,a T124 was one of 15 121 class locomotives built by General Motors for CIÉ in 1960. In fact, these were the first GM-built locos to be exported to Europe. Based on the GM’s GL8 ‘Switcher’ design, they were distinct from other CIÉ mainline diesels in that they only had one cab. 124 (then B124) arrived in Dublin aboard the SS Irish Poplar (II) on 4th January 1961. Staff unloaded this locomotive first, making 124 the first GM-built loco in Europe. The 121 class were of five GM classes that would enter CIÉ/IÉ service over the following four decades. Initially, the locos carried a distinctive grey livery. CIÉ staff quickly dubbed them ‘the Yanks’. B124 entered service on 31st March 1961, and the type was so successful that CIÉ would go on to order 37 more locomotives shortly after, this time with two cabs.
CIÉ banned ‘nose first’ working of the locos early on, after an unfortunate incident with a platelayer’s trolley. However, CIÉ continued to permit such operation between Inchicore depot and the North Wall freight yards and between Dundalk station and Dundalk Barrack St goods depot. This ban meant that the locos had to use turntables at the end of the their journeys, in the 1960s there would still have been an abundance of these left over from steam days.
CIÉ fitted the class for multiple working in the 1970s. This enabled them operate in multiple both within their own class and with the 141 and 181 classes. In such cases the need to turn the locos around was removed. They would go on to work passenger and freight trains all over the CIÉ system, and were know to venture into Northern Ireland as well, with the class taking over ‘Enterprise’ duties between Dublin and Belfast in the early 1960s. Notably, B124 worked the last down Mallow to Waterford train on the now closed route via Fermoy on 27th March 1967. Originally number B124, CIÉ dispensed with the letter classifications in the 1970s, when she became simply ‘124’.
The 121s were a natural fit on push-pull duties, given their single cab format. Some of the 121 class locomotives took over from the C class diesels on the infamous ‘Greystones shuttle’ using an AEC railcar set (which included our own 6111) in the 1980s. The class had a second bout of push-pull duties with the arrival of the mkIII push-pull sets in 1989. One of these small locomotives would haul/push 6 heavy mKIII carriages laden with commuters between Dublin and Dundalk. Around this time Irish Rail gave 124 a temporary experimental livery incorporating a green dash along the cab side. (Irish Rail soon abandoned this experiment, but we have found evidence of it while restoring the loco). Even in the early 1990s it was not unknown for the class to work passenger trains single handed on the Dublin-Rosslare route. Fortunately this route retained turntables at both ends.
The arrival of the more powerful 201 class GMs in 1994/5 saw the 121 class locomotives ousted from their Dublin push-pull workings, but they still remained the mainstay of the Limerick-Limerick Junction ‘short’ push-pull set right up until early 2004.
Inchicore Works began a comprehensive rebuild programme of the locos in In the early 2000s. However, the decline in freight traffic saw this programme stopped after just four locomotives. Iarnród Éireann withdrew most of the 121 class locomotives by March 2003. They made two exceptions; 124, along with 134, continued to work the Limerick push-pull service. They remained on this duty until sufficient 2700 class railcars were available to take over in early 2004.
124 and 134 kept going, finding gainful employment on freight workings. Very occasionally, the pair hauled the Friday Only Dublin-Ennis working forward from Limerick to the Clare town. Naturally, they became very popular on enthusiast railtours around this time; both 124 and 134 featured on a number of railtours during the mid-2000s. Towards the end, their main duties tended to be around Permanent Way trains. The pair worked their final such train to Portlaoise in March 2008. Both locomotives then returned to Inchicore Works. Iarnród Éireann then took the locos out of service after over four and a half decades use.
In 2009, the Irish Traction Group (ITG) purchased locomotive 124 for preservation, and moved her to the West Clare Railway’s Moyasta premises in November of that year. ITG volunteers covered the loco under a tarpaulin, and 124 would slumber for there for another 16 years. In late 2024, the ITG reached agreement with DCDR to transfer 124 and the other ITG-owned Moyasta locos to Downpatrick. 124 arrived at DCDR on 1st June 2025. ITG volunteers successfully started the loco for the first time in preservation just two weeks later. Two months frenzied work saw 124 ready for the August 2025 Diesel Day, during which it worked the first 121 class passenger train in preservation.
124 was very first GM locomotives to set wheel in Europe. This makes it a very worthy candidate for operation at Ireland’s only standard gauge heritage railway. The engine represents an important step in the development of locomotive traction not just in Ireland, in Europe in general.
