[CHAPTER V--Sefton to the Rescue]
"A tug and a couple of lighters bearing down, sir," reported the Calder's look-out before the diver had reappeared from his errand of investigation.
Approaching at the modest rate of 7 knots was a paddle-wheel steamer towing two unwieldy craft resembling overgrown canal barges.
The tide was now well on the flood. It wanted about a couple of hours to high water, and, since the falling glass and clear visibility of distant objects betokened the approach of bad weather, urgent steps would have to be taken speedily to extricate the captured submarine from the embraces of the sand-bank.
The examination of the prize by her captors was now practically complete. The U boat was one of a new type, and had left Wilhelmshaven on her maiden trip forty-eight hours previously. She had either lost her bearings or had purposely approached shoal water. Anyhow she had been neatly strafed before she had had time to do much mischief.
Already the Calder's crew had taken steps to assist the salvage people in the task of floating the prize. The hatchways, with the exception of that of the conning-tower, had been hermetically closed, and the watertight doors in the for'ard bulkhead shut and shored up to withstand the pressure of water in the holed fore-peak.
By the time the lighters were made fast, one on either side of the submarine, the level of the water was up to within fifteen inches of the conning-tower hatchway. Quickly hoses, connected to Downton pumps, were led from the lighters to the water-ballast tanks of the submarine, since it had been found impossible to "start" the ballast by means of hand pumps.
It was a race against time and tide. The mechanical appliances won, and soon the Calder's officers and crew had the satisfaction of seeing the submarine's deck appear close to the surface.
She still had a pronounced "dip", the flooded for'ard compartment tending to depress her bow; but, supported by the two lighters, she was prevented from sinking. Then, taken in tow by the tug, the prize, with her cumbersome attendants, waddled slowly for Harwich.
Her part in this supplementary business ended, the Calder slipped off at full speed to the position where the Dimpled Lassie and the Carse o' Gowrie still held a resolute grip on the recovered cable.