Then he began to get out his plan for righting the vessel, the intricate calculations such a plan involves being not only amazing, but perfectly incomprehensible to the average man who is not possessed of engineering ability. He calculated on obtaining 1000 tons of lift by pumping compressed air into some of the compartments of the overturned vessel, and looked to pontoons attached to the tower and other parts of the structure to aid him in his plans. But, for the real work of pulling the ship over, he determined to rely on the power of steam-engines operating on the shore and hauling on a series of giant steel cables attached all along the ship. The risk of pulling the ship to pieces in a job like this is so great that the novice would drag the ship apart far quicker and easier than he would drag it upright. If a cable were placed round the hull and a powerful steam-engine given full play ashore, that cable would crumple up the steel plates and gradually cut through them like a wire through a cheese, instead of moving the ship. These were the risks that had to be avoided. Divers started to strengthen the ship with gigantic logs, 12 and 14 inches square, in order to withstand the terrific strain. A huge, strong frame of similar logs, protected by steel grooves, was fixed to the hull, to prevent the cables from cutting the ship to pieces. It was slow work, for the salvors could only devote time to the wreck when there were no important war jobs to claim their attention. However, they managed to get in a day now and again, preparing for the great tug-of-war, upon which depended a fortune. Materials were not easy to obtain owing to the demand for munitions at the Front, so the salvors had to make shift with anything that would serve their purpose. The divers, who set to work with hacksaws to cut holes through the steel plates for the passage of some of the cables, were greatly handicapped by the rust and mud, which made the water so cloudy that the work was difficult to see. Yet they stuck to their job and slowly, monotonously ate a way with their saws through the metal. Then they took up the task of preparing the seabed for the ship to come over on. She was practically lying on a submerged hill, and about a thousand yards of the seabed had to be removed to make a flat table on which the ship could rest in safety without slipping over again. All this took time as well as money.