Hydraulics at Work

Written by: TrainSim-James

Main image above, copyright Les Chatfield.

Coming soon to Train Simulator, the Western Hydraulics Pack propels the Riviera Line in the Fifties into the clag-filled and characterful 1960s!

Following the publication of the 1955 Modernisation Plan, all regions of British Railways were required to eventually abolish their steam locomotives in place for a whole new generation of rail traction, the diesel engine. Most of the network opted for diesel-electric technology for their locomotives, the Western Region however took a different approach with their early diesels, and turned towards hydraulic transmission…

The Hymek

Image above, copyright Geof Sheppard.

One of the locomotives produced for the Western Region was the BR Class 35, which was built by Beyer Peacock (Hymek) Ltd between 1961 and 1964 as a single engine, mixed-traffic, diesel-hydraulic locomotive for use out of Bristol, Cardiff, and London. The Class 35 would fill the roles of secondary passenger and freight services left vacant by a disappearing fleet of steam locos.

A total of 101 Class 35 diesels were built, and were quickly put to work on local and semi-fast passenger services in the west of England and out of London Paddington. None of the locos built were named, so the Class 35s adopted Hymek as a suitable nickname. Despite only having a single Maybach engine, the Class 35s could rather effectively haul trains at upwards of 90mph, and it wasn’t long until they were trialled on main line expresses, which they could haul, but would soon be replaced by more powerful hydraulic locomotives.

After a few years of service, the Class 35s were taking care of inter-regional workings, however their unique diesel-hydraulic nature meant most other drivers in the rest of the country were not trained to handle them, so the 35s were timetabled to get out and back in the Western region with haste.

One location where the Class 35s both excelled and suffered was the Lickey Incline, 3 locomotives working in multiple (which required two drivers) would often serve as bankers helping other trains over the peak. A problem soon arose as 35s would constantly try to change gears on the incline, causing accelerated wear; BR fixed the issue by locking out first gear in the A cab and ensuring that cab was always in front when on the way up.

By the 1970s, the rush of modernisation had come to a slow, diesel locomotives were no longer needed so quickly, and more standardised designs were favoured over anything else. Diesel-Hydraulic traction was deemed non-standard, and the Class 35s were forced to retire after only 10 years of service. Of the 101 locomotives built, only 4 survived into preservation.

The Warship

Image above, copyright Tony Hisgett.

While the Hymeks were ideal for bulking out the medium power roles, BR’s Western Region also required locomotives that could perform on the main line, replacing the mighty King and Castle classes, and also be relatively light to save fuel on the ruling gradients between Exeter and Plymouth.

By the mid-1950s, diesel-hydraulic transmission was still in its earlier days, and the leading experts were of West Germany. At this time, buying in locomotives from abroad was unheard of, and attempting to do so from a German company, so soon after the Second World War, was an absolute no. Instead, a licence agreement between BR’s Western Region and German manufacturers was reached, where the Germans would design a scaled-down V200 type diesel locomotive, and the British would build it.

Therefore, the Western Region’s new locomotives started to take shape, Maybach engines of German design were constructed by Bristol Siddeley, and the final locos were brought to life at Swindon Works. The resulting locomotive bared uncanny resemblance to the German V200, but there was no denying, with 2 Maybach engines each, that these hydraulic 90mph leviathans would be able to dominate the hill-bound western expresses.

A total of 38 locomotives, which would be classified as the Class 42, were produced between 1958 and 1961. Each locomotive was named after a Royal Navy vessel, and so it was not long until they were collectively known as the Warship Class. In 1960, a second batch of Warships were built by North British Locomotives and featured differing equipment, the North British batch was to become the Class 43 (not to be confused with the more modern Class 43 ‘HST’).

Much like the Hymeks, the Warship fleet spent roughly 10 years working on trains in and out of Paddington, heading crack expresses such as the Cornish Riviera Express and The Bristolian. For a time, the Warships also worked out of London Waterloo, providing semi-fasts to Exeter. However, when all diesel-hydraulic locomotives were deemed non-standard, the Warships too fell to the cutters torch with only 2 surviving today.

The Western

Image above, copyright Roger Geach.

Warships were not the only locomotives derived from a German design, when the Western Region required even more powerful traction for top-link services, a larger variant of the Warship was built. The new fleet of 74 locomotives featured a C-C wheel configuration, as opposed to the Warships’ B-B, and housed two engines of a higher combined horsepower, resulting in a much higher maximum tractive effort.

Each locomotive was named some heraldic term prefixed by the word ‘Western’, hence the given name for the fleet, the locomotives would also be classified as the Class 52. In service, the Westerns were able to provide the power that the Hymeks and Warships could not, and were the staple traction at London Paddington throughout the late 1960s and 1970s.

All diesel-hydraulic locomotives of the Western Region could obtain a maximum speed of 90mph, however reports of 102, and 110 mph were recorded from Western locomotives. There was no denying that the Westerns were among the most powerful hydraulic transmission locomotives, but they also began to show their shortfalls in comparison to the more widespread diesel-electric traction.

Out of all the Hymeks, Warships and Westerns, the latter would be the last to remain in service on the Western Region, lasting until 1977 when displaced Class 50s and the introduction of the High Speed Train sparked their final demise. A majority of the Westerns were scrapped, however they remain the most prolific British diesel-hydraulic locomotive in preservation with 7 examples either operational, undergoing overhaul or on static display to this day.

The BR Class 52 ‘Western, along with the BR Class 42 ‘Warship’ and BR Class 35 ‘Hymek’, will be coming soon to Train Simulator as they were in the 1960s, in a multitude of classic liveries, to bring the Riviera Line in the Fifties into the roaring diesel age!

We’re always happy to receive your comments below but please ensure they are related to the subject of the article, we’ll remove any that appear to be unrelated.



  • I am looking forward to this pack, I do have the earlier versions from IHH, but there was one (or was it 2) that had no cab or a very rudimentary cab, so basically were suitable only as an AI model.

  • A polite request – if DTG now owns Paul Godber’s original model of the Class 22 Baby Warship, would you consider releasing this with the pack? I do realise that the model only came with a very basic cab but it would prove incredibly useful as an AI model for Western Region scenarios, particularly for the target route of the Riviera in the 50’s, that would otherwise not look so authentic.

    Thanks, Ash

    • This won’t be included Ash but may be something we’ll consider for the future. I’ve now added it to the list to look into.

      • Thanks for the reply Steve. Fingers are crossed for DTG’s further consideration of the Class 22. I only mentioned it now because it would have made a good addition to this forthcomign WR Hydraulic pack, without necessarily making good business sense to put it out on its own. No point in asking for a D600 hydraulic, then? 🙂

        Seriously though, many thanks for your reply.

        • You’re most welcome Ash

        • I would also really enjoy a D6000 Class 22 Baby Warship and a D600 Class 41 Warship. And maybe also a Class 43 Warship (I think – and that’s a big “I think” since I could be wrong – that you’d only have to take the existing 42 Warship, then change some plates from Swindon Works to North British Locomotive Company, and change the sounds to MAN engines rather than Maybach, and maybe the numbering and names of the loco). Another suggestion from me would be the DHP1 and/or the Blue Pullman (or maybe with that Western livery). The cab view kind of reminds me of a cross between a Hymek and a slam-door. 😀

  • Looking forward to the Class 42 Warship in this pack.

  • Homely locos with personality!

  • This sounds great, we needed the Warship so badly. Is there any chance of a decent variation in the Mk1 choices as found in the 6MT or Coronation package, as they are very good.


    • The hydraulics pack will include an array of Mk1 coaches in a variety of appropriate liveries. I’ll have more details on the Hydraulics pack as we move toward release Matthew

  • You have no idea how excited I am to see this! I cannot wait to get the extra names and livery’s for the 52 and the addition of the 42. I do have a few questions though:
    1. Will the Class 35 just be in BR Green or will there be BR Blue?
    2. Will there be a discount for current owners of the 35, 52 and/or Rivera 50’s?
    3. Is there any chance of the GWR Diesel Railcar joining these early diesels on the Rivera 50’s line?

    • The Class 35 will be in both Green and Blue Dan. As for pricing, there won’t be a discount for existing owners of the 35 and 52 as this pack includes an entirely new scratch-built Class 42 and an array of appropriate Mk1s, etc. though I don’t anticipate the pricing to be any higher than our usual locomotive packs (think BR Blue Pack). Let’s also not overlook the fact that an “in-service” Class 52 is entirely different to an “in-preservation” Class 52. As for the GWR Diesel Railcar, there are no current plans to do this though you never know what the future might hold.

      • Thanks for the info Steve, guess the pricing is fair due to the new stuff like the 42 and In-service 52 (which is going to be awesome). Would the Class 14 also be suitable for this pack? I’m glad to see so much work has been put into this add-on. 😀


        • No problem Dan, either James or I will have some more details coming up where we’ll show off some in-game shots. As for the Class 14, that’s a very good suggestion and if it’s something you would like to see in the pack, I’ll see what I can do.

          • Yeah the 14 would be awesome in the pack if that’s possible.


            • I’ll see what I can do Dan but no promises

  • Can’t wait to see what other schemes come in the pack.

  • I hope the sounds on the Hymek are better than the previously released version which had Class 37 sounds mixed in. There are a number of preserved Hymeks around the UK to get good sound recordings.


    • Just because a locomotive exists in preservation doesn’t necessarily mean that the owners will grant us access Peter. Whilst there has been some work done on the audio, I have no details as to what extent. I would, therefore, in the interests of making sure you’re properly prepared, advise that you should expect the audio to be no different than what has already been represented.

  • SO HYPED! This is like a miracle.

  • I’m looking forward to the warship!

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