Volume Two - The Era of Optimism, Investment & Development - The gridiron and slipway of the Penarth Shipbuilding & Ship Repairing Co. . . .

In another instance of a slipway with a gradient of 1 in 24, friction accounted for the expenditure of power equal to 3.33 per cent. of the weight lifted. The friction in slipways, however, varies within wide limits, and it is towards the elimination of as much as possible of the friction that the efforts of designers should be directed.

In situations where mud is freely thrown down by the water and the slipways are not often used, accumulations of mud may very much increase the power required and a considerable margin of power is advisable.'

Without doubt, the Penarth gridiron and slipway were situated upon the banks of a river that freely gave mud since the entrance to the dock and Ely tidal harbour required constant dredging work to keep them safe for the ever larger tonnage of shipping that visited.

The foregoing explanation of the technicalities and limitations of working a gridiron and slipway provides us with some idea that at by the turn of the twentieth century the facilities at the Penarth Shipbuilding and Ship Repairing Company had progressively reached a limit in terms of dimensions of ships they could service.

The manager of the yard was a Mr. George Cooper and in 1883 the Cardiff Times contained a reference to a Mr. G. Cooper also as the former manager of the Patent Slipway Company:

'At the Penarth Patent Slipway, the personnel was altered during the past year, Mr. G. Cooper, the manager, having resigned, and was succeeded by Mr. B. Munroe, formerly engineer of the works.' Cardiff Times [019] 6th January 1883.

Mr George Cooper had a part in a patent for a slipway arrangement which was documented in the 1883 Minutes of Proceedings of the Institute of Civil Engineers [320]:

'A new method of relieving (Thompson and Cooper's patent) has just been brought out by one of the Authors, and Mr. George Cooper, the late manager of the Penarth Slipway Company, Limited. It is shown in Plate 6, Figs. 8 to 11, and may be thus described: