A ship I was on some years ago was rammed by a coal barge while at anchor in the harbour of Brest, France, and was forced to go into dry dock for repairs. Being familiar with dry-dock procedure only in the United States I was unprepared for what has always since seemed to me to be a thoroughly picturesque method of placing the shores.
Our ship was hauled into the dock, the gates were closed, and the pumps began to lower the water. Finally she settled on to the keel blocks and the shores were floated into place, each end being held from above by a line. As the water sank lower the wedges were inserted between the shores and the dock walls, and a man with a large wooden mallet took his place at each wedge. Then the foreman, standing at the head of the dock began a song which the mallet bearers took up, singing beautifully in unison, their voices booming upward from the dry dock, halfway down the sides of which they stood. And as they sang they kept time with great strokes of their mallets on the wooden wedges, the musical wooden sound ringing in unison with their song as every man drove his crashing blows with every other man.
I stood on the bridge of the ship listening to the lilting song, and the great musical crashes that punctuated it, every man striking at exactly the same instant that every other man struck. Never before or since have I seen a more practical demonstration of the uses of song or heard so beautiful a song of industry. It was an “Anvil Chorus” with a different setting.
There is another type of dry dock that is widely used and is of great importance where it is too expensive or difficult to build the type to which I have just referred. This other type is the floating dry dock. In principle it is a huge barge, rectangular in shape, and with highly raised and very thick sides and open ends. Its bottom is built up of many compartments and its “reserve buoyancy” must be at least a little greater than the total weight of the largest ship it is designed to accommodate. That is, it must be able to float while carrying a load of 15,000 tons if it is meant to be used by ships up to that displacement.
THE AQUITANIA
A British built ship operated by the Cunard Line.
These floating dry docks need only to be placed in a sheltered spot where the water is deep enough for the dock to be sunk so that the dock floor is a little farther beneath the surface than is the keel of the ship that is to be docked. When everything is in readiness—that is, when the keel blocks are properly placed and the incoming ship has been otherwise prepared for—water is allowed to enter the inner compartments of the dry dock. Gradually the whole thing sinks until only the two high sides are visible above the water. When it has sunk until there is enough water over the dock floor for the incoming ship to float in, the valves are closed and the ship is hauled in and made fast. Then giant pumps begin to expel the water that has been allowed to enter the compartments. This causes the dry dock to come once more to the surface, and as it rises beneath the ship the keel blocks press up on the ship’s keel, shores or bilge blocks are put in place, and when the ponderous float regains the surface there is the ship, high and dry, where men can scrape and paint and repair her or accomplish the other tasks assigned to them.
It is interesting to watch the labours of a crew of workmen in a dry dock. If a ship looks large in the water, it looks startlingly gigantic in a dry dock, especially if one walks down to the dock floor and views the high bow or the overhanging stern from the level of the keel. Propellers from a distance look small, but with half-a-dozen men realigning their blades or working about them, they look huge indeed.
