Why do trains slow down so far away from stations?

[Deltic1961]

Specifically looking at Aberdeen to Dyce. Inward to Aberdeen the tain travels at 70 then slows down to 40 a couple of miles out for no apparent reason then 30 about a mile from the station. Same coming back to Dyce .... it slows down to 30 quite a bit away from the station. I get why there are speed restriction for cars in buit up areas but why trains?

It's double tracked, no obstructions or other trains so why the sudden slowdown on a clear track.

 

[hexagon789]

Specifically looking at Aberdeen to Dyce. Inward to Aberdeen the tain travels at 70 then slows down to 40 a couple of miles out for no apparent reason then 30 about a mile from the station. Same coming back to Dyce .... it slows down to 30 quite a bit away from the station. I get why there are speed restriction for cars in buit up areas but why trains?

It's double tracked, no obstructions or other trains so why the sudden slowdown on a clear track.

Do you mean why do they brake to slow down so far out or why are there the low speed restrictions?

 

[Deltic1961]

Why are there speed restrictions so far away from the stations?

 

[hexagon789]

Why are there speed restrictions so far away from the stations?

Looking at the sectional appendix it doesn't look like they are very far out. From Aberdeen the speed limit drops from 75 to 40mph 10 chains (200m) from the station, and then rises to 60mph only 3 chains (60m) the other side.

 

[Deltic1961]

No, in reality it's a lot further than that.

 

[hexagon789]

No, in reality it's a lot further than that.

Where the limits apply from or where the trains brakes?

 

[Deltic1961]

Where the train slows down from 60 to 40

 

[Mattyblob]

It's leaf fall so drivers may be increasing their braking distance (but are well within their rights to do so all year round anyway), it could be a company instruction, it could be a nasty set of overspeed grids preceding the PSR etc

 

[Deltic1961]

Been lke that since the double track went live, and that was some time ago. It does speed up journeys on the main section being 70 but it is still very slow for quite a distance out of the stations.

 

[hexagon789]

Where the train slows down from 60 to 40

Trains take a good distance to slow down unlike cars and autumn leaf fall extends braking distances?

I can't really offer any other explanation, I'm sure the drivers will start slowing down where experience says is the best point, and then even earlier at thhistine of year.

The limits are in the sectional appendix as I stated and I'd expect that from 60mph to a stop at the platform I think you'd be looking at around 1/2mi braking distance on a defensive approach using light braking, maybe even longer.

 

[Deltic1961]

Are there any diagrams of the track layout and speed limits set?

 

[Darandio]

Are there any diagrams of the track layout and speed limits set?

Yes, in the Sectional Appendix for Scotland. Page 805.

 

[ArchangelA]

Could be for all sorts of reasons, temporary or actual speed restrictions, track/bridge/embankment geometry meaning trains should slow down for safety reasons, seasonality (adhesion issues), level/foot/UWCXings, distant signal showing danger ahead...take your pick!

 

[hexagon789]

Are there any diagrams of the track layout and speed limits set?

From the Sectional Appendix:

 

[Deltic1961]

Thanks for the diagrams. Will check when I get the train tomorrow to see if it matches.

 

[Deepgreen]

Specifically looking at Aberdeen to Dyce. Inward to Aberdeen the tain travels at 70 then slows down to 40 a couple of miles out for no apparent reason then 30 about a mile from the station. Same coming back to Dyce .... it slows down to 30 quite a bit away from the station. I get why there are speed restriction for cars in buit up areas but why trains?

It's double tracked, no obstructions or other trains so why the sudden slowdown on a clear track.

Are you basing the question on your observation of the placement of speed restriction signs or from your estimations of speed travelled?

 

[Deltic1961]

Estimation of speed travelled.

 

[Mattyblob]

Thanks for the diagrams. Will check when I get the train tomorrow to see if it matches.

What are you hoping to achieve with this line of enquiry anyway? I'm stumped

 

[Deepgreen]

Estimation of speed travelled.

OK. Speed travelled at will depend on the permanent (and temporary) speed restrictions in place, assuming all else is normal. Signal aspects at the time may then add further controls on speed experienced on a particular train. Permanent speed restrictions will have been determined historically based on track layout, gradients, signal spacing/sighting and so on. Some of those factors may not be immediately obvious to the traveller.

 

[trebor79]

Stopping trains approach my local station at very slow speed for reasons I've never been able to fathom. Line speed is 70 I think and non-stop do come through at that speed.
But stopping trains slow down to about 20 long before the station, and then creep over the level crossing at little more than walking pace.
There was one once that hit the end of the platform at about 60 (I suspect the driver forgot) and managed to stop within the platform, albeit further down than usual. So it's odd that they crawl on so slowly.

 

[hexagon789]

Stopping trains approach my local station at very slow speed for reasons I've never been able to fathom. Line speed is 70 I think and non-stop do come through at that speed.
But stopping trains slow down to about 20 long before the station, and then creep over the level crossing at little more than walking pace.
There was one once that hit the end of the platform at about 60 (I suspect the driver forgot) and managed to stop within the platform, albeit further down than usual. So it's odd that they crawl on so slowly.

Company policy may require it. ScotRail for example have a 25mph entering through platforms policy I believe and a Step 1 initial brake application policy.

Many TOCs are similar since the whole modern defensive driving policies appeared in the early 2000s.

 

[TheEdge]

Stopping trains approach my local station at very slow speed for reasons I've never been able to fathom. Line speed is 70 I think and non-stop do come through at that speed.
But stopping trains slow down to about 20 long before the station, and then creep over the level crossing at little more than walking pace.
There was one once that hit the end of the platform at about 60 (I suspect the driver forgot) and managed to stop within the platform, albeit further down than usual. So it's odd that they crawl on so slowly.

It depends on the exact location, signaling, professional driver policies and an abundance of other things.

Brundall heading away from Norwich could look like this to an observer on the platform. If the distant at Brundall Gardens was yellow by the time I round the curve at Brundall to long platform with a now green signal at the end it would appear I was crawling around. But that would be because I'm anticipating a red and being careful of the two sets of TPWS loops on approach.

 

[MoleStation]

Approaching Durham from the north it gets really really slow on any stopper even though there's no change of lines, whereas through trains, those London ones, keep a really good speed even though they have to slow down for the viaduct curve. Standing on the southbound platform watching a through train steam through takes no time but a stopping train on a straight-ish line seems to take ages to approach Durham.
A northbound train if stopping has those flashing double yellow signals miles down(up?)the line, at a place called Littleburn. Although then they go into the down loop at Durham, but at 40mph max.
I had to reply as I totally don't understand it too. It's been the same since when I was a kid, apart from the flashing double yellows at Littleburn....

 

[scotraildriver]

Company policy may require it. ScotRail for example have a 25mph entering through platforms policy I believe and a Step 1 initial brake application policy.

Many TOCs are similar since the whole modern defensive driving policies appeared in the early 2000s.

Not quite. Scotrail policy is 20mph (maximum, not target) at the start of a through platform and 15mph for a buffer end platform unless occupied then it's 10mph. Initial brake is step 2.

 

[driverd]

Not quite. Scotrail policy is 20mph (maximum, not target) at the start of a through platform and 15mph for a buffer end platform unless occupied then it's 10mph. Initial brake is step 2.

Gosh I really do dislike overly prescriptive driving policies - takes a lot of the professional judgement out of the equation. Also for numerous reasons can actually introduce more risk.

Absolute tangent anywho, so to come back on topic, if an approach in general is slow the most likely reason is signalling. Approaching a station (at a TOC where our PDP isn't as restrictive) on greens would typically see me be at 20-30mph at the start of the platform (depending on traction, platform length, weather conditions); on restrictive aspect, with a starting signal and an AWS magnet at/before the start of the platform, I'd be hitting the platform at absolute tops 15 mph.

Makes quite a significant difference, especially in known low adhesion areas.

 

[Val3ntine]

Stopping trains approach my local station at very slow speed for reasons I've never been able to fathom. Line speed is 70 I think and non-stop do come through at that speed.
But stopping trains slow down to about 20 long before the station, and then creep over the level crossing at little more than walking pace.
There was one once that hit the end of the platform at about 60 (I suspect the driver forgot) and managed to stop within the platform, albeit further down than usual. So it's odd that they crawl on so slowly.

That may just be your answer there, you mention a level crossing. Non-stopping trains perhaps get green signals all the way through (the crossing is lowered way in advance as to not cause the train to needlessly slow down then pick up speed again potentially losing time), whereas stopping trains get restrictive signalling and the crossing is lowered later. Not a definite answer but a possibility.

 

[Seehof]

As a driver you always drive with care, obey all speed restrictions to the letter and use your experience and local conditions to judge braking distance before any station. Those that know York might be interested to know that I was taught that if you had green signals coming from the south you still never did more than 70mph passing Tesco’s.

 

[Deepgreen]

Stopping trains approach my local station at very slow speed for reasons I've never been able to fathom. Line speed is 70 I think and non-stop do come through at that speed.
But stopping trains slow down to about 20 long before the station, and then creep over the level crossing at little more than walking pace.
There was one once that hit the end of the platform at about 60 (I suspect the driver forgot) and managed to stop within the platform, albeit further down than usual. So it's odd that they crawl on so slowly.

Not knowing which is your local station makes it hard to help here, but there is no station in the UK which has a line speed and platform length combination which would allow a train entering the platform at 60 to stop in the platform. Trains simply cannot stop that quickly even in ideal railhead conditions.

== Doublepost prevention - post automatically merged: 4 Nov 2021 ==

Gosh I really do dislike overly prescriptive driving policies - takes a lot of the professional judgement out of the equation. Also for numerous reasons can actually introduce more risk.

Absolute tangent anywho, so to come back on topic, if an approach in general is slow the most likely reason is signalling. Approaching a station (at a TOC where our PDP isn't as restrictive) on greens would typically see me be at 20-30mph at the start of the platform (depending on traction, platform length, weather conditions); on restrictive aspect, with a starting signal and an AWS magnet at/before the start of the platform, I'd be hitting the platform at absolute tops 15 mph.

Makes quite a significant difference, especially in known low adhesion areas.

I suspect that incidents such as Salisbury can only add prescription to driving policies (without ascribing any blame to the driver there).

 

[driverd]

Not knowing which is your local station makes it hard to help here, but there is no station in the UK which has a line speed and platform length combination which would allow a train entering the platform at 60 to stop in the platform. Trains simply cannot stop that quickly even in ideal railhead conditions.

You'd be amazed what modern brakes can do - certainly based on the traction I'm familiar with, anything built after 2015 could probably manage that on a platform of circa 150-200m. Of course you'd never do this intentionally in service (only found out through practical handling experience during traction training), as it requires an emergency brake application, but it's certainly well within the capabilities of modern brake systems.

I suspect that incidents such as Salisbury can only add prescription to driving policies (without ascribing any blame to the driver there).

Pulling any comment at this moment as I personally think it behoves us all to wait for the full report before speculating, especially given the media attention at present.

 

[Deepgreen]

You'd be amazed what modern brakes can do - certainly based on the traction I'm familiar with, anything built after 2015 could probably manage that on a platform of circa 150-200m. Of course you'd never do this intentionally in service (only found out through practical handling experience during traction training), as it requires an emergency brake application, but it's certainly well within the capabilities of modern brake systems.



Pulling any comment at this moment as I personally think it behoves us all to wait for the full report before speculating, especially given the media attention at present.

So it is possible to bring a train to a stop from 60mph in 150m such that the whole train is in the platform? The poster didn't mention anything about reversing back, being unable to open the doors, etc., so I assume the whole train was in the platform. Wow, that is very impressive.