General Electric GTEL Series
There are few places in the world where freight tonnage on one train could even come close to the log distances and lengthy, heavy loads of the seven railroads - Great Northern, Northern Pacific, Milwaukee Road, Union Pacific, Denver and Rio Grande Western, Atchison, Topeka and Santa Fe and Southern Pacific - that cross the American Continental Divide, and it was no surprise then that in the age of steam the locomotives used on this route simply grew and grew and grew, ultimately culminating in the titanic Union Pacific Big Boys, Southern Pacific AC-11s and the 2-8-8-4 Yellowstones of the Northern Pacific and Denver and Rio Grande Western. These behemoths were some of the largest locomotives ever to steam and were capable of handling huge loads, but as the traction and economics of diesel locomotives came to the forefront in the 1950s, a problem was created - while the multiple-unit ability of diesels allowed as many locomotives as needed to be hooked up to handle a load, many railroads believed that they could have more efficient operations through having heavy trains led by fewer, more powerful engines. Many railroads considered Pennsylvania-style electrification, but while the Milwaukee Road's 3000-volt DC system was capable even it could - and sometimes did - run short of available power with the company's giant General Electric EF-4/EP-4 "Little Joes".
Into this came GE's plans for a gas turbine-electric locomotive. The first unit, developed and built by General Electric in 1948, was sent to Union Pacific for testing, as UP had envisioned the gas turbine-electric locomotives as a replacement for their mighty Big Boys. The experiment proved successful, and the first generation of such engines, the GTEL-1, began service with Union Pacific in 1952.
The GTEL-1 was a eight-axle unit with four trucks, with each pair connected by a span bolster, powered by a single General Electric gas turbine and a single Cummins backup diesel, driving all eight axles. The big turbines initially ran on Bunker C heavy fuel oil - a cheap source of fuel but one which required heaters built into the fuel tanks of the locomotives to make the very thick, low-viscosity fuel able to be pumped into the turbines. This fuel proved difficult to handle in other ways - the corrosive ash built up as a result of turbine operation caused problems with turbine blade erosion that plagued all of the turbines early in their lives. Despite the technical difficulties the turbines were very powerful - the GTEL produced 4,500 horsepower, over double what was available from diesel-electric locomotives at the time - and Union Pacific, pleased with the power results, quickly ordered a second generation of the locomotives, the GTEL-2. The GTEL-2, known to railfans as 'Verandas' for their distinctive hybrid of a carbody and hood locomotive, were evolutionary improvements of the original, and all GTELs gained fuel tenders in 1957-58 to allow them to travel greater distances than their traditional territories on UP's Overland Route, and the turbines could - and did - steadily allow the retirement of the Big Boys, as well as getting the attention of the Southern Pacific and Rio Grande, both of whom began trialing GTEL-2s on their roads in 1956. UP also developed a way for the Turbines to multiple-unit with diesel locomotives in 1957, and eventually all first and second-generation units were equipped as such.
The GTEL-3, however, was where things changed. The GTEL-3 was a three-unit locomotive, with the A unit housing a Cooper-Bessemer diesel engine, cab and control systems and cooling radiators, while the B unit contained the main turbine and generators and the C unit was the 24,000-gallon fuel tender, all three units riding on a pair of powered three-axle trucks under each unit. Producing some 8,500 horsepower (and that claimed at 6000 feet of elevation and 90-degree heat) to eighteen driven axles, the power of the GTEL-3 was immense - the locomotives were routinely used for 6700-ton loads on the Union Pacific's Overland Route, and even with that the GTEL-3s were outfitted for multiple-unit operation if the loads were even higher.
The huge power of the locomotive was matched by its prodigious thirst for fuel, which proved problematic to say the least. The problem with turbine blade erosion and soot buildup was even more pronounced here than in other units, and improved abilities by the petroleum industry to better refine fuel oil and the use of Bunker C as a plastics production feedstock dramatically increased the price on the locomotives, making the turbines very expensive to operate. The Union Pacific, realizing this and knowing the locomotive builders were getting better and better at improving power on conventional diesel-electric locomotives, began retiring the turbines in 1963, striking all of GTEL-1 and GTEL-2 units from service in April 1964, by which point both SP and Rio Grande had both long done the same.
But just after the units were retired, Canadian National Railway bought all 27 of the first two generations of the locomotives built in May 1964, and all twenty-seven were delivered to CN's legendary Transcona Shops in Winnipeg, Manitoba. The Transcona shops, famous for the complete classes of 2-8-4s built from obsolescent 2-8-0s during the Great Depression, created the GTEL-2TR, stripping the locomotives to their frames and rebuilding them with new Rolls-Royce Marine Spey gas turbines in (crucially) a combined cycle mode, using a water tank in place of the original fuel tank using the Veranda and the use of heat exchangers in the exhaust and geared steam turbines. All of the units were modified to GTEL-2 exterior designs, using the upper roof of the Verandas as condensers for the water for the combined cycle system. The tenders on these units used the same B+B-B+B truck arrangement and were motorized, and the turbines were built to run on the same diesel fuel as other locomotives.
The first of these units, CN 2000, began testing in April 1966, and true to what many had expected, its power was immense - over 10,500 horsepower was available at full power and the sixteen powered axles of the GTEL-2TR, thanks to new Siemens traction motors built into trucks. Fuel efficiency was dramatically improved, as the newer turbine and combined-cycle unit improved efficiency to a remarkable degree. CN happily ordered the other 26 for rebuilds in January 1967, and all of the GTEL-2HRs entered CN service between September 1967 and November 1968. GE, more than a little stunned by the results of the Canadian rebuilds, quickly took in retired unit UP 22 and set to work, ditching the aged Frame 5 gas turbine for a new unit based on the TF34 turbofan developed for the military S-3 Viking jet.
The GTEL-4, unveiled in July 1970, was the result. The GTEL-4 also abandoned the use of fuel oil, instead going with liquified propane, with an all-new tender to suit this. Propane fuel and better metallurgy all but eliminated the problems with turbine wear of previous locomotives and also dramatically reduced the air pollution resulting from it. The unit used all-new trucks borrowed from the E60C electric locomotive, and the new electrical components could handle every bit of the locomotive's prodigious power. GE dispensed with the use of a combined-cycle unit, preferring instead to use Stirling engines instead to capture energy from the turbine's exhaust on the grounds of less complexity and lower maintenance costs. A tractive effort of 260,000 lbs - a world record still to be beaten - and the use of short gearing and larger wheels gave the locomotives immense starting power and pulling power. The unit also dispensed with the old Cooper-Bessemer auxillary diesel in favor of a GE-built 7FDL8 unit, The nosed cab of the A unit was replaced with a cab design similar to the E60C and the electrical control systems were all water cooled to improve reliability.
The propane-fueled monster quickly proved its worth for UP's freight haulers, and the other 29 units of the UP fleet were sent to GE for rebuilds starting in April 1971. To the happiness of GE and UP (and somewhat to CN's chargin) the energy crisis hit not long after the turbines were delivered to UP, and the sudden rise in diesel fuel prices suddenly gave the propane-fueled turbines a considerable economic advantage. The Rio Grande was the first new-build order, ordering twelve units from GE in March 1974, with Santa Fe ordering twenty-five two months later and Southern Pacific buying eighteen in January 1975. All units were delivered to their owners in 1976, and they went on to have long lives. The UP units, re-commissioned into the fleet in 1972 and 1973, went right back to being the heavyweights of the Overland Route, and they were as good as everyone expected at it. Despite proposals to do so, CN's GTEL-2TRs remained fueled by diesel fuel through their operational lives, differing from the other units in that important way.
On April 16, 1986, the problems of propane fueling of the locomotives became apparent when Rio Grande unit 1006, at the head of a heavy manifest train, slammed into the back of a stopped coal train doing nearly 60 mph in Grand Junction, Colorado, destroying the units and severely damaging the nearly-full fuel tank, which was subsequently buried in the rubble and was unknown to the firefighters arrived to fight the blaze. It exploded as fire crews were attempting to fight the blaze, in the process causing six tank cars behind it loaded with toluene, polyproplene and liquified natural gas to explode in two subsequent explosions. Thirty-nine people, including twenty-five members of the Grand Junction fire department and Colorado State Police died in the explosions, and over 70 people suffered injuries as a result. Investigations of the crash found that the locomotive was overdue for a fuel tank inspection. Furious, the state of Colorado banned the use of propane-powered locomotives in the state, at a stroke forcing Rio Grande to either convert or sell its eleven remaining units - they chose to do the latter, trading the units to the Santa Fe for twenty-five SD40-2s in November 1986. But the high-profile disaster at Grand Junction led to the NTSB investigating all of the turbines for flaws. Few had any and none were safety-deficient, but the high-profile press made the locomotives look dangerous, and the state of California used its own leverage to force Southern Pacific to refit or replace its locomotives in 1987.
SP chose to work with GE on rebuilding the GTEL-4s to run on diesel fuel, rebuilding all of its units at its Sacramento Shops. Santa Fe quickly followed, doing the same with its units at its shops in Cleburne, Texas. The resulting GTEL-4R lost out a little on power and lost out more on fuel efficiency, but the rebuilds at both Sacramento and Cleburne also saw the Dash 8 Series' microprocessor control units fitted to the Turbines and many other improvements made to the units. UP persisted with the use of propane power, but after the disaster at Grand Junction public pressure forced UP to keep them out of major cities, effectively limiting their range to the section of the Overland Route between Kearney, Nebraska, and Odgen, Utah. Facing this and with rising operational costs and increasing diesel engine power, UP announced the turbines' retirement in 1994, with all of them removed from service between September 1994 and June 1995.
SP and ATSF units, however, had rather more life left in them yet thanks to their late-1980s rebuilds, as they remained key pieces of both railroads' heavy freight operations well into the 2000s. The 'Bird Burners', as Santa Fe crews somewhat-infamously called them, were particularly useful on difficult high-traffic lines and regions such as SP's tough Salt Lake Division over Donner Pass and along the fast-paced ATSF Transcon, particularly in its Arizona and New Mexico divisions. Improvements in the turbines continued to make the locomotives more efficient with every passing overhaul, much to the approval of both railroads. The ATSF began withdrawing the mighty turbines in 2005, with the last ones being retired in the winter of 2007. The SP units saw their last service in the late 2000s as well, most frequently in heavy freight service on Cajon and Tehachapi passes and on the Salt Lake Division. By the time of their retirements, however, they had become so well liked by railfans that the company ran a series of excursions across Donner Pass led by SP 7000 in the summer of 2008, giving the Gas Turbine Electric one last hurrah before retirement.
