The Anonymous Widower

More Class 99s Expected To Be Ordered For Caledonian Sleeper Work

The title of this post, is the same as that of this article on Rail Magazine.

  • It would appear that thirteen locomotives are intended to be ordered.
  • They will have a 100 mph top speed.

Currently, Caledonian Sleeper have the following fleet.

  • 2 – Class 67 diesel locomotives
  • 6 – Class 73 electro-diesel locomotives
  • 7 – Class 92 electroic locomotives

Some of the locomotives are geeting old and reliability is suffering.

I wonder how far each route has to do on onboard power.

  • Aberdeen – If Electrified to Ladybank – 91.4 miles has no wires.
  • Aberdeen – If Electrified to Kirkcaldy – 104.6 miles miles has no wires.
  • Fort William – Electrified to Craigendoran junction – 99.5 miles miles has no wires.
  • Inverness – Electrified to Dunblane – 146.2 miles miles has no wires.

Note.

  1. Obviously, this range must be doubled, if there is no fuelling at the destination.
  2. Between Ladybank and Kirkcaldy will be electrified by 2029.

This gives the required range of a hydrogen-powered or battery-powered locomotive, that could work each route.

  • Aberdeen – If Electrified to Ladybank – 182.8 miles
  • Aberdeen – If Electrified to Kirkcaldy – 209.2 miles
  • Fort William – 199 miles
  • Inverness with refuelling/charging at Inverness – 146.2 miles.
  • Inverness with no refuelling/charging at Inverness – 292.4 miles.

I have some questions.

Do Cummins Make A Hydrogen Version Of A QSK50 Diesel Engine?

The Class 99 locomotive is equipped with a Cummins QSK50 diesel engine.

As many of Cummins smaller diesel engines also have a hydrogen version, I asked Google AI, the title in this section.

I received this answer.

No, Cummins does not make a hydrogen-fueled or dedicated hydrogen internal combustion version of the QSK50 diesel engine.

Key Details on Cummins Hydrogen and QSK50 Engines:

QSK50 Alternatives: Cummins offers a dual-fuel option (diesel and natural gas) for the QSK50, as well as hybrid systems aimed at reducing fuel use in heavy-duty mining and off-highway applications, rather than a pure hydrogen version.

Cummins Hydrogen Platform Focus: Cummins develops hydrogen internal combustion engines (H2-ICE) and fuel cell products, but these are currently focused on smaller or mid-range displacement platforms such as the 6.7-liter (B6.7) and 15-liter (X15 / B15) engine series rather than massive high-horsepower industrial blocks like the 50-liter QSK50.

Are QSK50 Diesel Engines Widely Used In Railway Locomotives?

I asked Google AI and received this answer.

The Cummins QSK50 V16 diesel engine is widely used in railway locomotives, particularly for switcher locomotives, line-haul repowers, and dual-mode/hybrid locomotives rather than heavy mainline freight locomotives (which typically use larger block engines like the Cummins QSK95 or EMD/GE power plants).

Key Applications in Rail

Switcher and Yard Locomotives: Frequently utilized in pre-packaged power modules (delivering around 1,350 to 2,500 HP) for local switching and yard operations.

Locomotive Repowers: Often selected by companies like Western Rail Inc to upgrade older frames to meet modern Tier 4 or Stage V emissions standards.

Dual-Mode Locomotives: Integrated into modern hybrid builds such as the Stadler Class 99 diesel-electric locomotives operated by GB Railfreight and Beacon Rail.

Note.

  1. Switcher and yard locomotives work around people, who may not like the diesel emissions.
  2. It appears for repowers the engine, offers better emissions.
  3. Certainly, in the UK repowering a locomotive gives it up to 30-40 years of reliable working life, at a competitive price. Just look at what it did for the InterCity 125!
  4. But the three key applications listed will increase the numbers of railway locomotives, that are still pouring out carbon dioxide.

As Cummins have a policy of families of engines, where different versions can run on diesel, hydrogen and natural gas, I wouldn’t be surprised to see a hydrogen-fuelled QSK50 join the family.

I also did a consultacy on quality for Cummins in Darlington and a Senior Manager told me, that Cummins aim to give the customer, what they want. Even, if this means a new sub-variant of an engine! How very un-American!

Do Stadler Make A Battery-Electric Version Of The Stadler Euro Dual Locomotive?

I asked Google AI and received this answer.

No, Stadler does not make a battery-electric version of the classic six-axle Stadler EuroDual (which is a Co’Co’ electro-diesel locomotive).

However, Stadler offers other hybrid and panto-battery locomotives in its broader modular portfolio that incorporate battery power:

Stadler Euro9000: A high-performance electric-diesel/battery hybrid locomotive that combines pantograph electric power, diesel engines, and a high-performance battery module (and has been ordered as a panto-battery variant by companies like Nexrail).

Eurolight / Tri-mode Class 93 / EuroDufour platform: Four-axle locomotive variants that offer dual-mode or tri-mode options combining electric, diesel, and battery propulsion.

This looks very much like a “No, but show us the money!” answer.

Nexrail has a web site, which even has a page for the Euro9000Battery.

So it is definitely not a paper locomotive.

After the electrification reaches Ladybank, the following distances would apply for each leg without electrification.

  • Aberdeen – 91.4 miles
  • Fort William – 99.5 miles
  • Inverness – 146.2 miles.

Note.

  1. I believe that a battery-electric locomotive could probably handle the Aberdeen and Fort William routes.
  2. But it would need charging before returning South.
  3. However, 146.2 miles seems to be a long way for a battery-electric locomotive to haul a nearly 400 tonne train.
  4. I would expect that Caledonian Sleeper would want to have a fleet of identical locomotives, so battery on some routes and hydrogen on others would be not a good idea.
  5. Obviously, the route could be run on diesel but it wouldn’t have the marketing attraction of a zero-carbon sleeper train.

My engineering and mathematical logic is telling me, that to run a reliable Caledonian Sleeper service with a unified fleet of locomotives, that hydrogen-powered Class 99 locomotives would be my preferred option.

These are my thoughts and questions on a hydrogen-powered Class 99 locomotive.

What Range Would Be Needed On Hydrogen?

After the electrification reaches Ladybank, the following distances would apply for each leg without electrification.

  • Aberdeen – 91.4 miles
  • Fort William – 99.5 miles
  • Inverness – 146.2 miles.

146.2 miles with a 400 tonne train should probably be achievable.

Would Refuelling Be A Problem?

Consider.

  • In the 1960s, I worked in ICI’s hydrogen plant at Runcorn in Cheshire.
  • In those days days, hydrogen was taken all over the country by custom-built Foden artics hauling a trailer with lots of tubes containing hydrogen.
  • Google AI confirms my memory, that ICI had an impeccable safety record transporting pure hydrogen.

Nearly sixty years later, I doubt standards have got any worse and safe refuelling techniques will be developed alongside the locomotives.

Would There Be Advantages For The Caledonian Sleeper?

Operations would probably be very similar, with the exception of the fuel and a slightly different splitting and joining procedure, as one locomotive would be doing the full route and wouldn’t need to be changed.

There would also be less pollution and possibly noise along the very scenic route.

But would the attraction of going from London on a zero-carbon sleeper train be a good marketing move?

Would The Caledonian Sleeper Be Faster On The Electric Sections?

I feel that there could be a very worthwhile time saving on the electric sections of the route.

Avanti’s Class 390 trains can do the journey between Euston and Glasgow in four hours and 30 minutes, whereas, the Caledonian Sleeper takes three hours longer.

 

A time of six hours or less could mean new markets opening up.

  • As a seated coach has up to thirty seats, could these be discounted to fill them with students and others on a limited budget?
  • The powerful electric haulage could speed-up the stops at Watford, Birmingham International, Crewe and Preston, which could help those going to Manchester for a very early start.

I feel Caledonian Sleeper have some cunning plans.

Would There Be Advantages For Cummins And Stadler?

They would obviously have the same marketing advantages as the Caledonian Sleeper.

But daily services between London and Scotland would surely give the locomotives a thorough test.

It should be noted, that QSK50 diesel engines are built in Daventry in England.

Could Hydrogen Fuel Cells Be Used?

I suspect they could be a possibility, but would they have enough power.

Conclusion

This is going to be a very interesting locomotive procurement.

 

 

November 1, 2026 Posted by | Artificial Intelligence, Hydrogen, Transport/Travel | , , , , , , , , , , , , , , , , , , , , , , | Leave a comment