15 May 2025 – Future UK Locomotive Strategy by Karl Watts – MD of Railmotive Limited
The presentation started with a statement from Karl that he is still passionate about railways even after 47 years as a railwayman and this enthusiasm was clearly evidenced throughout.
Karl gave an outline of his background from formal railway beginnings in 1978 where he was taught as both a driver and an engineer, learning every aspect and detail. Driving was almost secondary as, for Karl, the training was about learning and understanding better, with a fascination for engineering. Once he started driving, his career progressed much faster and his reminiscence at the age of 23 of driving an express on the East Coast Mainline stays with him. But what would the next 40 years bring? Management training. Using photographs as illustration, Karl did all kinds of things and learned about many different aspects of railways including rail links to airports illustrated by his experiences of Kuala Lumpur. He also gained much experience with GB Railfreight, Colas Rail etc. By 2012/2013 he recognised that passenger franchising was going ‘barmy’ bidding for new trains rather than refurbishing as, at this time, money was cheap to borrow and there were new companies building trains with competition driving down prices. Karl was watching and saw the numbers that ATOC (Association of Train Operating Companies) used to refresh their rolling stock strategy.
Karl realised that all the potentially new vehicles would need testing and delivery and a cascade programme to manage all of this. Here was an opportunity as no TOC (Train Operating Company) was doing this, so he and some others together created the Rail Operations Group (ROG) at Somers Town Coffee House (near Euston Station in London). The business went from strength to strength but needed modern traction to replace their old locomotives, so they talked to Stadler in Valencia. It was hard work but good fun too. It was not easy and one of the lessons they learned was the difficulties of moving all the new vehicles around largely because of the incompatibility eg completely different brake systems and incompatible couplings. Incompatible brake systems meant that the vehicles were mostly unbraked so had to be included in a freight system with a translator vehicle to sort out the incompatibility and two sets of six extra wagons to provide sufficient braking. This meant a massive train which was slow and inefficient energy-wise. The ROG moved forward by modifying some older locomotives to ensure compatibility regarding braking and coupling which meant a journey moving the new stock that had previously taken 2 days could be done much faster, at 90mph, and taking only 2.5 hours. DB asked for help but ROG refused to bail them out and in the end DB handed over their contract.
Karl retains his co-ownership and links with ROG but also set up Railmotive in 2022 – pioneering the Class 93 multi-mode ‘state of the art’ and versatile locomotives and looking at future locomotive strategy. The next part of the presentation was split into 3 parts:
Part 1 What do we use locomotives for?
Part 2 Why replace what we have?
Part 3 What should we replace it with?
Part 1 - What do we use locomotives for?
This includes freight eg heavy haulage with a maximum 60mph, and ‘express’ freight, intermodal at 75mph so faster and often with lighter containers, noting that maximum container weight needs to work with road traffic. Locomotives are also used for network recovery eg for breakdowns and when the overhead wires are down; and for infrastructure services and monitoring with examples provided; as well as being used for systems and infrastructure testing, for example testing trains under new overhead systems both before and after the power is put through. In addition they can be used for testing new signalling systems. Locomotive use for passenger train operation is diminishing as most new unit forms are not loco-hauled. However, there are opportunities for passenger charter operations and other rolling stock services. It is a huge but dynamic market with freight picking up, coal traffic down, aggregates up and containers and intermodal both increasing. There was a question here about UK express intermodal only reaching 75mph whereas in Europe speeds of 100mph are common, plus piggybacking. There are some faster freight services in the UK on intermodals but there are constraints in the UK with a smaller loading gauge than in Europe and there is little interest here in changing.
Part 2 – Why Replace?
There are 5 key areas driving the need to replace older locomotives, with some challenging targets to meet both nationally and within the railways such as reducing CO2 emissions. Also to be considered are diesel engines and locomotives, asking the question are they fit for purpose in the future regarding sustainability etc. There are questions too of performance, lots of aging locomotives, and technical advancements and improvements where things are changing massively which in itself can be quite scary.
National targets are for net zero on CO2 emissions by 2050 which is driving critical decisions for sound environmental reasons, as well as the target to remove diesel only traction by 2040 in England and Wales, with the Scottish target moved back to 2045. There is also a target to increase rail freight by 75% by 2050. A wonderful set of photographs showing diesel locomotives belching out black smoke and fumes helped illustrate why!
Phasing out diesel only locomotives is environmentally friendly. The Class 66s filled a requirement at the time but they are ‘big, noisy, fuel guzzling monsters’ in Karl’s words. Today they are inefficient and very environmentally unfriendly as was illustrated by the example of a Class 66 hauling a heavy freight train over Shap at 15 mph, such a slow speed is inefficient and there is pressure to speed things up as slow freight trains are ‘gobbling up’ capacity on the West Coast Main Line (WCML). Because of their relatively slow speeds, freight services have to stop all over the place at present to allow other trains to pass through which slows them down further making this form of transport less attractive. There are definitely questions to answer about priorities on the railways as to which is more important ie some freight services or passenger services which can hold up millions of pounds worth of freight, and Karl provided some details here of pricing models for freight operations. Even when electricity is expensive, modern electric locomotives are still better than diesel ‘gas guzzlers’. There were questions about tare weight and gross weight of freight trains, Scottish progress with electrification – they will still need new traction even without the whole railway being electrified. Further questions took in diesel electric or electric only; powering some freight cars and the conflict between passenger and freight services.
Part 3 – What should we replace them with?
There are decisions to be made with a number of possibilities including alternative fuels, electric, internal combustion, hydrogen (H2), battery, gas. The economics of hydrogen are not great and it is not a good choice for long distance. The other problem with hydrogen is that the energy density is only about 12% that of diesel and the implications of this relative energy inefficiency. Battery technology is moving on significantly for the better with new lithium-titanate batteries although there are pros and cons for everything. The recharge speed is good and there are constant improvements coming forward eg lithium-niobium. Gas is a fossil fuel producing CO2 emissions and is not a good choice commercially or environmentally. Karl showed some interesting diagrams whilst explaining the energy flow from source to wheel and this helps to explain too, some of the efficiencies/inefficiencies. Other possibilities include bi-mode or multi-mode powered locomotives. Further questions arise with regards to 4 axle or 6 axle bogies and the pros and cons of each.
The next aspect under consideration was gearing. Whereas road vehicles have multi-ratio gear boxes, this is not possible with locomotives meaning that a decision has to be made on which specification to choose for which purpose eg lower gearing for freight, higher gearing for express passenger and in between for mixed traffic services. Karl provided diagrams and explained simply how this works. Once they are built, they cannot be varied so a clear and considered decision on which gearing and clarity on what services they are to be used for are vitally important as the gearing decides the locomotive type. A clear graph showed tractive effort comparisons for different types, taking loads and required speeds into account.
Comparisons were made between different locomotive classes with Class 93s not quite so powerful in some modes but excellent running under the wires with a ‘go faster’ button to boost power without requiring any huge change to achieve this. Class 88s can already achieve 55 mph over Shap which is far better than the Class 66s. One of the pros of the electric locomotives is better acceleration and tractive effort particularly on gradients, with faster speeds that help to free up capacity on the WCML. Class 93s can achieve around 65mph over Shap – a further improvement.
The Class 93 is multi-mode locomotive with a hybrid diesel alternator which is Stage 5 compliant. The locomotive can also be powered by battery where necessary or it can use a combination of power sources together where appropriate. However, once under the pantograph, it is massively more powerful than a Class 66 and can recharge the batteries when the pantograph is up or the diesel is running. There is also regenerative braking to further maximise energy efficiency. If the batteries are full and the pantograph is up, then any additional regenerative power goes back into the overhead. Here a photograph of the inside of the Class 93 cab was shown as illustration of the driver’s controls, and Karl explained how the human/machine interface works and how the choices are made between which energy mode to use. All this is positive for the environment. To ensure further improvements, Railmotive are also looking at freight wagons eg considering a faster and lighter base for containers with newly designed bogies that are more like those on passenger services. When asked why the specification was only for 75 mph running, the reply was that no-one had asked for better. So back at the drawing board, new bogies were designed to be able to go up to 110mph - for a freight wagon. However, there can be problems with ‘fast’ such as aerodynamics and the speed versus energy consumption physics – more speed, more energy required with an exponential increase in energy requirement as speed increases. This means that there are commercial limits to what is economically sensible. Based on the economics, if the railway system is relatively quiet, then a freight service can travel a little slower to conserve energy whilst increasing speed where necessary if the system is busier and requires this. All this helps to avoid the current costly delays where freight trains are stuck in freight loops, thus improving asset utilisation. This is about keeping the wheels turning and earning money in the most commercially and energy efficient way.
In conclusion we need locomotives which:
- Serve multiple markets effectively;
- Are multi-mode;
- Use and recover energy efficiently;
- Embrace new and future technology;
- Significantly improve operating capability;
- Maximise asset utilisation;
- Reduce operating costs.
We have the strategy and are working to achieve it.