Class 150 / 153 / 156 overspeed or speed limiter?

[Ghawk2005]

Back when they were first designed did they have speed limiters to 75mph or did the drivers just get in trouble if they went over the designed max speed?

also today - same question, have they since been modified with a speed limiter if not originally fitted ?

thanks

 

[O L Leigh]

My experience (although not related to Sprinters) is that a lot of stock does not have any speed limiter. Some of the newer classes may do, but pre-privatisation (and maybe some of the early post-privatisation stock too) is capable of over-speeding. I've accidentally crept over the maximum stock permitted speed a few times so I know it's possible.

On the Sprinter front, I heard a story from a colleague who was involved in delivering the first Cl156s to Norwich. He claims that the Met-Camm engineers wanted to brake test them en route, so they were wound up to 90mph down Stoke Bank and the emergency brake applied.

 

[RJ]

I was on a 156 tagged onto the back of a 158 which got up to 83mph. No sign of the 156 fuel supply being cut out or anything.

 

[hexagon789]

Back when they were first designed did they have speed limiters to 75mph or did the drivers just get in trouble if they went over the designed max speed?

also today - same question, have they since been modified with a speed limiter if not originally fitted ?

thanks

No speed limiters as built, very easy to make 85, even 90 on the 75mph 15x classes. And back then exceeding limits wasn't as strictly monitored as now, indeed I have heard that unofficially exceeding linespeed by a small-ish margin was tolerated, but PSRs less so.

I haven't seen anything about limiters being retro-fitted either.

There has been more than one story told of a 158 hauling a Pacer at close to the 'ton'.

 

[robbeech]

I was on a 156 tagged onto the back of a 158 which got up to 83mph. No sign of the 156 fuel supply being cut out or anything.

This is quite (unofficially) common on the Liverpool to Nottingham parts where you often see this mix of units. Similarly with a 158 + 153 historically.

 

[O L Leigh]

This is quite (unofficially) common on the Liverpool to Nottingham parts where you often see this mix of units. Similarly with a 158 + 153 historically.

It's also a bit different to a train overspeeding on it's own. It's not technically difficult for a faster train to cause a slower train it's in multi with to overspeed while staying within it's own operational parameters.

 

[Hairy Bear]

Early days, Flat out, they would consistently go up to 88mph which was the maximum the transmission would allow you to go.

 

[hexagon789]

Early days, Flat out, they would consistently go up to 88mph which was the maximum the transmission would allow you to go.

Would tie in nicely with the 85-90 reports. Any idea roughly what the engine speed would be at 88mph, presumably a fair bit higher than the nominal 2100rpm the engine is rated at?

 

[craigybagel]

The only Sprinters that I am aware of having a speed limiter retrofitted to are the ERTMS fitted 158s, where if you go much past 90 (don't ask me how much, I've obviously never tried it!) an alarm will sound. If you keep going any further the brakes will apply.

This can also be set up so that it applies above 75mph if running in multiple with a 150 or 153, avoiding the overspeeding issues that have occurred with such combinations in the past.

== Doublepost prevention - post automatically merged: 17 Dec 2021 ==

Early days, Flat out, they would consistently go up to 88mph which was the maximum the transmission would allow you to go.

These days of course in a 153 you're hard pushed to do even 75 without gravity assistance! With 150s even though they're well into their 30s they will happily sit at 75 in about notch 4 when on the level, suggesting there's still plenty more speed in them.

 

[LowLevel]

This is quite (unofficially) common on the Liverpool to Nottingham parts where you often see this mix of units. Similarly with a 158 + 153 historically.

I wouldn't say common - the usual high tech method of avoiding it is to put a small post-it note over the speedo on the 158 to cover the bit past 75.