ENGINE: NOT ENOUGH THRUST
No existing engine has the power to lift the 13 tonne rocket, so the Nazis must develop one themselves.
The enemy’s cities are hundreds of km away, and existing rocket engines have neither the lifting power nor the reach to carry 1,000 kg of explosives that far.
Luckily for the Nazis, physicist Robert H. Goddard in 1926 invented a rocket, powered by liquid fuel instead of solid fuel, providing high stable performance. On the downside, it requires a more complex engine – a problem for a large, heavy rocket such as the V-2. Many problems arise. Either the high temperture mix of fuel and liquid oxygen burns through the walls of the combustion chamber, or the engine thrust is too low to produce sufficient lifting force.
The Nazis experiment for a long time before developing a powerful, barrel-shaped combustion chamber with alcohol- cooled, double-skinned walls. Moreover, they boost the engine with two turbo pumps, which inject fuel and oxygen into the combustion chamber at an unprecedented rate of 125 litres per second.
All in all, the V-2 produces a thrust of 25 t – 17 times more than any other rocket of the time.
FUEL BOOSTS PROPULSION
Liquid oxygen and ethyl-alcohol/water in two separate tanks makes for a volatile but more powerful fuel system.
PUMPS BOOST THE ENGINE
Two steam-powered turbo pumps increase the fuel flow pressure, so more fuel is forced into the combustion chamber, boosting the engine's force tenfold.
NEW SHAPE TAMES COMBUSTION
The combustion chamber is shaped for a more efficient mixture of oxygen and fuel, and enables the walls to withstand the 2,600 °C heat of the propellant.
NOZZLE REDUCES FRICTION
The propelling nozzle's tilt is altered from 10 to 30 degrees, reducing the friction between the steel and the exhaust gases, boosting propulsion.