The first Bermuda Dock, launched at North Woolwich by Messrs. Campbell, Johnstone and Co., in September 1868, was the largest built up to that time, and was ordered by the Admiralty for the use of British ships in the West Indian Squadron. It was 381 feet in length, 123 feet 9 inches in extreme breadth, and had a total depth of 74 feet 5 inches. Caissons enclosed a dock space of 333 feet by 83 feet 9 inches in width, capable of receiving a vessel of 3000 tons. The section of the dock is of =[U]= form throughout, though for convenience of towing, a tapered bow of wood was added, and remained until it rotted off at Bermuda. The dock was designed by Mr. Campbell. The sides consisted of a cellular space 20 feet in width, and midway between the inner and outer skin was a water-tight bulkhead, running the whole length of the structure. Each side was subdivided by longitudinal bulkheads into three compartments, named from the bottom, the “air,” “balance” and “load” chambers, and was further subdivided into twenty-four water-tight cells. The dock was fitted with four steam engines and pumps on each side. Hitherto all floating docks had been built in sections, shipped to their destinations and erected there. The Bermuda dock, however, was towed there, experimentally, and so successfully was the work accomplished that the towing of floating docks across the ocean has become the rule, and some wonderful feats of towing have been performed. This dock, becoming unequal to the requirements of modern shipping, gave place to the present dock built at Wallsend in 1902. [Illustration: MODEL OF THE BERMUDA DOCK.] The length of the present Bermuda dock is 545 feet over the keel blocks, its width of entrance 100 feet, and it is capable of normally taking vessels drawing 33 feet of water over keel blocks 4 feet high. The walls themselves are 53 feet 3 inches high, and 435 feet in length, and they form girders of enormous strength. Three pontoons, secured to the lower portions of the walls by fish-plate joints, lugs, and taper-pins, form the bottom or deck of the dock. The middle pontoon is a rectangle 96 feet by 300 feet; the end pontoons, each 120 feet long, taper for 49 feet towards their outer extremities to facilitate towing.