Blanket speed restrictions

[waverley47]

There is another thread that has just opened up about the impact of the latest winter storm to hit the UK. While up in Scotland we have seen few effects of this, I know there has been flooding in Lancashire.

The introduction of a blanket speed restrictions across the network to combat this, and other storms across the country, seems to be a new development. Personally, I don't remember the introduction of such wide ranging measures until about three years ago, and then only sporadically. These seem to be used more regularly, and while they are undoubtedly necessary, I was wondering when policy changed towards introduction of such measures.

Are these a new thing, or did I just miss them in the last decade?

How extensive/often are these, and who makes the call?

What happens to delay repay, allocation of delay minutes ect when these are in place?

What is the reasoning behind a blanket maximum; is it proportional to line speed, driving line of sight, to combat wet rails ect?

Obviously this is a safety thing, and it's pretty self explanatory, but I was wondering if we could have a more in depth discussion into the use of blanket speed restrictions, as it's a newish and interesting development from an ops perspective.

 

[Bletchleyite]

A question I'd like to ask on this subject - do the TOCs have a set of timetables/diagrams for this eventuality, or does everything just run late and end up in a right mess by the end of the day?

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

 

[Horizon22]

I've seen Sussex and Kent routes often do these blanket speed restrictions for wind of approximately 60mph. They'll be made by the Route Control Manager by NR, often alongside TOC representatives and other people within Control teams. The reasoning is normally the risk of trees / embankments falling onto the track and/or flooding (in the case of high winds).

They are normally are accompanied by service alterations - terminating short etc. with some diagrams amendments made by Control teams (usually ad-hoc & overnight). The more notice, the less messy the end of the day is. For instance in the Kent area, longer distance trains might terminate at Tonbridge or Orpington and a slightly reduced service into London. This is normally only the case on weekends though - on weekdays peak trains are often taken out of the timetable and there's more general late running

Most routes probably do have a "base" to go from, which is usually from past experience of similar events.

 

[waverley47]

A question I'd like to ask on this subject - do the TOCs have a set of timetables/diagrams for this eventuality, or does everything just run late and end up in a right mess by the end of the day?

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

God that is an interesting question.

To add, what about single track lines? Somewhere like the West Highland, trains are timetabled to pass at specific intervals.

With a blanket speed restrictions, does everything just get later throughout the day, waiting where necessary? Or do certain trains get cancelled, for example if waiting at Rannoch for a token exchange means you miss your departure from the fort, does that second train not run? But that would imbalance units, because suddenly one train gets stuck at Fort William as more trains are on their way north, and that southbound train suddenly hasn't got a path southbound?

 

[Domh245]

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

Which emergency scenario do you prepare for, bearing in mind that your poor timetabling/planning staff have barely had a moment to breathe this year, or even the last few on certain TOCs that've been fighting to try and fix various issues? The emergency timetable you need for blanket speed restrictions in one area is different to the one you need for a closure in one place which is different to the one you need for a closure in a different place. And that's before considering the different combinations of 'emergencies' you get and how they'd interact

Reactively firefighting by cancelling trains on the day is the only practical solution as I see it, unless of course there are particular lines which are more prone to failure than others (Conwy cough cough)

 

[Bletchleyite]

Which emergency scenario do you prepare for, bearing in mind that your poor timetabling/planning staff have barely had a moment to breathe this year, or even the last few on certain TOCs that've been fighting to try and fix various issues? The emergency timetable you need for blanket speed restrictions in one area is different to the one you need for a closure in one place which is different to the one you need for a closure in a different place. And that's before considering the different combinations of 'emergencies' you get and how they'd interact

Reactively firefighting by cancelling trains on the day is the only practical solution as I see it, unless of course there are particular lines which are more prone to failure than others (Conwy cough cough)

I was specifically referring to pre-announced blanket (usually 50mph?) speed restrictions, common due to high winds (though I suspect due to rain is a new one, based on the response to the Scottish HST derailment), not to more "random" stuff.

The Conwy Valley (which bit will wash away today, I wonder? ) and the Marston Vale (due to crewing issues and 230 reliability issues) are probably ones where you just want a pre-arranged bus contract to call in when needed.

 

[Horizon22]

I was specifically referring to pre-announced blanket (usually 50mph?) speed restrictions, common due to high winds (though I suspect due to rain is a new one, based on the response to the Scottish HST derailment), not to more "random" stuff.

The Conwy Valley (which bit will wash away today, I wonder? ) and the Marston Vale (due to crewing issues and 230 reliability issues) are probably ones where you just want a pre-arranged bus contract to call in when needed.

Depends of course how much "pre-announcement" there is. 24h will allow a Control overnight team the potential to do probably one day's amendments. If it's a prolonged period as per any service alteration, the amended timetable will get smoother as each day progresses.

 

[Domh245]

I was specifically referring to pre-announced blanket (usually 50mph?) speed restrictions, common due to high winds (though I suspect due to rain is a new one, based on the response to the Scottish HST derailment), not to more "random" stuff.

Ah yes, would I see what you mean. I still think you'd have issues with finding the resource to pre-plan said emergency timetable, as well as the 'combinations' issue - unless you limit the preplanned timetables, and areas of restrictions, to a certain number beforehand but then you'd just get accused of being overly cautious for putting blanket restrictions on large areas that are advantageous for the planning ("why are we running the emergency timetable on line X when here in line Y the weather is fine")

 

[The Planner]

I was specifically referring to pre-announced blanket (usually 50mph?) speed restrictions, common due to high winds (though I suspect due to rain is a new one, based on the response to the Scottish HST derailment), not to more "random" stuff.

The Conwy Valley (which bit will wash away today, I wonder? ) and the Marston Vale (due to crewing issues and 230 reliability issues) are probably ones where you just want a pre-arranged bus contract to call in when needed.

Ah yes, would I see what you mean. I still think you'd have issues with finding the resource to pre-plan said emergency timetable, as well as the 'combinations' issue - unless you limit the preplanned timetables, and areas of restrictions, to a certain number beforehand but then you'd just get accused of being overly cautious for putting blanket restrictions on large areas that are advantageous for the planning ("why are we running the emergency timetable on line X when here in line Y the weather is fine")

You would need pre-defined agreed geographical limitations and timetables off the back of them. If the impact is bigger or smaller within that geographical area then its either over reaction or it still falls over and you live with it. A myriad of options is unfeasible and unwieldy.

 

[bunnahabhain]

A question I'd like to ask on this subject - do the TOCs have a set of timetables/diagrams for this eventuality, or does everything just run late and end up in a right mess by the end of the day?

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

EMR are terminating trains at Manchester Piccadilly for a right time restart heading back East due to the 40mph restriction imposed on their services from Dore to Birchwood. They're expecting a 20-25min delay upon arrival at Piccadilly which would probably translate into a 45-60min delay at Lime Street.

 

[driver9000]

Certainly been used for the last 15 years at least. In my experience Network Rail Scotland would put them out less frequently than LNW would and you could sometimes have worse weather in Scotland running at 100mph than on LNW where running at 50mph over a large area would be in force.

The idea behind them is risk mitigation usually against Infrastructure failure such as landslip and gives trains a better chance of stopping while keeping a service running.

 

[GB]

Not just used for bad weather. Blanket speed restrictions can and are used for very hot weather for OLE purposes and critical rail temperatures.

 

[alangla]

A question I'd like to ask on this subject - do the TOCs have a set of timetables/diagrams for this eventuality, or does everything just run late and end up in a right mess by the end of the day?

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

From observation, it always seemed like VT had pre-prepared plans for the immediate aftermath of most likely scenarios, e.g. north WCML problems = Birminghams turning at Preston, Trent Valley going as close to the blockage as possible & Edinburgh/Glasgow running as 1/9Zs from Carlisle as required/available. I got caught up in a wires down in the Oxenholme area on a Sunday a few years ago and it was really impressive how quickly a plan came together & staff turned out from home to assist.

 

[Bald Rick]

Are these a new thing, or did I just miss them in the last decade?

You missed them. I was putting them on over a decade ago.

How extensive/often are these, and who makes the call?

Whenever extreme weather leads to a significant risk of obstructions on the line (usually high winds, but sometimes heavy rainfall on saturated ground across a wide area leading to potential earthworks failures), or extremely high temperatures lead to a risk of track buckles over an extended area.

The decision is taken by the senior NR operations manager for the route, usually following an ‘extreme weather’ phone conference with all relevant parties a couple of days in advance.

What happens to delay repay, allocation of delay minutes ect when these are in place

Delay minutes still apply for trains that run. The weather is Network Rail’s fault. Delay repay is slightly different, as that applies only to trains confirmed as scheduled to run by 2200 the previous evening (with some exceptions).

What is the reasoning behind a blanket maximum; is it proportional to line speed, driving line of sight, to combat wet rails ect?

High wind blanket speeds are usually 50mph, sometimes 80mph (in some OLE areas).

The 50 does two things. It enables drivers to have a much better chance of spotting an obstruction on the line and stopping before it. Clearly this doesn’t apply everywhere, but the stopping distance of a modern passenger train at 50mph in emergency braking is about 200-250 metres, so the risk of striking an obstruction is greatly reduced. Secondly, in the event the train does not stop in time, the risk of derailment and / or damage to the train is also reduced. (After one storm in Kent, I remember about 20 units being out of action with damage to the cabs).

The 80 is about protecting the OLE - less force on the wire from the train reduces the risk of a ‘blow off’ dewirement, and it also gives drivers the chance to drop the pantograph(s) if they see an obstruction on the wire.

A question I'd like to ask on this subject - do the TOCs have a set of timetables/diagrams for this eventuality, or does everything just run late and end up in a right mess by the end of the day?

Generally not something off the shelf. But TOCs will usually make short notice changes to the plan I’m the 48 hours before the day of the storm. Typically this is whole cancellations, with added time at termini; and Avanti / LNER may put in some ‘slow running’ in their timings, as they are affected most by the restrictions.

If not, why not? Pre-prepared emergency timetables/sets of diagrams like the south WCML 2-track timetable are quite useful.

Several reasons:

1) it takes as much effort to prepare a workable, reliable, fully resourced contingency timetable as it does to prepare the normal timetable. Clearly you also need one for Saturday and Sunday too. It is a lot of effort for (potentially) little use. And there aren’t enough train planners to do it.

2) the contingency timetable would have to be rewritten each time the normal timetable for a given service group changes. For most service groups this most years.

3) TOCs with wide geographical areas would need multiple contingency options, depending where the speed restriction is.

4) because TOC timetables are so interlinked, one TOC moving to a contingency timetable on its own might introduce conflicts with operators that aren’t changing. Hence the need to consider each event on its own ‘merits’, and plan accordingly.

5) TOCs can change schedules and diagrams at a day’s notice - but they can’t do that with rosters. Therefore any change has to take into account likely staff availability (particularly important now!) and also rolling stock availability.

From observation, it always seemed like VT had pre-prepared plans for the immediate aftermath of most likely scenarios, e.g. north WCML problems = Birminghams turning at Preston, Trent Valley going as close to the blockage as possible & Edinburgh/Glasgow running as 1/9Zs from Carlisle as required/available. I got caught up in a wires down in the Oxenholme area on a Sunday a few years ago and it was really impressive how quickly a plan came together & staff turned out from home to assist.

That’s a contingency plan swinging in to action, not a contingency timetable.