What diesel engines could the LNER Class 897s use?

[tfw756rider]

It's my understanding that in terms of CAF Civity UK train builds, the London North Eastern Railway (LNER) Class 897 units will start build after the last few Transport for Wales Rail Class 197 units have finished build, (which will surely be in the current year, 2025).

The 897s will of course be tri-mode units (overhead electric, battery electric and diesel), but, given the line they'll be running on, will also surely be the first CAF Civity UK units *with diesel engines* to have at least a 125mph top speed (rather than 100mph).

Given the surely higher top speed (125mph+) of the 897s, I wonder what diesel engines they could be fitted with?

Each vehicle of a 100mph 195/196/197 has an MTU 1800 series 12.8-litre inline-6 turbo-diesel engine with between 503hp and 523hp, driving through a 6-speed ZF gearbox, similar to the 172s and the Northern Irish C4Ks.

The 897s will of course use their electric traction as electric transmission for their diesel engines, but will they also need to be capable of full performance on diesel, and therefore require more powerful diesel engines than what CAF have used in the UK up until now?

Would more powerful engines (such as the MTU 1600 series 750hp 21-litre V12 turbo-diesel engines of LNER's 800s) even fit under the floors of the 897s' vehicles? And how many of the 10 vehicles of a unit would be able to fitted with an engine, especially considering the space taken up by the batteries?

Perhaps there's a better solution from an alternative engine manufacturer that could be used? Looking forward to any responses

 

[Blindtraveler]

I don't suppose for a moment they'll be expected to be either required to perform fully on diesel or indeed reach line speed of 125 on diesel except perhaps in very exceptional circumstances, can their existing IET fleet even achieve this kind of lick on diesel power? I don't think they can, the engines on those I was led to understand were geared for climbing Scottish gradients which they seem to manage. Okay, although the one time I went up the Highland main line on one it did seem like the engine was working extremely hard under the vehicle I was travelling in and couldn't help wondering if it was struggling a bit.
I don't suppose the same gearbox option will be utilised either. Given that again, as far as I'm led to understand, the diesel units on these trains will simply be acting as generators for the electric traction motors and hotel power and services
I shall now sit back and wait for all the people better informed on this subject than me to debunk everything I've just said, but this is my understanding as it stands of the situation

 

[hexagon789]

Given no performance specs have published, my expectation is that they will simply be a 397 with diesel and battery capabilities.

I'd expect the same 125mph design maximum (so not 140 as per the 800/801s) and probably only 100mph performance specified for diesel/battery.

 

[tfw756rider]

Thanks both for your replies. So the 897s could well have the same engines as the 195s/196s/197s, but obviously with the electric transmission rather than the gearboxes. If so, that could be interesting, but surely in that case every vehicle would have to have an engine, and I wonder if there would actually be enough space with the batteries etc.

 

[Snow1964]

Do they need to be capable of 125mph on diesel ?

I am not sure how far they will work off the wires, but I would guess they could do at least 30 miles (and probably nearer 50-60 miles) on battery. So diesel is likely to be lower speed add ons and diversions where speed limits are around 70-90mph

Without knowing the specs can they use diesel and battery together for short bursts to allow acceleration. If so about 500HP on about 60% of vehicles might be sufficient

 

[tfw756rider]

Do they need to be capable of 125mph on diesel ?

I am not sure how far they will work off the wires, but I would guess they could do at least 30 miles (and probably nearer 50-60 miles) on battery. So diesel is likely to be lower speed add ons and diversions where speed limits are around 70-90mph

Without knowing the specs can they use diesel and battery together for short bursts to allow acceleration. If so about 500HP on about 60% of vehicles might be sufficient

That makes sense. Using diesel and battery together is parallel hybrid, right? MTU (for example) states that the 1800 series PowerPack power rating for parallel hybrid can be up to 630hp, compared with up to 523hp for the normal diesel-only version, so maybe it would be something like that.

 

[Nym]

That makes sense. Using diesel and battery together is parallel hybrid, right? MTU (for example) states that the 1800 series PowerPack power rating for parallel hybrid can be up to 630hp, compared with up to 523hp for the normal diesel-only version, so maybe it would be something like that.

The battery pack is very unlikely to be provided as part of the power pack from the likes of MTU etc. So "Parallel Hybrid" as a powertrain and automotive marketing term would not apply in this circumstance. Rail systems tend to be integrated at a unit level for these, not a power pack level.

 

[800001]

My understanding was the 897 were to replace and stick to similar diagrams to the 91s, with some shuffling of diagrams to include Harrogate services, which then allows the 800 bimode fleet to operate the 2 hourly Middlesbrough service.

 

[Halish Railway]

Given no performance specs have published, my expectation is that they will simply be a 397 with diesel and battery capabilities.

I'd expect the same 125mph design maximum (so not 140 as per the 800/801s) and probably only 100mph performance specified for diesel/battery.

I believe that a 90mph maximum has been mentioned a few times. The only time they’ll ever diesel/batteries will be on the Lincolnshire/Cambridgeshire diversions which are flat and 75mph maximum and the Harrogate line which is 60mph. I’m not sure if they’re intended to go to Hull or not.

Having the incline from Leeds to Garforth electrified by the time the 897s are introduced will reduce some of the need for high performance independent power on one of the diversionary routes.