at its Roundhay Road plant in Leeds. The Blue Danube was 24 ft long x 62 inches diameter. It was known to the RAF as "Bomb, Aircraft, HE 10,000 lb MC". Released from 45,000 ft at 500 knots (930 km/h) its maximum velocity was 2480 ft/s (Mach 2.2). It bears a likeness to the Tallboy and Grand Slam "earthquake" bombs designed by Barnes Wallis. Wallis was a consultant on the design of Blue Danube. The airframe for Red Beard, the second generation tactical nuclear bomb was also built by Hudswell, Clarke. This tactical atomic bomb had perforated baffles to reduce bomb bay buffeting when dropped from a Canberra bomber; they were not needed on other aircraft. Red Beard was known to the RAF as "Bomb, Aircraft, HE 2'000 lb MC", although its actual weight was 1650 lb. It was deployed on a wide variety of aircraft of the RAF and Royal Navy, being stockpiled in the UK, Cyprus, Singapore and afloat on carriers. Hudswell, Clarke also worked on Violet Club, the Interim Megaton Weapon. All the bombs detonated at the Christmas Island H-bomb tests were contained in airframes designed and built by Hudswell Clarke. The company were also major contributors to other military projects, including the Centurion main battle tank conversion into an armoured bridgelayer, that served with the British Army for many years. The contraction of defence manufacturing in the mid-1960s contributed to the sale and demise of the company. Preservation Locations of preserved Hudswell Clarke locomotives include: United Kingdom Aln Valley Railway, Northumberland Buckinghamshire Railway Centre, Quainton Road, Buckinghamshire Chasewater Railway, Staffordshire East Lancashire Railway, Greater Manchester and Lancashire Ecclesbourne Valley Railway, Derbyshire Embsay and Bolton Abbey Steam Railway, North Yorkshire Great Central Railway (Nottingham), Ruddington, Nottinghamshire Keighley and Worth Valley Railway, West Yorkshire Middleton Railway, Hunslet, West Yorkshire Nene Valley Railway, Wansford, Cambridgeshire North Bay Railway, Scarborough, North Yorkshire North Norfolk Railway, Sheringham, Norfolk Penrhyn Castle Railway Museum, Bangor, North Wales Pontypool and Blaenavon Railway, South Wales Ribble Steam Railway, Lancashire Rutland Railway Museum, Cottesmore, Rutland Statfold Barn Railway, Tamworth, Staffordshire Swindon and Cricklade Railway, Blunsdon, Wiltshire Tanfield Railway, County Durham Ireland Railway Preservation Society of Ireland, Whitehead, Co. Antrim New Zealand Oamaru Steam and Rail Restoration Society, New Zealand Denmark Nordsjællands Veterantog, Græsted, Denmark Danmarks Tekniske Museum The Danish museum of Technology, Helsingør/Elsinore, Denmark United States Edaville Railroad, Carver, Massachusetts See also List of early British