|
Post by carlovel1 on Feb 28, 2009 9:08:53 GMT
Wonder if they will have faster acceleration than the current trains
|
|
Colin
Advisor
My preserved fire engine!
Posts: 11,317
|
Post by Colin on Feb 28, 2009 9:35:13 GMT
You'd already know the answer to to that if you'd read the whole of this thread!! ;D ;D A couple of posts stand out from pages 1 & 3 of this very thread: I fully expect the 'S' Stock to wipe the floor with a 92ts in both acceleration and top speed terms. The 'S' Stock will indeed be limited when it enters service to match the profile of an 'A' Stock. Everyone is correct. S stock will be pegged to existing stock performance until the new signalling is installed and operational with ATP
|
|
|
Post by citysig on Feb 28, 2009 15:53:52 GMT
Just to add to the speed issue, new signalling and new stock is one thing (or two things I suppose) but track condition is also a very important factor. There are a few "excitable" areas of track on the Met, and coupled with new lightweight trains, could prove to be rather interesting.
As long as they do the job they were ordered for, looks do not matter that much. However, I do think they look quite good. They do give the impression from the side view that anyone over 4ft 6in tall will have to duck down to get in. The fronts have a certain character about them.
6 months? Along with a couple of others here, I too am beginning to wonder where will we keep them?
|
|
Colin
Advisor
My preserved fire engine!
Posts: 11,317
|
Post by Colin on Feb 28, 2009 16:37:25 GMT
As far as the track goes, this why there is so much work going on at the moment - we've got to change from Bullhead rail on wooden sleepers to flat bottom rail on concrete sleepers.
The flat bottom rail on concrete sleeper combination gives us the superior track required for S stock.
|
|
|
Post by 100andthirty on Feb 28, 2009 16:51:58 GMT
as to weight, they are not all that lightwight - less than A and C stock motors but as all cars are motor cars, the total weight will be higher than an A stock.
Regarding comments about a lively ride, they do have air suspension, and the the ride can be tuned; I expect the first attempt won't be right, but it can be altered
|
|
Ben
fotopic... whats that?
Posts: 4,282
|
Post by Ben on Feb 28, 2009 16:56:25 GMT
But surely flat bottom on concrete would give better ride on any stock?
Presumably when the Met did 70mph regularly before 2000 the bullhead track with wooden sleepers was not in such bad condition?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 28, 2009 18:34:28 GMT
Existing trains, especially A60s aren't doing the new tracks any good though. You notice the ride quality slightly deteriate after a few months after track replacement.
|
|
slugabed
Zu lang am schnuller.
Posts: 1,480
|
Post by slugabed on Feb 28, 2009 20:23:22 GMT
But surely flat bottom on concrete would give better ride on any stock? Presumably when the Met did 70mph regularly before 2000 the bullhead track with wooden sleepers was not in such bad condition? Did they lower the max speed in 2000? Was this explicitly due to track condition,or some other reason? I always remember the Finchley Rd to Wembley Park section of the Met (late 70s-early 80s) as being exciting to the point of terror! How often is track renewed?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 28, 2009 21:24:48 GMT
But surely flat bottom on concrete would give better ride on any stock? Presumably when the Met did 70mph regularly before 2000 the bullhead track with wooden sleepers was not in such bad condition? Did they lower the max speed in 2000? Was this explicitly due to track condition,or some other reason? I always remember the Finchley Rd to Wembley Park section of the Met (late 70s-early 80s) as being exciting to the point of terror! How often is track renewed? The A60s max speed was reduced just before 2000 to 50mph due to the bogies cracking and showing signs of fatigue due to age and poor track condition.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 28, 2009 21:26:42 GMT
Wonder if they will have faster acceleration than the current trains Certainly they will accelerate faster, they cant accelerate any slower can they?
|
|
|
Post by singaporesam on Mar 1, 2009 9:23:55 GMT
Regarding comments about a lively ride, they do have air suspension, and the the ride can be tuned; I expect the first attempt won't be right, but it can be altered Air suspension only allows the secondary spring rate to be changed and would have upper and lower level limitations so the ability to Ā“tuneĀ“ would be quite limited. Anyway, the most common problem with ride on trains is normally secondary under damping and that can only be ĀØtunedĀØ by changing the dampers.
|
|
|
Post by 100andthirty on Mar 1, 2009 17:51:44 GMT
Air suspension only allows the secondary spring rate to be changed and would have upper and lower level limitations so the ability to Ā“tuneĀ“ would be quite limited. Anyway, the most common problem with ride on trains is normally secondary under damping and that can only be ĀØtunedĀØ by changing the dampers. the vertical damping can be changed by altering the chokes in the pipes between the air bags and the surge tanks (this is getting a bit technical); horizontal damping does need the horizontal damper to be changed; a relatively trivial job on the first train! It would be a lot more trouble if it were to be decided that they'd be changed after all the cars have been delivered!!!
|
|
|
Post by citysig on Mar 1, 2009 19:50:50 GMT
Existing trains, especially A60s aren't doing the new tracks any good though. You notice the ride quality slightly deteriate after a few months after track replacement. On top of this, we simply do not look after the track once we've replaced it. Network Rail replace track. It's done properly, with everything right down to a couple of feet below track level. Drainage, ballast, perfectly aligned track. Then regular maintenance and tamping to ensure the track is kept at that standard. On LU, the track is replaced - maybe even to the standard on NR. But then what. Nothing. No tamping. No maintenance except that which has to be done. Regardless of the S-stock suspension, and whether it can be adjusted, run a train any faster than we do now, and it's simply going to bounce off the track.
|
|
|
Post by astock5000 on Mar 1, 2009 20:22:21 GMT
|
|
Colin
Advisor
My preserved fire engine!
Posts: 11,317
|
Post by Colin on Mar 1, 2009 20:41:30 GMT
Regarding my comments about the track needing to be the flat bottom / concrete sleeper combination - I have been told this is the requirement by at least three different P-Way guys. It's on that basis that I believe what I said is quite correct.
|
|
prjb
Advisor
LU move customers from A to B, they used to do it via 'C'.
Posts: 1,840
|
Post by prjb on Mar 1, 2009 21:37:42 GMT
No, the numbering of train 2 is correct. There have been a few changes to the numbering scheme since we last discussed this on the forum and I should have updated you all. One of the big changes is that the de-icing units are now numbered first in the series and as such train 1 is: (DM)21001-(M1)22001-(M2)23001-(MS)24001/(MS)24002-(M2D)25002-(M1)22002-(DM)21002 We didn't want two de-icing units to start with as the pre-series trains, so we picked one de-icer (above) and one non de-icer which is train 2: (DM)21099-(M1)22099-(M2)23099-(MS)24099/(MS)24100-(M2)23100-(M1)22100-(DM)21100 I am pretty sure this is correct but I have typed these 'off the top of my head' on a Sunday evening just after putting the baby to bed! I will blow the dust off my numbering folder in the week and give you all a full update.
|
|
slugabed
Zu lang am schnuller.
Posts: 1,480
|
Post by slugabed on Mar 1, 2009 23:22:48 GMT
Regarding my comments about the track needing to be the flat bottom / concrete sleeper combination - I have been told this is the requirement by at least three different P-Way guys. It's on that basis that I believe what I said is quite correct. I'm neither a P/Way man nor a (qualified) engineer,Colin,but what you say makes perfect sense. Reinforced concrete sleepers of equal X-section will,if bedded correctly in the ballast,always be far resistant to deflection than the wooden ones they replace. And the X-section of Flat-Bottom rail will,by virtue of the substantially webbed base,give greater resistance to deflection than the older Bullhead rail. Further,I believe the Pandrol-type fixing provides a firmer hold,less prone to self-loosening than the hammered keys used on Bullhead and chaired track. This is before bed construction and subsequent maintenance are taken into account. On NR,Bullhead these days seems to be confined to very low-speed applications such as sidings etc giving an indication of their views on the rails' differing characteristics. As a (generally) low-speed railway,LT has stuck to Bullhead for much longer than BR did,and on the higher-speed sections,the difference in ride between BR and LT has always been noticeable,though this may also have something to do with suspension characteristics,too. Interestingly,though,I've noticed that some recent track replacement work on Deep-level lines has used Flat-Bottom rail,presumably for the reasons given above. On the subject of suspension,however,there is also the question of pre-load to consider....A friend who worked as a guard on the 83ts said that empty,they pitched like a trawler in a gale,but as they filled up fowards Town,the suspension would "settle" to a working characteristic. Presumably the S-stock will be tested a various speeds,on various track,subjected to various loadings?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 2, 2009 14:26:59 GMT
I must admit to liking the way the S stock looks.
prjb please do update us, that way I can update the website.
|
|
Oracle
In memoriam
RIP 2012
Writing is such sweet sorrow: like heck it is!
Posts: 3,234
|
Post by Oracle on Mar 2, 2009 14:55:39 GMT
I wondered if there is a limit on towing speed on NR?
|
|
Chris M
Global Moderator
Forum Quizmaster
Always happy to receive quiz ideas and pictures by email or PM
Posts: 19,430
|
Post by Chris M on Mar 2, 2009 16:03:54 GMT
On NR,Bullhead these days seems to be confined to very low-speed applications such as sidings etc giving an indication of their views on the rails' differing characteristics. As a (generally) low-speed railway,LT has stuck to Bullhead for much longer than BR did... I think I remember reading somewhere that part of the reason for the Underground sticking with bullhead rail longer than BR/NR has is that it is easier (or was it quicker?) to replace in confined spaces such as tube tunnels.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 2, 2009 17:04:04 GMT
I wondered if there is a limit on towing speed on NR? I would be shocked if the barrier wagons did not have the necessary circuitry to charge and release the Westcode brakes on the S stock. I did see in the photos that a through air line was fed through a small hole in the M door (?), presumably to bypass the S stock main line air system.
|
|
|
Post by 100andthirty on Mar 2, 2009 19:27:35 GMT
I wondered if there is a limit on towing speed on NR? I would be shocked if the barrier wagons did not have the necessary circuitry to charge and release the Westcode brakes on the S stock. I stand to be corrected, but I think you should be shocked - for this move at least!
|
|
|
Post by astock5000 on Mar 2, 2009 19:32:09 GMT
|
|
|
Post by uzairjubilee on Mar 2, 2009 19:54:41 GMT
Oh right, now I realise that the M door is not visible.
Thats why it looked weird..
|
|
|
Post by citysig on Mar 2, 2009 20:24:02 GMT
One of the big changes is that the de-icing units are now numbered first in the series.. An excellent development ;D Now on those cold winter evenings, we won't have to hunt out the list of car numbers, interrogate the train sheets for which units are on each train, just to find the de-icers to get them filled up.
|
|
|
Post by singaporesam on Mar 2, 2009 23:11:00 GMT
the vertical damping can be changed by altering the chokes in the pipes between the air bags and the surge tanks (this is getting a bit technical); horizontal damping does need the horizontal damper to be changed; a relatively trivial job on the first train! It would be a lot more trouble if it were to be decided that they'd be changed after all the cars have been delivered!!! Its really not that simple at all. Adjusting this choke only changes the allowable rate of change of spring rate and isnĀ“t strictly damping the motion as air is a poor damping medium. Air suspension has poor lateral stiffness characteristics and is also susceptible to roll problems , so whilst what you say may affect vertical performance and have a little bit of impact on roll , its debateable just how much tweaking is possible during tesing. Especially as I doubt Bombardier would want to change dampers or roll bar bushes. However the suspension is set up it will be a bit of a compromise and almost inevitably this will mean that performance in the crush loaded condition will be underdamped.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 3, 2009 2:39:11 GMT
I wondered if there is a limit on towing speed on NR? Postings to various email lists, at the time the move came to light, suggested the train was restricted to 40mph. It was also deemed to be out of gauge and it's run to Old Dalby involved it working from Derby via Burton-on-Trent, Coalville* and Leicester. * Much to my irritation, as I live near Coalville, but was staying with my girlfriend in Bradford. Sorry prjb. The sides look remarkably like C stock, but that front is truly ugly and those windscreens will, to my mind, make the sets vulnerable to attack by the obligatory stone throwing morons that live along the route of the Met mainline.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 3, 2009 6:56:59 GMT
those windscreens will, to my mind, make the sets vulnerable to attack by the obligatory stone throwing morons that live along the route of the Met mainline. Cab windscreens are all made of toughened glass.
|
|
metman
Global Moderator
5056 05/12/1961-23/04/2012 RIP
Posts: 7,400
|
Post by metman on Mar 3, 2009 9:10:33 GMT
I thought the stone throwers were on the District Line?
|
|
Ben
fotopic... whats that?
Posts: 4,282
|
Post by Ben on Mar 3, 2009 11:45:00 GMT
Coalville eh? Shame, I'm only down the road in Loughborough, would have been good to see them.
|
|