HST's are mostly kept on the limited stop services to reduce time lost by stopping/starting.
That is a misleading statement. The 7:24 from Leeds is a HST that stops at 8 stations after Sheffield, the 7:29 is a 222 which calls at 4 - Journey time is longer on the HST, clearly it's a service catering for capacity on the intermediate journeys.
Not sure if i've understood correctly, but are you suggesting that it would be more economical than electrification, to carry on with the 222's for another 15 years, then buy more diesels for another 25years? If that were the case it would be pointless electrifying ANY route.
That's building a bit of a strawman there - It is clear that electrification is the way forward for the railways - I'm talking specifically about the MML, which unlike the GWML has about 70% of its 125mph units as diesel electric multiple units built just over 10 years ago, not 92% diesel loco hauled 125mph units that are getting on for at least 33 years old and have a replacement being built currently. That's putting aside the issue that HS2 largely replaces MML for its Sheffield-London traffic in potentially 15 years from now.
www.railwaysarchive.co.uk/.../NR_NetworkRUSElectrification2009.pdf
I can't seem to make the link work, but the above document makes the case for electrification over diesel.
To be fair, that document is 6 years old and nicely sidestepped the limited resource issues of completing electrification on operational track in 4hr possessions through the night - unlike Crossrail/HS2 which will be stringing wires on a construction sites
Enough to make electrics more economical than diesels. There's a lot more to diesel maintenance than pulling out an engine and popping a new one in. If only it were that simple.
Clearly, but can we quantify that difference ?
See above electrificationRUS document. Section 7.3.2 Once again, the above document should provide the answer.
I don't see the word infinite - I see the loose words "strong case" and argued by local/regional groups - there's a strong case for me personally to have a 140mph direct railway from SE Sheffield to Manchester - doesn't mean it fits the national agenda :-/
I did point out that electric acceleration is superior to diesel? If you want more, it's due to the greater power to weight ratio (no engine or fuel to lump around) Power is also immediately available, no delay waiting for an engine to spool up to the correct rpm for the situation. The engine also powers other things like oil pumps, hydrostatic pumps, coolant pumps etc, so not all power is available for traction. As an engineer you'd know all that though.
Well I'm a civil engineer, but I'm aware that electric is superior to diesel - but again, no one appears able to quantify this in an operational environment - having trains that get up to speed quicker is next to useless if the paths aren't available to take advantage of the quicker pace - what I'm getting at is just how much difference are we talking in terms of operational feedback vs isolated units based upon timings outside of an operational environment.
Be a lot of end cars doing nothing in the sidings, or intermediate cars. The numbers don't add up.
Possibly - but again, saying the sums don't add up and demonstrating are quite different - as we have seen before, sometimes we have to throw a few things onto the proverbial sword to allow progress to provide something better - just simply saying no, won't work isn't really an answer - as a civil engineer looking at alignments and options, we rule in the mad ideas to be able to rule them out - the recent A9/A96 road dual carriageway assessments not only looked at online schemes, but new routes close and far, even tunnels to give a more direct route - the tunnels failed at the first hurdle, but at least we can say definitely that they aren't an option.
It is theroretically possible to turn a train straight round in the time it takes a Driver to change ends, as long as you're not bothered about the train being cleaned, re-stocked, toilet water topped up, security checks done, etc, etc.
Given five trains run from four platforms it's a fair assumption that at least two trains have to be turned around in an hour - so theoretically, without any corner cutting and with enough staff, 8 trains could be turned around in an hour if necessary, which could be increased further by some clever on train cleaning and servicing trains at the opposite end of route on some shorter services. I do accept that 8 plus trains per hour heading out of St Pancras will substantially upset Thameslink though
Probably very difficult and expensive to make Mk4's HST power car compatible seeing as the wiring is totally different.
Yep, I get this, but again, difficult in what quantifiable sense - it's not like upgrading the Nimrods surely, but a lot more difficult than changing couplings - a new multiple unit might be £20-30m, what would the cost of rewiring a pair of Class 43's ? £1-2m perhaps ?
You could refurbish Mk3's, but then you're left with the knackered out power cars. Did you know an HST Mk3 coach can't work with a loco either? Different wiring again.
These the same knackered Class 43's that are currently in front line services on GWML, ECML, MML, XC ? Or are you thinking of other power cars ? Scotrail seem to be happy proposing them as an interim solution.
But it won't cost less than electrification in the medium to long term. Pacers "do the job" of getting people from A to B. Is everyone a winner in Pacerland?
Well your going off on a tangent there - Pacers aren't fit for their role, HST's are currently fit for the role of express 125mph operation and many people prefer them to the 222's - I'm largely indifferent but like the extra seat space on a HST :-/
There's a lot to be said for having a bigger glass than needed. An approach I wish would be applied to the railways, rather than the "as cheap as possible" approach.
It's not a case of doing MML on the cheap - there's not enough resource to do the job at the same time as GWML - so we need alternatives rather than just doing nothing - I'd rather have a 80% solution next teeth an wait 10 years for a 100% solution.