HST Speed Limit sign at Ashurst New Forest

I believe that the "HST" limit also applies to other types of trains including the likes of cl170s, Voyagers and pendos.

 

didnt know they were still called 253/254 units! (should we add 255?)

 

Class 67's are also HST speed permitted in certain areas

 

395 ?

 

Presumably the 395 isn't on the list as there's been no need to add it. North of the Thames they've not ventured outside HS1? presumably if someone did fancy testing one on the ECML (for example) it would be relatively easy to get it added.

 

Isn't the "HST" list more about how quickly the train can decelerate than how fast it can go or how good its acceleration? I.e. if the limiting factor on linespeed in a particular location is the overall stopping distance then trains with better brakes can be allowed to go faster?

 

It's also about the effect on track- a 185 could probably brake as fast, but allowing them to do HST speeds (up to the unit's own maximum) would cause damage.

 

Wondering why 170s and etc are so classified, but EMUs that are also designed for 100 mph aren't? Is it because of axle loadings?

 

My copy of SP has an amendment from December 2009 that includes 158/159 under HST.

For some reason they aren't listed in the online copy.

 

I think it is because 253/254s don't have engines under each carriage

 

Must have a look for the sign. The onyl one I know of is the 90 one the Totton side of the overbridge, on the Up.