The Brayton Cycle and Other Rare Engines

Some old engines, like the Brayton cycle engine, are as fascinating as they are inefficient.


| September 2005



The Brayton cycle engine, as it came to be known, used a compressed fuel/air charge for ignition.

The Brayton cycle engine, as it came to be known, used a compressed fuel/air charge for ignition.

Pity poor George Bailey Brayton. Born in Rhode Island in 1830, his formal education stopped before high school. Even so, Brayton displayed a talent and capacity uniquely suited to the emerging age of engines in the mid-1800s.

Brayton, in case you've never heard the name, developed an engine that was commercially available in 1872, a full five years before Nicolaus Otto patented his 4-stroke design in 1877.

The Brayton cycle engine, as it came to be known, used a compressed fuel/air charge for ignition. Unlike Otto's design, however, it did not compress the charge in the combustion cylinder. Instead, a pumping piston compressed the fuel/air charge in a separate cylinder, which was then delivered to the cylinder and combusted, driving a piston that worked a beam to stroke a crank. Later versions utilized a connecting rod directly connected to the crankshaft.

Although effective, compared to Otto's 4-stroke, Brayton's old engine design was grossly inefficient. Even so, Brayton continued to develop his engine for several years, particularly oil-burning versions. His last patent was issued in 1890, but by then it was clear the market he hoped to capture had moved beyond his grasp. The Otto engine ruled the gasoline engine market, and development of the Brayton engine ceased.

This issue of Gas Engine Magazine presents a unique and little-known application of a Brayton engine - a submarine. Reader Paul Gray came across the engine quite by accident, displayed in the Paterson Museum in Paterson, N.J.

Well, not really on display, more like hidden inside a prototype submarine, the Fenian Ram, built in 1881.