GP15-1 Missouri Pacific GP15-1s Missouri Pacific was the largest buyer of the EMD GP15-1, a small road switcher intended to take advantage of the railroads' interest in rebuilding GP9s and GP7s. MP took delivery of 190 GP15-1s, as follows: 1555-1574, 20 units delivered in June and July 1976; 1575-1589, 15 units delivered in December 1976; 1590-1614, 25 units delivered in July 1977; 1615-1644, 30 units delivered September-November 1979; 1665-1704, 40 units delivered in February and March 1982; 1705-1714, 10 units delivered in March and April 1982; and 1715-1744, 30 units designated GP15AC (but with no external differences from the previous order) delivered in November and December 1982. Following the UP-MP merger in 1982, UP retained the number series, but locomotives began to be repainted in UP yellow and gray, but with MP lettering and numbers. After 1985, units were relettered Union Pacific. Detail Differences EMD introduced the 88 inch nose on its hood units in December, 1976. Thus MP/UP 1555-1574 had the earlier 81 inch nose, while all subsequent MP/UP units had the 88 inch nose. Units aparently after MP/UP 1665 had four exhaust pipes on the roof rather than two. It appears that some, though possibly not all, units in the first MP order had Blomberg M trucks rather than Blomberg B. However, all or nearly all subsequent units were delivered with Blomberg B trucks. In addition, while the standard Blomberg B truck has two brake shoes per wheel, variations on this truck have only one brake shoe per wheel. Some UP/MP units appear to have this variation. Also, some MP/UP units have an all-weather cab window extension mounted on the engineer's side of the cab. Most have MP style spark arrestors on the exhaust pipes. A feature apparently unique to the MP/UP units is a grab iron ladder on both sides of the long hood end. Chicago and North Western GP15-1s Chicago and North Western received 26 GP15-1s, numbered 4400-4425, in mid-1976. These differed from the MP/UP units in having a different form of engine air intake filter, which makes the area behind the cab look very different on the ex-CNW units. In addition, by the mid-1980s, the CNW added additional louvered air intake openings on the engine room doors. The CNW units all had 81 inch noses and an all-weather cab window extension on the engineer's side of the cab. Prior to the UP merger in 1995, CNW disposed of 13 of its GP15-1s to the California Northern. Current rosters indicate that the remaining ex-CNW GP15-1s will be numbered into the UP group 1542-44 and 1545-54. UP GP15-1s can be found singly or in multiple with other low-horsepower units in yard and local service. HO Scale Model GP15-1s Smokey Valley Smokey Valley offers a kit of flat plastic moldings and a metal frame to build a GP15-1, although the modeler must provide a motor, drive train, cab, and trucks, as well as aftermarket detail parts. The parts do not fit especially well, and since the modeler must provide so much additional material, it is less a kit than a start toward a kitbash, and it is not a trivial project. Assembly of the kit to produce an MP/UP version of the loco is covered in the Volhard reference below. The drawings in the MR and RMC references are also necessary for this kit. Walthers Walthers released an HO ready-to-run plastic GP15-1 in late 1998. This is available painted for the UP with details that are generally correct for units MP/UP 1575-1664. Like other recent Walthers locomotives, it is reasonably priced, although its running qualities are not as good as Atlas or Kato units, and the detailing is somewhat minimal. Addition of aftermarket parts and running in will result in a good model. The photos and drawings in the references below are useful for upgrading the Walthers model. Because the HO GP15-1 is more than an inch shorter than a U23B or B23-7, it is a good possibility for very small UP based layouts. It appears that the 88 inch hood on the Walthers model would not make it a good candidate for modeling the ex-CNW units, even though Walthers does offer the unit with the non-inertial style air intake arrangement. References Cockle, George. Union Pacific 1990. Halifax, PA: Withers Publishing, 1991. ISBN 0-9618503-8-8 EuDaly, Kevin. Missouri Pacific Diesel Power. Kansas City, MO: White River Productions, 1994. ISBN 0-89745-99-1 Moyers, Jerry. "The Replacement Locomotive: EMD GP15-1" Railroad Model Craftsman, September, 1979, pp. 76-80. Sperandeo, Andy. "The GP15-1: EMD's Down-sized Road Switcher" Model Railroader, January, 1990, pp. 110-115. Volhard, Jim. "Build a Missouri Pacific GP15-1" Model Railroader, August 1997, pp.88-92.