The key, however, is that this is not a new locomotive… it is a repowering project.
Rather than a class rebuild, like the Class 57 conversion project with which Brush was involved between 1998 and 2004, this is more akin to the MTU engine project on High Speed Train fleets (that Brush was also involved in) between 2006 and 2011.
Tiller was hugely involved in the latter. A senior member of the Diesel and Electric Preservation Group, he knows hydraulic equipment. And through his DEPG contacts and the need for Maybach components, it is his relationship with MTU that provides the equipment.
When the First Great Western HST power cars were fitted with MTU engines, Tiller led the project. Even now, Tiller says that no other companies would have been considered - MTU and Wabtec were the only options, he says.
The locomotives retain their multiple working equipment, but their operation needs to change, and so new equipment needs to be fitted. They have to not only work with other ’73/9s’, but also other ‘73s’, Class 66s, Network Rail Driving Van Trailers, and NR Guards Luggage Vans. The electric train heat equipment has been retained, but for the first time it will be able to work on diesel power as well as electric.
The English Electric (EE) engines were supposed to provide 600hp. But Moss explains that when they were load banked at Loughborough, they offered only 420hp (70hp more than an ‘08’). In contrast, Tiller says a test run in Kent showed the electric power of a ‘73’ could reach 2,400hp (nearly that of a Class 47).
The plan is for the new MTU engine to offer 1,600hp, a significant improvement in power. “It is a dual-mode Type 3,” says Tiller.
He explains that the new MTU engine, although wider, is more than three tonnes lighter than the less powerful EE engine. It is also more economical in terms of fuel. Because of the lighter weight of the engine, ballast blocks have been installed inside the locomotive.
The rebuilt ‘73s’ are being fitted with brand new engines and alternators. The traction motor blowers are being retained, while air intake filters are being fitted at the cantrail.
A lot of the design is based on the HSTs fitted with MTU engines. “It is half an HST,” says Tiller. He adds that the MTU engine requires a lot of air to keep it cool, hence the additional grilles on the cantrail.
Pre-heaters are being fitted to the locomotives. The temperature must be 25°C for an MTU engine to fire up, and the pre-heater warms the engine, enabling it to be started. This will apply for when working on either electric or diesel duties.
A new exhaust silencer has been fitted to the locomotive - it is in a well, so effectively it is out of the engine. A new hydraulic cooler group has also been installed. “I had to get something hydraulic in it,” smiles Tiller.
There are still two cubicles for electrics, although all the auxiliary systems are now AC motor-driven. This cuts down on maintenance requirements, says Tiller. There is a chopper cubicle for the controls for the motor, and Tiller explains that this should give an improved motor performance.
The brake system on the ‘73/9s’ has been simplified - the design was built to operate with many different trains, and so all manner of components formed the brake system. Some are still fitted with vacuum brakes, but that will change. Two locomotives (73119 and 73136) remain dual-braked, and these will be the last to be rebuilt, because they currently offer even more flexibility.
A Capos power supply is being fitted to the rebuilt locomotives. This is fitted to MTU engines across the globe, and enables engines to be started, and then hold the charge.
Says Tiller: “The locomotive doesn’t therefore need to rely on traction batteries to start. This is the first time this has been used in the UK, and is a big reliability key for the locomotive.”
Inside the cabs, the twin driving position has been retained, and new indicators and lamps are being fitted.
The distinctive indicator blinds, so common of SR designs, have been removed and the central window blanked out. Partly this has been done for cost reasons, as a windscreen costs more than £10,000 to fit to today’s safety standards. That would be more than £20,000 per locomotive, more than £100,000 for the current five ‘73s’ in the project, and potentially more than £300,000 on unnecessary glass for which GBRf would have to pay.
So Tiller isn’t paying. Instead, invertors and GSM-R (Global System for Mobile Communications - Railway) radio equipment will be fitted behind the blanked out panel.
Additional soundproofing has also been fitted to the cabs, while the windows have been sealed shut. This will surely prove popular when travelling along the West Highland Line on a freezing winter’s night.
New headlights have been fitted to the locomotives, as well as a roof-mounted headlight. The locomotives retain their roof-mounted horns. And on the cab front, while the multiple working pipes remain, a multiple working plug (a 27-way AAR system) and socket (as fitted to the Class 66s) is also now a feature.
Tiller says 73212 and 73213 are the only GBRf ‘73s’ fitted with snowplough brackets, and while these prove useful, there are no plans for more to be fitted. “We only have three sets of ‘ploughs anyway,” he says.
https://www.railmagazine.com/trains/current-trains/built-in-the-1960s-rebuilt-for-the-21st-century
www.thescottishsun.co.uk
