In November 1945, Shorts flew a further refined conversion of one of BOAC's Sunderlands from their Rochester works, with revised low-drag fairings on the aircraft's nose and tail, and a refurbished interior, which was known as the Sandringham. All the Sandringhams were civil conversions of former Royal Air Force Coastal Command Short Sunderlands. The first prototype retained the Pegasus engines of the Sunderland III and Hythe, and was designated the Sandringham 1 by Shorts, but later Sandringhams, converted by Short and Harland Ltd at Belfast Harbour, were based on the Sunderland V, and were powered by Pratt & Whitney "Twin Wasp" engines.