RD-111

Glushko LOx/Kerosene rocket engine. R-9 stage 1. Developed for R-9 ICBM. It had special flexible pipelines and gimbals, allowing LOx loading in 20 minutes. First flight 1961.

The 121-140,000 kgf RD-111 was developed for combat missiles. It had special flexible pipelines and gimbals (simpler than bellows). You'd expect pre-launch pressurization to be simple and quick with a military missile but the LOX on the R-9 missile took two hours to load. It was just too complicated for military use and would have been knocked out by bombers let alone missiles before it could be used. The final version took just 20 minutes to prepare and veterans claimed just 10 minutes in their tests. It was used in both silo and pad based missiles. Diameter is per chamber.

Chambers: 4. Thrust (sl): 1,385.000 kN (311,360 lbf). Thrust (sl): 141,240 kgf. Engine: 1,492 kg (3,289 lb). Chamber Pressure: 78.50 bar. Area Ratio: 18. Propellant Formulation: Lox/RG-1. Thrust to Weight Ratio: 112.22972972973. Oxidizer to Fuel Ratio: 2.39.