CIE 121 Class

Córas Iompair Éireann 121 Class

Preserved 121 Class locomotive (134)

Type and origin Power type Diesel-electric Builder General Motors Electro-Motive Division, La Grange, Illinois, USA Order number 702667–702681 Serial number 26271–26285 Model EMD GL8 Build date December 1960 – January 1961 Total produced 15 (for CIÉ — 149 worldwide)

Specifications AAR wheel arr. B-B UIC class Bo′Bo′ Gauge 1,600 mm (5 ft 3 in) Wheel diameter 40 in (1,016 mm) Length 39 ft 10 in (12.14 m) Loco weight 64 tonnes (63.0 long tons; 70.5 short tons) Prime mover EMD 8-567CR 126-129 Re-engined with EMD 8-645E Engine type Two-stroke diesel Aspiration Roots-type supercharger Traction motors EMD D47, axle-hung, nose-suspended, 4 off Cylinders 8 Transmission D25 DC generator DC traction motors Train brakes Air and Vacuum

Performance figures Maximum speed 77 mph (124 km/h) Power output EMD 8-567CR: 960 hp (720 kW) EMD 8-645E: 1,100 hp (820 kW) Tractive effort 197 kN (44,000 lbf) starting

Career Operators Córas Iompair Éireann Iarnród Éireann Number in class 15 Numbers B121–B135 (later 121–135) Withdrawn 1986-2008 Disposition 2 preserved, remainder scrapped

The Córas Iompair Éireann 121 Class was a railway locomotive which was manufactured by General Motors Electro-Motive Division. These locomotives were in regular service on the Irish railway network until 2002, with the last two remaining in service until 2008.

The 121 Class locomotives were manufactured in December 1960 and January 1961 and numbered B121 to B135. The last two locomotives that survived in traffic (Nos. 124 and 134) were both withdrawn from service on 3 May 2008. Prior to 1961, almost all Irish diesel locomotives were built in Great Britain, but from the 1960s onwards, GM became the sole supplier of locomotives to CIÉ, which eventually also extended to Northern Ireland Railways locomotives at a later stage. These were EMD's first ever fully American-built locomotives delivered to Europe.

The Class 121 locomotives were a typical American-style single cab ‘road switcher'. The layout of the cab was quite different from the other conventional CIÉ diesel models of the time, with the controls to the side of the driver, rather than the front. Due to apparent driver complaints of reduced visibility when operating with cab trailing, it was ultimately decided that these locomotives should only operate in a cab-leading formation. Later conversion for multiple-unit working allowed two 121 class locomotives to be coupled hood-end to hood-end, removing the need to turn them around for their return journey.

Although originally fitted with an EMD 8-567CR engine of 960 horsepower (720 kW), all were later fitted with 645 type "power packs" (piston & liner assemblies) for parts standardisation, while at the same time keeping their original power output for reliability reasons. They weighed 64 tonnes (63.0 long tons; 70.5 short tons) and had a maximum speed of 123 km/h (76 mph). Numbers 126-129 were later rebuilt with an EMD 8-645E engine of 1,100 horsepower (820 kW); as used in the 181 Class locomotives.

All but three (121, 125, and 135) were fitted with Train Door Control equipment for operation with the Inchicore-built, BR Mark 3 based, Push-Pull train units. The push-pull equipment of locomotive 132 was subsequently decommissioned. Entering service in 1989, these trains, consisting of a single 121 Class and up to six carriages, were mainly used on the Dublin northern suburban passenger railway service. These were to be the last regular passenger duties for the 121s within Greater Dublin. The Limerick shuttle continued to be worked by 121s for several years after this date. In 1994, a railcar "revolution" had begun, and the push pull carriages were later re-deployed to inter-city duties with the 201 Class locomotives.