any tank or tanks could be diverted to any particular engine. The supply of lubricating oil for each engine was carried in a tank in the gondola itself.
Control. Vertical and horizontal stabilizing surfaces of conventional form were built on the sharply tapering rear end of the frame, the elevator and rudder being similar to those used in aeroplane construction, except that the rudder was in two sections, the larger of which was placed on top of the envelope. The control of these surfaces, the operation of all the engines, the control of the water ballast, the air supply to the balloonets, and the fuel supply to the motors were all concentrated at a panel board in the commander’s cabin, the forward end of which bore a close resemblance to the bridge of a man-of-war. By means of thirty-eight push buttons, half red and half white, air could be released from or pumped into the balloonets, while in a similar manner the contents of any one of the water-ballast tanks could be emptied. Elaborate controls were provided for the power plant, it being possible to vary the speed or stop any one or more of the motors from the bridge. The rudder and elevators were operated by means of small hand wheels, similar to a marine steering wheel. One of the most prominent features of the operating cabin was a huge chart frame, capable of carrying a large scale map covering a considerable area, as well as an ample supply of maps. Few instruments were found in the captured ship and it is thought highly probable that everything not fastened in place had been dumped overboard at the last to increase its lifting power.
Fig. 24. One of Six Gondolas, or Power Units of the Zeppelin L-49
Copyright by Underwood and Underwood, New York
Apart from the use of standardized fittings and parts and the employment of a great deal more power in a slightly different manner than had characterized the earlier types of Zeppelins, the L-49 revealed nothing of unusual importance in airship design and certainly none of the world-beating features that German propaganda had been heralding for some time previous.
Destruction of Zeppelins. Mention has already been made of the fact that practically the only use made by Germany of her huge airships has been the bombardment of open cities, and that always at night. From the first of September, 1914, up to the end of 1917, between thirty and forty had met disaster, but only two were captured intact. The first of these was discovered by a Russian cavalry patrol while at anchor and its crew of thirty men were made prisoners. This was at an early period in the war, while the second one to be captured was the L-49, already referred to, which formed one of a squadron of five evidently sent out on a bombing expedition against London. Owing to adverse winds, they never reached their destination and four of them were known to have been put out of action, all except the L-49 being destroyed in the air. Not a few of these big airships have fallen victims to their own weakness and succumbed to the elements, in one instance a high wind tearing the airship loose from its moorings while the crew was not aboard. This was at Kiel, and after traveling a number of miles unguided, the big bag fell into the North Sea. In quite a number of other cases head winds have prevented the return of the raiders to their base and they have either been destroyed by their crews or wrecked at sea in attempting to return. In still other instances the unwieldy monsters have been wrecked by high winds when attempting to land, as was so frequently the case prior to the war.
Aeroplane and Anti-Aircraft Fire Effective. Before the war broke out the ability of either the aeroplane or the anti-aircraft gun to overcome the Zeppelin was purely theoretical, but actual experience has demonstrated that much of the theory was well founded. At least three Zeppelins have been destroyed by British aviators in mid-air, all or most of the crews being killed, while probably an equal number have been accounted for by French aviators in open battle. The war had not been under way a month before French anti-aircraft gunners showed their skill by bringing down-a "Zep," while only a week later a Russian battery accomplished the same feat, in this instance killing the entire crew. In 1916, British and French gunners succeeded in either "winging" or setting on fire three or four, while two dropped into the North Sea and one was blown up by its crew, having run out of fuel while raiding Scotch towns.
Bombing Raids against Zeppelin Sheds. Not the least of the disadvantages from which such huge and unwieldy craft suffer is the fact that the correspondingly large structures required to house them make exceedingly easy marks for the raiding aviator. Bombing, however, is such an uncertain art that even such large buildings as these cannot be struck from any altitude with a fair degree of accuracy. Consequently, in the number of raids that have been carried out against Zeppelin sheds, success has been due very largely to the temerity of the aviators, who have descended within a few hundred feet of their mark despite the fire directed at them from all quarters. At least three and probably more of the big airships have been destroyed in this manner by British aviators, who have made flights of several hundred miles to reach their destination, while the destruction of as many more has been ascribed by the Germans to the "accidental" explosion of a bomb in the shed. In view of the great precautions taken against accident from the explosion of the bombs carried by the airship itself, it is not considered at all likely that there was anything accidental about the wrecking of these craft.
One of the earliest attempts against Zeppelin headquarters at Friedrichshafen on Lake Constance, which resulted in the destruction of the L-31, is typical of the plan followed in attacks of this kind. Two British aviators flew from their base in France, about 250 miles distant, at a high altitude. They became separated before reaching their destination owing to a mist. This, however, prevented their discovery until they had dropped within a few hundred feet of the surface of the lake, which it was necessary to do to obtain a view of the airship sheds. The first pilot dropped his cargo of bombs from a height of only 100 feet or so over the shed and was rewarded by seeing it catch fire. He had hardly straightened out on his return course before he heard the attack of his companion. The latter was not so fortunate in escaping unscathed, as a bullet pierced his fuel tank and compelled him to descend. In the majority of instances, however, the raiders have succeeded not only in carrying out their task but in escaping undamaged as well.