Hitachi 807 and 810 different max speeds?

[38Cto15E]

Am I correct in saying that the new Class 807's on the WCML Chester/Holyhead trains are limited to 110mph max on the WCML?
Yet the 810's being constructed for the MML will be able to run up to 125mph when the OHLE has been upgraded?
If I am correct why the different max speeds?

 

[Rich McLean]

Am I correct in saying that the new Class 807's on the WCML Chester/Holyhead trains are limited to 110mph max on the WCML?
Yet the 810's being constructed for the MML will be able to run up to 125mph when the OHLE has been upgraded?
If I am correct why the different max speeds?

Both 125mph (designed for 140mph). 805 & 807s currently restricted to 110mph on the WCML.

 

[MCR247]

Am I correct in saying that the new Class 807's on the WCML Chester/Holyhead trains are limited to 110mph max on the WCML?
Yet the 810's being constructed for the MML will be able to run up to 125mph when the OHLE has been upgraded?
If I am correct why the different max speeds?

The trains don’t have different max speeds, the lines they operate on do.

 

[pokemonsuper9]

The trains don’t have different max speeds, the lines they operate on do.

While that is true to some extent, it's also due to 80x not having the speed supervision of TASS (I know 80x have their own speed limiter, but I believe TASS does some things the base 80x can't).

 

[Halish Railway]

The trains don’t have different max speeds, the lines they operate on do.

This isn’t quite correct - The 805s and 807s, as with any 80X have a design speed of 140mph, although they are currently limited by railway infrastructure (lack of in cab signalling primarily) and computerised limiters as requested by their operators to prevent overspeeds.

The 810s have a design speed of 125mph as their shorter carriages (24m as opposed to 26m) has resulted in a smaller crumple zone to maximise space efficiency, thus not enough crash protection to allow a design speed greater than 125mph.

 

[LNW-GW Joint]

While that is true to some extent, it's also due to 80x not having the speed supervision of TASS (I know 80x have their own speed limiter, but I believe TASS does some things the base 80x can't).

It's the lack of tilt (which needs TASS) that prevents 80x running at Pendolino speeds on the WCML.
We are told the MU speed profile planned for the WCML will allow some 125mph running by non-tilt trains, but not as much as the tilt-equipped 390s.
HS2 trains will likely have the same MU speed profile on the classic WCML.

 

[pokemonsuper9]

It's the lack of tilt (which needs TASS) that prevents 80x running at Pendolino speeds on the WCML.
We are told the MU speed profile planned for the WCML will allow some 125mph running by non-tilt trains, but not as much as the tilt-equipped 390s.

My post was considering the MU profile ("to some extent"), since that's what ihe infrastructure can do, it's just not signed off yet.
There are already some 125mph areas of the WCML that they would be able to go 125 on if not for the lack of Speed Supervision.

 

[Tilting007]

My post was considering the MU profile ("to some extent"), since that's what ihe infrastructure can do, it's just not signed off yet.
There are already some 125mph areas of the WCML that they would be able to go 125 on if not for the lack of Speed Supervision.

It works out at around 30 miles between Euston and Crewe for 125 MU, with other spots 115 or 120. There are over 30 speed changes planned in the MU sites between Euston and Weaver, whereas the EPS for class 390 had very few changes in comparison.
The EPS for 221s will remain so any curves that could take an MU speed will be unable to have one implemented where the EPS differential exists.

 

[38Cto15E]

Thks for all of your replies.

 

[Doomotron]

The 810s have a design speed of 125mph as their shorter carriages (24m as opposed to 26m) has resulted in a smaller crumple zone to maximise space efficiency, thus not enough crash protection to allow a design speed greater than 125mph.

That said, I think Hitachi would have been perfectly capable of designing the trains for 140mph despite the coach length - the 395s only have 20m coaches.

 

[notadriver]

There’s also a possibility that 810s have an inferior power to weight ratio than other 80x in electric mode. Only 2 coaches of 5 are motored albeit at a higher rating.

 

[D365]

There’s also a possibility that 810s have an inferior power to weight ratio than other 80x in electric mode. Only 2 coaches of 5 are motored albeit at a higher rating.

All the more reason to replace the 810s once MML is electrified to Nottingham and Derby.