By Don Strack (May 1998)

(This article is an updated and expanded version of an article published in Diesel Era, Volume 9, Number 4, July-August 1998)

Both Union Pacific and Missouri Pacific had considerable experience with General Electric locomotives before the C36-7s were delivered in 1985.

UP's first experience with GE locomotives dates back to 1939 when the carrier took delivery of two experimental steam turbines. This led to the development of a fleet of high horsepower gas turbines, 30 of which operated into the late 1960s. Following the gas turbines, came U25Bs, U50s, U28Cs, and U50Cs, all helping to move the road's freight during the Sixties. It wasn't until 1972 that GE locomotives occupied a prominent place on the roster. Between 1972 and 1976, 150 U30Cs were acquired. This was followed by 140 C30-7s, the U30C's successor.

In 1981, UP returned to GE for new locomotives and placed an order for 30 of the builder's newest C36-7. Introduced in 1978, the C36-7 found its first domestic buyer in 1981 when Norfolk & Western purchased six units. These early C36-7s resembled their predecessor model U30Cs, but with exhaust silencers. The following year, N&W took delivery of 25 additional C36-7s, with the same external appearances.

Following negotiations and design-review meetings held during 1981 and into early 1982, UP increased its original 30-unit order to 50 units, then decreased it down to just 20 units. Finally, in late 1982, the order was canceled due to the ongoing recession. UP proper would not buy another new locomotive from EMD until 1986, and from GE until 1987.

In the meantime, the C36-7 was undergoing numerous changes as the builder continued to refine the design. After a two year lull in orders, N&W, now Norfolk Southern, returned with a 12 unit order in 1984. These units came equipped with what would become the first Dash 8 components--the components of the dynamic brake were relocated to a large boxy housing structure behind the cab. The horsepower rating was increased to 3,750 from the original 3,600. In 1985, Conrail received 25 C36-7s. Although completed as 3,750 horsepower locomotives, these CR units were built using the original C36-7 platform with the dynamic braking components located at the rear of the carbody.

Missouri Pacific was next to receive the improved C36-7. Following its 1984 order for 60 SD50s from EMD, the carrier, now heavily influenced by recent merger partner Union Pacific, placed an order for 60 C36-7s in early 1985. For MP, it seemed only natural to order both EMD and GE locomotives, but it wasn't always this way.

The turning point was in 1968 when MP ordered six U30Cs, its first non-EMD locomotive purchase in nine years--the last was an order for Alco RS-11s in 1959. The U30Cs, like their SD40 counterparts (MP purchased 20 SD40s in 1967 and 14 in 1968), were marked by a major shift in MP motive power philosophy--from four-axle, non-turbocharged power, to turbocharged power riding on six-axle trucks. Eventually, 35 U30Cs, 90 SD40s, and 306 SD40-2s were moving coal, grain, and other freight on MP lines, including subsidiary Texas & Pacific. Although outnumbered, the U30Cs represented an inroad in the EMD dominated MoPac roster. An inroad that led to the purchase of 39 U23Bs, 85 B23-7s, and 55 B39-7As between 1973 and 1981.

Following its announcement in January 1980, the UP-MP consolidation was approved in September 1982 and took effect in December 1982. By mid-1983, integration of the two locomotive fleets (as well as smaller merger partner Western Pacific) began. Missouri Pacific suspended locomotive purchases during the merger talks, so by 1984, post-merger traffic increases on MoPac lines resulted in UP scrambling for power. Relief for MP came in the form of lease of 80 UP SD40-2s and the reactivation and sale to MP of 18 long-stored UP SD45s. By late 1984, the dust had settled, traffic patterns were analyzed, and orders placed with EMD for 60 SD50s. A year later, a like-sized order was placed with GE for its comparable C36-7 model. While the SD50s were rated at 3,600 (early SD50s were rated at 3,500 horsepower), the C36-7s were similarly rated at 3,750 horsepower. In the first reflection of the merger, both EMD and GE locomotives were built to UP specifications, including the paint scheme they would wear. On May 31, 1984, UP's new Missouri Pacific subsidiary had announced that its official paint scheme would be Union Pacific Armour yellow and Harbor Mist gray, with Missouri Pacific lettering. Over the following 18 months, the SD50s and C36-7s (as the only new units delivered in the new scheme) were joined by 246 ex MoPac locomotives, 22 ex CRI&P GP40s, and seven ex WP GP40s and GP40-2s. The separate Missouri Pacific lettering came to an end in January 1986 when the two roads formally consolidated their operating departments.

To support its long distance operations philosophy, UP/MP requested the application of a larger than standard 4,500-gallon fuel tank, which required the relocation of the air reservoirs from below the platform to the inside of the radiator compartment. In a test of available designs, the railroad requested the application of three different types of air compressors. Units 9000-9029 and 9045-9049 were equipped with Wabco model 3CDCL air cooled compressors, 9030-9041 and 9050-9059 had Gardner-Denver/Triangle WBO water-cooled versions, and 9042-9044 had Gardner-Denver WKO air-cooled versions. Externally these variations were indistinguishable as GE chose to standardize on radiator compartment grilles for the air cooled versions. The 60 units weighed in at 391,000 pounds operating weight, and were equipped with 83:20 gear ratio.

The last 10 MP C36-7s differ from the rest of the fleet in that they have anti-climbers. This feature difference stems from the fact that they were built on modified C30-7 platforms originally intended for Nacionales de Mexico's C30-7 kit program. The platforms were never delivered due to that country's mid-1980s financial woes. Another, not so obvious, detail is that the last 20 locomotives used remanufactured truck bolsters from MP U30C trade-ins.

One of the high tech features of the MP, now UP, C36-7 fleet is their use of GE's microprocessor controlled Motor Thermal Protection (MTP). This device analyses and calculates the maximum current that can be fed to each motor should it enter its short-time rating, based on the temperature of each traction motor's windings, along with ambient air temperature, amperage levels, and the motor's recent operational demands. The feature alleviates the need for the engineer to keep a close eye on the ammeter to avoid traction motor burnout.

The MTP device allows a locomotive operating on the heavy grade of Sherman Hill on a cold January day to have substantially longer short-time rating because of cold traction motor cooling air, allowing full horsepower and higher speed on the grade. Conversely, if the locomotive was on Cima Hill in the Mojave Desert on a 115-degree day in July, the MTP would allow a much less short-time rating.

All C36-7s were delivered with provisions for installation of Coded Cab Signals (CCS) equipment. Shortly after arriving on the property the first 30 units were so equipped and soon began frequenting UP territory on hot TOFC trains and on UP's developing double-stack trains.

After their initial year or so of service, even while delivering availability rates of as high as 96 percent, the units began to experience increased engine failures. Beginning in January 1988, after the units had been in service for just 2-1/2 years, the prime movers on the entire fleet required a complete change-out and upgrading of such vital components as the radiator cores. The upgrade and engine change-out work was completed at North Little Rock, using prime movers rebuilt by GE's Grove City, Penn., facility. In June 1988, after six units had been completed, UP decided to change the units' lettering from Missouri Pacific to Union Pacific. All subsequent units left North Little Rock with full UP lettering, with the first six receiving new lettering within 90 days. The first unit to be relettered was 9025, which was in the shop having wreck damage repaired following a November 1987 collision at Nugget, Wyoming. Although 9025 was the first, UP 9040 actually left the shop first, on June 8, 1988, compared to 9025's out-shop date of June 17. The upgrade program was completed on March 17, 1989, when UP 9023 was released for service.

Beginning in September 1995, to clear the 9000 series numbers for use by former C&NW C40-8CWs, the 60 C36-7s were assigned numbers in the 2600-2659 series. By October 1996, following the merger with SP, and with plans to increase the ranks of 2,000 horsepower locomotives, a change came in the number series for the C36-7s. After 27 units were renumbered from the original 9000 series to the new 2600 series (UP 9053 was the first when it became UP 2653 on September 18, 1995), UP changed their assigned number series to 600-659. The first to be completed was UP 622, renumbered from UP 2622 on October 25, 1986. Also released on October 25th was UP 619, renumbered from 9019, the first 9000 series unit to be renumbered directly to the new 600 series. By May 1998, there were still 18 units in the 2600 series, and 19 units still remaining in the 9000 series, with a total of 23 units operating in their new 600 series numbers. There are five C36-7s with the short-lived "We Will Deliver" slogan: UP 601, 603, 2609, 9031, and 9061.