Class 800 - Updates

[Coryton]

As a maintainer  I agree with the Hitachi view on plug doors, far too many points of failure. Keep it simple.

 

As a passenger I like plug doors because I don't want to get the seats next to the door pocket.

 

Can't speak for maintenance other than that I've travelled on trains with swing plug doors on many occasions and don't recall being on a train where one has failed.

 

On the other hand I was once thrown out of a 313 (traditional sliding doors) in the middle of nowhere on a cold night because of a door failure.

 

Maybe we can all agree they were right not to use bus style folding doors?

[andy stroud]

As a maintainer  I agree with the Hitachi view on plug doors, far too many points of failure. Keep it simple.

 

Slam doors

[Titan]

Slam doors

 

OK then. Jim Morrison could not sing to save his life.

[Zomboid]

OK then. Jim Morrison could not sing to save his life.

Evidently.

[modfather]

Slam doors

that for a laugh. Slam doors need a lot of test and inspection and there's usually more of them. The 800 doors are proven and seem to be a really well considered solution.

[david.hill64]

Not only high, but also as the coaches are 26m long (as opposed to the 23m of Mk 3 and 4 used by Virgin East Coast) the distance from the door to the platform edge is also greater at stations with curved platforms such as York.  No doubt DafT considered this point when they 'wrote' the specification.  Sorry my mistake - no doubt DafT overlooked this point when they 'wrote' the specification.

As the doors are (mostly) over the bogies, your statement is true only if the cars are narrower (which being longer, they may need to be). Totally agree with your sentiments about DafT.

[david.hill64]

As a maintainer  I agree with the Hitachi view on plug doors, far too many points of failure. Keep it simple.

But do these doors have the Shinkansen style of inflatable seal to keep them airtight and stop them rattling? This system is a maintenance headache.

As a maintainer  I agree with the Hitachi view on plug doors, far too many points of failure. Keep it simple.

But do these doors have the Shinkansen style of inflatable seal to keep them airtight and stop them rattling? This system is a maintenance headache.

[modfather]

 

No, I need to see if any information has been released before I discuss what they do have though.

[4630]

As the doors are (mostly) over the bogies, your statement is true only if the cars are narrower (which being longer, they may need to be). Totally agree with your sentiments about DafT.

 

 

Relying on a couple of separate internet sources (and I appreciate that they might not be wholly accurate), rather than using a tape measure to provide a definitive answer, produces the following;

 

Mk 3 - 2.74m  

Mk 4 - 2.73m

Class 800 - 2.7m 

[Coryton]

As the doors are (mostly) over the bogies, your statement is true only if the cars are narrower (which being longer, they may need to be). Totally agree with your sentiments about DafT.

 

If the platform facing the train is convex, so to speak, doesn't the distance from the platform to doors over the bogies increase with increasing coach length? (Or rather distance between bogies, which isn't necessarily the same thing)

[The Stationmaster]

If the platform facing the train is convex, so to speak, doesn't the distance from the platform to doors over the bogies increase with increasing coach length? (Or rather distance between bogies, which isn't necessarily the same thing)

 

Logically that would be the case.  There appears to be a potential problem with both stepping height (at some places?) and stepping distance (at some places) and maybe even both in a few cases.  Interestingly the recent York photos would appear to suggest that nothing could be done to increase the platform height as it looks to me as if it might then foul the bodywork at the centre of the vehicle.  

 

As 'Ron Ron' has pointed out the IE Project does include alterations at stations in order to handle the trains but I wonder how far that can go when station platforms also have to cater for C1 and C3 or C4 loading gauge stock plus various freight vehicles as well as the class 80X?   So the original question about DafT possibly overlooking the gauging issue when specifying 26m body length and, presumably, either specifying or accepting the door step height would seem to have some validity.

[Ron Ron Ron]

The bogie centres (distance between bogies) are said to be fairly close to that of the Mk3 and the extra length of the coaches is outboard of the bogies at the end of the coaches.

Hence the slight tapering between the doors and coaches ends.

The coaches are slightly narrower than a Mk3 or Mk4... 1.5 and 0.7 inches respectively. Would anyone notice?

 

The IEP spec. required platform stepping distances on curves of less than 260 metres radius to be the same as, or less than that for a Mk3 coach (all platforms inc. non-compliant).

 

On platforms with curve radii greater than 260 metres, stepping distance must comply with the requirements of Railway Group Standard GI/RT7016, Issue 4, September 2010, 'Interface between Station Platforms, Track and Trains' and Section B6.3 of Railway Group Standard GM/RT2149, Issue 3, February 2003, ‘Requirements for Defining and Maintaining the Size of Railway Vehicles’. 

 

There are some calculations of centre throw, end throw and platform stepping distances on curved platforms (inside and outside curves), out there on the "net".

 

Centre throw is about the same as for a 23 metre Class 444 unit and less than for a Mk3 or Mk4.

End throw is obviously greater, hence the slightly tapered bodies which keep the whole thing within gauge and clear of curved platforms.

 

Using Newcastle Station's platforms 2 and 3 as examples....

...figures suggest that on an inside curve (platform 3), the platform gap is just 7mm greater than a Mk3 and 45mm greater than a Mk4.

The same source calculates that on an outside curve (platform 2), the gap will be 160mm greater than a Mk3 and 121mm greater than a Mk4. However, this is still much less than for an Electrostar, Turbostar or 20 metre Desiro.

 

How realistic these calculations are, I have no idea, however this is all beyond conjecture as the real trains are now out there daily on the network, under test.

 

The DaFT project team, which included engineers from train builders and the infrastructure world, looked at all the pro's and con's of different coach lengths when drawing up the spec. 

The issues surrounding the choice of 26 metre stock are detailed in the various documents released at the time.

The potential or actual impact on the rail infrastructure, was a component of the programme from the outset.

 

 

 

..

 

.

Edited February 25, 2017 by Ron Ron Ron

[cheesysmith]

informed sources reported last year that the doors had door seals that engaged to stop the rattles from passing trains.

[Ron Ron Ron]

informed sources reported last year that the doors had door seals that engaged to stop the rattles from passing trains.

 

Is it not the same door system as used on the Class 395?

 

 

.

[modfather]

The crew doors are interlocked slam doors with inflatable air tight portal seals.

The saloon doors are a sliding pocket type, forced against a soft portal seal by four actuators, once the train passes the low speed threshold.

 

 

Of the stock I have previously worked on;

 

14x - the doors do the job, but have lots of issues with settling and they wear out fairly quickly compared to others. If they are opened/closed on low air pressure they don't lock, despite appearing to. 

 

150 - good, simple above door mechanism, one ram, one adjuster for the local door, one regulator for the saloon. Limited obstacle detection, but very rugged. Until the bottom runners snap or the pockets get a bit mucky and need cleaning out... 

 

153 - fine, although over complicated, with far too many microswitches. There's one switch that will close the door with no detection, which apparently hurts a lot when you are testing according to one of my colleagues.

 

158 - far too over complicated, rarely understood well. If you have any problems past centre over locking pressure, you may as well give up now - the four hard stops and four turnbuckles per door leaf require a huge amount of patience to get right. If in doubt, don't change components, ignore your modern VMI, set it up to the BREL manual then test to the modern spec to check. 

14x and 158 always seem to get themselves out of sync, no-one cares why, open and close them all to fix!

 

HST - simple to check but theres a fair degree of measuring and testing the latches as per any other mk2/3 door, nothing complicated, even CDL once you understand it isn't too scary.

Edited February 22, 2017 by modfather

[david.hill64]

If the platform facing the train is convex, so to speak, doesn't the distance from the platform to doors over the bogies increase with increasing coach length? (Or rather distance between bogies, which isn't necessarily the same thing)

Assuming that the doors are in line with the bogie pivot points (which is the sensible place for them as it reduces the stepping distance), then the distance from the platform to train doors will remain the same irrespective of train length, unless the overall width of the vehicle has been reduced to take into account underthrow (the problem at the centre of the coach where the longer the distance between bogie centres the further away from -or closer to - the track centre line the vehicle will be on curves) and overthrow (the problem at the ends of vehicles where the corners stick out from - or get closer to - the track centre line on curves).

 

The further away from the bogie pivot point the doors are moved, the greater will be the stepping distance on a curved platform. This would be a problem in a long commuter car with 1/3, 2/3 spacing. (Or depending on which way the curve is the stepping distance could become small depends on 'convex or concave'

 

If as Ron Ron Ron says the bogie spacing is essentially the same as a mark 3 then the vehicle underthrow will be similar to that of a mark 3, while the overthrow will be worse, but as the GWR showed us many years ago, you can overcome that by tapering in the ends. 

[Coryton]

The DaFT project team, which included engineers from train builders and the infrastructure world, looked at all the pro's and con's of different coach lengths when drawing up the spec. 

The issues surrounding the choice of 26 metre stock are detailed in the various documents released at the time.

The potential or actual impact on the rail infrastructure, was a component of the programme from the outset.

 

I've read various things suggesting that BR had been thinking of 26 m coaches too, in which case it's nothing new.

 

Assuming that the doors are in line with the bogie pivot points (which is the sensible place for them as it reduces the stepping distance), then the distance from the platform to train doors will remain the same irrespective of train length, unless the overall width of the vehicle has been reduced to take into account 

 

Ah I see where my logic and back-of-the-envelope scribblings went wrong. If you take a coach and extend the bogie spacing while keeping the same body width, at some point you have to increase the platform-to-track spacing for a "convex" platform face and therefore the gap even for doors over bogies increases.

 

But if (as we are told and would be expected) the coaches are designed so that no changes to the platform spacing are required then the gap at doors over bogies must remain the same no matter what the bogie spacing is - but not for doors elsewhere in the body (though on convex platforms doors in the middle win out).

[Ron Ron Ron]

I've read various things suggesting that BR had been thinking of 26 m coaches too, in which case it's nothing new.....

 

That is absolutely correct.

The proposed BR Mk5 coach ( IC250 project and other applications) was to be 26 metre long.

 

The IEP proposal wasn't dreamt up out of nothing.

Quite a lot of the project concept and subsequent train specification, was based on BR's pre-privatisation development work.

 

The IC250 project was intended to replace the cancelled APT for the WCML.

IC250 was stopped along with all other projects, in the run up to privatisation and BR being dissolved.

The Class 390 Pendolino was subsequently procured post-privatisation (by Virgin) to fill the void left by the cancellation of the IC250 project.

 

After introduction on the WCML, it was planned that IC250 trains would then be introduced on the ECML and GWML, to replace IC125 (HST) and ultimately the Mk4 based IC225.

 

It's worth reflecting on the fact that if privatisation hadn't happened and BR had been permitted to continue with its plans for new trains, locos and rolling stock; the HST's would have all been replaced or demoted to secondary roles about 10 years ago. It's doubtful if many, if any, would still be in service today.

 

 

 

.

[andy stroud]

 

 

 

It's worth reflecting on the fact that if privatisation hadn't happened and BR had been permitted to continue with its plans for new trains, locos and rolling stock; the HST's would have all been replaced or demoted to secondary roles about 10 years ago. It's doubtful if many, if any, would still be in service today.

 

 

 

.

 

...and there might still have been a railway  research department.

[pete_mcfarlane]

It's worth reflecting on the fact that if privatisation hadn't happened and BR had been permitted to continue with its plans for new trains, locos and rolling stock; the HST's would have all been replaced or demoted to secondary roles about 10 years ago. It's doubtful if many, if any, would still be in service today..

 

On the other hand, a lot of the HSTs were replaced by more modern units about 10-15 years ago. The only reason they're still around is the increase in passenger numbers meant that the ex-Cross Country units were put back in service as a relatively cheap way of getting extra capacity. 

[Glorious NSE]

 

It's worth reflecting on the fact that if privatisation hadn't happened and BR had been permitted to continue with its plans for new trains, locos and rolling stock; the HST's would have all been replaced or demoted to secondary roles about 10 years ago. It's doubtful if many, if any, would still be in service today..

It's pretty likely that if it had just been left to the post privatisation operators, a fairly large percentage would have been replaced in their original roles by now as well, without the need for the government to try and disprove the laws of physics!

 

In that case though, different operators would have likely made different choices, and nobody would have instigated a massive electrification project part way through (and then half abandon it) resulting in multiple re-writes to the spec...

 

 

 

[kryten65]

In between delivering many shells and bogies to Hitachi at Aycliffe, this pair of bogies came past the yard. 

 

for IEP train 15..

 

the shells for the driving cars for train 23 go to Aycliffe tomorrow

 

 

[Coach bogie]

Northallerton Station is to be extended by 20m on platform .“The work we are carrying out at Northallerton station is an important part of our Railway Upgrade Plan and will allow all carriages of the new Azuma trains to fit into the station. “It is a vital piece of enhancement work to the railway and will bring even greater benefits for passengers traveling on the East Coast Main Line. The work is part of a wider project of improvements and we have recently begun a similar project at Durham station.

 

The platforms at Northallerton are straight and accomodate a class 91, 9 x mk IV and a DVT, so I am unclear why the platform needs extending for a nine car set.

 

Mike Wiltshire

[Coryton]

Northallerton Station is to be extended by 20m on platform .“The work we are carrying out at Northallerton station is an important part of our Railway Upgrade Plan and will allow all carriages of the new Azuma trains to fit into the station. “It is a vital piece of enhancement work to the railway and will bring even greater benefits for passengers traveling on the East Coast Main Line. The work is part of a wider project of improvements and we have recently begun a similar project at Durham station.

 

The platforms at Northallerton are straight and accomodate a class 91, 9 x mk IV and a DVT, so I am unclear why the platform needs extending for a nine car set.

 

Mike Wiltshire

 

11 x 23 m coaches requires ~ 253 m (ignoring the spacing between vehicles) - maybe a bit less if the 91 and/or DVT are shorter than 23 m.

 

Two 5 coach trains running together with 26 m coaches needs 260 m. 

 

Hmmm.

 

When a 225 set is in Northallerton, is all of it alongside the platform?

[Glorious NSE]

91 + DVT are both shorter than 23m.

Wikepedia reckons 19.4m for the 91 and 18.8 for the DVT.