Bidding for the new 'standard' type 4 locomotive several locomotive builders supplied a sample locomotive to British Railways. Falcon was the Brush prototype, powered by two 1,440bhp Maybach engines like the Westerns, but allied to electric transmission system Falcon was thoroughly tested in regular service. Although BR settled on a single engine locomotive based on the Birmingham RCW Lion with a 2,750bhp Sulzer engine the failure of the Birmingham company saw Brush gain the contract for what became BRs class 47 locomotives.
The Falcon story did not end there however, the locomotive being hired to and later bought by British Railways and sent to the Western region, working alongside the similarly powered Westerns. Later fitted with air barkes Falcon went to Ebbw Vale shed in Newport for iron ore service, where fitters qualified on both Maybach engined hydraulics and diesel electric class 37s kept the Falcon flying until 1975, when the locomotive was made a 'planned withdraw' alongside the run down of the diesel hydraulic fleet.