New Class 37/9 from Accurascale

The first release of the Accurascale Class 37/9 covers three of the Mirrlees examples over the full life of the sub class, from original conversion, through their classic late sectorisation period right through to the present day.

Each of the three versions is unique with different silencer configurations and nose side grilles depending on the period, and they also feature the whole host of upgrades afforded to the other models in the third run, which includes a working roof fan on both DCC ready and DCC sound versions, switchable tail lights (right on, left on, both on), revised bonnet top doors, see-through radiator shutters with radiators behind, and engine room detail visible through the windows.

A comprehensive new sound project has been also recorded with assistance from Europhoenix and UK Rail Leasing.

Both BR versions will be available both direct and through Accurascale's network of stockists, while 37901 in Europhoenix livery will be an "Accurascale Exclusive", coming with special presentation packaging, a limited-edition certificate and available only directly via the Accurascale website.

Available to pre-order now, DC/DCC Ready locomotives are priced at £189.99 and the DCC Sound Fitted locomotives are priced at £289.99 and delivery is expected in winter 2025.

About the prototype

Introduced in 1986-7, the repowered Class 37/9s were an off-shoot of the ill-fated ‘Class 38’ project, a proposed 1,800-2,250hp Class 31/33/37 replacement with the haulage capability of a Class 56 or 58. As many as 500 units were planned, which attracted significant interest from locomotive builders and engine manufacturers from the UK, Europe and the USA. Two British manufacturers quickly established themselves among the front runners with engine designs that boasted incredible fuel efficiency.

The Mirrlees Blackstone MB275T from Hawker Siddeley and the Ruston RK270T from GEC Transportation, could both develop over 2,000hp from a straight six-cylinder layout, providing a significant reduction in maintenance costs. Having both passed BR’s punishing approval process, a further two-year trial was undertaken using six Class 37 donors that were undergoing ‘refurbishment’ at BREL Crewe Works. As the Mirrlees unit was slightly heavier than the English Electric 12CSVT they were replacing, they were included in the 120-tonne ballasted group, otherwise known as ‘heavyweights’.

Hawker Siddeley offered four engines for Nos. 37901-4 and these were mated to a Brush BA1005A alternator, while the Ruston in Nos. 37905/6 was partnered with GEC G546AZ electrical equipment. Both engines were set to deliver just 1,800hp to avoid overloading the existing EE traction motors. There were external modifications too. The Mirrlees unit with silencer was longer and taller than the unit it replaced, resulting in a new ‘peaked’ roof, while the Ruston, which tipped the scales at just 13.75 tons, also featured a revised roof to accommodate a new silencer layout.

The first pair, Nos. 37901/2 (ex-37150 and 37148), left Crewe at the end of October 1986, while the two Rustons (ex-37136 and 37206) were completed by mid-December. Nos. 37903 (ex-37249) and 37904 (ex-37125) followed in February and April 1987 respectively. Cardiff Canton was chosen to look after the small fleet and these were allocated to the Metals sub-sector for local steel operations, although they were also fitted with slow-speed control for coal duties. All were delivered in Railfreight grey, with No. 37901 quickly being named Mirrlees Pioneer and No. 37905 Vulcan Enterprise.

The Class 37/9s quickly found their feet, despite being intensively diagrammed, and working in pairs had no problem taking over from the double-headed Class 56s on the 3,060-tonne Port Talbot-Llanwern iron ore trains. However, they were found to load much more slowly leading to the ‘slug’ nickname for the class. Their reliability was also impressive, although some issues were experienced with both the turbochargers and the silencer configurations on both designs. The latter resulted in both types receiving modified roof layouts.

Unfortunately, the ‘Class 38’ project was cancelled in December 1987. Despite this setback, BR chose to purchase the engines rather than return them to standard condition. Happily, the incredible fuel efficiency and extended maintenance periodicity displayed by the Mirrlees design likely contributed to Brush winning the Class 60 contract in 1988, and this was specified with the eight-cylinder version of the power unit.

By August 1988, Nos. 37903/6 had both been outshopped in the new triple-grey Metals scheme, with Nos. 37904/5 being similarly repainted in 1990 and Nos. 37901/2 in March 1991, by which point the fleet was beginning to wander much further afield. However, it wasn’t long before their non-standard nature began to count against them and nearly all spent periods in store during the 1990s. While all six passed to Trainload Freight South West / Transrail in 1994, with Nos. 37901/6 also receiving big ‘T’ logos, No. 37904 was the first to be permanently stopped at Canton in April 1996.

The resurgence of freight in the early EWS era saw regular work return for the remaining quintet, but with Class 66s starting to arrive the inevitable was held off only until November and December 1998 when Nos. 37901 and 37903/5 were also sidelined. The final pair, Nos. 37902/6, were switched off in January 1999, although unofficially named No. 37906 Star of the East was reprieved as part of the EWS ‘heritage fleet’ for galas and open days and was even repainted back into Railfreight grey ahead of the Old Oak Common open day in August 2000.

No. 37903 was scrapped at Crewe Diesel in October 2005, while No. 37904 suffered the same fate at CF Booth, Rotherham, in November 2004. No. 37902 was acquired by Direct Rail Services in 2002, which then disposed of it to Sims Metals, Beeston, in April 2005 after cancelling its overhaul. Happily, No. 37901 was saved in 2003 and was a regular performer in preservation before being acquired by Colas Rail and then Europhoenix in 2016 and gaining the operator’s house colours. It subsequently returned to main line operations in 2022 for the EP Rail ‘spot hire’ subsidiary and was recently repainted back into Railfreight Metals livery. The two Ruston locos also both worked in preservation at various points over the last 20 years, although they are now owned by UK Rail Leasing and are undergoing a slow return back to operational, albeit non-main line, condition.

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