A REPORT ON GAS TURBINES
From the TRUE magazine Automobile yearbook for 1955
BY KENNETH KINCAID
The turbo-car engine has only a small fraction of the moving parts of an internal-combustion engine; it has no transmission, needs no antifreeze in the winter and presents no ignition, spark plug, coil or battery problems and it will be available sooner than you think
There is probably no cliché in the English language noire worn and weary than the phrase “dawn of a new era.” Captains of industry love it, politicians can scarcely do without it and at Rotary lunches it’s served up regularly with the creamed chicken and green peas. The phrase has been applied so often to the subject of gas-turbine power for automobiles that familiarity has dulled it’s impact. Since 1950, when the first discussion of gas turbines for cars was printed in a U. S. automotive magazine, the press has repeatedly predicted that the turbo-car is just around the corner, and the corner, in the eves of the skeptical American public, has vet to be reached.
In this case, however, 160 million Americans can be wrong. Their observation has been limited by the fact that they cannot see through closed doors into the manufacturers’ planning rooms or over high walls at private test courses. If they could, they would know that the touted new era is not only coming but almost here.
Look at the evidence. A handful of years ago, the only two firms in the world that did not seem totally indifferent to gas-turbine research were Rover, a small car manufacturer in England with a lot of foresight but no great amount of capital and no reputation for aggressive salesmanship, and Boeing Aircraft, a dynamic U. S. firm that had only secondary interests in the automotive field. Boeing consistently and successfully tinkered with turbine research, but did not relate it specifically to passenger-car production. Rover built the world’s first turbo-car, a historic machine that made a big but temporary splash in the headlines and then for several years retreated into near oblivion. These may have been straws in the wind, but they did not constitute a major revolution.
But now?A list of the manufacturers attacking the turbine problem reads like an international Who’s Who in big-time car production. In this country, it’s the Big Three - General Motors, Chrysler, Ford - plus, it is rumored, Packard. In England, it’s the British Motor Corporation, the recently formed merger that combines the not inconsiderable resources of Nuffield (MG, Morris, et al) and Austin. In Italy, it’s Fiat, the massive and powerful organization that makes most other European manufacturers look like back-yard hobby shops. These are most of the world’s Big Boys in automobiles, the titans. They are not notorious for wasting time and money on research projects that won’t pay off. And all of them are studying, building and testing automotive gas turbines as quickly as they know how.
At this point, there seems to be little doubt that one of them will come up with the answer that will put a turbo-car in your garage - and soon. The question that nags at theism is not whether turbines are coming, or even when they’ll be here, but who - who will be the first with the most, who will reap the sales, profits and prestige of being the first manufacturer to present. The motoring public with the most important innovation in automobile design since the internal-combustion engine made horse-drawn buggies obsolete.
This concentrated interest in the turbine principle has been a long time in coming. Actually, it’s been known for many generations that if you compress a mixture of gas and air and ignite it, the result will be a violently expanding gas that can push the blades of a bucket wheel and make it perform useful work. The windmills that sprouted up all over Europe in the Middle Ages were primitive, heatless applications of the principle. The smokestacks of the 1600’s were the next step - they were simply windmill rotors mounted horizontally in chimneys with shafts geared to perform such humble and useful labors as turning meat on a spit.
Using the hot gases from a cooking fire to turn a windmill is, of course, a far cry from an efficient, self-contained gas turbine, but to anyone who studied the turbine principle even in its most rudimentary forms, it was apparent that with its few moving parts and its continuous flow of power, the turbine was potentially the most rational heat engine imaginable, far more so than the complex labyrinth of a piston engine. After all, the effect of a gas turbine is that of a piston moving at constant speed in an endless cylinder.
But gas turbines have their own little difficulties, too, and some of them have been and still are lulus. One, for example, was the problem of getting a fuel-mixture compressor that would not consume too much of the turbine’s power output. Another was the problem of keeping the turbine’s blades (or “buckets” - a term borrowed from water-wheel practice) from being destroyed by the heat of combustion. The first blade coolant used in turbines was water, but engineers realized that they could simplify the over-all design if they used one of the ingredients that they had to use anyhow to make the turbines work - air. The modern gas turbine compresses the mixed air and fuel, burns it, cools the hot gas with excess air to a temperature that will permit the longest possible bucket life and then sends this cooled gas against the buckets of a turbine wheel.
These are problems that have been at least partially solved. But there are others, some of which in recent months have been giving the top research men of the manufacturers in the turbo-car race sleepless nights, sour dispositions and a sudden susceptibility to ulcers.Look at this one. The gas in a turbine burns at 3,800°, but if it’s not going to melt the blades it has to be diluted with cold air to about 1,500° before it ever hits them. The cooled blast that’s directed against the blades does what little it can and then escapes to the atmosphere. Only a tiny amount of the original 3,800° has done any useful work; the “thermal efficiency,” as the engineers call it, runs about 5 percent as compared to an average piston engine’s 26 percent.
So, Problem Number One is bringing the gas turbine’s thermal efficiency up to where it will be economically feasible to operate. One way is via metallurgy - developing new alloys for the buckets that can stand more heat so that the gas doesn’t need to be cooled so drastically. Another way is to work out some way of reusing the heat in the turbine’s exhaust gas.
And this brings us to still another difficulty. Walking close by the tails of most of the turbo-cars that have been built to date would be as suicidal as standing behind a jet plane at take-off. You’d be fried. The jet plane uses a turbine engine that propels itself and the plane by means of sheer exhaust thrust. It needs the hot, powerful blast of exhausted fuel to push it forward. In the air, it seldom meets burnable traffic. But a 1,300° exhaust blast on land is something else again, the sort of thing the Highway Patrol is likely to find objectionable. This has given added incentive to the search for a device that can feed the heat back into the turbine where it can do some good.
These are big problems, but for the technology that produced the hydrogen bomb, penicillin and chlorophyll dog food, their solution is obviously only a matter of time.Practical, efficient, economical turbo-cars are as inevitable a part of our future as death and taxes. Cracks in the industry’s iron curtain of secrecy indicate that the two major challenges of turbine design outlined above are already being met.
But before we examine the information that’s leaked through about the odds-on favorites - General Motors, Ford and Chrysler - let’s take a look at the two dark-horse entries, Rover and Boeing.
Rover’s JET 1, the world’s first turbo-car, came on the automotive scene like a lion in 1950, set the first speed record for turbo-cars in 1952 at over 151 mph and thereafter was heard from no more. British technical journals of a year or so later, hearing the rumbles and rumors about turbine progress in the U. S., publicly bewailed the apparent fact that their countrymen had fumbled the ball after a brilliant head start and that the U. S. is about to pick it up and score.But a discreet and unobtrusive announcement in the English press in time spring of 1954 indicates that Rover still has some tricks it hasn’t displayed.
The announcement described a new descendant of the 260-hp JET I in the form of a small 60.hp unit intended for various uses as a portable power plant.But tucked casually into the story was a pregnant promise. Rover, it reported, was simultaneously working on a larger unit for use in vehicles and boats, a unit which they hope to equip with a heat exchanger - the elusive waste-heat recover) device that would solve two of the gas turbine’s biggest problems.
Rover, like its larger corporate colleagues, is not giving away much free information about its turbine developments. It is particularly close-mouthed about this device. But S. K. Hambling, Rover’s chief engineer, states unequivocally that his company’s current project is aimed at developing a vehicle for sale to the public that will be a “sound commercial proposition . . . and in no way a freak or an oddity of mere novelty value.”
Boeing, in the meantime, has been proceeding with its turbine research with quiet thoroughness. Right after Rover introduced the JET I, Boeing engineers revealed that they had installed a gas turbine unit in a huge Kenworth truck. Since then, this first turbo truck in the world has been tested through well over 40,000 miles of motor freighting. It has operated with great reliability and success. But this experiment has not yet faced head-on time problems of exhaust blasts and heat recovery. The turbo truck’s engine vents above the cab like an ordinary diesel, high enough above the roofs of most cars so that it causes no discomfort to other motorists.
More than 300 Boeing turbines have been built. They have driven pumps, air compressors and generators, powered Navy launches, Army Ordnance trucks and even a helicopter. The most recently announced Boeing experiment has been to put a turbine in a Cessna XL-19B light plane, the first aircraft in its class to use turboprop power - that is, a jet engine driving another bucket wheel that is attached to a propeller or drive shaft.
Boeing has been working with automotive-size turbines for ten years now, perhaps longer than any other big U. S. plant, but the very variety of its interests probably means that it will not be the outfit that pulls in the laurels and the profits when the first mass-consumption turbo-car is rolled onto a showroom floor. There is too much competition from the automotive industry itself. There is, for instance, General Motors.
It’s safe to say that when the great majority of the hundreds of thousands of people who saw Motorama in 1954 think of gas turbines, they do not remember Boeing’s careful and considered experiments or even the much-publicized hut soon-forgotten Rover JET I - they think of GM’s wild and wonderful, daring and dramatic show car, the Firebird.
When GM tossed its hat into the turbine ring, it did it with a grand flourish and calculated showmanship. The Firebird has been exhibited throughout the U. S. and Europe, not only in all it’s in person delta-winged glory, but also on a great panoramic screen. Every showing of Motorama featured a film of the Firebird making a roaring, rocketing test run across GM’s Arizona proving grounds.
The gas turbine that powers the Firebird is a compact 370-blip unit known to company engineers as the GT-300. For public bedazzlement, it’s called “Whirlfire-Turbopower.” It Was clearly designed to supply GM’s research boys with turbine data in the high performance range, a function it no doubt performed in the test runs made by Indianapolis ace Mauri Rose during which the Motorama sequence was filmed.
But the same GT-300 has been applied too less glamorous ends as well. It has, for one thing, been installed in a standard GMC transit bus.
The world’s first turbo bus has been a big success from nearly every operating standpoint and, most important, has been a source of priceless new data. The bus is roomy enough inside for it to be a real rolling laboratory.The Turbo-Cruiser Coach, as GM calls it. Has been equipped with a big and elaborate set of instruments. Technicians can work in it comfortably while it’s in motion.Furthermore, it has enough space for ballast, so all conceivable conditions can be duplicated.After 2,500 hours of carefully observed operation, the head of GM’s Gas Turbines Department, W. A. Turunen, makes these observations:
“The turbine’s fuel consumption is about twice that of the diesel engine it replaces. We expected this even when the GT-300 was on the drawing board, but at this point we’re more interested in keeping the design simple so that we can pinpoint the problems more accurately than when we are in working, for example, with the recovery exhaust heat.
“The turbine runs fine on any one of a broad variety of fuels regardless of octane and cetane numbers. Its torque is immense and it’s most powerful when you need it most - when the vehicle is at a standstill. Over-all acceleration is better than the diesel’s but there’s a lag between the time the throttle is opened and when the power comes through because it takes a couple of seconds to wind the gasifier turbine up to its top 26,000 revs. But acceleration throughout the speed range is very smooth.”
In most respects, the GT-300 stacks up pretty well in comparison with the diesel that used to do the job. It fits the same space, is 1.500 pounds lighter, produces almost twice as much power. But Turunen says cautiously that there’s still a lot to do before the gas turbine takes over. Fuel economy needs to be improved, - the acceleration lag must be eliminated and something equivalent to piston-engine-type engine braking has to be developed. “We need better components, heat exchangers, cheaper materials,” tic says. “In a nutshell, we have to find out how to build a gas-turbine car that will be as cheap and reliable as a Chevvy”
Ford, in the meantime, is moving in on turbine development, too. In February 1954, this announced completion of a giant laboratory that will be devoted exclusively to gas-turbine research. But Fords position then and now is one of Cautious, cost-conscious exploration. Ford claims to not have an engine and, what’s more, their executives say they don’t want one - yet.
Their view is that there is little point iii working with an experimental engine that easily costs 510,000 to produce because an engine with such a price couldn’t possibly be sold to the public on a mass basis. First things first in the Ford opinion.The laboratory will first work on metallurgical research will try to crack the problem of finding materials that can stand the heat anti stresses of the gas-turbine engine. When Ford engineers have developed metals that cost pennies rather than many dollars per pound, they can then go ahead and build an economical, practical turbine engine that can be adapted to mass production.
But Forth and even razzle-dazzle GM may be moving too slowly in the gas turbine race. While they’ve been making more-or-less publicized progress in the general direction of a passenger turbine car, Chrysler has moved up quietly on the outside and unless Ford and GM are lot farther a long than they’re willing to admit. Chrysler is now in the lead.
Chrysler burst on time scene suddenly and with little previous warning. Back in ‘49, we queried all the U. S. car manufacturers on their interest in gas turbines.From George J. Huebner, Jr., Chrysler’s head research engineer, we received this polite but unmistakable brush-off: - - we are sorry to be unable to give you any information on the subject of automotive gas turbines. Our only experience on gas turbine work has been confined to a project, which we carried for the United States Navy. This project has now been completed, but pertinent data and information about it remain classified so that it will he necessary to refer you to the Navy for information on any of this work.”
The first public inkling of the most sensational gas turbine development to date broke in a magazine in December 1953. Writer Stewart Cram, in the course of researching an article, pinned Chrysler’s engineering vice president, Jim Zeder, to the wall in a weak moment and subjected him to a certain amount of educated needling about competitors’ progress in the turbine field. Zeder took it as long as he could and at last thundered, “Our gas-turbine development has continued since the war . . . and Chrysler knows as much about it as anyone else. We have a gas turbine that gives excellent results . . . when the time comes, we’ll be ready.”
Buried in the last paragraph on the last page of now-defunct Cars magazine, Zeder’s pregnant quote drew little attention. A few weeks hater, at the Chicago Auto Show’s press preview, Chrysler’s president. Tex Colbert dropped another hint of the bombshell that was about to be detonated. Here, again, someone made a heckling comment about other firm’s gas-turbine claims. Colbert grinned knowingly and said, “When the rope gets long enough, we’ll hang ‘em”!
The execution took place hate last March. Chrysler suddenly announced that they had a car which was equipped not only with a gas turbine but with a regenerative turbine, one that had a heat exchanger! Their turbo-car, they said, had fuel economy comparable to that of a ‘piston-engined car of similar power. This was the biggest event in turbo-car history since Rover built JET I,
Chrysler’s GT-1001 was to all appearances a standard Plymouth sport coupe. Its only distinguishing features were a larger-than-ordinary tailpipe and the word “Turbine” in chronic script on the trunk hid. This was actually the world’s first turbine-powered production-model passenger car. Its builders deliberately and intelligently chose the least expensive car in their line for launching the regenerative turbine.
In June, GT- 1001 was demonstrated to the national press. Sports commentator Ed Thorgersen rode with engineer Huebner and gave the assembled newsmen a running account of his turbo-car ride via two-way radio. The gauges registered a fuel-consumption rate of 14.9 miles per gallon (of unleaded gasoline) at a steady 40 mph. This isn’t the greatest economy that’s ever been registered for a passenger car, of course, hut it’s by Far the best that’s beets recorded for a turbine engine. The heat recovery is so complete that you can hold your hand against the tailpipe and feel only comfortable warmth.
This reporter spent a leisurely afternoon talking about the GT-1001 project with Huebner. He is a tall, massive, good-looking guy in his early forties with enormous vitality and mental energy. He talks about advanced engineering with the same kind of unrepressed delight that a sportsman might display when he’s describing a limit of 15-inch trout that he had caught with red-flannel bait. This is what he says about the GT-1001 and the revolutionary heat exchanger:“A fundamental thing to realize about the gas turbine is that because you’re pumping excess air to cool the metal in the engine, you’re using about two and a half times as much air in all as a reciprocating engine uses. In effect, you’re burning two and a half times as much fuel because you’ve got to pay for pumping that air. There’s only one way to get good fuel economy and that’s to recover the heat from the exhaust - and that’s what we’ve done.
“But there’s another factor too. Suppose you take the exhaust gas after it has done its work in the turbine and run it back through the system. By this time, it is relatively cool and you can use it to serve the cooling needs of the engine. That’s all right. But you’ve already burned the oxygen out of this gas, so you can’t do it over again. You have to rig up a heat exchanger that will use the exhaust gas to heat the fresh air that’s on its way to the combustion chamber,
“The trouble is this, with conventional heat-exchanger techniques, the amount of heat-exchange surface you need is really fantastic. If you figured it out on the basis of the surface you’d need for a car, you’d find yourself filling the entire passenger compartment with heat exchangers. You might just have room for the driver, and maybe not even that.”
Chrysler has spent many years working on this problem. The automotive gas turbine has been studied there since before World War II. Right after the war, they started to make serious progress on regenerator design. The Navy heard about it if no one else did and commissioned Chrysler to go to work on a regenerative aircraft turbine.
“Before defense-budget cutbacks killed the project,” Huebner recalls, “we came up with a regenerator that threw 70 percent of the waste heat back into the cycle. That 70-percent heat recovery was obtained at 70 percent of the engine’s power potential. At lower speeds, we lost it and fuel economy went to hell.
“Still, that degree of heat recovery was an important accomplishment in a more-or-less constant-speed aircraft engine. For an automotive engine that spends most of its life at maybe 25 percent of its power potential, it just wouldn’t do even though when we convert 26 to 28 percent of a piston engine’5 heat into mechanical energy, we think we’re doing pretty good.
“In order to match the over-all efficiency of the automotive piston engine with a gas turbine, we’d have to recover almost all of the waste heat from the excess air. And that’s approaching the magical figure of 100 percent. We don’t know of any mechanical processes except levers that get anywhere near that kind of efficiency. Nevertheless, that was the problem we faced. And met. We’re not ready yet to disclose just what the efficiency of our regenerative turbine is, but it’s considerably higher than 70 percent. In fact, it’s fantastically high as far as mechanical processes are concerned.”
The new engine’s reliability, as demonstrated in dynamometer and road tests to date, seems to be excellent. And while these test runs have nowhere near approached the exhaustive shakedown a new piston engine receives, Huebner still does not anticipate any insoluble turbine durability problems.
In the meantime, the turbine race goes on here and overseas. Rover has its still nebulous heat exchanger and the other big companies are also breathing on Chrysler’s neck.
Fiat of Italy revealed continental Europe’s first turbo-car at the Turin Motor Show in April 1954. This car demonstrated speeds up to about 140 mph at the local airdrome and a few weeks later at the Grand Prix of Rome. Like GM’s engine, Fiat’s makes no attempt at heat recovery. Also like GM, Fiat has taken this opportunity to go adventuring in the fields of body and chassis design.
Right at press time, still another manufacturing colossus, the British Motor Corporation, has tossed its hat into the ring. The scant details that are available currently indicate that BMC is running tests on a large Austin Sheerline fitted with a 125-bhp gas turbine, wit/i heat exchanger, and that they are about to go all-out in the development of a practical automotive turbine.
Next we can look for turbine engines to invade the motor-racing field where noise and fuel consumption are secondary to performance. The wait should not be a long one. Back in 1950, Alfred Neubauer, chief of Mercedes-Benz’ racing department, prophesied, “Beginning in 1956, gas turbines must be reckoned with in international racing. The racing automobile is the best qualified for determining the value of this motive force.” Recently, the late Wilbur Shaw indicated that he expected to see turbo-cars running at the Indianapolis Speedway in 1957. Famous racecar builder Frank Kurtis has a chassis designed specifically for cradling turbine units as soon as engines are available.
Attentive to these signs of the times, motor racing’s international sanctioning body, the Federation Internationale de L’Automobile, has drafted a set of primitively simple regulations to govern turbo-car competition when it begins. Cars are to be separated into two competing classes. Class A is for vehicles weighing more than 2,204 pounds (1,000 kilograms) and Class B is for turbo-cars weighing less than that. And when the racing begins, world automobile production will be watching. Once again there will be truth in the claim that “the racing car of today is the passenger car of tomorrow.” - Kenneth Kincaid
Page last up-dated 5-14-2004