EMD SDP45

Infobox Locomotive
name=EMD SDP45
powertype=Diesel-electric
gauge=RailGauge|ussg

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caption=BN 6597, showing the extended long hood aft of the radiators for the steam generator.
aarwheels=C-C
poweroutput= convert|3600|hp|abbr=on|sigfig=3
builder=General Motors Electro-Motive Division (EMD)
buildmodel=SDP45
The EMD SDP45 was a six-axle, C-C, convert|3600|hp|abbr=off|lk=in|sigfig=3|adj=on diesel locomotive built by General Motors' Electro-Motive Division of La Grange, Illinois. It was fundamentally a passenger-hauling version of the SD45 on a stretched locomotive frame and with an extended long hood at the rear, aft of the radiators, giving space for a steam generator for passenger train heating. The end of the long hood on steam generator-equipped units was squared, unlike the pointed end of the regular SD45. The Erie Lackawanna Railroad ordered a number of SDP45s for freight service purely for their longer frames that permitted a larger fuel tank, which gave the locomotives the greater range the EL was looking for. These units had a pointed long hood end; the extra space aft of the radiators was empty.

The Southern Pacific Railroad used their SDP45s for commuter service on the San Francisco Peninsula after Amtrak took over long-distance routes in 1971. SP's commuter service was very demanding work and the locomotives required electrical modification in order to meet those demands. They stayed on the commute route until 1985 when Caltrain equipment arrived, and they were placed into freight service until their retirement.

One SDP45 ( [http://www.trainpix.com/BN/EMDORIG/SDP45/6599B.HTM photo of BN 6599] ) built for the Burlington Northern Railroad was retrofitted with an articulated four-axle truck by EMD, converting it to an A1A-B+B wheel arrangement. The middle traction motor in the lead truck was removed and placed in the rear truck. The rear truck, called the HT-BB, for High Traction B+B arrangement, was tested successfully ( [http://www.northeast.railfan.net/images/bn6599a.jpgcloseup of HT-BB truck] ) but has not been produced for sale to date (February 2008). This testing was not related to the development of the HTCR three-axle radial truck first seen under SD60 EMD 3 and SD60MACs, and made standard on the early SD70 series.

References

* [http://www.northeast.railfan.net/diesel66.html Photographs of SDP45s] including the one-of-a-kind seven-axle unit
* Sarberenyi, Robert. " [http://users.inna.net/~jaydeet/sd45.htm EMD SD45 and SDP45 Original Owners] ". Retrieved on August 27, 2006