Why London closes when there is snow
Snow Day!!! \o/
As a person who originates from Snowy Parts I'm usually somewhat dubious about disruptions due to snow in Southeast England. Generally the media seems to hype up the disruption rather more than is warranted. Naturally people hear that there is severe weather and sensibly stay home. This time though, there's sufficient snow that frankly, you all may as well go back to bed.
The southeast (and London in particular) is just not equipped to deal with snow. I mean that quite literally. Five years ago when I was fresh from Snowy Parts there was a cold snap with lots of ice piling up everywhere. When I enquired as to why it wasn't cleared I was told that London as a whole owns something like three snowploughs. I mocked this idea as clearly three snowploughs are insufficient to deal with severe weather in such a large city. But now, five years later, I'm of a different opinion. If we only get severe weather once every five years then there really is no point spending millions on preparations for something that rarely happens.
Of course, there are lots of curmudgeonly media types *waves to the Togmeister* who grumble about things like the tube not running when it snows heavily. There are accusations that LUL's shutdown means that nobody can get to work. This is true. But nobody thinks through to the logical extension. In London very few people live near to the place they work. Many come from outside using national rail. So when the big boys shut down their train service nobody gets to London. Why does this affect LUL? Because tube staff are no different from any other person who works in London. We also don't tend to live within walking distance of our place of employment and many come from outside. So if there is no national transport and road conditions are dangerous to drive on then we end up with having nobody to run the LUL network.
This reasoning impresses nobody. 'It's London UNDERGROUND!', they holler, 'There's no WEATHER underground!'. Actually no. Over half of LUL track is not in tunnel sections which means trying to get trains through appalling conditions. Not to mention that nearly all of the trains are stabled outdoors overnight as those pesky victorians were too lazy to dig out huge, underground caverns so that we could park up out of the rain. Tsk.
I hate driving in snow. Or any inclement weather really. Aside from anything else the cabs of trains are never sealed properly and the heaters are often poor. This means that the passengers might feel slightly chilly in the back but the driver is sitting in a tiny metal box with air currents (and often snow and rain) roaring through the gaps in the doors and windows. Not to put too fine a point on it, it's fucking freezing. But can we huddle over and resign ourselves to our fate and dream of hot cuppas? No we flippin' can't because of all the ice skating we need to do.
Trains have thin metal wheels. These balance on top of thin metal rails. When the rails are wet due to rain, snow or ice the train has a nasty habit of developing wheelspin. What's happening with wheelspin is a lack of traction. The driver tries to move the train forward but the wheels can't gain any grip and spin rather uselessly on the wet, slippery rails. That's not the problematic part. Wheelspin when trying to move a train is a mere inconvenience and can be mostly got round by reducing the amount of power being fed to the motors and keeping the train in shunt for a while before gradually increasing the speed. Any idiot can get a train moving in wet weather, wheelspin or no wheelspin. Even poor visibility isn't too much of a problem if the driver is mindful of what signals mean and keeps the speed down where necessary. So once the train has got going it can (assuming there's no buildup of ice or snow) race along as speedily as ever. Moving trains ain't really an issue. No, it's the stopping that's tricky.
The thing you'll have noticed about trains is they are big. Very big. And heavy. Each LUL train takes at least a thousand passengers which just adds to the weight. Fully loaded my train weights about 300 tons. As I've mentioned many times before in this blog: Trains don't just stop. It takes a while. In wet weather there are two possible methods of stopping a train - each comes with it's own difficulties.
One approach would be to bring the train slowly into the platform. Seems sensible on the face of it but that style of driving doesn't account for trainstops. Trainstops are devices fitted to the track at points where there is signalling. Their job is to knock the brakes on from underneath so that if a train goes past a danger signal for some reason, the train will automatically have an emergency brake application. They stop trains going up the arse of the one in front. This means that anyone sitting in the crumple zone (aka 'the cab') does not die. I like trainstops. Lots. They are nifty.
The problem is that on some platforms you can either continue on in the direction you are travelling in or be told to reverse. In which case you'd go to the other end and drive in the opposite direction. This means a signal and trainstop at either end of the platform. Trainstops at the 'wrong' end (i.e. the rear) of the platform aren't really required if the train is just going to continue on. They are only there to stop the train going the other way without permission. In fact, they are potentially a problem as they'd knock the brakes on at the rear of the train when there is no reason for it to be stopped. So as the train enters the platform they smoothly tuck down so as not to hamper the brakes. They stay down for a fixed amount of time - however long it takes for a train to enter and fully berth in the platform at normal line speed. Then they rise up again. Have you spotted the problem? Yes, it's that bit about 'normal line speed'. If the train is creeping in because the driver doesn't want to skid or overshoot the platform then it's going to take longer to fully berth. So the trainstop will rise again before the train has fully passed over and the brakes get knocked on. Then there's an eight minute delay as the driver shuts down and goes back to manually take the brakes off. Now imagine that every train which enters the platform has the same problem. Clearly driving slowly isn't a sensible option.
The alternative is to come in at normal line speed and brake normally. In dry weather that's no issue but when it's wet and slippy then the wheels lock and the train quite literally slides along the track. This happened to me over a set of very bumpy points once and my heart nearly stopped as I tried to work out if I was going to derail or not. The only way to counter the wheels locking is to release the brakes which is not exactly conducive to stopping. If the driver cannot then get the train under control then there's a good chance it will go through the station starter signal. If that's red then there's going to be a long delay as the driver phones the signaller and reports a signal passed at danger. So that's not a good plan either.
The trick to driving in the wet is to use the Westinghouse brake to add tiny amounts of air to the brake chamber. This slows the train slightly and means that once the normal brake is applied there is already some pressure in the brake chamber so the wheels don't lock and the train doesn't skid. Why not just use Westinghouse all the way in? Well it's a bit more complicated than this but basically there's only so much air held in reserve and it takes time for the compressors to create more. So the driver can only use a touch of Westinghouse and then has to use the other brake. Which requires a hell of a lot of concentration and is oddly tiring. Add to that a freezing, rain-soaked, windswept driver who is having to concentrate lots to get the train running smoothly in the first place and who is battling poor visibility and you can see why I hate driving in the rain and snow. Frankly, it sucks and I'd far rather be driving in the snuggly warm tunnels. But the only line which is wholly underground is the Victoria Line. Which brings me neatly to my next point. Or rather, points.
Points are bits of track which move between two fixed positions. They are the railway equivalent of steering wheels. Fixed in one position the train rolls onto the lefthand road. Fixed in the other position and the train takes the righthand road. Very simple, very useful, VERY much a moving metal part which is therefore prone to freezing in one position when you leave them lying around outdoors in winter. It's a bit of a bummer really. I remember a few years ago we had a moderate amount of snow. All the staff turned up, all the passengers turned up and together we all waited on the platforms for our trains to also turn up. The passengers weren't worried because there were loads of staff milling about so clearly we were running. The staff weren't worried because all week LUL management had been putting up notices advising of the coming cold-snap and had arranged for the sleet trains and de-icer units to run throughout the night, keeping the track clear of slush and snow.
After a good long wait phonecalls were made: It transpired that the drivers who had been bringing the trains out of the various depots and sidings had been unable to move them. Although points all have heaters they - crucially - didn't have very good heaters and the company supposed to be responsible for points *cough*Metronet*cough* hadn't bothered checking them. They were probably all too busy trying to find ways to spend the millions they ripped the government off for. So all the drivers trudged back to their depot and left the station staff to tell the customers. This came as something of a relief as it's somewhat embarrassing to have to tell a passenger that there are no trains available due to the cold weather only to have them turn around, point and say 'What about those eight trains though?'. 'Well.....'
So all in all, it's generally not worth anyone bothering to attempt going to work in London today. A far better option is to stay home and wrap up warm. Let's face it - if the weather is so bad that even Severe Delays isn't turning up then it ain't worth bothering.
ETA: Oh! I certainly wasn't expecting *this* amount of feedback! So in case I miss anyone - Welcome and thanks for stopping by. :-)
A few people have asked if they may friend. Of course you may, it does my ego good (though I may need wider doors to fit my head through).
As a person who originates from Snowy Parts I'm usually somewhat dubious about disruptions due to snow in Southeast England. Generally the media seems to hype up the disruption rather more than is warranted. Naturally people hear that there is severe weather and sensibly stay home. This time though, there's sufficient snow that frankly, you all may as well go back to bed.
The southeast (and London in particular) is just not equipped to deal with snow. I mean that quite literally. Five years ago when I was fresh from Snowy Parts there was a cold snap with lots of ice piling up everywhere. When I enquired as to why it wasn't cleared I was told that London as a whole owns something like three snowploughs. I mocked this idea as clearly three snowploughs are insufficient to deal with severe weather in such a large city. But now, five years later, I'm of a different opinion. If we only get severe weather once every five years then there really is no point spending millions on preparations for something that rarely happens.
Of course, there are lots of curmudgeonly media types *waves to the Togmeister* who grumble about things like the tube not running when it snows heavily. There are accusations that LUL's shutdown means that nobody can get to work. This is true. But nobody thinks through to the logical extension. In London very few people live near to the place they work. Many come from outside using national rail. So when the big boys shut down their train service nobody gets to London. Why does this affect LUL? Because tube staff are no different from any other person who works in London. We also don't tend to live within walking distance of our place of employment and many come from outside. So if there is no national transport and road conditions are dangerous to drive on then we end up with having nobody to run the LUL network.
This reasoning impresses nobody. 'It's London UNDERGROUND!', they holler, 'There's no WEATHER underground!'. Actually no. Over half of LUL track is not in tunnel sections which means trying to get trains through appalling conditions. Not to mention that nearly all of the trains are stabled outdoors overnight as those pesky victorians were too lazy to dig out huge, underground caverns so that we could park up out of the rain. Tsk.
I hate driving in snow. Or any inclement weather really. Aside from anything else the cabs of trains are never sealed properly and the heaters are often poor. This means that the passengers might feel slightly chilly in the back but the driver is sitting in a tiny metal box with air currents (and often snow and rain) roaring through the gaps in the doors and windows. Not to put too fine a point on it, it's fucking freezing. But can we huddle over and resign ourselves to our fate and dream of hot cuppas? No we flippin' can't because of all the ice skating we need to do.
Trains have thin metal wheels. These balance on top of thin metal rails. When the rails are wet due to rain, snow or ice the train has a nasty habit of developing wheelspin. What's happening with wheelspin is a lack of traction. The driver tries to move the train forward but the wheels can't gain any grip and spin rather uselessly on the wet, slippery rails. That's not the problematic part. Wheelspin when trying to move a train is a mere inconvenience and can be mostly got round by reducing the amount of power being fed to the motors and keeping the train in shunt for a while before gradually increasing the speed. Any idiot can get a train moving in wet weather, wheelspin or no wheelspin. Even poor visibility isn't too much of a problem if the driver is mindful of what signals mean and keeps the speed down where necessary. So once the train has got going it can (assuming there's no buildup of ice or snow) race along as speedily as ever. Moving trains ain't really an issue. No, it's the stopping that's tricky.
The thing you'll have noticed about trains is they are big. Very big. And heavy. Each LUL train takes at least a thousand passengers which just adds to the weight. Fully loaded my train weights about 300 tons. As I've mentioned many times before in this blog: Trains don't just stop. It takes a while. In wet weather there are two possible methods of stopping a train - each comes with it's own difficulties.
One approach would be to bring the train slowly into the platform. Seems sensible on the face of it but that style of driving doesn't account for trainstops. Trainstops are devices fitted to the track at points where there is signalling. Their job is to knock the brakes on from underneath so that if a train goes past a danger signal for some reason, the train will automatically have an emergency brake application. They stop trains going up the arse of the one in front. This means that anyone sitting in the crumple zone (aka 'the cab') does not die. I like trainstops. Lots. They are nifty.
The problem is that on some platforms you can either continue on in the direction you are travelling in or be told to reverse. In which case you'd go to the other end and drive in the opposite direction. This means a signal and trainstop at either end of the platform. Trainstops at the 'wrong' end (i.e. the rear) of the platform aren't really required if the train is just going to continue on. They are only there to stop the train going the other way without permission. In fact, they are potentially a problem as they'd knock the brakes on at the rear of the train when there is no reason for it to be stopped. So as the train enters the platform they smoothly tuck down so as not to hamper the brakes. They stay down for a fixed amount of time - however long it takes for a train to enter and fully berth in the platform at normal line speed. Then they rise up again. Have you spotted the problem? Yes, it's that bit about 'normal line speed'. If the train is creeping in because the driver doesn't want to skid or overshoot the platform then it's going to take longer to fully berth. So the trainstop will rise again before the train has fully passed over and the brakes get knocked on. Then there's an eight minute delay as the driver shuts down and goes back to manually take the brakes off. Now imagine that every train which enters the platform has the same problem. Clearly driving slowly isn't a sensible option.
The alternative is to come in at normal line speed and brake normally. In dry weather that's no issue but when it's wet and slippy then the wheels lock and the train quite literally slides along the track. This happened to me over a set of very bumpy points once and my heart nearly stopped as I tried to work out if I was going to derail or not. The only way to counter the wheels locking is to release the brakes which is not exactly conducive to stopping. If the driver cannot then get the train under control then there's a good chance it will go through the station starter signal. If that's red then there's going to be a long delay as the driver phones the signaller and reports a signal passed at danger. So that's not a good plan either.
The trick to driving in the wet is to use the Westinghouse brake to add tiny amounts of air to the brake chamber. This slows the train slightly and means that once the normal brake is applied there is already some pressure in the brake chamber so the wheels don't lock and the train doesn't skid. Why not just use Westinghouse all the way in? Well it's a bit more complicated than this but basically there's only so much air held in reserve and it takes time for the compressors to create more. So the driver can only use a touch of Westinghouse and then has to use the other brake. Which requires a hell of a lot of concentration and is oddly tiring. Add to that a freezing, rain-soaked, windswept driver who is having to concentrate lots to get the train running smoothly in the first place and who is battling poor visibility and you can see why I hate driving in the rain and snow. Frankly, it sucks and I'd far rather be driving in the snuggly warm tunnels. But the only line which is wholly underground is the Victoria Line. Which brings me neatly to my next point. Or rather, points.
Points are bits of track which move between two fixed positions. They are the railway equivalent of steering wheels. Fixed in one position the train rolls onto the lefthand road. Fixed in the other position and the train takes the righthand road. Very simple, very useful, VERY much a moving metal part which is therefore prone to freezing in one position when you leave them lying around outdoors in winter. It's a bit of a bummer really. I remember a few years ago we had a moderate amount of snow. All the staff turned up, all the passengers turned up and together we all waited on the platforms for our trains to also turn up. The passengers weren't worried because there were loads of staff milling about so clearly we were running. The staff weren't worried because all week LUL management had been putting up notices advising of the coming cold-snap and had arranged for the sleet trains and de-icer units to run throughout the night, keeping the track clear of slush and snow.
After a good long wait phonecalls were made: It transpired that the drivers who had been bringing the trains out of the various depots and sidings had been unable to move them. Although points all have heaters they - crucially - didn't have very good heaters and the company supposed to be responsible for points *cough*Metronet*cough* hadn't bothered checking them. They were probably all too busy trying to find ways to spend the millions they ripped the government off for. So all the drivers trudged back to their depot and left the station staff to tell the customers. This came as something of a relief as it's somewhat embarrassing to have to tell a passenger that there are no trains available due to the cold weather only to have them turn around, point and say 'What about those eight trains though?'. 'Well.....'
So all in all, it's generally not worth anyone bothering to attempt going to work in London today. A far better option is to stay home and wrap up warm. Let's face it - if the weather is so bad that even Severe Delays isn't turning up then it ain't worth bothering.
ETA: Oh! I certainly wasn't expecting *this* amount of feedback! So in case I miss anyone - Welcome and thanks for stopping by. :-)
A few people have asked if they may friend. Of course you may, it does my ego good (though I may need wider doors to fit my head through).