Tay Rail bridge closed

[R4_GRN]

Tay rail bridge closed today because of 87 mph winds. I have never heard of any rail bridge being closed before is this a normal occurrence during very strong winds?

 

[Murph]

Tay rail bridge closed today because of 87 mph winds. I have never heard of any rail bridge being closed before is this a normal occurrence during very strong winds?

Not terribly surprising, really. The Tay Bridge is quite exposed to the winds. Putting it in context, 87mph is "hurricane force 12" (>= 64 knots / 74 mph), the highest wind force on the British Beaufort scale. I'd say it's quite prudent for them to close it under the circumstances.

 

[dysonsphere]

Not terribly surprising, really. The Tay Bridge is quite exposed to the winds. Putting it in context, 87mph is "hurricane force 12" (>= 64 knots / 74 mph), the highest wind force on the British Beaufort scale. I'd say it's quite prudent for them to close it under the circumstances.

And im sure they all remember what happened to the first bridge.

 

[Class 170101]

Tay rail bridge closed today because of 87 mph winds. I have never heard of any rail bridge being closed before is this a normal occurrence during very strong winds?

Well I think the Forth weas closed the last time Scotland had high winds - though that was due to the fact all trains were cancelled rather than closure of bridge.

 

[najaB]

Tay rail bridge closed today because of 87 mph winds. I have never heard of any rail bridge being closed before is this a normal occurrence during very strong winds?

No, it's not common for the rail bridge to close. The Firth of Tay is very exposed and gusts of >70mph aren't uncommon.

The road bridge closes to double-deckers when the gusts get above 60mph45mph, to high-sided vehicles around 7060mph and completely at 80mph, but this is the first time I've seen the rail bridge closed.

 

[PaxVobiscum]

And im sure they all remember what happened to the first bridge.

As eloquently(?) described here.

A "must read" if you are unfamiliar with it.

 

[Mugby]

And im sure they all remember what happened to the first bridge.

It's a subject which has always interested me and I've read extensively about it but I'll never subscribe to the theory that one of the carriages was blown off the rails by the wind.

Allowing that carriages were much lighter in those days, even Dugald Drummond, the Chief Mechanical Engineer of the North British Railway at the time said, after he had examined the vehicles following recovery, that he could not give any credence to such a suggestion.

 

[Murph]

It's a subject which has always interested me and I've read extensively about it but I'll never subscribe to the theory that one of the carriages was blown off the rails by the wind.

Allowing that carriages were much lighter in those days, even Dugald Drummond, the Chief Mechanical Engineer of the North British Railway at the time said, after he had examined the vehicles following recovery, that he could not give any credence to such a suggestion.

I think the idea is that it wasn't the wind load on the carriages alone, but the combination of wind load on the carriages and wind load on the structure (i.e. the rails were either moving about sideways, or displaced sideways).

 

[LWB]

It's a subject which has always interested me and I've read extensively about it but I'll never subscribe to the theory that one of the carriages was blown off the rails by the wind.

Allowing that carriages were much lighter in those days, even Dugald Drummond, the Chief Mechanical Engineer of the North British Railway at the time said, after he had examined the vehicles following recovery, that he could not give any credence to such a suggestion.

It's an incontrovertible fact that in a similar period** some carriages were blown off the rails on Levens viaduct. Photographs exist of the aftermath.


edit: From Wikipedia

To give a subsequent, well documented example, in 1903 a stationary train was overturned on the Levens viaduct but this was by a 'terrific gale' measured at Barrow in Furness to have an average velocity of 100 mph, estimated to be gusting up to 120 mph

** Actually some years later but trains essentially similar.

 

[R4_GRN]

I am 68 and I cannot remember of the bridge being closed before, the road bridge gets closed to high sided vehicles often but I had never heard of the rail bridge being closed.
Is it dangerous for the passengers? The middle sections are box sections so I would think they would protect from too much buffeting might be interesting at either end though especially at the Fife end as it is much higher than the Dundee end.

 

[jopsuk]

As eloquently(?) described here.

A "must read" if you are unfamiliar with it.

Exposing the unwary to McGonagall is cruel...

 

[12CSVT]

And im sure they all remember what happened to the first bridge.

An inquiry into the Tay Bridge disaster concluded a combination of bad design and poor workmanship.
http://en.wikipedia.org/wiki/Tay_Bridge_disaster

 

[johnnychips]

But you do know this one

http://www.mcgonagall-online.org.uk/gems/the-railway-bridge-of-the-silvery-tay

Bit embarrassing he had to write the second!

 

[PaxVobiscum]

But you do know this one

http://www.mcgonagall-online.org.uk/gems/the-railway-bridge-of-the-silvery-tay

Bit embarrassing he had to write the second!

Ahem! (Did you not see post #6?) :roll:

 

[NotATrainspott]

How high do crosswinds need to be to pose a danger of derailment?

 

[johnnychips]

Ahem! (Did you not see post #6?) :roll:

Yes. The one I posted is not the same. That one did actually bring him what he considered to be 'fame'. The one in post 6 is a sort of retraction. Please do not use your 'sarcastic eyes' emoticon before reading things properly.

 

[marks87]

In many ways, it's a bloody miracle that both bridges exist in the first place. The firth is incredibly exposed, so to have two bridges over it (one of which was built twice) is testiment to the engineering involved.

I'd find it a bit hairy to be on a train crossing the bridge in such strong winds. It's always better to be safe than sorry.

 

[SignalSighting]

I am 68 and I cannot remember of the bridge being closed before, the road bridge gets closed to high sided vehicles often but I had never heard of the rail bridge being closed.

To my certain knowledge the Tay Bridge was closed for two consecutive days during high winds in 2012 and around 12 hours during a bad storm in 2009. There is an agreed protocol for the management of rail traffic during high winds which has been in place for at least 20 years now. The Bridge closes to locomotive hauled trains at windspeeds between 50mph and 80mph and all trains at windspeeds in excess of 80mph. This is the same limit for complete closure as the road bridge. There is an anemometer located in the middle of the high girders which can be remotely interrogated by Network Rail Operations Control in Glasgow and this is supplemented by a handheld anemometer which is operated by the signaller at Tay Bridge South signalbox.

 

[St Rollox]

The Tay Bridge disaster, never seems to lose it horror after all the years.
Am i right in saying some of the passengers were never found.

 

[dysonsphere]

Exposing the unwary to McGonagall is cruel...

Extremly cruel having just read it

 

[PaxVobiscum]

Yes. The one I posted is not the same. That one did actually bring him what he considered to be 'fame'. The one in post 6 is a sort of retraction. Please do not use your 'sarcastic eyes' emoticon before reading things properly.

My apologies to you, and the offending emoticon is hereby withdrawn.

I would point out however, that the original poem was referenced (and linked to) in the link I posted, and those who read all the way down the page would have seen that:

If the events of the 28th December 1879 have indeed been long remembered outside the ranks of civil engineers and Dundonian rail passengers it is thanks to McGonagall’s poem. The Tay Bridge Disaster is by far his best known poem. How it became so is unclear. By his own account, it was his initial address to The Railway Bridge of the Silvery Tay that “was the only poem that made me famous universally”.

So my reply is not withdrawn, merely the emoticon.
Apologies, however, for any offence.

 

[Dougman]

I am 68 and I cannot remember of the bridge being closed before, the road bridge gets closed to high sided vehicles often but I had never heard of the rail bridge being closed.
Is it dangerous for the passengers? The middle sections are box sections so I would think they would protect from too much buffeting might be interesting at either end though especially at the Fife end as it is much higher than the Dundee end.

I used to get the train to Fife for work every day and I can think of two or three occasions in those five years that the rail bridge was closed for high winds.

Of course that means the road bridge is closed completely too so just had to work from home!

 

[DaveNewcastle]

Extremly cruel having just read it

Reference "Paula Nancy Millstone Jennings" of Essex, the author of the very worst poetry in the universe after whom the poetry of the Vogons, although potentially fatal, rated only the third bottom place. ("HitchhikersGuide to the Galaxy" Douglas Adams).

I wonder if Adams was inspired by the reputation of McGonagall, who is alleged to carry an umbrella to his readings to protect himself from the rotten fruit thrown at him.

 

[Joseph_Locke]

How high do crosswinds need to be to pose a danger of derailment?

Straightforward (and unhelpful) answer is when they are strong enough to create enouigh force to cause the windward wheels to lift off the rails. For a static, typical, modern passenger coach I make this about 115mph (1600Pa) on a 60 square metre sail acting about a point 3m up.

However, if the train is already experiencing lateral force due to cant deficiency on a curve then this can reduce dramatically.

 

[najaB]

However, if the train is already experiencing lateral force due to cant deficiency on a curve then this can reduce dramatically.

It also could be reduced if the train is in motion in a straight line and picks up a side to side oscillation.

 

[PHILIPE]

I did read elsewhere, how correct it is or the full details I don't know, that a train actually came onto the bridge but had to return to Leuchars.

 

[SignalSighting]

I did read elsewhere, how correct it is or the full details I don't know, that a train actually came onto the bridge but had to return to Leuchars.

No. A train was detained at Leuchars when the Bridge shut and after a short delay went through the road to start a service back to Edinburgh. The wind speed management protocol requires that any train on the Bridge is allowed to continue before the structure is closed to rail traffic. It takes a train four minutes to cover the length of the Bridge so it's far quicker to let a train cross normally than it would be to arrange an unsignalled wrong direction movement back to either end.