Very probably, also, the large airship was responsible for the success which attended the U boats during their attack on the cruisers Nottingham and Falmouth, and also at the Hogue disaster.
Various experiments were carried out in towing airships by cruisers, in refuelling while in tow and changing crews, all of which would have borne good fruit had the war lasted longer.
An exceedingly interesting experiment was carried out during the closing stages of the war by an airship of the S.S. Zero type. At this period the German submarines were gradually extending their operations at a greater distance from our coasts, and the authorities became concerned at the prospect that the small type of airship would not possess sufficient endurance to carry out patrol over these increased distances. The possibility was considered of carrying a small airship on board a ship which should carry out patrol and return to the ship for refuelling purposes, to replenish gas, and change her crew. To test the feasibility of this idea S.S. Z 57 carried out landing experiments on the deck of H.M.S. Furious, which had been adapted as an aeroplane carrier. S.S. Z 57 came over the deck and dropped her trail rope, which was passed through a block secured to the deck, and was hauled down without difficulty. These experiments were continued while the ship was under weigh and were highly successful. No great difficulty was encountered in making fast the trail rope, and the airship proved quite easy to handle. The car was also lowered into the hangar below the upper deck, the envelope only remaining on the upper level, and everything worked smoothly. If the war had continued there is no doubt that some attempt would have been made to test the practical efficiency of the problem.
Anti-submarine patrol was the chief work of the airship during the war, and, like everything else, underwent most striking changes. Submarine hunting probably had more clever brains concentrated upon it than anything else in the war, and the part allotted to the airship in conjunction with the hunting flotillas of surface craft was carefully thought out.
In the case of a suspected submarine in a certain spot, all surface and air craft were concentrated by means of wireless signals at the appointed rendezvous. It is in operations of this kind that the airship is so superior to the seaplane or aeroplane, as she can hover over a fixed point for an indefinite period with engines shut off. If the submarine was located from the air, signals were given and depth charges dropped in the position pointed out. Incidents of this kind were of frequent occurrence, and in them the value of the airship was fully recognized.
The most monotonous and arduous of the airship's duties was the routine patrol. The ship would leave her shed before dawn and be at the appointed place many miles away from land. She then would carry out patrol, closely scanning the sea all round, and investigating any suspicious object. For hours this might last with nothing seen, and then in the gathering darkness the ship would make her way home often against a rising wind, and in the winter through hail and snow. Bombs were always carried, and on many occasions direct hits were observed on enemy submarines. A sharp look-out was always kept for mines, and many were destroyed, either by gunfire from the airship herself or through the agency of patrol boats in the vicinity. This was the chief work of the S.S. ships, and was brought to a high pitch of perfection by the S.S. Zero. These ships proved so handy that they could circle round an object without ever losing sight of it, and yet could be taken in and out of sheds in weather too bad to handle bigger ships.
The hunting of the submarine has been likened to big-game hunting, and certainly no one ever set out to destroy a bigger quarry. It needs the same amount of patience and the same vigilance. Days may pass without the opportunity, and that will only be a fleeting one: the psychological moment must be seized and it will not brook a moment's delay. The eye must be trained to pick up the minutest detail, and must be capable of doing this for hour after hour. For those on submarine patrol in a small ship there is not one second's rest. As is well known, the submarine campaign reached its climax in April, 1917. In that month British and Allied shipping sustained its greatest losses. The value of the airship in combating this menace was now fully recognized, and with the big building programme of Zero airships approved, the housing accommodation again reached an acute stage.
Shortage of steel and timber for shed building, and the lack of labour to erect these materials had they been available, rendered other methods necessary. It was resolved to try the experiment of mooring airships in clearings cut into belts of trees or small woods.
A suitable site was selected and the trees were felled by service labour. The ships were then taken into the gaps thus formed and were moored by steel wires to the adjacent trees. Screens of brushwood were then built up between the trees, and the whole scheme proved so successful that even in winter, when the trees were stripped of their foliage, airships rode out gales of over 60 miles per hour. The personnel were housed either in tents or billeted in cottages or houses in the neighbourhood, and gas was supplied in tubes as in the earlier days of the stations before the gas plants had been erected.
This method having succeeded beyond the most sanguine expectations, every station had one or more of these sub-stations based on it, the airships allocated to them making a periodical visit to the parent station for overhaul as required. Engineering repairs were effected by workshop lorries, provided that extensive work was not required.