For most people, Thomas Edison is the man who came up with the first practical light bulb. But Edison was also an inveterate entrepreneur who parlayed his patents into new industries and enduring businesses.
Take GE, the result of an 1892 merger between his Edison Electric Co. and Thomson-Houston Electric Co. It has since grown into an industrial giant with $148 billion in annual revenues making everything from MRI scanners to gas turbines and jet engines.
Although these businesses may seem very different, they often trace their origin to a his lab and a point in history where Edison, light and electricity intersect. The light bulb led him into X-rays and the medical imaging business, and GE’s expertise in power generation and gas turbine engineering gave birth to the company’s aviation business. (This sharing is a two-way street. Aviation engineers are now helping their colleagues in power generation help build more efficient gas turbines with their jet engine know-how.)
It’s in part because of these synergies – GE executives call this cross-pollination “the GE store” – that GE Power & Water and GE Aviation alone produced a combined $50 billion in revenues in 2014, more than a third of the company’s total. Take a look at their intertwined history.
Edison’s light bulb and the wave of electric devices that followed created a huge demand for electricity. Initially, companies were using piston engines to power generators, but they quickly switched to more efficient steam turbines.
In 1903, GE engineers Charles Curtis and William Emmet built what was then the world’s most powerful steam turbine generator for a power plant in Newport, R.I. (see above). It required one-tenth the space and cost two-thirds less than the equivalent piston engine generator.
It was also in 1903 that GE hired young turbine engineer Sanford Moss (above). Moss had just received a doctorate in gas turbine research from Cornell University. At GE, he started building a revolutionary radial gas compressor using the centrifugal force to squeeze the air before it enters the gas turbine – the same force pushing riders up into the air on a swing carousel.
Moss’s early experiments failed; his machine guzzled too much fuel and produced too little power. But his patent and his revolutionary compressor design were sound and found many applications: from supplying air to blast furnaces to powering pneumatic tube systems. He didn’t know it, but he had pointed the way to the jet engine before the Wright Brothers even took off.
In November 1917 – at the peak of World War I – GE President E.W. Rice received a note from National Advisory Committee for Aeronautics, the predecessor of NASA, asking about Moss’s radial compressor. WWI was the first conflict that involved planes and the agency wanted Moss to improve the performance of the Liberty aircraft engine.
The engine was rated 354 horsepower at sea level, but its output dropped by half in thin air at high altitudes. Moss (right in the picure above) believed that he could use his compressor to squeeze the air before it enters the engine, making it denser and recovering the engine’s lost power.
Using a mechanical device to fill the cylinders of a piston engine with more air than it would typically ingest is called supercharging. Moss designed a turbosupercharger that used the hot exhaust coming from the Liberty engine to spin his radial turbine and squeeze the air coming inside the engine.
In 1918, when he tested the design at 14,000 feet on top of Pike’s Peak, Colo. The engine delivered 352 horsepower, essentially its rated sea level output, and GE entered the aviation business.
The first Le Pere biplane powered by a turbosupercharged Liberty engine took off on July 12, 1919. “The General Electric superchargers thus far constructed have been designed to give sea-level absolute pressure at an altitude of 18,000 feet, which involves a compressor that doubles the absolute pressure of the air,” Moss wrote.
Planes equipped with Moss’s turbosupercharger set several world altitude records.
In 1937, on the eve of World War II, GE received a large order from the Army Air Corps to build turbosuperchargers for Boeing B-17 and Consolidated B-24 bombers, P-38 fighter planes, Republic P-47 Thunderbolts, and other planes.
GE opened a dedicated Supercharger Department at Lynn, Mass. In 1939, Moss proposed to build one of the first turboprop engines. Trained as a gas turbine engineer, he later joined the National Aviation Hall of Fame.
But GE’s aviation business was just getting started. In 1941, the U.S. government asked GE to bring to production one of the first jet engines developed in England by Sir Frank Whittle. (He was knighted for his feat.)
A group of GE engineers called the Hush Hush Boys designed new parts for the engine, redesigned others, tested it and delivered a top-secret working prototype called I-A.
On October 1, 1942, the first American jet plane, the Bell XP-59A, took off from Lake Muroc in California for a short flight. The jet age in the U.S. had begun.
The demand for the first jet engines, called J33 and J35, was so high that GE had a hard a time meeting production numbers and the Army outsourced manufacturing to General Motors and Allison.
GE decided to double down and invest in more jet engine research. The J33 and J35 engines used a radial – also called centrifugal – turbine to compress air, similar to the design that Moss developed for his turbosuperchargers.
But GE engineers started working on an engine with an axial turbine that pushed air through the engine along its axis. (All jet engines use this design today.) The result was the J47 jet engine that powered everything from fighter jets like the F-86 Sabre to the giant Convair B-36 strategic bombers. GE made 35,000 J47 engines, making it the most produced jet engine in history.
The J47 also found several off-label applications. The Spirit of America jet car used one, and a pair of them powered what is still the world’s fastest jet-propelled train. They also served on the railroad as heavy-duty snow blowers.
In 1948, GE hired German war refugee and aviation pioneer Gerhard Neumann, who quickly went to work on improving the jet engine. He came up with a revolutionary innovation called the variable stator. It allowed pilots to change the pressure inside the turbine and make planes routinely fly faster than the speed of sound.
When GE started testing the first jet engine with Neumann’s variable stator, the J79 (see below), engineers thought that their instruments were malfunctioning because of the amount of power it produced. In the 1960s, a GE-powered XB-70 Valkyrie aircraft was flying in excess of Mach 3, three times the speed of sound.
The improved performance made the aviation engineers realize that their variable vanes and other design innovations could also make power plants more efficient.
Converting the engines for land use wasn’t difficult. In 1959, they turned a T58 helicopter engine into a turbine that produced 1,000 horsepower and could be used for generating electricity on land and on boats. A similar machine built around the J79 jet generated 15,000 horsepower. In Cincinnati, where GE Aviation moved from Lynn in teh 1950s, the local utility built a ring of 10 J79 jet engines to power a big electricity generator.
The first major application of such turbines, which GE calls “aeroderivatives” because of their aviation heritage, was as power plants for the Navy’s 76,000-ton Spruance-class destroyers. The turbines now also power the world’s fastest passenger ship, Francisco. It can carry 1,000 passengers, 150 cars and travel at 58 knots
Today, there are thousands of aeroderivatives working all over the world. Most recently, they have been helping Egypt’s growing economy slake its thirst for electricity.
Neumann’s variable vanes (above) are also part of GE’s most advanced gas turbine: the 9HA Harriet, the world’s largest, most powerful and most efficient gas turbine. Two of them can generate the same amount of power as a small nuclear power plant.
At the same time, GE Aviation is working on the next-generation jet engine called ADVENT, or Adaptive Versatile Engine Technology (above). “To put it simply, the adaptive cycle engine is a new architecture that takes the best of a commercial engine and combines it with the best of a fighter engine,” says Jed Cox, who leads the ADVENT project for the U.S. Air Force Research Lab.
Filed Under: Aerospace + defense