10 Locomotives That Were Simply Too Powerful for Their Time

[00:00:00]They weren't built to be practical. They were  built to dominate. Locomotives so monstrous they cracked their own frames, caught fire  on the rails, and roared so loud that cities slammed their doors shut. Engineers bolted jet  turbines and twin engines into single machines, chasing raw power no railroad could tame. Most  burned out fast. Most were cut up for scrap. But for one brief, thunderous moment, they ruled the  rails. These are 10 locomotives too powerful to survive. Number 10, Krauss Mafay ML4000. Our  countdown starts with a machine so foreign to American railroading that crews reportedly  called it, among other things, the Kraut. In 1961, two Western giants, the Southern Pacific and the  Denver and Rio Grand Western, grew tired of the horsepower ceiling on American diesels. The most  powerful single unit road diesels of the day made only about 2,400 horsepower. And both railroads  had brutal mountain grades to conquer. So they did something almost nobody in the United States had  dared. They went shopping in Germany. The builder was Krauss Mafay of Munich. And the product was  the ML4000. What made it radical wasn't just the power. It was the transmission. Instead of the  diesel electric setup every American railroad used where the engine drives a generator that  feeds electric traction motors, the ML4000 was a diesel hydraulic. Two Maybach V16 engines sent  their power through VO hydraulic transmissions and drive shaft straight to the axles. It was rated  at roughly 3,540 horsepower. The 4,000 in the name pointing at the design target. And it packed all  of that into a lighter, more compact car body than anything comparable in America. Six prototypes  came over first, three for each railroad, arriving by ship and unloaded at the Port  of Houston on October 31st, 1961. On paper, hydraulic drive promised full tractive effort from  a standstill, no wheel slip, burning out traction motors and simpler maintenance. In practice,  the American West destroyed them. The Rio Grand found them unsuitable in the high Rockies almost  immediately and offloaded its trio to the southern Pacific in early 1964. On Donna Pass and across  the Sierra Nevada, the engines struggled. They had been designed for German operating patterns  where a locomotive spends only a small fraction of its time at full throttle. American railroads  ran them wide open for hours in thin mountain air and blistering heat, conditions the design never  anticipated. The Southern Pacific even built a special track at its Roseville shops just to  service these oddballs. They lasted less than a decade. The North American units were withdrawn  in 1967 and 1968, and almost all were scrapped.

[00:02:43]Barely 20 of these hydraulics ever reached  American soil, and today just one survives, preserved and restored in California. The ML4000  wasn't too powerful in raw numbers. It was too advanced, a drivetrain concept ahead of what  American conditions could tolerate, and it set the tone for everything else on this list. In the  horsepower race, ambition and reliability rarely arrived together. Number nine, English Electric  Deltic. Now, we crossed the Atlantic because the two powerful story wasn't only an American  obsession. In October 1955, at English Electric's works in Preston, a private company rolled out  a gamble. British Railways was staring down the end of steam and weighing a hugely expensive  electrification program. English Electric bet that a diesel could be so powerful, so fast, and  so light that it would make electrification look unnecessary. That gamble was the prototype  known simply as Deltic. The heart of it was extraordinary. The Napia Deltic engine had been  developed for the Royal Navy's fast patrol boats, and its layout was unlike anything on rails. 18  cylinders arranged in a triangle with opposed pistons and three crankshafts, one at each corner  of the Delta. The locomotive carried two of them, producing 3,300 horsepower. That figure alone  made it at the moment of its debut the most powerful diesel locomotive in the world. But the  real magic was the weight. At around 106 tons, it delivered nearly 50% more power than the  designs Britain was then considering. At a fraction of the weight to power ratio, it could  run at 100 mph when British expresses were still hauled by steam. The prototype toured Britain's  main lines and proved the concept. Then in March 1961, it was sidelined by a major engine failure  and never returned to service. It survives today in the National Railway Museum's collection, but  its performance had already done its job. British Railways ordered 22 production versions. the  class 55 built in 1961 and 1962. These machines took over the east coast mainline between London  and Edinburgh, replacing 55 steam locomotives and became the first locomotives to run regular 100  mph service in Britain. At their introduction, they were again the most powerful single unit  diesel locomotives in the world. So why does a success story sit on a list of machines that were  too powerful? Because that power came wrapped in complexity and cost. The Deltic engine was a  specialized high-string marine design, expensive to maintain and utterly non-standard. As a small  fleet of exotic locomotives, the Class 55s had no cheap fallback roll once faster, more modern  trains arrived. When the Intercity 125 came, there was simply nowhere economical to put them.  All 22 were withdrawn between 1980 and 1982.

[00:05:37]retired not because they were slow, but because  keeping that much specialized power alive stopped making financial sense. Six were preserved  and enthusiasts still keep the triangular scream of the Deltic alive today. Number eight,  Norfolk and Western John Henry. For number eight, we go back a step in time and technology to one of  the strangest, most defiant machines ever built, a locomotive that tried to make steam beat the  diesel at the diesel's own game. In May 1954, the Norfolk and Western Railway took delivery of a  one-of-a-kind giant. It nicknamed John Henry after John Henry, the folk legend steel driving man who  raced a steam drill, won, and dropped dead. It was a fitting name because this machine would also  lose its race against the machine of the future.

[00:06:24]The NW was the last major American railroad  still devoted to steam, and for good reason.

[00:06:31]It sat on top of vast cheap coal reserves, giving  it nearly free fuel. Rather than surrender to the diesel, the railroad partnered with Baldwin Lemur  Hamilton, Westinghouse, and marine boiler maker Babcock and Wilcox to build a coal fired steam  turbine electric. The idea was to combine the electric drive of a diesel with the raw power of  steam. Inside its long streamlined car body sat an automatically controlled water tube boiler  running at a ferocious 600 lb per square inch, more than twice the pressure of an ordinary steam  locomotive. That steam spun a turbine, the turbine spun a generator, and the generator fed electric  traction motors on every single axle in a C plus C minus C plus C arrangement. The numbers were  monstrous. John Henry produced 4,500 horsepower at a time when a typical diesel road switcher  managed around 1,750 and it generated enormous tractive effort on the order of 144,000 lb. It  could outpull conventional steam locomotives while burning less fuel, at least at low speeds.  And it was almost absurdly large. Measured with its water tender, it stretched more than 160 ft,  likely the longest steam locomotive ever built.

[00:07:44]But complexity was its undoing. A marine flash  boiler with automatic controls, a turbine, a full electrical system, and coal handling machinery all  crammed into one locomotive meant countless things that could break. And they did. The maintenance  demands were relentless, and the machine spent too much time in the shop and not enough on the  road. The diesel, simpler and endlessly reliable, kept winning. In January 1958, less than four  years after it was built, the Norfolk and Western gave up, scrapped John Henry, and began  buying the very diesels it had fought so hard to avoid. It was the last serious American attempt  to save steam through sheer power, a magnificent doomed swing at holding back the future. Number  seven, AMD DD35 and DD35. Now, the horsepower race gets serious, and we arrive at the machine  that kicked off America's era of the double diesel. In the early 1960s, the Union Pacific, a  railroad that had always loved oversized power, wanted something extreme, a 3-unit locomotive set  producing a combined 15,000 horsepower to replace its aging fleet of gas turbines. The trouble was  that Electrootive's best road units of the day, the GP35 and SD35, topped out at 2500 horsepower  each. To hit Union Pacific's target, EMD had to invent something new. Its answer was the DB35.  Essentially, two GP35 locomotives fused onto a single enormous frame. Under one long hood sat  two 16cylinder 567D3A engines, each making 2500 horsepower for a combined 5,000 horsepower in one  unit. To carry all that weight, EMD rode it on two four axle trucks, a DD wheel arrangement that  put eight powered axles under a single locomotive, something almost never seen in North America.  To show off the concept, in September 1963, EMD assembled a demonstrator set painted in striking  red and white. a GP35 on each end, sandwiching a pair of Cables DD-35 boosters. Together, the four  units delivered exactly the 15,000 horsepower Union Pacific had asked for, the equivalent of six  GP35s wrapped into four bodies. The demonstrator toured the country, but most railroads simply  weren't ready for locomotives this big or for the heavy four axle trucks that pounded the track.  Only Union Pacific and Southern Pacific bought in.

[00:10:12]UP took the whole demonstrator set and ordered  more cables DD-35 boosters delivered in 1964.

[00:10:18]Then in 1965 came the DD-35A, a cab equipped  version, 15 of them numbered 70 through 84 for the Union Pacific alone. They worked, but the  double diesel was a solution to a problem that was already solving itself. As electrootive developed  more powerful and more reliable single engine locomotives, the whole rationale for cramming  two engines into one body began to evaporate.

[00:10:43]The DD35 and DD35A soldiered on into the early  1980s before retirement. And then every last one of them was cut up for scrap. Not a single example  was preserved, but they had proven a point that a 5,000 horsepower locomotive was possible. And  in doing so, they lit the fuse for an all-out arms race between America's three big builders.  Number six, GEU50 and U50C. When Union Pacific went looking for its 5,000 horsepower monster,  it didn't just ask electromotive. It asked all three major builders. General Electric answered  with the U50 and later the U50C. Machines that show what happens when engineers chase big power  and then start cutting corners to make it fit.

[00:11:27]The first U50 built from 1963 followed the  same recipe as the DD35. Two 16cylinder engines producing a combined 5,000 horsepower riding on  four two axle trucks joined by a span bolster.

[00:11:41]Union Pacific liked the engines well enough  to buy 26 units. But the design was heavy and ungainainely and the four truck arrangement  limited it to slower drag freight work. So GE went back to the drawing board and produced  the U50C in 1969. A machine built to make its power at higher speeds. 40 of them were built for  Union Pacific through 1971, numbered 5000 to 539, developed to the very same specification that  produced EMD's famous Centennials. Here's where it went wrong. To save weight and let the locomotive  ride on two six-axxle trucks, recycled remarkably from Union Pacific's retired 8,500 horsepower  gas turbines, GE made a fateful decision. It used aluminum wiring instead of copper throughout the  electrical system along with lighter 12cylinder engines that still made the full 5,000 horsepower.  The aluminum wiring proved prone to overheating and the results were exactly as bad as they sound.  The U50C's began catching fire. By 1974, roughly 10% of the fleet was out of service following  electrical fires, and the sheer weight of the machines was also cracking their frames. Number  five, EMD SD90 MechH. Now we jump forward three decades to the second great horsepower war and to  a locomotive that has become a textbook case of ambition outrunning engineering. By the mid 1990s,  the magic number railroads dreamed of was 6,000 horsepower from a single engine. Electrootive's  entry was the SD90 MAC and its centerpiece was a brand new engine called the 265H or simply the  H engine. A 16cylinder twinturbocharged diesel designed to deliver a full 6,000 horsepower  with modern AC traction and radial steering trucks. On paper, it was one of the most powerful  single engine locomotives ever conceived. There was just one problem. The H engine wasn't ready.  When production began, the new power plant was still riddled with teething troubles. So, EMD did  something telling. It offered the locomotive as a convertible. Early units were delivered with  a proven conventional 16cylinder 710 engine, making 4,300 horsepower, holding the place until  the real 6,000 horsepower H engine was finished.

[00:13:55]Union Pacific, the first big customer, took dozens  of these, and they were often distinguished as the SD943 MAC. The 43 quietly admitting they  made 4,300 horsepower, not 6,000. The plan was to upgrade them to the H engine later. That  upgrade almost never happened because when the 265H finally arrived in the true 6,000 horsepower  SD90 MACH, it revealed serious expensive flaws.

[00:14:23]The engine suffered reliability problems that the  railroads never accepted, and the timing could not have been worse. General Motors was moving to sell  off Electrootive as a non-core business, which starved the H engine program of the research money  it desperately needed to mature. On top of that, tightening EPA tier 2 emissions rules meant the  265H couldn't be developed and sold much longer in the United States. Anyway, the result was one  of the least successful designs EMD ever produced.

[00:14:53]The convertible units with their reliable 710  engines actually outlived and outperformed their high-powered siblings. The true 6,000 horsepower  SD90 MACH machines were mostly pulled from service, sent into storage, or scrapped. The dream  of a bulletproof 6,000 horsepower single unit had been real, but the engine to make it work reliably  simply wasn't there yet. Number four, GAK 6000 CW.

[00:15:23]If EMD's 6,000 horsepower gamble ended in failure,  its great rivals attempt landed only slightly better and became one of the most brutally  powerful production diesels ever to work American rails. This is the GEAC 6000CW. General Electric  had watched EMD announce its 6,000 horsepower ambitions and refused to be outgunned. Rather  than simply push its dominant AC 4400 CW harder, GE developed an entirely new, more powerful  prime mover. The 16cylinder HDL engineered in partnership with Deuts MWM in Germany and aimed  squarely at delivering a true 6,000 horsepower with AC traction. Built from 1995 into 2001,  roughly 314 of these giants were produced.

[00:16:10]The main customers were CSX and Union Pacific  in the United States along with a fleet sent to the mining railroad BHP in Australia to haul  enormous ore trains. But the AC 6000CW ran into the same wall as its EMD competitor. The new HDL  engine wasn't ready in time. So just like EMD, GE and Union Pacific hedged their bets, delivering  many units with a more modest, proven engine and the promise of an upgrade later. The early  HDL power plant had real reliability troubles, echoing the very same new engine big problem story  playing out across the industry at EMD. Here's where the two rivals diverged. After a rough start  and a long list of improvements, GE eventually got the HDL working far more reliably than EMD ever  managed with the 265H. The AC 6000CW lasted longer and worked harder, especially on CSX, where some  units were later re-engineed with G's newer GE Evo engine while keeping their full 6,000 horsepower  rating. Yet, even this relative success carried a quiet lesson. The industry as a whole discovered  that a single 6,000 horsepower locomotive wasn't actually the smartest way to run a railroad. Two  well-matched 4,400 horsepower units offered more flexibility, better reliability, and easier  maintenance. The 6,000 horsepower monsters had won the spec sheet, but the market moved on  without them, settling on power that was merely enormous rather than absurd. Number three, Alco  Century 855. Every arms race has a competitor who swings for the fences and misses catastrophically.  In America's 1960s horsepower war, that competitor was Alco, the American locomotive company, and  its desperate haymaker was the Century 855. When Union Pacific went to all three builders asking  for a 5,000 horsepower unit, Alco decided not just to match its rivals, but to beat them. The  Century 855 was built to produce 5,500 horsepower from two 16cylinder Alco 251C engines, making it  at a stroke the most powerful diesel locomotive Alco had ever built. And at that moment in 1964,  the most powerful diesel locomotive ever built by anyone. It would hold that title until Union  Pacific's own Centennials arrived 5 years later.

[00:18:33]It rode on four two axle trucks grouped in pairs  and linked by span bolsters. A B plus B minus B plusB arrangement borrowed from the railroads  turbine locomotives. It was a giant and it could pull almost anything and it was a disaster.  Only three were ever built. Two cab equipped A-units numbered 60 and 61 and a single cableist  B unit number 60B. All constructed in June 1964, all for the Union Pacific. The trouble was that  Alco fighting for survival against EMD and GE had rushed the design into existence without nearly  enough development. The consequences were exactly what you'd expect from cutting corners on a 5,500  horsepower machine. Like the ill- fated GE50C, the Century 855 used aluminum wiring to save  money, and it caught fire. The engines chronically overheated and shut down. The frames, another  victim of the rushed build, began to crack.

[00:19:29]The trio was usually kept together, and when they  worked, they worked well and pulled hard, but they spent far too much time broken. Union Pacific  quickly soued on them. And after just a few years of trouble-plagued service, all three were pulled  from the roster, and scrapped by early 1972, shipped off to Texas, and cut up with nothing  preserved. For Alco, the story was even bleeer.

[00:19:54]Unable to keep pace with its rivals, the company  left the American locomotive business entirely in 1969. The Century 855 was its last loudest, most  powerful gamble, and it failed almost completely.

[00:20:07]Number two, Union Pacific GTL 8500 horsepower. Big  blow. For number two, we reached the machine that inspired this video's hook, because it really was  more or less a jet engine on rails. Meet the Union Pacific 8,500 horsepower gas turbine electric,  universally known as the Big Blow. Throughout the 1950s, Union Pacific chased ever higher  horsepower, and it found it not in diesel engines, but in gas turbines, essentially the same  technology as a jet engine. A GE built turbine spun a generator, which fed electric traction  motors. The earliest up turbines made 4500 horsepower at a time when competing road diesels  made just 1,500 to 1,750. But the railroad wasn't satisfied. Between 1958 and 1961, GE delivered  the ultimate expression of the idea. 33 unit sets, each rated at a staggering 8,500 horsepower.  Nothing else on the continent came close. They earned their nickname. Honestly, the turbines were  catastrophically loud, a deafening, howling roar that gave them the name Big Blow. They were  so loud that Union Pacific had to restrict where they could run. The city of Los Angeles  became essentially offlimits to them after a few earsplitting visits in 1962. So the big blows  were sent to roam the wide open, thinly populated country between Council Bluffs, Iowa, and Ogden,  Utah, where they frequently hauled entire freight trains all by themselves. One turbine set doing  the work of a small fleet of diesels. It was a spectacular sight and an even more spectacular  sound. There was a clever economic idea underneath the noise. The turbines were built to burn  bunker C, a thick, heavy fuel oil that was cheap at the time, far cheaper than diesel fuel.  But that advantage was the whole ball game, and it didn't last. Gas turbines are ferociously thirsty,  gulping fuel even while idling. And as the price of Bunker C climbed, and the machine's maintenance  demands mounted, the economics collapsed. These 8,500 horsepower behemoths, the most powerful the  turbine era ever produced, were all retired by the early 1970s. They were arguably the most literally  overpowered locomotives ever to turn a wheel. Too loud for cities, too thirsty for a changing fuel  market, and utterly magnificent while they lasted.

[00:22:39]Number one, Union Pacific DDA 40X Centennial.  And at number one stands the king, the most powerful single unit diesel electric locomotive  ever built. A record that has never been broken.

[00:22:52]This is the Union Pacific DDA4X, forever known as  the Centennial. By the late 1960s, Union Pacific had experimented with turbines, with EMD's DD35,  with G's U50, and with Alco's doomed Century 855.

[00:23:10]A decade of chasing the perfect big locomotive  with mixed and often disastrous results. In 1968, the railroad tried EMD's 20-cylinder SD45 for  high-speed service, but it didn't fully satisfy management. So, Union Pacific commissioned EMD to  build something that would outpower the DD35, the U50, and the C855 all at once. The result was the  largest, most powerful diesel locomotive the world had ever seen. The DBA40X carried two 16cylinder  645E3A engines, each upgraded to 3,300 horsepower on a single frame stretching an astonishing 98  ft 5 in, a length record all its own. Together, those engines produced 6,600 horsepower, a  figure that more than half a century later, still stands as the most powerful single  locomotive unit ever produced. 47 were built between 1969 and 1971. Numbered 6900 to 6946. The  very first number 6900 was rushed to completion so it could take part in the celebration of  the 100th anniversary of the driving of the Golden Spike at Promontory Utah on May 10th, 1969.  The completion of the transcontinental railroad.

[00:24:24]That centennial gave the class its enduring name.  But here's what makes the Centennial the perfect number one. Unlike almost every other machine on  this list, it worked. These 270 ton giants hauled priority freight at up to 90 mph, powering trains  over the fearsome grade of Sherman Hill. They were reliable, they were hardworking, and they  were beloved. Each unit averaged around 22,000 m a month, and by the mid 1970s, everyone had  racked up more than a million miles of service.

[00:24:55]Of all Union Pacific's massive experiments, the  Centennials were the undisputed success. And yet, even they couldn't escape the logic that killed  the others. As reliable, easy to maintain single engine locomotives improved. The whole reason  to build a double engine monster faded away. Two ordinary units could now do the job with less  complexity and less risk. The Centennials were gradually retired between roughly 1980 and 1985,  made obsolete not by failure, but by a smarter, simpler kind of power. Several were preserved,  and one number 6936 kept running for decades as the last operational Centennial and the largest  operational diesel locomotive in the world before passing into the hands of a railroad heritage  group. The most powerful diesel ever built was in the end simply too much locomotive for a  railroad that had learned it no longer needed one.

[00:25:48]Which of these monsters was your favorite? The  screaming big blow, the record setting centennial, or one of the beautiful failures in between? Let  me know down in the comments. And if you enjoyed this ride through railroading's most overpowered  machines, subscribe for more. Thanks for watching.