Union Pacific Fuel Tenders

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This page was last updated on July 23, 2016.

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Natural Gas Program

During 1993 to 1998, Union Pacific tested the use of natural gas in locomotives intended for use in mainline cross-country service. All of the tests took place at each locomotive builder's facility, and on test trackage within each facility. The locomotives never entered revenue service on Union Pacific tracks. The tests ended due to failures in the cryogenic systems to keep the LNG at a constant temperature on the tenders, problems with the fuel injectors on the engines, and problems with the pumping systems to move the gas between the tenders and the locomotives. The tests also ended because the builders needed to move their development personnel and resources to other programs to meet upcoming EPA Tier 0 emissions controls.

The natural gas program (actually called LNG, for Liquefied Natural Gas) progressed no further than extensive engineering studies, and the program was cancelled due to increased costs for LNG, and technical difficulties with the locomotives themselves. At the conclusion of the LNG tests, all four units, two GE C41-8Ws and two EMD SD60Ms, entered regular service using diesel fuel. As a side note, UP 9554 had a plaque on its nose commemorating the safety record of UP's Salt Lake City shop.

UP 9554 and 9555, a pair of General Electric C41-8W locomotives built in December 1993, were modified by GE to burn natural gas. In a similar program EMD modified SD60s 6364 and 6365 (built in October 1992). Although converted to burn natural gas, all four units never formally entered service with the modifications. Sean Graham-White wrote on September 1, 2003, "Testing of both EMD and GE units were conducted at their respective plants (McCook and Erie). None of the four units or any of the fuel tenders actually touched the Union Pacific capable of operating on LNG. The fuel tender for the SD60Ms still sits at EMD's McCook plant."

Sean Graham-White wrote in his article, "Alternate Fuels, Part 1: Natural Gas," published in the June 2002 issue of CTC Board magazine:

Testing could not consistently produce high-horsepower without mechanical problems. There were problems with maintaining a high-enough pressure for the gas, the gas burning too hot while not producing enough Btu's, and because natural gas burned too hot it melted the fuel injectors. Not to mention the physical implementation of massive piping in the engine compartment to supply two fuels.

M-K chose a straight LNG system rather than dual-fuel because they believed the latter is harder to control. One disadvantage was that the combustion technology available when the units were built resulted in reduced engine RPM (1500 vs. normally 1800) meaning a reduction in horsepower from 2000 to 1200.

(Read more about the two LNG switchers, UP 1298 and 1299, assigned in Southern California, between 1994 and 1998)

The following comes from a study report published in November 2007:

UPRR R&D Program with Engine Builders (1992-1995) -- In 1992 the UPRR began separate research and development programs with EMD and GE Transportation Systems (GE) to investigate the use of natural gas in line-haul, high-horsepower locomotive engines. This was a significant, multi-year effort. By the time these programs ended in 1995, the UPRR had expended $15 million (and the locomotive builders had incurred their own undisclosed expenses) exploring basic engine and fueling technology issues. The UPRR-funded EMD effort was aimed at modifying two new EMD SD60M locomotives (3,800 hp rating) to run in a dual fuel or a diesel only mode. The UPRR-funded GE program was aimed at modifying two new Dash-8 locomotives (4,100 hp rating) similarly in dual-fuel or diesel-only mode. In both programs a late cycle high pressure (> 3,000 psi) natural gas injection, dual-fuel, compression ignition approach was pursued.

Experimental locomotives operated at the EMD facility at LaGrange, IL and the GE facility at Erie, PA, but due to technical limitations, these locomotives were incapable of revenue operation outside of the builder’s facilities. In fact, GE was only able to demonstrate approximately five continuous hours of operation in the LNG mode while stationary at the factory.

The technical difficulties in both programs included failure of gas injectors, cryogenic LNG pumps for handling the cryogenic fuel between the tender tanks and the locomotives, the engine control system software, the gas transition control system software, and fuel system joint leaks. All four locomotives were converted back to diesel-only operation and ultimately delivered to UPRR for general revenue service in 1995.

GE stated in in a paper released in 1994 that the two GE locomotives were then-currently in a field test on "a major western railroad." Such operation never occurred; the 1994 GE paper contained an incorrect statement that the engines were undergoing a field test.

In a 2003 email memo from GE to UP on the subject, GE noted that the dual-fuel engine had "several significant component durability issues that would make over the road testing impractical if not impossible." In fact, there were durability problems with the high pressure gas injector and the engine could be only continuously run using LNG for a maximum of five hours. The 2003 email memo also noted that "durability issues were not known and significant time and resources would have to be invested to attempt to find solutions." Because of these problems "GE and UP mutually agreed to suspend testing."

A summary of the challenges UP faces with its current research using natural gas as locomotive fuel, was presented in September 2012 by Mike Iden, UP's General Director Car & Locomotive Engineering, in which he states that the program of the 1990s extended between 1991 and 1998.

LNG Fuel

"Union Pacific awarded Amoco Corporation a supply contract for a special blend of liquefied natural gas (LNG) to be used in UP's LNG-locomotive test program. The 3-year test, to be conducted in four long-haul freight and two yard locomotives, began in January. The fuel is 99 percent methane and burns cleaner than any other fossil fuel. UP's test program requires about 200,000 gallons of LNG per month. What will carry this fuel? New 30,000-gallon-capacity tender cars made by Process Engineering. The cars are 71 feet long and nearly 11 feet wide. They were unveiled during a ceremony at the company's Manchester, New Hampshire, facility in November." ("Amoco Gets LNG Supply Nod", Changes [UPRR employee newspaper], Volume 7, issue 6 (November/December 1993), page 8; [photo caption] "First of six fuel tenders for LNG locomotives UP will place in service in 1994.")

"Amoco Production Co. is producing a special blend of liquefied natural gas at its Painter Complex Gas Plant in Evanston, Wyoming, for Union Pacific Railroad's locomotive test program. Michael P. Fitzgerald of Amoco's Alternative Transportation Fuels Business Unit, said, 'Union Pacific Railroad will be testing the LNG fuel to determine operating feasibility, environmental benefits and economics compared with diesel fuel.'" ("Amoco producing gas blend for Union Pacific", Deseret News, November 17-18, 1993, page B5)

Natural Gas Tenders

UPT 1 and UPT 2

The LNG tenders were numbered as UPT 1 and UPT 2. They were distinguished from UP's later diesel fuel tenders (UPT 5-8) by their longer length, and the enclosure along the tender's top. Photos of these two unique cars in service are extremely rare.

The following email exchanges concerning the LNG tenders, took place in November 1993 on the Prodigy "Interactive Personal Service." Original printouts furnished through the courtesy of Richard Webber, Stephens City, Virginia.

November 18, 1993
UP is expecting two SD60M units from EMD and two switchers from MK (Morrison Knudson) by the end of the year, and two Dash 8-40C units from GE in early 1994. The EMD and GE locos will have tenders for the fuel supply. The LNG is actually refrigerated liquid methane (RLM) and all but the switchers will probably be designed for both LNG and diesel operation. The UP switchers are destined for the freight yards of Los Angeles. Although railroads don't account for much of the pollution in L.A. (autos do), this is a good neighbor gesture. (Mark Williams to Richard Webber, November 18, 1993)

November 19, 1993
Let's define our terms first: LPG is liquefied petroleum gas familiarly known to the backyard barbecue grill; LNG is liquefied natural gas. In May, 1953, the UP converted one of the 4500 hp gas turbine locomotives to LPG on an experimental basis running between LA and Vegas in an effort to improve turbine maintenance by using a gaseous fuel compared to the heavy residual fuel oil being burned in what was essentially an aircraft engine. All the turbines were soon to be phased out in favor of the diesel engine. (Carl Lathrop to Richard Webber, November 19, 1993)

November 24, 1993
According to the Journal of Commerce (11-15-93) UP will be making a three-year test of LNG as alternative locomotive fuel starting in January. The two switch engines from Morrison Knudson will operate in LA and the two pairs of road engines (six units total) will operate over the entire system. UP wants to see if the locomotives will have the same pulling capacity and what type of wear they will experience. The road engines will be built by both GE and EMD. The Morrison Knudson units will have Caterpillar Inc. diesel engines. Amoco Corp. of Chicago will supply a special blend of LNG which will be produced at Evanston, Wyoming and the railroad expects to use 200,000 gallons per month. The units the UP will be experimenting with will burn gas only relying on high pressure injection into the cylinders.. (Richard Webber to Carl Lathrop, November 24, 1993)

November 24, 1993
You really have aroused my curiosity with your reply outlining the UP program. "....will supply a special blend of LNG...." Since natural gas, the NG of LNG, is around 85% methane with perhaps 12% ethane plus inerts I don't understand the meaning of "blend". I'm surprised that UP is involved after having run a very technically successful LPG program on a 4500 HP gas turbine engine many years ago but abandoned the project for safety reasons. It would seem that compared to LPG then LNG represents an even greater safety problem. As a former boss of mine said to me one day, "Come sit a while and dilute my ignorance." I'm truly interested in hearing about the program. (Carl Lathrop to David Crammer, November 24, 1993)

November 25, 1993
Carl, all I can do is quote from the article and I am sure that there will be further articles with further information in the future. "While LNG typically contains varying amounts of methane, ethane, propane, and inert gases, Amoco will supply 99% pure Methane. Methane contains less carbon per unit of energy than any other fossil fuel and therefore burns cleaner, an Amoco spokesman said." The article also stated, "Liquefied natural gas requires special handling, and Union Pacific will operate the pairs of test locomotives with special tenders that will carry the fuel under pressure at -260 Fahrenheit to keep it in liquid state." It also states, "Union Pacific's road units will be GE Dash 8 4,000 horsepower and EMD SD-60M 3,800 horsepower locomotives. The switch units are 1,350 horsepower engines. As for economy, "Gas prices generally are more stable than oil prices.."and , "A readily available domestic fuel it could lessen the reliance on imported oil." (David Crammer to Carl Lathrop, November 25, 1993)

November 27, 1993
From an article in the Manchester [New Hampshire] Union Leader supplied by George Cockle: "A local company [Process Engineering of Plaistow, New Hampshire] has developed a prototype of a liquefied natural gas fuel car for the Union Pacific Railroad which could change the way locomotives are powered. Governor Steve Merrill and U.S. Rep. Bill Zeliff R-N.H. are expected to join employees of Process Engineering...to celebrate the completion of the 30,000-gallon-capacity tender car ....The car consists of two concentric vessels -- an inner fuel-containing pressure vessel and an outer insulation jacket and vessel, like a large thermos bottle. Two pumps submerged in the liquefied natural gas in the inner vessel push LNG from the tender to the locomotive. Another pump, this one on the locomotive, raises the LNG to an even higher pressure. Then the LNG is vaporized, converted from liquid to gas, and injected into engine cylinders where it is burned. The submerged pumps deliver a constant amount of natural gas to the engine, which burns what it has to and returns the remainder to the tender. Process Engineering created several of the valves on the car specifically for this project and came up with several safety features, including housing to protect piping in the event the tender rolls over. The company was founded in 1938 by President Kenneth Paul's father, Lawrence C. Paul, and moved to Plaistow alongside the B&M Railroad main line in 1965." (David Crammer to Richard Webber, November 27, 1993)

Two additional tenders were planned, to be numbered as UPT 3 and UPT 4, but these were never completed.

Later History

As CNW 1 and CNW 2, and UP 101 and 102

UP's testing of natural gas ended in 1998. The two LNG tenders (UPT 1 and UPT 2) were still in storage at EMD's facility in LaGrange as late as March 2001; and again as late as September 2007.

Late 2011 to February 2012
UPT 1 and UPT 2 were changed to CNW 1 and CNW 2. The previous "Liquified Natural Gas" lettering had been blanked-out. They were seen again on February 3, 2012.

August 2012 to September 2013
CNW 1 was leased to CN, and repainted to CN's paint scheme, for a year-long test by CN of locomotives modified to use natural gas. The CN tests were in captive service between Edmonton and Lynton, Alberta. The tender was coupled between CN SD40-2W 5261 and 5258, which were modified to burn natural gas, and returned to burning diesel fuel at the end of the test.

September 2013
CNW 1 was returned by CN to Union Pacific by mid September 2013, with a temporary HazMat placard showing 1066, Compressed Nitrogen.

Summer 2015
CNW 1 and CNW 2 were changed to UP 101 and 102. UP 101 was seen en route from Chart Industries of New Prague, Minnesota.

June 20, 2016
UP 101 was seen en route from Chart Industries of New Prague, Minnesota, to EMD at LaGrange. Lettered as "Natural Gas Fuel Tender".

Diesel Fuel Tenders

In a letter dated May 4, 1984, Union Pacific's R. E. Nurse advised his upper management in Union Pacific's Motive Power & Machinery department of Burlington Northern's recent use of a 25,000 gallon tank car in consist with locomotives to eliminate fueling stops. The tank car was connected to the locomotive fuel tanks by quick-disconnects and the locomotives were automatically fueled while en route. Mr. Nurse advised that if Union Pacific were to adopt similar arrangements, the entire terminals at Las Vegas and Rawlins could be eliminated, along with mainline fueling stations at Pocatello, Kansas City, Elko and Hinkle. If adopted, westbound trains dispatched from Chicago, North Platte and Kansas City could run through to Los Angeles, Oakland and Portland/Seattle without being refueled en route. Eastbound trains dispatched from Los Angeles, Oakland and Portland/Seattle could run to their destinations without refueling, as well as trains dispatched from North Platte and bound for points on the Missouri Pacific. (R. E. Nurse to L. L. Miller, North Platte, et. al., dated May 4, 1984, file 471-640-002; attached to the letter was a photocopy of a page from the December 1983 issue of Modern Railroads magazine, showing the BN tank car in service)

UPT 5 to UPT 8

During 1995 to 1998, UP completed a series of tests and operations using four tenders for diesel fuel. There were four diesel fuel tenders.

October 4, 1996
"Omaha-Council Bluffs area employees are invited to view one of UP's new fuel tenders on Friday, October 4. The UPT-7 tender will be on display from 7 a.m. to dark on the intermodal yard track south of the Harriman Dispatching Center parking lot as part of the HDC Fuel Days celebration. The company now has four fuel tenders in service across the system. By carrying an additional supply of fuel, the tenders are reducing locomotive dwell time, extending the distance trains can travel and enabling the company to fuel more price competitively. The four UP tenders are numbered UPT-5 through UPT-8." (Update Line, Union Pacific Communications Department, October 3, 1996)

UP had four tank cars converted to serve as diesel fuel tenders 1995. The cars were numbered as UPT 5 to UPT 8, numbered following the four LNG tenders (UPT 1 to UPT 4). The diesel fuel tender program was initiated in late 1995, placing a single fuel tender between two new General Electric C44ACs. The combination of a fuel tender connected between two locomotives was usually assigned to unit coal trains coming out of the Powder River Basin in Wyoming. The fuel tender program came to an end due to wear and tear on the fuel tenders themselves, since tank car frames are not designed to take the buffeting and differing longitudinal loads that locomotives are designed for. The tank cars used were standard tank cars, which are also not designed to take the high mileage of being coupled between locomotives (approximately 90,000 miles per year, about four times what a standard tank car would see). The program was in operation during from approximately July 1996 through May 1998 (date range supported by dated photos of fuel tenders in service). All of the fuel tenders were out of service by April 2000, and stored at Council Bluffs at UP's Fox Park passenger facility. They were still there as late as June 2002. (part from Trainorders.com, January 26, 2006; See also: an article by Michael McGowen in "Union Pacific Modeler", Volume 3, pages 84-91)

The tenders were tested beginning in May 1996. They were converted from four Class O-70-1 tank cars from the 70000-70199 number series. The fuel tenders were numbered UPT 5 through UPT 8. The tank cars were originally built in the 1954-55 timeframe by American Car & Foundry. The cars were modified by Union Tank Car in Muscatine, Iowa. The cars were 51 feet long and had a capacity of 19,167 gallons. ("Fuel Tenders; UP's Answer To Better Delivery Times", The Streamliner [UPHS], Volume 13, Number 2, Spring 1999; article includes several photos and drawings)

UP assigned a total of six new GE C44CW (AC4400W) locomotives to their diesel fuel tender program. Their numbers were UP 6840-6845, built in October 1995. Several news reports also show four C40-8Ws, UP 9387-9390, built in February and March 1990, as being part of the program, but these were just planned and not actually converted.

Fuel tenders UPT 5 and UPT 6 were seen in April 2000, stored at Fox Park in Council Bluffs, Iowa. (Trainorders.com on February 1, 2001)

UP fuel tenders UPT 6 and UPT 7 were stored at Cheyenne, Wyoming, as of April 10, 2009.

UP fuel tenders UPT 6 and UPT 8 were seen at Provo, Utah, on November 1, 2013. (Photo posted by Ron Mitchell on Utah Rail Enthusiasts facebook page)


Photos of UPT fuel tenders at UtahRails.net

Other Railroads' Fuel Programs

At about the same time, in late 1994, CSX announced that they would also investigate the use of fuel tenders, having them connected to new GE AC4400CWs 28-30.

Another example is BN's fuel tender program in late 1982, which put fuel tenders into regular service. Beginning in October 1982, with 27 tenders being in use by 1984, BN's (and later, BNSF's) fuel tenders and matching SD40-2s (and later, SD60Ms) were used in helper service on unit coal trains leaving Wyoming's Powder River Basin, a service they remain in as late as September 2005. Initial success, with 78 fuel tenders in service by November 1988, was followed by later cutbacks; by June 1991, only 26 remained in service.

Smaller fuel tenders were used along BN's northern mainline, connected between GP50s, GP40-2s, GP38-2s, B30-7s and leased LMX Dash 8 40Bs. (For additional information on BN's fuel tender program, see Robert Del Grosso's 1980-1991 BN Annual)