The layout proposed by Isambard Kingdom Brunel is almost a mirror of the 1860's Penarth Dock with the entry into the 'Outer Basin' from the River Ely; the gates being opened at high tide to permit access and egress of vessels. To enter the 'Inner Basin' meant locking through. The hard about turn into the entrance of the 'Outer Basin' was protected from the extremes of weather but we must remember that back in 1836 ships were exclusively under sail and the tidal flow of the river could be very strong.

Brunel reported to the Board of the TVR that the location at the termination of the Ely Branch of the Taff Vale Railway had a good depth of water and a sheltered position and that the arrangement would be superior to that of the river Taff. He also envisaged expansion of the dock at the site over and above the proposal for a 2 acre outer and the 14 acre inner basin.

The south quay of the inner basin could accommodate approximately 20 coaling berths with vessels orientated bow to stern and that this could be increased to 30 if the berths were obliquely positioned. Utilisation of the north quay could double this number. The arrangement equated to the docking of 100 - 120 vessels. The outer basin could hold approx. 15 vessels of 200 tons in an emergency.

The question of mud accumulation within the basins was investigated by Brunel and he felt that these could be minimised by drawing off water from the outer basin at low tide and that the process adopted at Bristol at the 'float' would be appropriate in the case of the inner basin. I'm not sure what this procedure entailed.

However, a Bill for this dock was never presented to parliament, it being scuppered partially on the advice of Robert Stephenson! [385] [387]