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Post by abe on Mar 15, 2007 8:40:43 GMT
I was at Baker Street East (platforms 1-4) last night, about 18.00. The trains were all running a bit late, but unusually for Baker Street there were no platform announcements. It transpired from a chat with the Station Supervisor that due to the noise from wheel squeal on the platforms, Health & Safety had banned staff from remaining there. I returned to the platform, and when a train departed to the City the noise was horrific - one of the worst squeals I've heard on the Underground. About five minutes later a large gang of track staff in hi-vis appeared on Platform 3 with a large tub of grease. A smaller group of uniformed staff were with them - all staring at the track.
Does anyone know what might have caused this - might a track lubricator have failed? And how would they solve the problem during the evening peak - I presume that the current would need to be discharged for them to get on the track?
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Post by c5 on Mar 15, 2007 10:07:13 GMT
The station staff were quite rightly refusing to go onto the Met platforms because of the deafening noise which echoed round the ticket hall andcould be heard in the Met Bar upstairs.
They think that the greasers must be broken as they were reported on Monday and Metronet said they they had fixed the problem. The ERU were then called out to hand grease the sides of the running rails. Trains were being held as their protection and they didn't require the current off. Usually this would be done in Engineering Hours but the noise was horrible.
Now just to sort out the greasers everywhere else!
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Colin
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Post by Colin on Mar 15, 2007 12:34:57 GMT
Same thing happened at Mansion House yesterday evening - my train was one of few used as protection while the rails were 'hand greased'. I was gonna start a new thread on this very subject as it does seem to be a big problem since the nicer weather started. Eastbound between Putney Bridge & Parsons Green, Eastbound between West Brompton & Earls Court, Monument, Tower Hill and Aldgate all seem to be pretty bad areas. What are Metronet playing at? Last year it was the rail stressing debacle - I suppose it'll be lack of grease this year   |
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Post by edb on Mar 15, 2007 14:37:01 GMT
hmm that is interesting. In general is rail wear highest when going slow or fast, or is there no difference.?
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Post by version3point1 on Mar 15, 2007 14:43:19 GMT
Not sure whether speed affects the wear, but there's certainly more wear if the track has a curve in it, like Baker Street. Metronet know about all these problems, amongst others. It's just they lack organisation in their priorities. |
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Post by Deleted on Mar 15, 2007 15:01:25 GMT
I've seen guys out the last couple of nights greasing the rails.
The problem stems, from what I know, of the track being too tight a gauge. When the whole crossover was put in a few years ago (2002/3? with a 48 hour over-run too IIRC) the contractor who did it, simply did it wrong. This is what I've heard anyway.
The screech has remained ever since, even with greasers installed.
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Post by Deleted on Mar 15, 2007 19:11:53 GMT
monument was sorted last nite i was there with about 15 p-way members all they did was top up the greasers and manually applied some grease in certain areas
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Post by edb on Mar 15, 2007 19:32:24 GMT
monument was sorted last nite i was there with about 15 p-way members all they did was top up the greasers and manually applied some grease in certain areas That's a more skilled job than you might think is it not??? If you put too much on, you'll find the acceleration and braking controls have no effect, you just go for a nice slip along the track. I've always wondered how these greasers worked. I'm sure in "World of Trains" it said most were plunger fed, but from what i can see, that wouldn't work with the current LU designs. |
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Post by Deleted on Mar 15, 2007 21:45:37 GMT
This was a problem in 1996 on Railtrack where non filling of greasers caused severe wheel set damage to a TOC "somewhere in the SE" - wheel sets are about 10k each so it soon adds up.Litigation was avoided
Sounds like they have identifed the problem and are doing something before too much damage is done.
Incidentally - on a track walk with the PW once we found the up road greaser approaching Sth Kenton on the Dc line spraying grease onto the rail head - giving perfect skid pan conditions for my beloved 313s ....and the Bakerloo - problem soon sorted !
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Tom
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Post by Tom on Mar 15, 2007 22:02:39 GMT
The station staff were quite rightly refusing to go onto the Met platforms because of the deafening noise which echoed round the ticket hall andcould be heard in the Met Bar upstairs. It was a bit hard to hear oneself think at Edgware Road this evening for similar reasons... |
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Post by ttran on Mar 15, 2007 22:38:06 GMT
That's a more skilled job than you might think is it not??? If you put too much on, you'll find the acceleration and braking controls have no effect, you just go for a nice slip along the track. Ah but the trick is to ensure it's only applied to the inner sides of the rails, and NOT on the rail head because of course that would cause all manner of problems like you suggest. |
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Post by Deleted on Mar 15, 2007 22:40:24 GMT
Has anyone heard a Bakerloo 72 stock motoring away from Waterloo SB? That IS loud. I take it this Baker Street incident would have been even louder than that........I don't even want to imagine that  |
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Phil
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Post by Phil on Mar 15, 2007 22:42:34 GMT
It was a bit hard to hear oneself think at Edgware Road this evening for similar reasons... Blimey, the noise from Baker street MUST have been loud if it could be heard from ERD ;D ;D ;D |
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Post by Deleted on Mar 15, 2007 23:32:13 GMT
And to be able to hear it in the Met Bar above the din the customers make is also, quite surprising...
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Post by stanmorek on Mar 17, 2007 14:13:54 GMT
I've seen guys out the last couple of nights greasing the rails. The problem stems, from what I know, of the track being too tight a gauge. When the whole crossover was put in a few years ago (2002/3? with a 48 hour over-run too IIRC) the contractor who did it, simply did it wrong. This is what I've heard anyway. The screech has remained ever since, even with greasers installed. That cross over has had a problem with tight gauge and wheel/rail screech since it had been changed but I thought it was earlier during 2000/2001. From what I heard, allegedly, during the possession some of the rails weren't delivered and straight pieces of rail on site had to be crowed into the curve. The greaser gang used to be based at Baker Street past the buffer stops of platform 4 upstairs. They'd been trying to rectify the problem of rail screech by repositioning the track mounted lubricators many times to no avail. However, from other poster's observations, the problem appears to be more widespread. I recall when the new Portec type lubricators were being installed around the SSR and when we had a really warm summer, the lubricators were routinely checked and found to be applying less grease than required. Anyhow, it was hypothesised that the high temperatures were somehow affecting the viscosity of the grease and all the lubricators were adjusted to the maximum setting. Some months later when the weather was cooler, one morning rush hour several Met line trains had to be withdrawn with wheel flats. The lubricators were applying too much grease. |
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Post by stanmorek on Mar 17, 2007 14:37:09 GMT
Track mounted lubricators are installed on the high rail (outside curve) where the wheel flange rubs on the inside face or running edge of the rail head. The speed of the train and cant of the track affect how much wear occurs. Faster speeds cause greater centrifugal forces on the train pushing the bogie outwards from the curve against the high rail. On tight curves (radius< 200m) check rails are installed on the low rail e.g. Baker Street junction. Check rails act as a sacrificial rail restricting sideways movement of the wheel on the low rail into the four foot and prevents the high rail wheel from climbing over the crown of the rail and derailing the train.
The most common type of track lubricator on the SSR is the Portek mounted onto a sleeper. It has a grease reservoir that is kept under pressure. Texaco 904 grease is applied whenever two small plungers on rail mounted device are depressed by a passing wheel flange. The applicator is a spreader plate fixed to the rail and fed from the reservoir.
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Post by Deleted on Mar 17, 2007 21:54:49 GMT
That cross over has had a problem with tight gauge and wheel/rail screech since it had been changed but I thought it was earlier during 2000/2001. Thinking about it, it could have been around that time. As I had just started working nights in 2000/1 |
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Post by Deleted on Mar 17, 2007 22:15:06 GMT
Noticed at Monument the same problem affecting Eastbound [towards Tower Hill] trains, noticable more intense with Refurbed D's... Looks like the Check Rail has been renewed recently, so that may have summat to do with it...
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Colin
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Post by Colin on Mar 18, 2007 4:26:27 GMT
I heard a little rumour (and I stress it's only a rumour) that Metromess Metronet have been using "the wrong type" of grease. Could it be that they've tried 'going cheap' and it's backfired on them?
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Ben
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Post by Ben on Mar 18, 2007 15:55:42 GMT
ACME rail grease....
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Post by edb on Mar 19, 2007 13:29:01 GMT
However, from other poster's observations, the problem appears to be more widespread. I recall when the new Portec type lubricators were being installed around the SSR and when we had a really warm summer, the lubricators were routinely checked and found to be applying less grease than required. Anyhow, it was hypothesised that the high temperatures were somehow affecting the viscosity of the grease and all the lubricators were adjusted to the maximum setting. Some months later when the weather was cooler, one morning rush hour several Met line trains had to be withdrawn with wheel flats. The lubricators were applying too much grease. That is suprising, you'd have thought it would be the other way around, i thought that "most" grease became less viscous when it was warm, not more so. |
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Phil
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Post by Phil on Mar 19, 2007 22:43:07 GMT
That is suprising, you'd have thought it would be the other way around, i thought that "most" grease became less viscous when it was warm, not more so. Two theories that would fit these facts are that 1.once grease gets warm, some of it leaks round the pistons so more needs to be pumped or 2.the air contained in all grease expands and creates small bubbles resulting in a spongy action (especially in the 'suck' phase as opposed to the 'blow') as in brakes (car) that need bleeding. No idea if either of them IS the cause but just to show it could work that way round. |
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Post by stanmorek on Mar 19, 2007 23:03:22 GMT
That is suprising, you'd have thought it would be the other way around, i thought that "most" grease became less viscous when it was warm, not more so. You're correct that's what was thought to have been happening - the grease was getting runnier. The lubricator forces grease out under pressure through a piston in the resevoir as the plunger activated valve is opened. Pressure was lost as the grease thinned out. This was only someone's theory that fitted what was observed and I don't think it was scientifically validated. Phil's theory no.2 may equally apply. The levels of lubricant in reservoirs were checked and were found to be more or less unchanged. Any abnormal loss to the surroundings would be difficult to determine to as the lubricator gets covered in track grease pretty quickly. |
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