MUD DOCKS AT VIZAGAPATAM, INDIA.

CONTRIBUTED BY COMMANDER P. F. HARRINGTON, U. S. N.

Docking.

When a ship is to be docked, she is towed up the river from her moorings to near the dockyard. A large ditch of a little more than the ship's length and breadth, and deep enough to contain water of the depth of the ship's draught, is dug in the mud at right angles to the river. At high tide the water flows into this ditch and forms a basin into which the ship is floated or dragged. Two rows of strong stakes are now driven in across the entrance to the ditch and common palmyra, date, or bamboo mats tied to them. The space between these is filled up with sand and silt, and thus communication is cut off between the dock and the river. The basin in which the vessel is now floating being surrounded by a high mud bank formed by the mud excavated from the dock, the level of the water in the basin is raised by coolies throwing some of the mud of this bank into the basin, and thus raising the bottom of the basin, which must in consequence elevate the water in the basin and the vessel floating on it. The vessel is by this process elevated considerably higher than the level of the water in the river or inlet. If the bottom of the ship requires much repair, and has, therefore, to be elevated more than usual, more earth is dug up and heaped high against the sides of the vessel, leaving two or three yards of space in the dock unfilled fore and aft, and then water conveyed thither through a small channel is baled into the aforesaid spaces. This water also enters under the vessel and elevates it to the height of the mud heaped against it on either side.

Strong beams of wood are by the following process next placed transversely under the ship at two, three, or four different places, varying according to the length of the vessel. At the spot where the beams are to be placed, a mine so called (ghanee) is dug under the vessel from side to side, coolies working from either side of the ship at the same time until they meet each other under the ship's keel. Three beams one after the other are then dragged by a rope tied to the end of each under the keel and laid there one by the side of the other. The same thing is done, fore, aft and midships, or in more places if necessary. The mud on the sides of the vessel is then dug away to the level of the surrounding ground and the sides of the vessel caulked or otherwise repaired. After this is done-or simultaneously, if the vessel is to be repaired quicklythe mud under the bottom of the vessel is excavated except near the beams and the ship's bottom repaired; and the beams also, if necessary, are removed from one place to another to allow repairs where they were originally placed. When the ship's bottom is under repair, several props consisting of the stumps of palmyra trees are placed against or slightly under the vessel to prevent her from rolling over.

Undocking.

Ordinarily four sets of hawsers are used, each being coiled into the shape of a cone, the diameter of which at the base is about five or six feet, and where it touches the vessel a foot or two less. As the coiling is going on the cone is made solid by filling it in with mud. One cone is placed under the starboard bilge forward, another under the same bilge aft, and a third and fourth in corresponding positions on the port side. Four cones are ordinarily used at

Vizagapatam, unless the ship is of more than three hundred tons burthenwhen their number is increased according to the length and size of the ship. After this is done the transverse beams are one by one withdrawn, the dock having been first dug to the required depth, and then the vessel, which now rests entirely on these cones, is gradually lowered by withdrawing simultaneously from the base of each cone a coil or fake by which the four cones supporting the vessel bodily subside at a low speed and the vessel along with them. The cross-bund being now removed the water from the inlet flows into the dock and floats the vessel at high tide.

The docking and undocking of a vessel of two hundred tons ordinarily costs about 50 rupees,* including the rent of the dock and the props and beams; and the cost increases in proportion to the size of the vessel and its draught.

Vessels of four or five hundred tons burthen have been built and undocked at this port in the manner set forth above, such as the Gallant Neil, the Lady Sale, etc.

If, on account of any extraordinary season, a sufficient quantity of water does not flow into the dock, which is very rare, four or five large casks rented or belonging to the vessel, are tied fore and aft at low water, or if large casks are not procurable, a large boat or canoe is tied on when filled with mud, and this mud being gradually removed the rising of the canoe or boats assists in getting the vessel afloat.

*A rupee (silver) is about 39 cents, and is the current coin and unit of value throughout India.