Diesel locomotives of Ireland
The railways of both the Republic and Northern Ireland were amongst the first to changeover from steam to diesel locomotive tractive use. The initial engines were built and supplied by various British engineering works (predominately Sulzer and Crossley), with varying degrees of success. By the mid 60's however, the proven experience of the American manufacturer General Motors (GM) was taken onboard, with existing engines being re-engined with EMD 645 units and all new Locos being purchased exclusively from GM. The reliability of these engines is evident in that many of these locos remained in service until the mid 90s.
Republic of Ireland
Mass Dieselisation
In 1948, CIE commissioned a report on the problem of upgrading it's rail services from Sir James Milne (General Manager of the Great Western Railway). Contrary to his recommendations, CIE decided to push for the complete dieselisation of its railway system, expecting substantial economies of scale.
The first of the two mainline diesel locomotives built at Inchicore Works, the Sulzer-powered Class 113, entered service in April 1950, following completion of trials.
Subsequently one of the largest orders of it's time was placed for 94 locomotives (60 Metro-Vick 001 Class and 34 201 Class locos) with a consortium of four English companies:
- Diesel engines from Crossley
- Mechanicals from Metropolitan Cammell
- Electrical components from both the English Steel Corp. and the Metropolitan-Vickers Electrical Co.
These Crossley powered locos were delivered to Inchicore Works between 1957 and 1958. The 001 Class was to become the mainstay of mainline passenger and freight services on the Irish railway network for the next forty years. Parts were also ordered for 19 further locos to be built at Inchicore Works.
From the outset , the two stroke Crossley engines used were considered under-powered and unreliable. The 001s were not capable of handling the mainline work given to them with the reliability expected, while the 201 Class, no longer required on branch line work due to Todd Andrews's large scale branch closures, were unsuited to other work because of their low power (c.600 hp).
The General Motors Influence
From the early 60’s, CIE looked to GM, given their history of reliability. 15 Class 121s, were purchased in 1961. These were modified shunting locos ("switchers") and were an instant success. The one drawback was the single cab construction requiring the loco to be turned at the end of each journey as the drivers refused to operate them "long hood" forward. They were later modified for multiple unit operation in the 80s and operated in consist, "long hood" to "long hood", with their cabs at each end. 37 Class 141s, delivered in 1962, were fitted with a cab at each end to overcome this problem. The delivery of these engines brought an end to regular steam working in April 1963. A third batch of GM locomotives (Class 181) were delivered in 1966, which were essentially 141s with 1,100 h.p. engines.
With the experience of GM reliability, CIE decided in 1964 to fit higher powered engines in both 001 and 201 locos. However at the time, GM would only sell complete engine / generator assemblies and would not provide engines on their own. They finally agreed in ‘67 to supply engines to enable re-engining of the 001. The trials were a total success and over the next four years, all 90 Metrovicks were fitted with replacement EMD 645 engines.
Eighteen new locomotives, again from General Motors, were introduced in 1977. Visually resembling a stretched 141/181 Class, the new locomotives had a Co-Co wheel arrangement and were of significantly higher power, 2,450 h.p. The 071 Class with it’s speed and power went on to become the principal passenger locomotive on the Irish railway network for the next twenty years. They were superceded in 1994-1995 by the new 201 Class, again built by GM. These are currently the heaviest, fastest and most powerful diesel locomotives operating in Ireland (112 tons, max speed 102mph, 3,200 hp)
Classification
Initially, CIE numbered and classified its handful of early diesel locomotives in the same number series as steam. However, it soon developed a series based on Types according to engine power, with the highest-powered locomotives being Type A and numbered in the A0xx series, and the lowest powered being Type G and numbered in the G6xx series. Locomotive K801 was a one-off prototype and did not truly fit in this scheme.
Since all the locomotives were in fact numbered in series, the letter prefix was dropped in 1972, as was the allocation of numbers according to power. The low-powered locomotives rebuilt with higher-powered engines were not renumbered, and later locomotives have simply taken the next available number series.
In the early to mid 1980s, locomotives started to be designated with the suffix letters S and/or A after their number. For example, 124 was renumbered 124SA. The S was to indicate that the locomotive had been fitted with CAWS (Continuous Automatic Warning System) an in-cab system which displays the aspect of the next signal. Locomotives which hadn't been fitted with CAWS had restrictions imposed on their use until fitted. The suffix A was used to indicate that the locomotive's air brakes had been commissioned. Up until the introduction of the Mark 3 stock, all Irish coaching stock used vacuum brakes but all locomotives since the 121 Class had also been equipped with air braking, albeit never commissioned. Only those which had the air brakes commissioned could haul the new coaches. The 001 Class only had vacuum brakes so none had the A suffix. Once all locomotives had been fitted with CAWS and had their air brakes commissioned, the suffix letters were dropped and numbering continued as before.
Republic of Ireland
| Image | Class | Type | Image | Class | Type |
|---|---|---|---|---|---|
 |
001 Class | Numbers 001-060 (Type A) |  |
071 Class: | Numbers 071-088 |
| 101 Class: | Numbers 101-112 (Type B) |  |
113 Class: | Numbers 113-114 (Type B) | |
| 121 Class | Numbers 121-135 (Type B)
|
 |
141 Class | Numbers 141-177 (Type B) | |
|
181 Class | Numbers 181-192 (Type B) | 201 Class: | Numbers 201-234 (Type C) | |
| 301 Class | Numbers 301-305 (Type D) | 401 Class | Numbers 401-419 (Type E)
| ||
| 421 Class | Numbers 421-434 (Type E) | 501 Class | Numbers 501-503 (Type F)
| ||
| 601 Class | Numbers 601-603 (Type G) | 611 Class: | Numbers 611-617 (Type G) | ||
| 801 Class | Number 801 (Type K) |  |
GM 201 Class | Numbers 201-207 & 210-234 |
Northern Ireland
A variety of small classes of diesel locomotives have operated on railways in Northern Ireland. From 2001, all items of rolling stock in use on NIR had 8000 added to their number so as to be part of the Translink number series, which incorporates their road vehicles.
Belfast and County Down Railway (1848-1948)
Northern Counties Committee (1903-1948)
Northern Ireland Railways (since 1967)
- 1 Class: Numbers 1-3
- 101 Class: Numbers 101-103
- 104 Class: Numbers 104-109
- 111 Class: Numbers 111-113
- 208 Class: Numbers 208-209
See also
- Steam Locomotives of Ireland
- Multiple Units of Ireland
- Coaching Stock of Ireland
- Rail transport in Ireland