ALCo - RS and C Series Including Rebuilds and Slugs

Although Alco had ceased US locomotive production in 1969, many of the company's products were passed on to Conrail on April 1 1976. Conrail continued to use these locomotives into the 1980s. This album also includes Conrail's slug units made from Alco products, and the RS3m, Penn Central and Conrail's rebuilt RS3 roadswitchers.

Alco Based Slugs MT6 and MT4

Conrail's yard slugs, the 4 axle MT4 and 6 axle MT6 were rebuild from ALCO units to perform low speed switching duties. Most of the MT4s were retired by the end of Conrail's era, but, after a truck swap, the MT6s served on for their new owners.


Numbered 2072 to 2077 on the Conrail roster, the only Lehigh & Hudson River units to make it to Conrail were these Alco C420's. One, the 2072, was the only unit to receive blue (albeit at the hands of a Conrail employee at the Bethlehem Engine Facility). Number slots 2060 to 2071 were reserved for former Lehigh Valley units, but these went to the Delaware & Hudson when Conrail was formed. They did not have dynamic brakes, rode on AAR type B trucks and were mechanically similar to RS32's. All were retired by 1981, though a few may still be in Arkansas on the Arkansas & Missouri RR.

ALCO C424 and C425

Conrail inherited 41 Alco C425's from Penn Central (10 were former New Haven and the remainder were ex Pennsy) and 26 C424's of PC, EL and RDG ancestry in 1976. Originally scheduled to be 53 C425's, Erie Lackawanna's 12 units were sold to the British Columbia Railway as their 801 to 812 before Conrail took over.

Several C424's and C425's wore Conrail blue paint and logos. Twenty-nine C425's were renumbered to the 5060-5089 series in the early 1980's, but most were sitting in dead lines by this time and few pictures are known to exist of them in service in this number series.

Fifteen C424's came from the EL, 10 from the Reading, and one lone unit (CR 2474, ex PC, exx PRR 2415, nee Alco RS27 Demonstrator 640-1, rebuilt to C424 specifications) from PC. A few went on to serve other owners after being retired from Conrail in the early 1980's.


Twelve C430's came into the Conrail fold, ten from PC and two former Reading units. Four C430's were painted into Conrail blue (three ex PC, and ex Reading 5212). The C430 was introduced by Alco to compete with EMD's GP40, but only 16 were ever built compared to hundreds of GP40's. These units went to work for the NYS&W and Morristown & Erie upon their retirement from Conrail.


ALCo built the 2,750hp C628 from 1963-1967.  Conrail inherited 15 of the ALCo 251C V16-powered units from Penn Central, and 17 from the Lehigh Valley.  They were numbered in CR series 6721-6752.


ALCo built the 3,000hp C630 from 1965-1968. Conrail got 15 of the ALCo 251E V16-powered units from Penn Central and 12 from the Reading. Conrail assigned them the numbers 6753 to 6779.


ALCo built their most powerful single-engined unit, the 3,600hp C636, from 1967-1968.  Of the 34 total units built, Conrail inherited 15 of the ALCo 251E V16-powered units from the Penn Central.  They were numbered in CR series 6781-6794.


ALCo built the 1,000hp RS-1 from 1941-1960.  PRR purchased 27 RS-1's and the NYC 14. However, Conrail inherited only a few of the ALCo 539T Straight-6 powered units from the Penn Central.  They retained their PC class ARS10 9900s number series as CR 9908-9938.


Built from Feb 1956 to June 1961, the 1800hp 251B-powered ALCO RS11 gave strong competition to EMD's GP-9.

Even with it's quicker acceleration and higher tractive effort, the versatile RS-11 wasn't ultimately as successful as EMD's GP-9, and as a result Conrail inherited fewer of them than their GM counterparts. Being from a defunct manufacturer, they also became candidates for earlier retirement than the geeps as well.

Four RS11's were painted CR blue:  7630, 7644, 7651 and 7652.

ALCO RS2 and RS3

ALCO built the 1,500hp RS-2 from October, 1946 -May, 1950 and the 1,600hp RS-3 from May, 1950 -August, 1956.  The ALCO 12-cylinder 244B prime mover powered the RS-2 while the 244D powered the RS-3.  The initial CR roster listed RS-2's as 5200-5217 for inherited EL and LV units, and listed RS-3's as 5229-5593 for inherited CNJ, EL, LV, and PC units.  These units were all either rebuilt as RS3ms, or retired by the early 1980s.


ALCo built the 2,400hp RS-27 (specification DL-640) from 1959-1962.  Of the 27 total units built, Conrail inherited 15 ex-PRR ALCo 251B V16-powered units from the Penn Central.  They retained their PC class AF24 number series as 2400-2414.


CR had 24 RS32's, all of NYC heritage. CR tended to keep them in Upstate NY, and they were assigned to Dewitt Shops for maintenance.

ALCO RS3m Rebuilds

Conail's RS3ms were products of a rebuilding process started by Penn Central. They were ALCO RS3s that had their prime movers and electrical equipment replaced with that from EMD units, causing their distinctive looks.

ALCO RSD12 and RSD15

Conrail inherited 25 ALCo RSD-12's built for the PRR, with the PC number series 6855-6879.  Their ALCo 251B V12 prime movers produced 1,800hp.

Conrail inherited 6 ALCo RSD-15's built for the PRR, with the PC number series 6811-6816, but placed only 6812-6816 on the April, 1976 roster.  Their ALCo 251B V16 prime movers produced 2,400hp.

ALCO S-2 and S-4

ALCO built the S-2 from August, 1940 - June, 1950, and the S-4 from June, 1949 - August, 1957. Power for the S-2's and S-4's came from ALCO's 1,000hp 539T straight-6 prime mover.  The initial CR roster listed only PC-inherited S-2's in seried 9633-9660 and S-4's in series 9695-9701, as well as both units in non-consecutive series in the 9700's and 9800's.  The S-2 was delivered with ALCO Blunt trucks, while the S-4 came standard with AAR type A switcher trucks.


ALCO built the 1,000hp T-6 from 1958-1960.  Conrail inherited 6 of the ex-PRR ALCO 251B straight-6 powered T-6 units from the Penn Central.  The initial CR roster retained their PC number series 9844-9849.

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