Full-scale production of the two-inch pipe was started on 14 August 1942, using steel from the Corby Steelworks, and on 30 October, 30 mi (50 km) of it was loaded on board HMS Holdfast under the command of Commander Henry Treby-Heale, which was to be used as a full-scale rehearsal of Operation Pluto.[21] This trial occurred on 29 December 1942. A 30-mile length was laid across the Bristol Channel in rough weather at a rate of 5 knots (9.3 km/h) with the shore ends being connected at Swansea and Ilfracombe. The sturdiness of the cable pipe was further tested when two German 500 lb (230 kg) bombs were dropped on Swansea 100 feet (30 m) from the cable.