Trivia: Lowest EPS speed limit on the network

[HSTEd]

Well as you may or may not know, EPS speed limits are differential speeds used by Class 221s and Class 390s when their tilting system is operational.

Obviously there are EPS 125 speed limits on the network, but what is the lowest EPS speed limit?

 

[Ships]

I think there’s some 80/90 in places on CGJ7

 

[LNW-GW Joint]

I think there’s some 80/90 in places on CGJ7

There's a few 5mph differentials around Oxenholme and Penrith, and more 10mph EPS diffs over the fells.
It was part of the test stretch for tilt in the very beginning (2002-ish).
I'm not sure there were any changes (up or down) when it went into normal service.
Atherstone is 90/100 and Queensville is 75/85 which I think is the lowest/smallest diff on open line sections south of Acton Grange.
There are no EPS sections Acton Grange-Wigan.

 

[Joseph_Locke]

It can't be lower than 50, as that is the lowest speed the tilt/TASS system is specified for.

 

[a_c_skinner]

If those are the greatest differentials then tilt at best reduces lateral forces by about 25% which again (and I'm sorry to repeat this) seems to call into question the benefit of tilt on the WCML. That isn't to say tilt gains nothing, but that it gains only a little. Tilt does reduce the lateral forces (obviously) but the increase in going from 110 to 125 is about 29% (I think). Seeing all the other differentials quoted are less than this the benefit from tilt strikes me as modest. Apologies for something a little tangential (ha!) to the question posed.

 

[LNW-GW Joint]

If those are the greatest differentials then tilt at best reduces lateral forces by about 25% which again (and I'm sorry to repeat this) seems to call into question the benefit of tilt on the WCML. That isn't to say tilt gains nothing, but that it gains only a little. Tilt does reduce the lateral forces (obviously) but the increase in going from 110 to 125 is about 29% (I think). Seeing all the other differentials quoted are less than this the benefit from tilt strikes me as modest. Apologies for something a little tangential (ha!) to the question posed.

There are some larger differentials on the North Staffs line either side of Stoke.
95/125 around Aston and 95/120 south of Macclesfield.
The North Staffs PSR was originally 85mph and was raised in a few places under WCRM, unlike the main WCML.
The differentials are generally larger than on the 110mph WCML proper, but are usually only for a short distance (typically 2-3 miles).

 

[a_c_skinner]

I did wonder if the list was comprehensive. 95/125 is a 70% increase in sideways forces and I suspect very noticeable. OTOH if these are short sections...