Volume Ten - Pre-Victorian to the present day - even more aspects - The Patent for the Penarth Slipway - 1881 . . .

Discussion.

Mr. Robert Bruce Bell observed that he had been engaged in the design and construction of slip-docks for the last thirty years. The inventor of the slip-dock was the late Mr. Thomas Morton, as the Authors had stated, and the main features of the slip-dock remained much as he had left them. The first actual change was made upon the purchase-machinery or hauling power. The original machinery consisted of spur-gearing, driven by manual power, horses, or the steam engine. The change was the substitution of the hydraulic ram for the spur-geared winch, but the Authors were mistaken in ascribing this invention to Mr. Morton, who died many years before. The invention was that of Mr. Daniel Miller, M. Inst. C.E., and was patented by him in 1849.

The first application of it was on the slip-dock constructed by Mr. Miller and himself at Kelvinhaugh, on the Clyde, in the year 1850, the hydraulic machinery and cradle being made by Messrs. Samuel and Hugh Morton. This slip had taken up vessels of 1,000 tons. The length of the stroke of the ram was 15 feet ;  the pumps were driven by a 30-HP. engine. Shortly after the completion of the Kelvinhaugh slip-dock, another dock, with hydraulic purchase for vessels of 1,500 tons, was laid down at Melbourne for the Colonial Government, and about twenty-six years ago a large hydraulic purchase was designed and constructed for the Russian Government for war-vessels of 2,000 tons, and another slip od equal purchase on Miller's patent was that made for the Egyptian Government for war-ships of 3,000 tons. The stroke was 15 feet in length, the ram 18 inches in diameter, the weight of the cylinder 17 tons, that of the ram 5 tons, and the side-rods were each 5 inches in diameter.

Various other slip-docks on this principle had been constructed with various lengths of rams, but the handiest length of stroke appeared to be 10 feet ; the rods were whipped out of place by a crane, worked by steam or hydraulic power, and stacked at once ; a couple of men were all that were required for fleeting the rods, and no such expenditure of time as that stated by the Authors should be necessary in a properly arranged dock. No separate engine was required for up the empty cradle, this being done by gearing attached to the hydraulic apparatus ; various modifications had been made upon the hydraulic apparatus since it was originally designed by Mr. Miller.