Now available for the first time ever at Rails of Sheffield is the range of beautifully detailed Northern Irish Railways (NIR) Hunslet Class 101/ Class DL diesel locomotives in OO Gauge, produced by Irish Railway Models.

These charismatic diesel locomotives were produced for Northern Irish Railways to improve the iconic 'Enterprise' service between Dublin and Belfast and replace existing diesel railcars. They're closer to British mainland locomotives than you might think, featuring a more powerful version of the Class 20 power unit - and were designed by Hunslet - then built by British Rail Engineering Ltd at Doncaster.

With just a trio of locomotives and a small pool to choose from for variations, Accurascale IRM have decided to cover all major liveries for everyone in this first (and possibly only) production run. There's limited quantities available now at Rails, so secure yours today!

Having undertaken a programme of station refurbishment, improved its ticketing arrangements and introduced new on-track plant and shunting locomotives, in 1969 the still embryonic Northern Ireland Railways set out to improve the Dublin-Belfast ‘Enterprise’ service, by replacing the existing diesel railcar sets with a locomotive hauled service. Intended to reduce the time for the 180 km journey to just two hours, the NIR Class 101 (DL) locomotives were designed to run in a push/pull configuration, with a 270 ton 8-car set of BR Mk.2b stock, at a maximum speed of 80mph.

When Mrs Joan Humphreys, wife of Northern Ireland Railways’ chairman Myles Humphreys, unveiled the nameplate of 101 Eagle on May 8, 1970, it was an astounding triumph for the Hunslet Engine Company of Leeds; having beaten off stern competition from the likes of General Motors in the United States for the contract, with the event marking the remarkable culmination of a ten-month delivery programme.

The pace of the delivery programme was dictated by NIR’s lack of diesel-electric stock to haul the Enterprise to the new timings; the British United Traction 700/900 Class and UTA Class 70 railcars not being up to the task in hand and while Hunslet had secured the order, the company’s workshops were already full, being committed to other orders. For Hunslet, the answer was to sub-contract out the manufacturing work, so having designed the superstructure and bogies, fabrication of the superstructure, along with the final assembly, testing and painting were contracted out to British Rail Engineering Limited at their Doncaster site.

Traction was trusted to English Electric/AEI Traction, who designed the English Electric 8CSVT Mk II design prime mover for the project, which essentially was an updated version of the Class 20's prime mover, fitted with an additional intercooler. Linked to a Bo-Bo bogie arrangement, this unit provided 1,350 hp (1,010 kW), of which 350hp was required for the Mk2’s heating system!

Completed on schedule, 101 Eagle was handed over to NIR on May 8, 1970, with 102 Falcon following on May 22 and 103 Merlin on June 8 and all three locomotives (on temporary bogies) were subsequently shipped to Belfast on the Ferry from Preston (probably on the MV Ionic Ferry) and on arrival were moved to Queens Road for the fitting of the 5’ 3" gauge wheelsets.

The Press Launch/Test Train took place on July 3, 1970, with 102 Falcon leading out to Dublin from Belfast’s Great Victoria station and 101 Eagle trailing, and aside from a few comments regarding ‘hunting’ due to the push locomotive, all went well.

The three locomotives alternated on the Enterprise and continued to do so until they were succeeded by the General Motors’ NIR Class 111 fleet in 1983. When not required for Enterprise services, the 101s would run as single engines on locomotive hauled services such as the Saturday Excursion traffic to Portrush. This period also coincided with NIR being awarded the contract for the haulage of spoil from Magheramorne, to the Oil Terminal construction site at Cloghan Point (near Kilroot Power Station).

Between October 7, 1974, and August 22, 1975 these spoil trains were generally headed by one of the NIR 101 fleet, hauling the Cravens built wagons from the steam hauled spoil contract of the late 1960s.

Their ability to haul significant loads led to each locomotive being fitted with Multiple Unit cabling for Push/Pull working and after their replacement on the Enterprise, the three locomotives were moved to secondary services, such as to Derry and between Bangor and Portadown, along with working diagrams that included haulage of the CIÉ weed control train, freight turns with 42’ Fertiliser Flats and 40T Ballast Hoppers, as well as general shunting duties in Adelaide Yard.

All three locomotives were gradually withdrawn from service as mechanical woes set in, with 103 Merlin being first in 1989 and 102 Falcon last in 1998, although after having spent four years out of service Falcon was briefly re-instated as a working locomotive in 2002, before being placed back into storage at Whitehead. 103 Merlin was scrapped in 1997, but 101 Eagle and 102 Falcon remained at Whitehead for some time until being offered by Translink for sale.

Both locomotives were purchased by the Railway Preservation Society of Ireland (RPSI) in 2005, with Falcon being selected for full restoration, utilising parts from Eagle where possible. Unfortunately, despite getting tantalisingly close to restoration back into working order, the task proved too much, and 102 Falcon was sold to the Ulster Folk & Transport Museum at Cultra in 2011, where it now resides. 101 Eagle had become no more than a bare shell, as parts had been stripped from it and when no buyer for it could be found the remains succumbed to the cutter’s torch the previous year, in January 2010.

So, what of changes to the initial design, was there much variation in the designs of the three Class 101s? The answer, given their short working lives, is unsurprisingly not, but there are some subtle variations for modellers to be aware of.

As built, 101 Eagle, 102 Falcon and 103 Merlin were all identical, but somewhere between late 1974 and early 1975, small sections were removed from the headstocks, with each locomotive’s being slightly differently shaped, indicating an ad-hoc modification (a useful identification guide in the absence of visible numbering). Around this time, the roof aerial clusters also changed from the original housing to the more familiar GSM ‘shark-fin’ type at each end.

The next visible change came with the addition of Time Division Multiplex (TDM) cabling, allowing the transfer of multiple working data between locomotives and Driving Trailers. At some point in 1988, 101 Eagle obtained a second GSM aerial at No.1 End, but the greatest change in appearance belonged to 102 Falcon, with the removal of the buffing gear at both ends and the vacuum pipe being elevated and centralised at No.2 end.

The Class 101s wore all their liveries well, with four distinct livery periods for the trio. As delivered in 1970, all three locomotives were painted in a deep maroon over the body, a light grey roof, with an arced golden yellow panel at each end and a small NIR logo amidships in golden yellow. From 1974 all three locos had the front panel revised to a ‘V’ shaped arced panel, with the locomotive number appearing on the front end for the first time. In mid-1979, the NIR mid-blue livery appeared, with the ‘V’ arc being represented in luminous red and a slightly larger NIR logo in white featuring amidships.

As a body livery, the mid-blue did not wear very well, fading unevenly, and during 1988 the paint scheme was refreshed with new large NIR logos amidships, but this time with a luminous red chevron replacing the more elegant arc pattern which, again, faded badly and quite quickly.

Of the three, only 102 Falcon received the revised darker NIR blue, sometime in 1996, with small yellow panel, black roof and ‘Zorro’ mask across the cab windows, again with large NIR logo. In preservation, this locomotive is now presented at the Museum at Cultra in a representation of its original maroon livery.