Sunday, 4 April 2010
Sanger-Bredt Sub-Orbital Amerika Bomber
The Silverbird sub-orbital bomber crossing the Arctic, from the author's collection. Model by Magic Miniatures, 1:285 scale.
Dr Eugene Sanger started designing a rocket powered glider in 1933, when he was 28. In '39, he was pressured into designing a rocket powered long range bomber to strike North America from Germany. He, and his assistant (and girlfriend), Dr Irene Bredt, came up with a revolutionary single seat sub-orbital bomber. Work on the engines started in '41. The bomber was canvelled in '42.
Dr Eugene Sanger & Dr Irene Bredt
The 'Silverbird' would have been lanched along a 1.8 mile monorail track by a 600 tonnes thrust rocket with an eleven second burn. This would punch the craft up to 1,200 metres at a speed in excess of 1,000mph.
The internal rocket engine would then cut in with an eight minute burn of 100 tonnes thrust. that would power the plane to 90 miles high and a speed of nearly 14,000mph. As a point of comparison the International Space Station orbits at a height of about 210 miles, and the Blackbird spy plane flew at about 25 miles up.
The Silverbird would then glide, lift being provided mostly from the hull. It would 'skip' across the surface of denser air found at around 25 miles height in a series of bounces like a skimming stone on a pond. Predicted range was 14,600 miles. It would have carried a single 8,000 lb bomb.
After the war Eugen and Irene Sanger went to work for the French, where the KGB tried to kidnap him.
So, would the Silverbird have worked?
In theory yes, but there severe practical problems. Germany lacked the resources for such a complex weapon system and it was probably beyond the materials technology of the day. Heat would have been an issue. The Blackbird was built from titanium alloys.
Could the Silverbird have been intercepted?
Almost certainly not: the Russians made several attempts to shoot down Blackbirds without success (it was easy to track by its heat signature). Swedish Viggens used to intercept Blackbirds and lock on their missile systems (to prove a point) as they crossed the Baltic - probably on their way back to RAF Mildenhall. The Swedes would have eventually downed one if they wished but the Allies lacked a Viggen.
However, the Silverbird would have been extremely vulnerable when landing. It glided in and landed like a space shuttle on a tricycle undercarriage, large slow, well relatively slow, and vulnerable. The Mustangs, Mosquitoes and Tempests would have been waiting. After bombing New York, one can be certain that the Silverbed base would have attracted a great deal of interest from the heavy bombers of the RAF and USAAF. There are some interesting wargaming scenarious to be built around a Silverbird landing under fire.
For more info go to our old friend the Luft '46 site.