Alco RSD15 Builder List and Phases

RSD15 Rosters | RSD15 Phases

Alco RSD15 - AT&SF 840 at Los Angeles, California, date unknown. Photographer: William E Harmon.
Alco RSD15 – AT&SF 840 at Los Angeles, California, date unknown. Photographer: William E Harmon.


  • Phase I – August, 1956. One handrail stanchion on battery boxes on both sides. Both air tanks are mounted on one side of the fuel tank. Old style coupler box (buffer).
  • Phase II – March-July, 1959. Two handrail stanchions on battery box, old style coupler box, both air tanks on one side of fuel tank.
  • Phase III – July, 1959-March, 1960. New style coupler box.
  • Phase IV – May, 1960-November, 1960. A single air tank on both sides of the engine, no longer combined on one side, with fuel tank notched to accommodate.

Customer options –

  • Pennsylvania Railroad units were intended for hump service and had very small fuel tanks
  • Santa Fe engines had an extra box added in front of the normal battery boxes on each side, resulting in a third handrail stanchion
  • Southern Pacific 4816-4818 had a recessed ratchet type hand brake instead of a brake wheel; Cotton Belt 850-859 had brake wheels like all other RSD15s.
  • Pennsylvania and Duluth Missabe & Iron Range units were built with high short hoods, the only units so equipped.
YearMonthRailroadOrderBuilder No.PhaseQty
1956AugustPennsylvania Railroad 8611-8616S3258 81751-81755I6
1959MarchDuluth Missabe & Iron Range 50-53S325881756-81759II4
1959AprilDuluth Missabe & Iron Range 54-55S325881760-81761II2
1959AprilAT&SF 803-805S331583429-43431II3
1959MayAT&SF 806-808S331583465-83467II3
1959JulyAT&SF 800-802S325881762-81764II3
1959JulyAT&SF 809-823S331883468-83482III15
1959SeptemberSouthern Pacific 4816-4818S331883483-83485IIII2
1960MarchSouthern Pacific - SSW 850S331883486IIII1
1960MarchSouthern Pacific - SSW 851-859S332083524-83532IIII9
1960MarchAlco 824S332083533IIII1
1960MayAT&SF 830-841S332483566-83577IV12
1960JuneAT&SF 842-843S332483578-83579IV2
1960JuneAT&SF 844-848S330683054-83058IV5
1960NovemberAT&SF 824-829S332483560-83565IV6


  • – Santa Fe Alco RSD15 roster
  • Joseph A. Strapac, Southern Pacific Diesel Locomotive Compendium, Volume 1: Pre-1965 SP Numbers, T&NO and Cotton Belt Subsidiary Railroads, Shade Tree Books, 2004, pg 120
  • John D. Hahn, Jr., Pennsylvania Railroad Diesel Locomotive Pictorial, Volume 1: Alco RS Series, Withers Publishing, 1995, pg 54-55