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Post by Dstock7080 on Nov 19, 2007 13:22:40 GMT
I think I've answered my own question!
I was about to ask:
Anybody any idea why there was a 6-car train in EBY pfm5 this morning, departing empty at 06.00?
units: W.91219+92442+? E.
Upon arriving home and checking up I see the 92442 is the Sandite unit, so as it was slightly chilly this was the reason for the 6-car!
We get some good info from this forum!
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Post by suncloud on Nov 20, 2007 11:59:43 GMT
Why would it run as a six car? Would they be able to run a 6car train in passenger service?
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Post by ongarparknride on Nov 20, 2007 19:21:05 GMT
Please pardon request for a bit of clarification: From the OP and mention of "Sandite" and being slightly chilly, presumably this is some sort of de-icing equipped unit? Apologies if I've missed other relevant posts, but the OP is a bit mysterious. Is the OP actually referring to the "urban-myth" that a fully equipped restaurant/buffet car Underground Train exists, and is Top Secret and stabled locked away during daylight hours, that comes out only in the "wee hours" between line current being restored and the First Scheduled Passenger Train, to run up and down the line serving Steaming Hot Yorkshire Tea and Bacon Sarnies to all the other staff logging on for the Dawn Shift?  |
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Post by suncloud on Nov 20, 2007 23:01:57 GMT
Sandite (corrections welcome if I'm wrong) tackles poor adhesion due to leaves rather than ice...
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Colin
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Post by Colin on Nov 21, 2007 2:31:25 GMT
To go one further, Sandite is a mixture of 'gooey stuff' and metal bits - as 'suncloud' says, it is used to assist trains in getting grip during leaf fall. As we all know, jokes aside, leafs can [once squashed enough] leave a black shiny surface on which it is hard for train wheels to gain any grip; it has the same effect as trying to drive on ice and so this special mixture helps to overcome the problem. The metal bits, aside from helping the break down the smooth squashed leafs, also play a part in ensuring the track circuits can still operate. As to why this particular train is 6 cars, I should imagine there's a minimum length directive to ensure the signalling works properly and/or I assume the Sandite is dispensed from a trailer car which is made up of a 2 car unit without a cab at either end (so you then need two 2 car units with a cab). Also, there's no need to use 8 cars if it isn't necessary as that's one less unit that could be used for passenger service. On the question of six car trains in passenger service on the Central line.....I don't think it'd happen for several reasons: - line is too busy and needs all trains to have 8 cars
- the ATO system is configured for 8 cars, not 6
- running 6 car trains would leave a 2 car gap at every platform
- running 6 cars would leave too many units doing nothing, and not enough cabs to create more trains with
Feel free to pick away at that lot if I'm wrong................. |
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Post by Deleted on Nov 21, 2007 10:39:15 GMT
To go one further, Sandite is a mixture of 'gooey stuff' and metal bits - as 'suncloud' says, it is used to assist trains in getting grip during leaf fall. As we all know, jokes aside, leafs can [once squashed enough] leave a black shiny surface on which it is hard for train wheels to gain any grip; it has the same effect as trying to drive on ice and so this special mixture helps to overcome the problem. The metal bits, aside from helping the break down the smooth squashed leafs, also play a part in ensuring the track circuits can still operate. As to why this particular train is 6 cars, I should imagine there's a minimum length directive to ensure the signalling works properly and/or I assume the Sandite is dispensed from a trailer car which is made up of a 2 car unit without a cab at either end (so you then need two 2 car units with a cab). Also, there's no need to use 8 cars if it isn't necessary as that's one less unit that could be used for passenger service. On the question of six car trains in passenger service on the Central line.....I don't think it'd happen for several reasons: - line is too busy and needs all trains to have 8 cars
- the ATO system is configured for 8 cars, not 6
- running 6 car trains would leave a 2 car gap at every platform
- running 6 cars would leave too many units doing nothing, and not enough cabs to create more trains with
Feel free to pick away at that lot if I'm wrong................. 'Metal bits'? Isn't it actually sand (hence the name)? I'd hate to think of the effect metal bits would have on track circuits etc. Here it is applied to the rail on the GOBLIN: paulbigland.fotopic.net/p35310117.html |
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Post by suncloud on Nov 21, 2007 11:24:44 GMT
As to why this particular train is 6 cars, I should imagine there's a minimum length directive to ensure the signalling works properly and/or I assume the Sandite is dispensed from a trailer car which is made up of a 2 car unit without a cab at either end (so you then need two 2 car units with a cab). Also, there's no need to use 8 cars if it isn't necessary as that's one less unit that could be used for passenger service. Both those reasons are plausible. But why run a 6-car empty? Is there any reason for not deploying Sandite from an 8-car train in passenger service? (Even if it has to run unusual diagrams e.g. WER->WHC->EBD->WHC->WER). Otherwise it might as well be an engineering unit. |
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Post by Chris M on Nov 21, 2007 12:42:49 GMT
In that situation I think that only 7 cars would be available for passenger use, needing one or more staff to keep the punters out of the sandite car. Combine this with the confusion created by the unusual diagram (presumably it will also need to traverse crossovers and reversing sidings), its probably far simpler just to say the entire train is not in service. As to why its not an engineering unit I don't know.
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Colin
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Post by Colin on Nov 21, 2007 18:02:11 GMT
'Metal bits'? Isn't it actually sand (hence the name)? I'd hate to think of the effect metal bits would have on track circuits etc. Here is a quote from a Wikipedia page on the subject: The relevant page can be found HERE. But why run a 6-car empty? Is there any reason for not deploying Sandite from an 8-car train in passenger service? There's an image on Phil Wimbush's fotopic site that should answer that question - I'm sure Phil won't mind me linking to it on this occasion: ginstersrailwayphotos.fotopic.net/p9600549.html |
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Post by suncloud on Nov 21, 2007 19:01:17 GMT
Thanks Colin, I see now! It still seems strange to me taking a passenger carrying unit out of service to do this job... but there must be some method in the apparent madness. What other lines run Sandite cars? (I've seen pics of an A60 on the met) and do they run a similar arrangement?
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Post by Deleted on Nov 21, 2007 19:28:32 GMT
there was a 1962 unit though, but its performance wouldn't be up to scratch to keep up with the timetable these days.
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Post by Deleted on Nov 21, 2007 19:45:14 GMT
The 62ts was at Ruislip recently... the one with the green/brown coloured car!
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towerman
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Post by towerman on Nov 21, 2007 20:52:32 GMT
62TS Sandite train does the east end of the Central,usually runs after 19:00hrs on weekdays.
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Post by ongarparknride on Nov 23, 2007 1:55:01 GMT
Thanks. All, for info and pix links re: Sandite. Does modern tube stock (used on open sections like the Central etc) still have sanding facilities, or did this go out yonks ago? Don't remember any indication of it on control panels, cab switches etc. And does anyone know if any tests were done to use a - to describe it simply - rubber-type squeegee wiper forward of the driving axles on the leading car to try to prevent leaf debris build up? I can see that friction and the material used might be a problem, and the key point would it being rigid enough to always point down and forward (not flopping back on itself to trail the rail) where friction would then be an advantage in icy conditions, and it would just clear the actual contact section of rail in the pattern worn by normal operations. Very easy to fit just at the times of the year needed, by a simple although stronger clip like used in holding a sheet of sandpaper in an orbital sander. Replace it each night in the stabling with clipping in a new blade? It looks like 2/3 of the Sandite gunge is wasted, and it ties up rolling stock and engineering timetables just to treat the tracks once a day, so after the first couple of service trains have run no further improvement would be obtained until the following application. Absolutely no disrespect intended, but to the uninitiated Sandite doesn't sound like a particularly cost-effective solution to the problem. (And, taking on board, the reduction almost to zilch of weedkiller trains and other trackside maintaining, like trimming back the trees causing the leaf fall problem, that are probably in the majority of cases rooted on the railway land anyway. Drivers will know from experience where problem areas occur - trim the trees every few years for a few miles of the affected track, and help reduce the problem at source?) And one other possibly relevant solution already developed but under a different guise: the rail grinding engineering equipment. After all, the problem is exactly the same, except instead of grinding the whole rail surface back to profile, the object is to just skim a few millimeters off the rail, using an abrasive that is softer than the rail but stronger than the compacted leaf mulch. Gee, again emphasis no disrespect intended, but it sounds rather like some outside outfit was commissioned to investigate, report and advise on the problem, then their buddies have literally cleaned up selling the solution on a somewhat arguable cost-effectiveness basis to LU? Rather a significant question along these lines - did the initial order of TS specified for the line's operation include a 6 car unit dedicated solely for this Sandite purpose? Just a few thoughts........ Cheers. |
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Post by c5 on Nov 23, 2007 9:56:44 GMT
There is a lot of vegatation control work that goes on, plus weedkiller trains (though the chemicals used in the old days are no longer allowed!).
Plus if there are specific areas that need dealing with, they can be reported to the Infraco Fault Report Centre and vegatation can be cut back.
Also at times of poor railhead adhesion the Permanent Way gangas can also be tasked to assist.
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Post by Deleted on Nov 23, 2007 21:06:18 GMT
I think at least, most European railway operators use high pressure steam or water jets on the rail... and I think Amtrak or similar has a flame/burning system...
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Post by ongarparknride on Nov 24, 2007 3:06:22 GMT
Art, I did a little bit of "Googling" and research out of interest from looking at the pix link posted showing the treated rail. I guess steam, water-jet or burning would be rejected on LU because of current supply restrictions, storage space for materials on the rolling stock profiles and fire risk etc. even though all such facilities would only (properly) be deployed on open sections.
I guess "sanding" went out with the steam loco's then. Towerman's post explains older stock form the Sandite train, except with running during service hours that affects the ATC?
Thanks, JTD.
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Post by c5 on Nov 24, 2007 8:54:05 GMT
Water Jetting is used on LUL.
It is the NR/Chiltern railway unit and is permitted to spray on permission of the Service Controller. And runs on the Met Fast lines. The train in the rear must be advised.
Their Sandite unit however is not allowed to lay sandite.
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Colin
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Post by Colin on Nov 24, 2007 19:03:26 GMT
Just to clarify a point - Sandite is not exclusive to LUL; many railways (including NR) use it as well as or in combination with water jetting etc.
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