EMD SD24

File:Union Pacific SD24 408.jpg

Union Pacific #408, an EMD SD24, is seen at the company's Portland, Oregon Albina Yard in July, 1968. The unit's roof-mounted "torpedo tube" air reservoirs, a signature feature, are clearly visible just aft of the locomotive's cab.

The EMD SD24 was a 2,400 hp (1,800 kW) C-C diesel locomotive built by General Motors' Electro-Motive Division of La Grange, Illinois between July, 1958 and March, 1963. A total of 224 units were built for customers in the United States, comprising 179 regular, cab-equipped locomotives and 45 cabless B units. The latter were built solely for the Union Pacific Railroad. The SD24 was the first EMD locomotive to be fitted with an EMD turbocharged diesel engine, several months before the four-axle (B-B) model GP20. Power output was substantially higher than that provided by the previous SD18s 1,800 hp (1,350 kW) with the same engine displacement.

In order to provide room for a larger fuel tank, the air reservoirs were located on the roof just behind the locomotive's cab. The tanks were known as "torpedo tubes" due to their long, thin design. Factory-installation of these tanks was peculiar to this model locomotive.

References

• Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Milwaukee, Wisconsin: Kalmbach Publishing. ISBN 978-0-89024-026-7.
• Diesel Era staff. EMD's SD24. Diesel Era Vol. 9 No. 3, pp. 10-29, 51-63