CHAPTER XXIII
Driven to Destruction
THREE days later, No. 0916, in company with three other patrol-boatsof similar type, left Malta for Grecian waters. They were not alone,for acting as a parent ship was the sea-plane carrier _Fleetwing_.
Osborne would not have recognized in the _Fleetwing_ one of his oldvessels of the Royal British and Pacific Company. In pre-war days shehad been employed as an intermediate steamer between Vancouver andYokohama, calling at Honolulu each way. In those days she was knownas the _Flightaway_, and was painted black, with white deck-houses;she sported two funnels and two masts, the former being colour-washedin a vivid yellow hue.
In her new rôle the renamed vessel was completely disguised. Auniform garb of "battleship grey" covered her from truck towater-line. Her foremast had disappeared, while, from her bows towell abaft the position of her funnels, a long, gradually slopingplatform had been built for the purpose of enabling the sea-planes toascend while the vessel was under way. Then, since the foremostfunnel interfered with the "clear run" of the launching platform, ithad been removed, and a pair of smaller ones erected in its place, sothat the _Fleetwing_ now had three funnels set on a triangularbase--two well abreast, the third and original one being on thecentre line.
As if these drastic conversions were not enough, the ship had been(to use a nautical expression) "gutted" aft, and a huge tank builtin. The top of this was flush with the upper deck, while its base wasfar below the water-line. In this receptacle were stowed four large"kite" balloons, while adjacent was the necessary gear for inflatingand repairing their unwieldy yet necessary fabrics.
Practically the whole of the remaining portions of the main deck wasa vast repairing workshop. High-class machines of all sorts anddescriptions filled every available space, while a veritable forestof belting gave a stranger the impression that he was in some largefactory ashore, rather than on board a converted liner. There werealso carpenters', plumbers', shipwrights' and painters' shops--inshort, every necessary for the care and maintenance of those delicateyet supremely important adjuncts to a modern navy--the sea-planes.
Had it been considered desirable, the patrol-boats could have beenslung on board the parent ship; but, as the weather was fine and thesea comparatively smooth, No. 0916 and her consorts were to proceedunder their own power in order to give their crews an opportunity ofmanoeuvring in company.
Somewhere to the south'ard of Cape Matapan, the _Fleetwing_ receivedwireless information that a large German submarine had beenparticularly active in these waters, and, while expressing theadvisability of extreme vigilance, the authorities ordered that stepsshould be taken to capture or destroy the enemy.
Towards the position in which the U-boat was last reported seen, thepatrol-boats sped, keeping a far-flung formation extending over afront of three miles. A mile astern came the _Fleetwing_, whileoverhead flew a couple of sea-planes of the most recent type.
They were tri-planes with a huge wing-spread of over two hundredfeet, the planes being in adjustable sections to ensure compactstorage and rapid assemblage. Power was supplemented by means of six200-horse-power motors, coupled in twin units and driving three15-feet propellers. While taxi-ing on the surface a water-propellerwas provided, giving the sea-plane a speed of fifteen knots; whilewhen in flight her speed could be altered at will, ranging from aminimum of 40 to the terrific rate of 180 miles per hour.
Each of the sea-planes carried a crew of ten men, and was armed witha 3-inch non-recoil quick-firer; while as a specialized means ofoffence against submarines she carried a torpedo-tube discharging a3-inch projectile.
The torpedo was fired by the ignition of a small charge of petrolgas, and could be aimed with considerable accuracy. At the head ofthe weapon was a small fan, the use of which was to prevent prematureexplosion of the charge on impact with the surface of the water. Thedepth at which the torpedo exploded could be regulated by adjustingthe fan to a certain position on its threaded axis.
The sea-planes had been up for less than ten minutes when a wirelesswas received reporting the position of the quarry. The U-boat was"sounding" at a depth of twelve fathoms--too deep for the aerialtorpedoes to reach with accuracy. Her grey hull could be discerned bythe airmen with tolerable ease as she lay upon the sandy bottom.
It was now the _Fleetwing's_ task to get the submarine to bestirherself. The German captain would be too wily to attempt to rise tothe surface with the churning of four high-speed propellers soundingover his head. So the patrol-boats eased down while the sea-planecarrier forged ahead, thrashing the water with her twin screws, thesea-planes describing vast circles over the spot where the U-boatlay.
Presently another message was received that the submarine was moving.She was about to take stock of the apparently solitary vessel. If shedid rise to the surface the patrol-boats could almost with certaintydestroy her, either by gun-fire or by ram. On the other hand, if sheexposed the tips of her periscopes only, such tactics would not belikely to result in definite destruction.
Breathlessly Osborne and Webb awaited developments, ready at thefirst warning to urge No. 0916 at full speed towards the enemy.
Still the sea-planes circled. It was the only means of keeping intouch with their prey, for the former were travelling through the airat fifty miles an hour, compared with the latter's maximum submergedspeed of fifteen knots. Trained downwards, and only a few degreesfrom the perpendicular, were the grey-painted torpedo-tubes of eachtri-plane.
Presently the upward movement of the U-boat ceased. Her periscopesrippled the surface. Something glistening shot from the sea-planenearest overhead. Like a silvery dart the object plunged seawards,struck the water with hardly a splash, and disappeared.
Almost simultaneously a column of foam was hurled skywards, to theaccompaniment of a muffled detonation.
"Missed!" was the laconic wireless message from the air-craft thathad discharged the missile. "She's heading nor'east."
Two more aerial torpedoes were fired, with no better result than tosend the U-boat scurrying off at a depth of ten fathoms. It was nowthe patrol-boats' turn to take up the pursuit.
Directed by the aerial pilots the four swift craft converged. Thenbegan a sort of marine waltz, the lively vessels dodging to and fro,circling and crossing each other's bows in a most daring fashion--all with the idea of confusing the fugitive U-boat.
In this they succeeded. With their nerves shaken by the narrow escapefrom the explosions of the torpedoes, and in the knowledge that theywere hunted by an unknown number of the dreaded patrol-boats, theHuns were literally in a panic. Their sole idea was to keep at a safedepth and steal away from their pursuers, trusting that the latterwould be unable to discern their presence by the "surface wake" andthe trail of air-bubbles.
But the U-boat had reckoned without the sea-planes. Remorselessly,the wireless reports from the observers kept the patrol-boats inclose touch with their prey. Ceaselessly, the churning of the smallyet powerful propellers betokened the grim fact that for once themodern pirate could not shake off pursuit.
Suddenly a huge air-bubble rose to the surface, agitating the waterin ever-widening circles. No. 0916, fairly in the thick of themaelstrom, was swept from fo'c'sle to taffrail. Then, almost asquickly as it had risen, the sea calmed down under the influence of arapidly-spreading patch of iridescent oil.
"How about it?" wirelessed No. 0916.
"Get out of the light and we'll see," was the sea-plane's laconicreply. Then a minute later: "She's properly strafed."
In her blind dash for safety the U-boat had crashed, bows on, againsta rock that rose abruptly for ninety feet to within nine fathoms ofthe surface. In spite of her strong construction the steel bowscollapsed like an egg-shell. An inrush of water under terrificpressure followed, and yet another of the Kaiser's boasted submarineshad ceased to exist, save as a waterlogged wreck upon the bed of theMediterranean.