Should 185s be permitted to use MU speed limits and possible future use

[MattRat]

What I mean is that people get excited about assigning vehicle numbers to new/converted vehicles before even thinking about whether their proposals make engineering sense.

The engineering part makes sense. Modern technology allows lighter, more efficient, but just as powerful engines, and also lighter but just as strong bogies.

The only two issues might be cost (which could be balanced out with money lost if they don't get used in the current state), and electronics, since modern engines are filled to the brim with computers, so might not be compatible with the old computer currently on 185s. But that could also hopefully be sorted in the retrofit.

 

[skyhigh]

The engineering part makes sense. Modern technology allows lighter, more efficient, but just as powerful engines, and also lighter but just as strong bogies.

The only two issues might be cost (which could be balanced out with money lost if they don't get used in the current state), and electronics, since modern engines are filled to the brim with computers, so might not be compatible with the old computer currently on 185s. But that could also hopefully be sorted in the retrofit.

The current engine in a 185 weighs roughly 1900kg. Compare that to the engine in a 197 which only weighs 900kg - fit modern engines like that and it seems like a decent saving, right?

But you have to remember the total weight of a 185 is around 170t. Swap all 3 engines and you reduce the total unit weight by 1.7%. But because you've put new engines in, you then need to add all the new emissions kit to meet the latest standards, which will reduce the weight saving even further.

Swapping the engines will cost a lot and go nowhere towards making 185s be able to use SP differentials.

 

[MattRat]

The current engine in a 185 weighs roughly 1900kg. Compare that to the engine in a 197 which only weighs 900kg - fit modern engines like that and it seems like a decent saving, right?

But you have to remember the total weight of a 185 is around 170t. Swap all 3 engines and you reduce the total unit weight by 1.7%. But because you've put new engines in, you then need to add all the new emissions kit to meet the latest standards, which will reduce the weight saving even further.

Swapping the engines will cost a lot and go nowhere towards making 185s be able to use SP differentials.

What about the bogies? That's the other thing mentioned, unless there's something else that hasn't been mentioned like bodyshell.

 

[RailWonderer]

The current engine in a 185 weighs roughly 1900kg. Compare that to the engine in a 197 which only weighs 900kg - fit modern engines like that and it seems like a decent saving, right?

But you have to remember the total weight of a 185 is around 170t. Swap all 3 engines and you reduce the total unit weight by 1.7%. But because you've put new engines in, you then need to add all the new emissions kit to meet the latest standards, which will reduce the weight saving even further.

Swapping the engines will cost a lot and go nowhere towards making 185s be able to use SP differentials.

In comparison a 3 car class 380/0 weights 146t so not wholly surprising. I think the Desiro platform is fundamentally heavy.
There is a good article here talking about the class 185 bogie though. https://www.globalrailwayreview.com/article/2729/the-bogies-for-desiro-dmu-uk-class-185/

However, some challenging tasks had to be mastered. One was the integration of the new drive concept. Each vehicle is driven by its own power unit consisting of a diesel engine and a turbo drive. From this car body-mounted drive, a cardan shaft transfers the power to the bogie’s master and slave axle drives which are connected by an inter-axle cardan shaft.

So now a universal shaft had to run lengthwise through the bogie cutting through transoms and traction links of the EMU design.

Furthermore, the new bogie had to be toughened up for a higher axle load of 18.5 tonnes instead of 16.5 tonnes capability of the EMU bogie. So the trailer bogie had to be strengthened as well and therefore it had to be changed from the EMU design, too.

Technology has imporoved and a 2018 6 car 717 Desiro City weights 204t (102t for 3 coaches), so a huge weight saving (though it is an EMU).

 

[dosxuk]

Technology has imporoved and a 2018 6 car 717 Desiro City weights 204t (102t for 3 coaches), so a huge weight saving (though it is an EMU).

IIRC one of the key reasons for the Desiro City to even exist was to hit the weight requirements of the Thameslink tender - the existing Desiro platform would not have met the requirements so they had to go back to the drawing board and shave off weight everywhere they could.

 

[skyhigh]

What about the bogies? That's the other thing mentioned, unless there's something else that hasn't been mentioned like bodyshell.

I've got no idea about bogies so I didn't mention them, but I'd be surprised if there was a significant saving to be had easily.

I think it's probably a case of the whole units are built for reliability not lightness (particularly given they were built for specific routes) and short of major reengineering of the entire vehicles and systems you're not going to make much headway on reducing impact on the track.

 

[Duncan-231192]

Voyagers are heavy trains with big engines but they're not restricted by MU speeds and the fact that 175s were cleared after initially being restricted means you can ask whether 185s could also be cleared. It isn't ideal on the Hope Valley line when you have 158s which can run at 90mph but 185s limited to 50 or 60.

Voyagers are RA2, Super Voyagers RA4. Class 185's are RA5 same as a Deltic or a HST. Maybe they should be allowed to use HST differentials. Afterall, RA7 Class 91's use HST differential despite their axle load.

 

[Duncan-231192]

The 185's with their extreme bloat, only make sense for the transpennine routes, and if we're honest, only the northern one at that. They have little future prospects away from those routes due to their weight and power. It's not a paperwork issue which stops them from using higher speeds, it's a side-effect of their fundamental design. They're also extremely costly to run, with the three engines and their weight making them very fuel inefficient - so even a cascade to Northern is unlikely to be entertained when the 195s/170s are faster, cheaper and more flexible to run.

You have a point of fuel efficiency and emissions. I read somewhere years ago that Voyagers, Meridians, and 185's emit more pollution per passenger than the equivelant car journey.

 

[Duncan-231192]

According to the Sectional Appendix, class 185 units - along with 170s, 175s, 220s and 221s - are not permitted between Settle Junction and Carnforth Station Junction.

Why not a 220? They are RA2 same as a 158.

 

[MattRat]

Voyagers are RA2, Super Voyagers RA4. Class 185's are RA5 same as a Deltic or a HST. Maybe they should be allowed to use HST differentials. Afterall, RA7 Class 91's use HST differential despite their axle load.

Well since the 91s and HST will all be gone soon, I doubt they want to add something into a possibly defunct category. Unless they rename it to 185 differentials or something like that.

 

[class 9]

Why not a 220? They are RA2 same as a 158.

They've never been needed to work over that route, so the assessment won't have been done.

 

[D365]

Well since the 91s and HST will all be gone soon, I doubt they want to add something into a possibly defunct category. Unless they rename it to 185 differentials or something like that.

No the HSTs won’t all be gone…

And who is ”they”?

 

[The Planner]

Well since the 91s and HST will all be gone soon, I doubt they want to add something into a possibly defunct category. Unless they rename it to 185 differentials or something like that.

It wont be a defunct catergory, its about braking capability and not the class of train.