Why is Swiss Cottage station so windy?

[Samuel88]

Whenever I get off at Swiss Cottage when you get to the top of the escalators it feels as if it's blowing a gale, what's the reason for this? I've only ever noticed this at Swiss Cottage.

 

[bramling]

Whenever I get off at Swiss Cottage when you get to the top of the escalators it feels as if it's blowing a gale, what's the reason for this? I've only ever noticed this at Swiss Cottage.

This is not uncommon in parts of LU, and is normally because the station as a whole has insufficient space to dissipate the air movements generated by trains, bearing in mind the “piston effect” where a train fitting tightly within a tunnel can cause quite significant displacement of air.

The normal solution is draught-relief shafts and tunnels, either purpose built or adapted from disused construction shafts or lift shafts. I don’t think Swiss Cottage has any of these features.

Nowadays standard practice is to have at least one shaft at each end of a station to deal with this issue, but even with complex modelling and planning unexpected air movements can happen.

 

[gottago]

Bethnal Green is like this and is absolutely freezing. Horrible in winter but great when you’re on a packed train in the summer and you get some brief relief when the doors open there.

Brixton’s escalator gusts will also ruin any hairdo you might have tried to style!

 

[edwin_m]

It's pretty windy up in the Alps...

(I'll get my coat. I'm going to need it.)

 

[rebmcr]

Kentish Town (Northern line) is absolutely phenomenal for this.

 

[Mikey C]

This is not uncommon in parts of LU, and is normally because the station as a whole has insufficient space to dissipate the air movements generated by trains, bearing in mind the “piston effect” where a train fitting tightly within a tunnel can cause quite significant displacement of air.

The normal solution is draught-relief shafts and tunnels, either purpose built or adapted from disused construction shafts or lift shafts. I don’t think Swiss Cottage has any of these features.

Nowadays standard practice is to have at least one shaft at each end of a station to deal with this issue, but even with complex modelling and planning unexpected air movements can happen.

Swiss Cottage is the first deep level station southbound, I can't think of any draught relief shafts between Finchley Road and Swiss Cottage as there would be no space, and Swiss Cottage presumably had escalators from the start so there are no disused lift shafts to reuse

I agree that it is an especially windy station, it really stands out!

 

[edwin_m]

Perhaps because the relative proximity of the tunnel portals means there is less resistance to the movement of air? At a station that isn't close to a portal the presence of other trains in front and behind limits the amount of air that can be dragged through.

 

[Adlington]

The weirdly powerful winds in metro stations might be explained by some basic rules of physics

The full version, by Kenny Breuer, an engineering professor at Brown University, can be read here.

 

[Far north 37]

Kilburn park station exact same as well.

 

[Ambient Sheep]

Chancery Lane was my thought.

 

[Jack Barry]

Getting back to Swiss Cottage, I had a walk round the area and there is a shaft in Adelade Road.

 

[Mikey C]

Getting back to Swiss Cottage, I had a walk round the area and there is a shaft in Adelade Road.

That's after the station though? (i.e. it's the other side of the first station once the trains goes into a tunnel)

 

[Jack Barry]

That's after the station though? (i.e. it's the other side of the first station once the trains goes into a tunnel)

In reply 2 it was mentioned about the piston effect and that there was no shaft, although the shaft is south of the station would it not ease the flow. Trains coming north go past before entering the station so there must be some effect.

 

[edwin_m]

The shaft just beyond the station means that air being pushed into the portals at Finchley Road has somewhere to go. It will improve ventilation but actually increase draughts.

 

[Jack Barry]

The shaft just beyond the station means that air being pushed into the portals at Finchley Road has somewhere to go. It will improve ventilation but actually increase draughts.

Thinking about it the air flow coming south from Finchley Road once at swiss Cottage platforms would go up the escalators to the booking hall. For northbound trains the shaft would help I suppose.

 

[bramling]

In reply 2 it was mentioned about the piston effect and that there was no shaft, although the shaft is south of the station would it not ease the flow. Trains coming north go past before entering the station so there must be some effect.

The Adelaide Road shaft is a tunnel fan shaft (*), not a draught-relief shaft, so it's not provided specifically for the purpose of easing draughts. Depending on the local dynamics it *may* well assist with that, or it could make things worse! The whole subject is a rather complex one, so not being expert I can't really offer more thoughts than that.

(* provided for the purpose of reducing tunnel temperatures)

 

[Jack Barry]

The Adelaide Road shaft is a tunnel fan shaft (*), not a draught-relief shaft, so it's not provided specifically for the purpose of easing draughts. Depending on the local dynamics it *may* well assist with that, or it could make things worse! The whole subject is a rather complex one, so not being expert I can't really offer more thoughts than that.

(* provided for the purpose of reducing tunnel temperatures)

Thanks for identifying what type of shaft. Can the fan be reversed if required?

 

[USBT]

Well apparently St. John's Wood is too. Special announcements as to its windy-ness will be made on Sunday for the Cricket World Cup final.

https://www.bbc.com/news/uk-england-london-48967296