Krauss-Maffei ML 4000R "Big Tiger"
Nation of Origin: Germany (many rebuilt in the United States and Canada)
Built: 1961-2003
Builder(s): Krauss-Maffei (initially), Southern Pacific Railroad Sacramento Works and Canadian National Railways Transcona Shops (rebuilds)
The stories of the first foreign-built diesel locomotives to arrive in North America ended up being interesting ones, as the German-manufactured Krauss-Maffei ML 4000 diesel-hydraulics and the British-built Class 55 "Deltic" locomotives both represented diesel locomotive advancements outside of North America, and both ended up maturing to the environments they found themselves in and teaching lessons to all involved.
The stories of both began at the end of steam era for the Southern Pacific Railroad in the western United States and Canadian National Railways in Canada, as the two retired the last of their giant steam engines, the famed AC-10 and AC-11 class "cab-forwards" of the SP and the monstrous V-1 Garratts of CN, both of which were retired in 1959 and 1960. While multiple-unit arrangements had made it possible for many diesel locomotives to be used in place of one steam locomotive, both SP's tortuous Tehachapi and Coast divisions and its heavily-graded Salt Lake division and CN's Rocky Mountain main lines (as well as hills in other places, most famously the Dundas Grade west of Hamilton Junction in Ontario) rated as many as twelve diesels to a single train to get the tonnage desired over the road safely and efficiently. While possible - both railroads had the motive power on hand, and could get more if needed - this was not a setup that either railroad desired. Both had been partners in many elements of technical innovation for decades, and CN under Sir Anthony McConnville and SP under Donald J. Russell made the partnership grow, as both saw the other's technical advances as ways of improving their businesses. Over time, this grew into a substantial working relationship that ended up being immensely beneficial to both railroads in the decades to come.
CN jumped at the motive power fight first. Despite the presence of Montreal-built Alco PA and FPA units for passenger services, CN was always aiming to do more, and in 1957 Sir McConnville came back from a trip to England, where he had been a guest of English Electric, who had demonstrated to him and other CN officials the mighty DP1 Deltic, whose power and performance would become a legend in the United Kingdom, and he had promptly begun the process of organizing the Canadian Locomotive Company's licensing of the Deltic for Canadian National's operation. That news quickly made it to SP, but CN's affinity for passenger services wasn't entirely shared by the Southern Pacific, which was more interested in a freight hauler. SP felt the high-speed Deltic was unsuitable for freight service - but it did raise its eyes to the idea of an imported engine, and the twin-prime-mover design did offer the promise of the power SP felt they needed. Within a year and a half, plenty of communications between SP, CN, the Denver and Rio Grande Western and Krauss-Maffei had come up with a design that all the railroads felt would work. On August 15, 1960, the three railroads announced they had placed a twelve-locomotive order with Krauss-Maffei - four for each railroad - for 1961 delivery.
The ML 4000s arrived in 1961, and true to form, they were tough, strong units, though the Rio Grande found they struggled with the high altitudes of the Rockies, and ultimately their four were sold to Southern Pacific in 1964. SP found their units struggled with the grandients of the Sierra Nevadas, a problem CN also discovered in the Rockies. Both railroads, however, weren't willing to give up on their investments, and neither was Krauss-Maffei. SP moved the mighty diesel-hydraulics to less-graded lines in California's San Joaquin Valley while CN moved theirs to Southern Ontario while their builder developed a plan to upgrade the locomotives. Krauss-Maffei came through in May 1965, developing an improved design known as the ML 4000R, raising their power from 3500 horsepower to 4250 using 18-cylinder Maybach engines driving improved Voith transmissions - and the existing engines could be rebuilt to the new specs. In 1966, CN sent its units to California for their rebuilds, and SP's Sacramento Shops did the rebuilds, coming back with rather-improved units. Happy with the result, SP ordered sixteen additional units in 1968, and CN followed with an order for twenty-seven more units the following year.
As higher-horsepower locomotives were offered by EMD, General Electric and Alco in the 1960s, the big Germans had competition, but the rebuilt diesel-hydraulics proved to be phenomenally reliable, and the ML 4000Rs ended up being the workhorses for SP in California's Central Valleys from the late 1960s until the late 1980s, helped from Bakersfield to West Colton (including Tehachapi and Cajon Pass areas) from 1976 onward by electrification, extending the reach of the mighty diesel-hydraulics across Southern California and well into Baja California. For CN, the rebuilds and new ML 4000Rs saw their maintenance base moved to the McCowan Works in Scarborough, Ontario, the locomotives used there until the electrification of CN lines in Ontario and Quebec in the 1980s saw the locomotives moved back to the West, with the locomotives after 1984-85 being based at the Transcona Shops in Winnipeg, operating east across the grain-hauling lines to Thunder Bay, Ontario, and West across Manitoba and Saskatchewan, with the locomotives regularly venturing as far as Edmonton and Lethbridge.
The Transcona Shops by the 1980s had quite an eclectic mix of locomotives under their care - the "Big Tigers", as CN crews called them, were joined by CN's fleet of gas turbine units, the Canadian Locomotive Company units still operated by CN (both Fairbanks-Morse designed H-24-66 "Train Masters" and the CLC Type 4A units, the Deltic-derived passenger units, were in common use in the mid-1980s) a stack of EMD and Alco units ranging from rebuilt-many-times F-units, PAs and FPAs to modern SD40-2Ws and Millenium 190DPs and a handful of GE C36-7s, virtually all built in Canada. This was a situation that demanded both ingenuity by the mechanical personnel and justification by the management, but such was the rapid growth of CN's freight traffic in the 1980s and 1990s, combined with the construction of the Nunavut Railway in the 1990s and the demand to eliminate two-stroke diesel railroad engines from service for emissions reasons[1], made sure the ML 4000Rs would have more than a little life yet. Rebuilding efforts based around EMD units and large orders from all three major locomotive manfacturers spelled the end for the ML 4000Rs, and the last were retired by CN in 2003.
The first ML 4000 cab unit built for CN was donated to the Canadian Museum of Science and Technology in Ottawa in 2000 and the very last cowl unit was donated to the Algonquin Heritage Railway in 2004, the very first SP unit went to the California State Railroad Museum, two others ended up at American museums and the second CN cab unit was donated to Deutsche Bahn's own transport museum in Nuremberg, Germany, in the aftermath of the devastating 2005 fire at the museum.
[1] This demand by the Canadian Government began in 1993, and it resulted in the vast majority of EMDs owned by CN being rebuilt by the Transcona, McCowan, Moncton and Westland shops in the 1990s, and EMD developing variants of the 265 engine for use in Canadian locomotives. This requirement also saw the retirement of the Deltic-powered units in the 1990s and emissions equipment added to the turbine units. This requirement was not an issue for Alco, GE or Krauss-Maffei units, as all use four-stroke engines.
