Great Western to be wired for 140!

[whole diary]

[bobm]

Is that a recent change?  I haven't caught an XC^▸ (Cross Country Trains (franchise)) from Reading for about six months - but in the two years before that I think I only got two or three runs on the main.

[IndustryInsider]

What about ATP^▸ (Automatic Train Protection) for the XC^▸ (Cross Country Trains (franchise)) running at 125?

What about it?  ATP isn't fitted to Voyagers.

Is that a recent change?  I haven't caught an XC from Reading for about six months - but in the two years before that I think I only got two or three runs on the main.

It can vary in each timetable change, but over the last few years I reckon at least one of the four train per hour have routinely been routed on the main lines for most of the day (I've just checked the last 'up' Bournemouth and 'down' Newcastle and they were indeed routed main line.)

[Btline]

What time difference is it? Does the different appear in the TT or is it left as slack?

I thought that all trains travelling at 125mph had to have ATP^▸ (Automatic Train Protection) working on ATP lines. Obviously not.

[IndustryInsider]

What time difference is it? Does the different appear in the TT or is it left as slack?

I thought that all trains travelling at 125mph had to have ATP^▸ (Automatic Train Protection) working on ATP lines. Obviously not.

It doesn't make a significant enough difference to matter as far as the timings are concerned (maybe 60-90 seconds I'd guess?), and Voyagers were restricted to 100mph east of Reading, but no longer work that way. 125mph is authorised between Didcot and Reading.

[paul7575]

I thought that all trains travelling at 125mph had to have ATP^▸ (Automatic Train Protection) working on ATP lines. Obviously not.

One of those enduring railway myths?  The ATP section of the online sectional appendix actually includes this:

ATP is an additional safety system, which must be used at all times by Drivers of ATP-fitted trains when operating
over the lines defined above. Trains not fitted with ATP may use ATP fitted lines without restriction, subject to any
relevant conditions that may be imposed under Vehicle Acceptance certification processes...

I'd have thought that might be the case, what with XC^▸ (Cross Country Trains (franchise)) Voyagers routinely running at 125 mph elsewhere on the network without ATP.

There are however some specific sections with speed restrictions for Voyagers:

CLASS 220/221 TRAINS ^ MAXIMUM PERMITTED SPEED
Permissible speed is restricted to the maximum shown below (subject to any lower permissible, temporary or emergency
restrictions) between the following locations on Down and Up Main lines:
Paddington and Reading 100mph
Didcot East Junction and Box Middle Hill Tunnel 100mph
Somerton Tunnel and Cogload Junction 90 mph
Wootton Bassett Junction and Stoke Gifford East 100mph

It seems people may have put 2 and 2 together previously, and assumed the speed restriction was a blanket restriction due to lack of ATP, but that doesn't seem to be the case.

Paul

[Btline]

Why are they restricted on these lines. And surely they have never on some of those routes?

[JayMac]

All those routes listed would be of use to CrossCountry for diversionary purposes.

[SandTEngineer]

Indeed.  When Bristol to Cogload is blocked XC^▸ (Cross Country Trains (franchise)) travel via Westbury.  Adds an hour to the journey but better than a bus

[IndustryInsider]

Common sense suggests to me that with ETRMS fitted trains and lineside signals, trains that are not ETRMS could be run up to 125 m.p.h. (based on sighting the signals) with those with are fitted with the new system where sighting is not required able to run faster. 

I can't see how the two systems would be able to work in tandem without restricting the speed of trains to the lower limit, i.e. conventional trackside signals at 125mph.  Drivers will still need to observe and react to yellow and red lights and I can see ETRMS being very much seen as a background signalling system over the years between its installation and the removal of conventional signalling.  Also, despite the technology being capable of it, I can see a lot of hurdles to overcome before speeds can be increased from 125 to 140mph anyway (level crossings, platforms, curvature etc.).

[Phil]

I'm more inclined to believe the title of this topic "Wired for 140!" than the underlying text.

140 kph I can just about believe.

140 mph though? Not in my lifetime.

[paul7575]

140 mph though? Not in my lifetime.

Why not - if you ignore all the above diversions about signalling, rolling stock, and ERTMS^▸ (European Rail Traffic Management System.) etc, and although the original post is only quoting a headline from 'Transport Briefing', it is also stated quite clearly in the GW^▸ (Great Western) ITT^▸ (Invitation to Tender):

The electrification infrastructure will be designed to facilitate future 140mph running by higher tensioning of the main lines between Airport Junction and Bristol Parkway.

That is all they need to do, and from what I've read they are introducing a new OHLE design standard for the GWML^▸ (Great Western Main Line) and future mainline electrification projects anyway.  There's unlikely to be much of a technological difference between newly installed OHLE designed for 125 mph, and that for 140 mph.  I can't see any major difficulties in dealing with the wiring, to be fair.

Paul 

[Zoe]

I can't see how the two systems would be able to work in tandem without restricting the speed of trains to the lower limit, i.e. conventional trackside signals at 125mph.

When approaching a double yellow the target speed could be no higher than 125 mph but I'm not sure this would prevent a higher target speed when there are sufficient clear blocks ahead.

[Electric train]

I can't see how the two systems would be able to work in tandem without restricting the speed of trains to the lower limit, i.e. conventional trackside signals at 125mph.

When approaching a double yellow the target speed could be no higher than 125 mph but I'm not sure this would prevent a higher target speed when there are sufficient clear blocks ahead.

I belevie ETRMS Level 2 allows for this.

140 mph though? Not in my lifetime.

Why not - if you ignore all the above diversions about signalling, rolling stock, and ERTMS^▸ (European Rail Traffic Management System.) etc, and although the original post is only quoting a headline from 'Transport Briefing', it is also stated quite clearly in the GW^▸ (Great Western) ITT^▸ (Invitation to Tender):

The electrification infrastructure will be designed to facilitate future 140mph running by higher tensioning of the main lines between Airport Junction and Bristol Parkway.

That is all they need to do, and from what I've read they are introducing a new OHLE design standard for the GWML^▸ (Great Western Main Line) and future mainline electrification projects anyway.  There's unlikely to be much of a technological difference between newly installed OHLE designed for 125 mph, and that for 140 mph.  I can't see any major difficulties in dealing with the wiring, to be fair.

Paul 

It is important to select the right OHL^▸ (Over-Head Line) equipment for 140mph running, the Mk3 (never sure if its 3 a, b, c, or d) on the ECML^▸ (East Coast Main Line) is basically a 125 mph rated design although changing certain components the speed can be increased on plain line and there would have been an increase in the level of maintenance to sustain higher than 125

[onthecushions]

The following:

http://www.rssb.co.uk/sitecollectiondocuments/pdf/reports/research/T346_summary_rpt_final.pdf

covers the subject with a nice colour map on page 11.

OTC