Following the end of the First World War, the British and Colonial Aeroplane Company looked at producing a general-purpose passenger or cargo aircraft. Frank Barnwell proposed a single-engined biplane for six passengers, powered by a 5000NaN0 Siddeley Tiger engine and named Grampus I. The directors of the company thought it too large for the proposed market and were concerned about the supply of Tiger engines. Barnwell returned with a smaller three-passenger Grampus II powered initially by a 1500NaN0 RAF 4a air-cooled engine which would be replaced by the Siddeley Lynx radial engine on production aircraft. The directors did not approve of the design, nor of two eight-passenger variants also proposed. In February 1920 the project was abandoned as none of the designs appeared to meet the criteria for an Air Ministry competition.