‘Passing trains cause air turbulence, please stand behind the yellow line’

[William3000]

I was travelling along the Chiltern Mainline the other day and noticed these signs, which are common place on much of the network. My question is what is the requirement (if there is one for stations to display these signs). I notice that they don’t exist on the West Anglia Mainline but do on the Great Eastern Mainline, noting the maximum speed limits on those are 90mph and 100mph respectively. So is the threshold for such a sign 100mph or is it at the discretion of the operating company.

A fast train travelling at 90mph must still cause a fair amount of air turbulence so why is 100mph apparently the threshold?

 

[hexagon789]

I was travelling along the Chiltern Mainline the other day and noticed these signs, which are common place on much of the network. My question is what is the requirement (if there is one for stations to display these signs). I notice that they don’t exist on the West Anglia Mainline but do on the Great Eastern Mainline, noting the maximum speed limits on those are 90mph and 100mph respectively. So is the threshold for such a sign 100mph or is it at the discretion of the operating company.

A fast train travelling at 90mph must still cause a fair amount of air turbulence so why is 100mph apparently the threshold?

The threshold is 100mph. At 100mph and above both the yellow warning line and warning notices are required.

There are other standards over platform widths as well.

Effectively you have three categories in this respect:

Less than 100mph: no lines or notices required
100 to 125mph: yellow warning lines and notices are required
125mph and above: platforms must be closed to passengers if unoccupied by train

 

[stuu]

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

 

[zwk500]

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

Agreed. The Car trains are even worse.

 

[pokemonsuper9]

There are other standards over platform widths as well.

Do you know the platform width requirements?

 

[hexagon789]

Do you know the platform width requirements

I can't find the standards right now, but from memory I believe that under 100mph it's 2.5m and over 100mph is 3m.

 

[zwk500]

Do you know the platform width requirements?

Basic requirements are minimum unobstructed width 2.5m per side for an Island platform, or 3m for a single-sided platform.

The Yellow line must be 1m back <100mph, and 1.5m from the edge >100mph, IIRC.

I can't find the standards right now, but from memory I believe that under 100mph it's 2.5m and over 100mph is 3m.

Don't believe the absolute width standard actually changes until 125mph, above which a physical barrier is needed I think.

 

[hexagon789]

Don't believe the absolute width standard actually changes until 125mph, above which a physical barrier is needed I think.

Thanks, I couldn't remember the precise details just the figures.

 

[12LDA28C]

I was travelling along the Chiltern Mainline the other day and noticed these signs, which are common place on much of the network. My question is what is the requirement (if there is one for stations to display these signs). I notice that they don’t exist on the West Anglia Mainline but do on the Great Eastern Mainline, noting the maximum speed limits on those are 90mph and 100mph respectively. So is the threshold for such a sign 100mph or is it at the discretion of the operating company.

A fast train travelling at 90mph must still cause a fair amount of air turbulence so why is 100mph apparently the threshold?

At Banbury and possibly other stations along the Chilterns you'll also hear PA announcements advising passengers to make sure pushchairs / buggies are properly secured with their brakes on due to passing trains causing air turbulence.

This is a direct result of an incident at Banbury a couple of years ago where an unsecured pushchair was sucked off the platform edge and under a passing Freightliner. Fortunately the child was not in the pushchair at the time.

 

[zwk500]

Thanks, I couldn't remember the precise details just the figures.

No worries, I could well be wrong - it's been a while since I looked at the platform standards and I no longer have RSSB access.

 

[AM9]

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

Although the OP is referring to a notice that mentions air turbulence, there is also the additional matter of speed of approach. Repeated warnings including blasts on the horn from the driver still seem to leave a few people surprised when a train gets within seconds of where they are standing (at 200km/h a train will travel nearly 278m, i.e. longer than almost every through platform on the railway). This can be a particular problem where there are already trains at other platforms.

 

[hexagon789]

No worries, I could well be wrong - it's been a while since I looked at the platform standards and I no longer have RSSB access.

That's partly the problem, because you used to be able view the RSSB standards publically. Not so easy to check now!

 

[zwk500]

That's partly the problem, because you used to be able view the RSSB standards publically. Not so easy to check now!

Yes, I have a friend who does have an account but they scoff at me for being nerdy if I ask too often

 

[swt_passenger]

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

That’s why there’s also a lower speed threshold of 60 mph (I think from memory) for container train routes.

But, could someone with RSSB access please check the latest standard for container services? AIUI that’s the main reason, (according to the standards), for you to get lines without warning notices.

Of course there are numerous instances where lines are painted without being needed, eg in terminating bays. Staff then usually reply that they’re needed for dispatch checks anyway…

 

[GRALISTAIR]

Peter Kay made an amusing joke about this subject a few years back. It is extant on YouTube. I will not post as it could run foul of forum rules.

 

[Ashley Hill]

Peter Kay made an amusing joke about this subject a few years back. It is extant on YouTube. I will not post as it could run foul of forum rules.

Was it to do with a certain sign at Penrith?

 

[Taunton]

The Down Main platform at Slough, where exit barriers were placed on the platform, and substantial exit crowds spilled over the yellow line with passing 125mph services, commented on by me here multiple times, has been sorted out, with half the platform width railed off, other station users confined to the rear side, and the barriers placed inside the historic station building which we were long told could not be touched because it was a Listed Building, but now, miraculously, has been no problem to place them in there.

 

[GRALISTAIR]

Was it to do with a certain sign at Penrith?

Live at Bolton it was Preston Station -but he may have used Penrith at some time too.

Bring on the train!

 

[AlbertBeale]

Although the OP is referring to a notice that mentions air turbulence, there is also the additional matter of speed of approach. Repeated warnings including blasts on the horn from the driver still seem to leave a few people surprised when a train gets within seconds of where they are standing (at 200km/h a train will travel nearly 278m, i.e. longer than almost every through platform on the railway). This can be a particular problem where there are already trains at other platforms.

You don't say how long it takes to travel that 278m - other than, implicitly, "within seconds" - hence leaving the point you're making unclear. About 5 secs by my reckoning... So yes - one end of a 125mph train can get from one end of a platform to the other in 5 seconds or so.

(I still find it easier to convert mentally between mph and ft/sec than between km/h and m/s!)

 

[AM9]

You don't say how long it takes to travel that 278m, other than "within seconds", hence leaving the point you're making unclear. About 5 secs by my reckoning... So yes - one end of a 125mph train can get from one end of a platform to the other in 5 seconds or so.

(I still find it easier to convert mentally between mph and ft/sec than between km/h and m/s!)

Sorry, I meant to type 5 seconds having calculated it first. I can do both but in the 21st century I try to do metric for most things, I made it 5 seconds, - 200,000m/3600 = 55.55m/s, 278m in 5 seconds. It surprised me how far they get in such a short time. An electric train approaching that fast might well not be noticed if there was another train in the station at the time.

 

[Cherry_Picker]

At Banbury and possibly other stations along the Chilterns you'll also hear PA announcements advising passengers to make sure pushchairs / buggies are properly secured with their brakes on due to passing trains causing air turbulence.

This is a direct result of an incident at Banbury a couple of years ago where an unsecured pushchair was sucked off the platform edge and under a passing Freightliner. Fortunately the child was not in the pushchair at the time.

That incident was at Nuneaton, there’s a thread on it here - https://www.railforums.co.uk/threads/empty-pushchair-incident-at-nuneaton.155712/

The announcements are played all over the network, you even get them at Leamington Spa where the line speed through the station is 30/35 and that’s on the middle roads which don’t have platforms near them, and 30/25 in the platform loops.

 

[12LDA28C]

That incident was at Nuneaton, there’s a thread on it here - https://www.railforums.co.uk/threads/empty-pushchair-incident-at-nuneaton.155712/

There may well have been a similar incident at Nuneaton, but the one I referred to was certainly at Banbury. I've seen the station CCTV footage, it wasn't pretty.

Leamington Spa where the line speed through the station is 30/35 and that’s on the middle roads which don’t have platforms near them, and 30/25 in the platform loops.

Indeed, 35 on the DCV and 40 on the UCV line.

 

[Annetts key]

The yellow lines often are painted on platforms regardless of the line speed, such as here on platform 1 (bay) and platform 15 (line speed of 15MPH) as well as all the other platforms at Bristol Temple Meads.
Note photos from January 2022.

 

[leytongabriel]

Tfl have been advising passengers at some District line stations not to wear hats and scarfs because of air turbulence caused by trains.
A tad under 100mph methinks

 

[najaB]

The yellow lines often are painted on platforms regardless of the line speed...

There is something to be said for consistency. The message to passengers is to avoid the platform edge.

 

[zwk500]

Wasn't one of the original purposes of the yellow line to keep passengers from being swatted by Slam doors being opened early by arriving passengers? so any platform required the lines. It's only the additional room of 1.5m required for high-speed platforms.

 

[Annetts key]

Wasn't one of the original purposes of the yellow line to keep passengers from being swatted by Slam doors being opened early by arriving passengers? so any platform required the lines. It's only the additional room of 1.5m required for high-speed platforms.

I don’t know. But many stations with relatively low lines speeds in my area, have only gained the yellow lines relatively recently. So at that time, only the unmodified HSTs had slam doors. Everything else used power doors.

 

[Irascible]

Aero risk assessment weightings of high-speed ( streamlined ) trains are 0.17, container trains 0.36, car trains are 0.59, to give some idea of the relative problems. There's a vast array of mitigations suggested ( including moving the yellow line ).

 

[ac6000cw]

I think the threshold of 100mph for those notices makes no sense at all - the worst turbulence from a passing train I have ever experienced is from an intermodal train with lots of empty spaces, which would be going no more than 75mph. Far worse than a pendolino at 125

If you think our container trains are are bad for creating turbulence, you should experience the turbulence you get from a North American double-stack container train running at speed (they run up to 70 mph). Basically a procession of 20 feet tall blunt-ended 'vehicles' spaced apart due to the articulated well cars they are carried on. It's a bit like having a train of two-storey houses separated by driveways going past at speed...

If the one in the photo below (running through the 'Rocky Mountaineer' station at Banff in Canada) was running through at speed (it wasn't), you would want to be much further away than the yellow line suggests...

 

[RPM]

The yellow lines often are painted on platforms regardless of the line speed, such as here on platform 1 (bay) and platform 15 (line speed of 15MPH) as well as all the other platforms at Bristol Temple Meads.
Note photos from January 2022.

View attachment 129695
View attachment 129694

Useful to have yellow lines at busy stations. If pax are told to stay behind them it allows proper sighting lines for safe dispatch.