No. 2 Flight Shed so that components and fittings could be applied and tested. In October 1945, construction of the first prototype's fuselage commenced in an existing hangar while a gigantic hall for performing final assembly of up to eight Brabazons was constructed; at the time of construction, the hall was the largest hangar in the world. the designer of the new assembly hall, T. P. O'Sullivan, was subsequently awarded the Telford Premium for the work. The runway was also lengthened to 8,000 ft (2,440 m), as well as being widened; this extension had necessitated the compulsory relocation of the inhabitants of the village of Charlton to neighbouring Patchway, which was a somewhat controversial measure at the time. Mark II During the early 1940s, the only means for providing propulsion to large aircraft was to produce increasingly complex and enlarged radial engines. The emergence of jet propulsion, specifically the turboprop engine, happened to coincide with the Brabazon's development. Accordingly, there was considerable interest in applying such an engine to the airliner as it potentially offered a simpler and more powerful alternative to the original Centaurus powerplant. Other advantages of turboprops included lower vibration levels (which would increase passenger comfort) and superior performance at higher altitudes. In 1946, it was decided to build the second prototype using eight Bristol Coupled Proteus turboprop engines – paired turboprops driving four-bladed screws through a common gearbox. This would have increased the Brabazon's cruising speed, from 260 to 330 mph (420–530 km/h), and its ceiling, while also reducing the aircraft's empty weight by about 10,000 lb (4,540 kg). This Brabazon Mark II would have been able to cross the Atlantic (London-New York) in a reduced time of 12 hours. However, by 1950, development of the Proteus engine had run into substantial difficulties, being both overweight and underpowered as well as being subject to fatigue issues at one stage. In addition to the adoption of the Proteus, there were other envisioned changes for the Brabazon Mark II. In particular, a revised wheel arrangement which had been planned would have enabled the type to use the majority of runways on both the North Atlantic and Empire routes. Although the Proteus was slimmer than the Centaurus, the wing thickness was not to be reduced in the Mark II but the leading edge would be extended around the engines. Testing In December 1945, Bristol Chief Test Pilot Bill Pegg