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

Sir Frederick Bramwell cont'd :

He believed it had been found better to get rid of that water-bed for the ship to lie upon, and let it bear upon rigid points of support at intervals along its length, and he thought that the water-bed difficulty was one of the reasons why the original sectional floating-dock in America, which he saw last autumn, after an interval of thirty years working, just as it worked thirty years ago, had never met with so much favour as the more rigid slipway, or the more rigid complete floating dock, where a firm floor could be given for the ship to bear upon, although, no doubt, at first sight, the floating support appeared to be one which might accommodate the patient in great comfort.

Mr. A. Giles.

Mr. A. Giles did not think the advantages were as great as had been suggested in the Paper. It was called a primitive form of repairing vessels, and the Author went back as far as the days of Carthage. He thought that a slipway, notwithstanding all the ingenuity of the hydraulic process for lifting ships, was a primitive form, and he demurred to the statement that it was applicable to vessels of the largest class. He concurred with Sir F. Bramwell as to the necessity of having a rigid foundation for the keel of a ship.

The Authors insisted that where the foundation had to be made partly on piles and partly on the ground, there was a liability to settlement or fracture at the points of junction. He quite agreed with that statement : what then must be said as to the foundation that the Authors proposed to lay below the waterline by dredging out a trench, by casting stones into the bottom, and by laying the floating platform thereon?

Was it to be supposed that that could be rigid and perfectly true for the purpose of hauling a vessel up? He thought there must be a practical difficulty in laying a slip below the water without a cofferdam, a difficulty that had not been sufficiently explained. He admitted that at such a place as Penarth, where the range at spring-tides was 39 feet, and at neap-tides 29 feet, it would be easy enough to make a good foundation on the shore, but how many ports were there in which there was such a range of tide, and where it was not wanted to dock or repair vessels drawing more than 12 feet depth.