Bristol Hercules

Hercules
Cutaway Bristol Hercules engine at the National Museum of Flight, East Fortune, Scotland
Type Piston aircraft engine
National origin United Kingdom
Manufacturer Bristol Aeroplane Company
First run January 1936
Major applications Bristol Beaufighter
Short Stirling
Handley Page Halifax
Number built 57,400
Developed from Bristol Perseus
Developed into Bristol Centaurus

The Bristol Hercules is a 14-cylinder two-row radial aircraft engine designed by Sir Roy Fedden and produced by the Bristol Engine Company starting in 1939. It was the most numerous of their single sleeve valve (Burt-McCollum, or Argyll, type) designs, powering many aircraft in the mid-World War II timeframe.

The Hercules powered a number of aircraft types, including Bristol's own Beaufighter heavy fighter design, although it was more commonly used on bombers. The Hercules also saw use in civilian designs, culminating in the 735 and 737 engines for such as the Handley Page Hastings C1 and C3 and Bristol Freighter. The design was also licensed for production in France by SNECMA.