Great Western Main Line electrification - ongoing discussion

[whole diary]

[grahame]

I thought I read somewhere else that the IET^▸ (Intercity Express Train) had chamfered ends so that the coach profile is the same as a MK3?

Yes, I think I saw that ... but then why do they need to reprofile the platforms at Bath for them to get through, and I think there's a problem with Narbeth Tunnel too which will stop through services from London on that line ...

[ChrisB]

The coaches are also longer, thus isn't there a different profile to the way the ends move when cornering?

[SandTEngineer]

The coaches are also longer, thus isn't there a different profile to the way the ends move when cornering?

Aren't the bogie centres the same as a MK3 as well, hence the chamfered coach ends designed to keep the overall profile the same despite the additional 3m length of the IET^▸ (Intercity Express Train)?  I'll have to see if I can find out where I read all this.

....and by the way, there is no such thing as 'cornering' on a railway, its 'curving and canting'....

Yes, I think I saw that ... but then why do they need to reprofile the platforms at Bath for them to get through, and I think there's a problem with Narbeth Tunnel too which will stop through services from London on that line ...

Not sure about Narbeth tunnel, but isn't Bath mainly to do with stepping distances?

[stuving]

I thought I read somewhere else that the IET^▸ (Intercity Express Train) had chamfered ends so that the coach profile is the same as a MK3?

Yes, I think I saw that ... but then why do they need to reprofile the platforms at Bath for them to get through, and I think there's a problem with Narbeth Tunnel too which will stop through services from London on that line ...

But every new design needs some work with angle grinders somewhere...

On paper, a 26 m carriage ought to be 3 m longer than a Mk 3. But Hitachi draw theirs with a dimensioned length of 25.000 m and a gap of 1.000 m. Obviously those are implausibly precise figures, and that 1 m gap looks way too big, but they are the best we have (I've not been able to sneak up to one with a measuring tape).

A Mk 3 is 22.57 m over its body proper, with bogie pivots spaced at 16 m. My best estimate off drawings is that for IEP^▸ (Intercity Express Program / Project.) that spacing is about 17 m, or a bit less. The important lengths for overthrows are half the bogie spacing and the bogie-end distance. So that 3 m has been reduced, then spread about equally over those lengths. 

Applying what GE/GN8573 says to those data, for a 300 m radius curve I get 14 mm greater inner overthrow. But that's offset if (as it appears) the body is a little narrower - at 2.7 m vs 2.79 m it has 45 mm more clearance. Of course width varies with height, so for platforms and other things the answer may vary.

For outer overthrow the formula gives 34 mm more, but that can be offset by the taper at the end of the bodyshells - it wouldn't take a lot.

So the answer ought to be some minor adjustments ... unless someone has done their sums wrong.
 

[Bmblbzzz]

Is the objection to underfloor engines only to actual engines, presumably due to noise and vibration, or is it a preference for separate locomotives? I understood the point of having all wheels driven (electrically) was to increase traction and both reduce and better distribute weight, thus improving acceleration and reducing wear and tear on the track?

In my case, the objection to underfloor engines is partly due to noise and vibration, but is also the fact that a short DMU^▸ (Diesel Multiple Unit), or even a pair of short DMUs coupled together simply do not feel like a proper intercity train.
A proper intercity train should be at least 10 coaches, and preferably 12 coaches, and be gangwayed throughout.
First class should be at one end, and preferably at the same end each day, with standard class at the other end and a buffet between the classes.
Seating should be mainly facing across full sized tables, with luggage space between the seat backs.

A pair of 5 car DMUs are a very poor substitute for a proper train, first class will be in two different and presumably random locations. And the first class host will be in other unit.

Haulage may be by diesel or electric locomotive as required. A locomotive or power car each end has a lot to be said for it. If the power cars are gangwayed to the rest of the train, then any spare space therein could be used for storage of luggage, cycles, and catering supplies.

EMUs^▸ (Electric Multiple Unit) are not as bad as DMUs, but for long distance or prestigious services I would still prefer an electric locomotive hauling an ample number of coaches, over an EMU. Several short EMUs coupled together and lacking gangways simply are not a proper intercity train.

Gangways are good. But we're not talking about DMUs or even EMUs; at least, I didn't think we were. I didn't think I was! The IEPs^▸ (Intercity Express Program / Project.) are to have underfloor traction to each wheel (so no underfloor engines) and gangways. I think?

[broadgage]

The IEPs^▸ (Intercity Express Program / Project.) DO have engines under the floors.
They are gangwayed WITHIN each unit, but do NOT have gangways between two units run in multiple.
Sure sounds like a DMU^▸ (Diesel Multiple Unit), even if it can also use electric power. Diesel operation will be substantial due to the ongoing electrification fiasco.

Since the majority of the fleet consists of half length units, I have a cynical suspicion that many services will be run by single units, as with voyagers. Those with more positive views assure me that double unit operation is expected regularly. So no access from front unit to rear unit.

Refreshment trolley will be in the other unit (no buffet remember)
First class host will be in the other unit.
Ditto the train manager, when needed to referee reservation disputes, of which I foresee great numbers.
What happens to those who have a reserved seat in coach "C" but have joined the portion containing coaches F,G, H, J and K ? Many passengers used to proper inter city trains would assume that after boarding that they can walk through to the coach containing their booked seat.

[Noggin]

I thought I read somewhere else that the IET^▸ (Intercity Express Train) had chamfered ends so that the coach profile is the same as a MK3?

Yes, I think I saw that ... but then why do they need to reprofile the platforms at Bath for them to get through, and I think there's a problem with Narbeth Tunnel too which will stop through services from London on that line ...

I believe that Bath is due to the electrification clearances for the canopies which are listed and cannot be altered, plus the platforms need to be extended and the trackbed needs to be dropped to reduce the step.

[IndustryInsider]

The IEPs^▸ (Intercity Express Program / Project.) DO have engines under the floors.

Just for the sake of clarity, the 5-car trains have 3 engines and the 9-car variant has 5 engines, so just over half the vehicles will have underfloor engines.  Reports from those who've travelled in them say they are very quiet when compared with a Voyager.

I don't personally mind an underfloor engine myself if reasonably quiet.  It means I'm less likely to be annoyed by my fellow passengers.  My preference is for airline seats for the same reason - unless traveling in a group of three or more.

[ChrisB]

Also other TOCs^▸ (Train Operating Company) run voyagers in myltiple & don't suffer the problems that Broadgage (repeatedly, sounding like a stuck needle now) forecasts. So why do you think GWR^▸ (Great Western Railway) pax are less intelligent that other TOCs, as they all serm to manage ok

[broadgage]

Also other TOCs^▸ (Train Operating Company) run voyagers in myltiple & don't suffer the problems that Broadgage (repeatedly, sounding like a stuck needle now) forecasts. So why do you think GWR^▸ (Great Western Railway) pax are less intelligent that other TOCs, as they all serm to manage ok

Voyagers are indeed run in multiple, though not that often IME^▸ (in my experience), and when they are in multiple people searching for and failing to find reserved seats seems a significant problem.
Also Cross country are not exactly a prestigious operator, and seem to get away with a prevailing view of "stop moaning, you got there did you not"

FGW^▸ (First Great Western), now GWR, passengers are hopefully no more stupid than those of other TOCs, but they have become used to "proper trains" and may find the down grade to DMUs^▸ (Diesel Multiple Unit) a bit of a shock. As someone remarked "you lot in the south west have had it far too good for far too long, welcome to what we have to put up with elsewhere"

[IndustryInsider]

It's certainly not ideal having two trains without corridor connections running in multiple, but then again it's certainly not ideal to have long trains running around for much of the day carrying mostly fresh air as happens now.

The 08:21 Paddington to Hereford is an example of how not to do it.  As a 6-car Turbo it leaves Paddington and stations en-route with information screens saying that the rear three are detached at Worcester Shrub Hill, so passengers for beyond there need to travel in the front portion.  That's perfectly correct, but what it doesn't say is that the rear three coaches are locked out of use at Oxford, so in effect anybody travelling beyond Oxford needs to be in the front three coaches.  The on-train APIS system makes no distinction announcing the whole train is going to Hereford, so it's left to the driver to make announcements if he/she chooses to.  The end result is a dozen or more people turfed out at Oxford each and every day and creates a very poor impression.

The key to making the least number of people make a mistake when boarding is to provide clear and easy to understand information on the stations and on the train.  Let's remember that the current HST^▸ (High Speed Train) fleet doesn't have any internal information screens and relies on window labels that often fall off, and paper reservation labels that are easily removed and sometimes not placed on the train at all.

Let's hope GWR^▸ (Great Western Railway) are on the ball in making sure proper information is supplied to minimise the number of people confused.

[ChrisB]

[Voyagers are indeed run in multiple, though not that often IME^▸ (in my experience), and when they are in multiple people searching for and failing to find reserved seats seems a significant problem.

Every weekend on XC^▸ (Cross Country Trains (franchise)), and I believe there's a regular Glasgow via the West Midlands that uses double voyagers.  I'm not sure you are up to speed with other TOCs^▸ (Train Operating Company)?

Seems to whom? I use both XC at weekends and the Glasgow services from Birmingham at least fortnightly. Never ever seen anyone not find their coach from the platform or get stuck in the 'wrong' half either. And staffing is such that on Virgin there is a TM^‡(resolve) & catering in both halves and on XC at least one member od on-board staff in each half. I think you need to travel more on these services before expressing such an opinion?

The key to making the least number of people make a mistake when boarding is to provide clear and easy to understand information on the stations and on the train. 

Which Virgin do well & XC not badly.

Remember that these are doubled for their entire journey & do not split en-route. Oxford to Cotswolds will need attention, but with on-train comms being far better on IEPs^▸ (Intercity Express Program / Project.), it is easily surmountable

[Tim]

I thought I read somewhere else that the IET^▸ (Intercity Express Train) had chamfered ends so that the coach profile is the same as a MK3?

Yes, I think I saw that ... but then why do they need to reprofile the platforms at Bath for them to get through, and I think there's a problem with Narbeth Tunnel too which will stop through services from London on that line ...

I believe that Bath is due to the electrification clearances for the canopies which are listed and cannot be altered, plus the platforms need to be extended and the trackbed needs to be dropped to reduce the step.

correct.  The work at Bath is probably worth doing even if we were not getting a new design of coach because the widening gives more space on increasingly crowded platforms, it reduces the "gap" which is a long standing problem at Bath especially at the front end of the up platform, and it allows at least one of the platforms to be slightly lengthened.   

[chrisr_75]

Voyagers are indeed run in multiple, though not that often IME^▸ (in my experience), and when they are in multiple people searching for and failing to find reserved seats seems a significant problem.
Also Cross country are not exactly a prestigious operator, and seem to get away with a prevailing view of "stop moaning, you got there did you not"

Virgin West Coast use double Voyagers on the north Wales services which (mostly) split at Chester. I've used these a fair bit and never noticed any issues as the carriage numbering is effective and presumably the seat reservation system is set up correctly to take this into account.

1tph in each direction so it's hardly a rarely used timetable oddity.

[IndustryInsider]

All four daily services between London and Shrewsbury, as well as some of the hourly trains between London and Glasgow (via Birmingham) and even the odd London to Birmingham service are also in the hands of 2x5 car Voyagers.