VP185's or MTU's?

[londonmidland]

Just a simple thread about what you like better and why.

Should Grand Central have replaced their HSTs with VP185s or how they are now with MTU's?

 

[Crossforth]

Of what I gathered from Work Ex at NL, the VP185s take alot less time to warm up and are easier to maintain as there is more room inside the engine room although their lifespan is not as long

 

[TGV]

does it matter? It's just an engine

If this forum was a bar in a cowboy movie, the music would just have stopped...

I made a similar comment to yours once though. Apparently no, it's not just an engine. For lots of bobble-hat reasons that are not really appreciated outside of spottersville, the old one was some kind of railway legend - all because it made a "nice noise".

 

[ainsworth74]

As far as I am aware MTU's are more reliable, fuel efficient and have lower emissions. In relation to the GC power cars the vast majority of Class 43s are equipped with MTU's which gives them greater commonality with the rest of the fleet therefore (coupled with the other factors) GC made the right choice.

 

[Techniquest]

I'm tempted to agree with starrymarkb on this topic. Back in the day, I could have been mightily vocal on the topic, but these days I'm not overly bothered.

All that said, I'd probably say VP185s are/were better than MTUs for the fun factor. Not much else worth adding to be honest!

 

[Fred26]

does it matter? It's just an engine

Thanks, I didn't even know they were engines until you said that.

Where's the option for, 'I couldn't give a monkey's'?

 

[Lampshade]

If VP185s were better, surely it'd have been the standard for engine replacements rather than the MTU. The MTU is quieter, cleaner and more efficient than the alternatives so from a common sense perspective, it's the right choice.

 

[Dai.]

Surely there is a good business reason for the engines being replaced?

Cost effectiveness?
Fuel efficiency?
Reliability?


The whole reason for switching in business is to save money.

 

[At_traction]

does it matter? It's just an engine

Tell that to the hardest-core steam enthusiasts - which is even called the "engine"... You've ridden one, you've ridden 'em all, huh?

As for the OP, I'll take one of each, delivered please.

 

[Kneedown]

All you Valenta fans should be voting for the Vee-Pee as it is basically a Valenta, albeit a modernised version.

I only drive VP's and so can't really comment on actual performance versus an MTU, but a VP is significantly derated (with 6 turbo's) and so on paper at least, should be more reliable.

 

[43034 The Black Horse]

They're quite similar with regards to life span:

Around 12500 for half-life (QL3 in MTU speak) and 25000 for full life (QL4 in MTU world).
The difference is in how they are worked out. I think VPs are done on TOPS hours, but MTUs on MDEC hours. MDEC hours are clocked up even if idling on depot....


EMT (I believe) have an average MPC figure of around 13-14k too.

If VP185s were better, surely it'd have been the standard for engine replacements rather than the MTU. The MTU is quieter, cleaner and more efficient than the alternatives so from a common sense perspective, it's the right choice.

I have to admit I had to ask someone about the below as it was before my time but here was the response:

It's a long story, that dates back to the lack of support to the initial VP installations back in 1994/5. At the time Paxman was owned by Alstom, famed for its lack of customer support (see Class 175/180/458 etc etc). Once Paxman was bought by MAN, support radically improved - but FGW was basically adamant it would not have VP, due to the legacy of Alstom.

Why did EMT stick with VP?
Because it's a good engine. There is no case for going from VP to MTU. In fact the VP is more efficient: specific fuel consumption at full power for both types shows a slight advantage to the VP in terms of less fuel used. Any other difference between them is purely down to the duty cycle

 

[Arriva158]

Never had a VP185 failure but had an MTU failure! So in my eyes its VP plus they sound 10x better!

 

[junglejames]

Ive heard something similar regarding MTU and FGW. FGW basically didnt care what the VP was like. They had made their mind up.
The big advantage with the MTU is how quiet it is. To be honest, there is no denying, the MTUs seem good engines. The trouble is, because we are used to HSTs scaring the hell out of little children, an MTU now sounds totally wrong. Its like to me, a 57 sounds wrong, because im used to the sound 47s make (seperate subject, are 57s any better than 47s in any sense?!!! They seem to be just as (un)reliable))

If HSTs had been built with MTUs to start with, would we be saying we didnt like them?

I dont know which is better between a VP and an MTU, but I know one thing for sure. The MTUs use a hell of a lot less fuel than an original Valenta, and im getting used to the noise it makes now. Its just the 66s and 67s I cant get my head round.

 

[At_traction]

If HSTs had been built with MTUs to start with, would we be saying we didnt like them.

Indeed & probably quite true. Thank God they didn't though...

Or if a V8 car engine had always sounded like a Nissan in-line 4, the yank car owners would have one less thing to feel sanctimonious about their rusting "wheels"...

 

[LE Greys]

Ive heard something similar regarding MTU and FGW. FGW basically didnt care what the VP was like. They had made their mind up.
The big advantage with the MTU is how quiet it is. To be honest, there is no denying, the MTUs seem good engines. The trouble is, because we are used to HSTs scaring the hell out of little children, an MTU now sounds totally wrong. Its like to me, a 57 sounds wrong, because im used to the sound 47s make (seperate subject, are 57s any better than 47s in any sense?!!! They seem to be just as (un)reliable))

If HSTs had been built with MTUs to start with, would we be saying we didnt like them?

I dont know which is better between a VP and an MTU, but I know one thing for sure. The MTUs use a hell of a lot less fuel than an original Valenta, and im getting used to the noise it makes now. Its just the 66s and 67s I cant get my head round.

It's strange, they've gone from soprano to baritone. MTUs don't sound too bad, there's a deep, powerful rumble underpinning the noise, even though it's quiet. VP185s sound like a soprano with a frog in her throat.

In terms of what I'd want to be powering my motor yacht, then an MTU. They use less fuel, don't break down as often and are quieter (I'd remove the turbo and have two engines instead, more reliable that way).

Actually, do MTUs have turbos? It doesn't sound as though they do.

 

[junglejames]

It's strange, they've gone from soprano to baritone. MTUs don't sound too bad, there's a deep, powerful rumble underpinning the noise, even though it's quiet. VP185s sound like a soprano with a frog in her throat.

In terms of what I'd want to be powering my motor yacht, then an MTU. They use less fuel, don't break down as often and are quieter (I'd remove the turbo and have two engines instead, more reliable that way).

Actually, do MTUs have turbos? It doesn't sound as though they do.

But didnt somebody claim VPs use less fuel? To be honest, I dont know the difference between VPs and MTUs. Just know the original Valentas were hellishly thirsty girls.
Yes, the MTUs do have quite a powerful sound, which as time goes by, I think we will start to see that perhaps this noise could sound right inside a HST. Afterall, they are powerful looking locos.

As for turbos. Virtually all diesel engines have turbos i think.
Im pretty certain the MTUs have turbos. The thing with the VPs and Valentas, is that due to the design of the engine, the turbo spun at a much much faster rate than on the MTUs. Hence the screaming banshee!! That is what the scream is on a Valenta. A turbo spinning bloomin fast.
MTUs dont require the turbo to spin as fast, and so you dont get the scream.

 

[43034 The Black Horse]

As for turbos. Virtually all diesel engines have turbos i think.
Im pretty certain the MTUs have turbos. The thing with the VPs and Valentas, is that due to the design of the engine, the turbo spun at a much much faster rate than on the MTUs. Hence the screaming banshee!! That is what the scream is on a Valenta. A turbo spinning bloomin fast.
MTUs dont require the turbo to spin as fast, and so you dont get the scream.

Turbo scream down to size as well as speed.

Valenta has one mahoooosive turbo
VP has 6
MTU has 4

Have a read up on this: http://www.paxmanhistory.org.uk/paxeng34.htm#vp185

The rest of the site is also a damn good read too!

 

[LE Greys]

As for turbos. Virtually all diesel engines have turbos i think.
Im pretty certain the MTUs have turbos. The thing with the VPs and Valentas, is that due to the design of the engine, the turbo spun at a much much faster rate than on the MTUs. Hence the screaming banshee!! That is what the scream is on a Valenta. A turbo spinning bloomin fast.
MTUs dont require the turbo to spin as fast, and so you dont get the scream.

Not surprised, makes sense for a locomotive in terms of keeping weight down. Deltics are unusual in not having turbos, which seems slightly odd considering their power, but they idle at the same speed that a Sulzer 12LDA28-C runs flat-out. Valentas and Maybachs are very high-revving as well, not sure about MTUs. Perhaps that's another thing that helps in producing a "good" sound, Westerns and Deltics are famous for it.

Incidentally, the reason for having a normally-aspirated engine on a boat is simple reliability. Gives you a big, comfortable engine that doesn't use too much fuel. Also best to have two, which makes manoeuvring easier and gives you a backup in case of failure. Having to maintain it at sea is another problem, best if there isn't too much to break.

However, I don't know of many motor yachts using 2,000-plus horsepower engines.

 

[jopsuk]

the Navy certainly have some boats with turbos- the Rigid Raiders used by the Marines have very high speed ones.

Most car diesels have them these days as on that scale/the way they're run they're very good for increasing power from a more efficient (emissions and consumption) engine. But I can remember a time when I and my cousin both had 1.7l diesel Astras- his van was normally aspirated, my estate was turbo. The van was normally aspirated as they're simpler engines.

 

[junglejames]

Not surprised, makes sense for a locomotive in terms of keeping weight down. Deltics are unusual in not having turbos, which seems slightly odd considering their power, but they idle at the same speed that a Sulzer 12LDA28-C runs flat-out. Valentas and Maybachs are very high-revving as well, not sure about MTUs. Perhaps that's another thing that helps in producing a "good" sound, Westerns and Deltics are famous for it.

Incidentally, the reason for having a normally-aspirated engine on a boat is simple reliability. Gives you a big, comfortable engine that doesn't use too much fuel. Also best to have two, which makes manoeuvring easier and gives you a backup in case of failure. Having to maintain it at sea is another problem, best if there isn't too much to break.

However, I don't know of many motor yachts using 2,000-plus horsepower engines.

Oh it goes without saying that its best to have 2 per yacht.
2 props, each with its own engine, and 2 rudders, one behind each prop. Also gives you more power for your bow thrusters as well. Much more manouverable.
Dont turbos mean less fuel consumption though? I know on cars it usually does. On a yacht turbos arent really necessary though.
Just to put this on topic. The Yacht will be pitted against a 43 in a manouvering competition to see who wins!! Hopefully shouldnt get shouted at now!!

 

[kestrel]

All you Valenta fans should be voting for the Vee-Pee as it is basically a Valenta, albeit a modernised version.

I only drive VP's and so can't really comment on actual performance versus an MTU, but a VP is significantly derated (with 6 turbo's) and so on paper at least, should be more reliable.

The VP185 is a complete new design

I was involved in a project about 15yr ago now and during a visit to the Paxman site saw an 18 cylinder version on test very impressive!

Whilst on my visit i was explained that they were working on an 'electronic' version of both the 12 and 18 cylinder versions for Rail and Industrial use, if they had continued this development it would have blown the pants off the MTU! but as has been said Alsthom (as it was known then) seemed to give up with it and then under the MAN group, which is a shame as it is a much more efficient engine compared to the MTU, low pressure and high pressure turbocharging with intercooling and aftercooling, torque output is better than the MTU which is all top end with its basic turbocharging (4 turbo's plus intercoolers) and smaller capacity.
Shame the renewed interest in the VP didn't come earlier, as for noise the VP and MTU are on par with eachother, the Valenta is on another level but alot of noise shows how inefficient it was
--- old post above --- --- new post below ---

Not surprised, makes sense for a locomotive in terms of keeping weight down. Deltics are unusual in not having turbos, which seems slightly odd considering their power, but they idle at the same speed that a Sulzer 12LDA28-C runs flat-out. Valentas and Maybachs are very high-revving as well, not sure about MTUs. Perhaps that's another thing that helps in producing a "good" sound, Westerns and Deltics are famous for it.

Incidentally, the reason for having a normally-aspirated engine on a boat is simple reliability. Gives you a big, comfortable engine that doesn't use too much fuel. Also best to have two, which makes manoeuvring easier and gives you a backup in case of failure. Having to maintain it at sea is another problem, best if there isn't too much to break.

However, I don't know of many motor yachts using 2,000-plus horsepower engines.

Valentas/maybachs/MTU's/Napier Deltics all run at 1500rpm, the Napier did have a turbocharger being fitted to the T9's in the 'baby deltics', being a 2 stroke engine it did need force feeding and had a supercharger to force the air into the cylinders which both the 9 and 18cylinder versions had

 

[starrymarkb]

it is interesting that FGW went for MTU - MTU was formed from Maybach which was rather popular on the western

 

[aspierail]

For me its VP185 as i prefer the sound of them however the sound of MTU's are certainly improving though.

 

[DaveNewcastle]

Valentas/maybachs/MTU's/Napier Deltics all run at 1500rpm, the Napier did have a turbocharger being fitted to the T9's in the 'baby deltics', being a 2 stroke engine it did need force feeding and had a supercharger to force the air into the cylinders which both the 9 and 18cylinder versions had

Yes, I was about to reply in a similar way to the point that a Napier Deltic engine didn't have a turbocharger.
The potential for a turbo in a 2-stroke engine is very restricted. Its a very different process. But they DID have a "scrubber" which forced the evacuation of exhaust, and also, the 2 opposing pistons in each cylinder were staggered in time to provide additional force to remove exhaust and vacuum to draw in fuel.

Dont turbos mean less fuel consumption though?

A tubocharger improves torque during higher engine speeds. If the design of the whole engine+transmission can use that torque to reduce fuel consumption, then yes. But it doesn't follow automatically.
A turbo takes advantage of engergy (and heat) that might otherwise be lost and uses it to assist in fuel intake. Outside certain ranges of rev.s then it is simply a hinderance.
A supercharger (as kestrel hinted) performs a similar improvement to fuel injection at lower revs.
The best efficiency, and therefore the best fuel economy, is achieved at a single, constant, designed operating speed and load.
One of the design engineer's tasks is to maximise the potential to operate within that optimal range of speeds and loads. This is hard in stop-start rail engines and even harder in domestic motor cars, but a lot simpler in power generaton.