Yes but that would make things even worse wouldn't it? Essentially you'd be announcing that after months / years of disruption not to mention noise at night the TOC won't be making use of those wires for the majority of it's services. The local media would have a field day.
Do we know this for certain, no... I'm challenging the assertion that it would be worse, we don't actually know this for sure. The wires would used the whole length by loco hauled Mk4s, capacity would be increased by the Mk4s, headline journey times would remain via the 222 fleet.
In terms of creating extra capacity I honestly can't see how the 225's would make much difference given that EMT already runs 7 - 8 - 9 car trains during the 'peak' and of course it's HST's. I'm afraid the headlines will be "All This Money / Disruption For Slower Trains".
The Mk4s would simply resolve he Mk3 DDA issues instantly. There are currently 12x HST sets and 27x 222 units, the DfT plan to add 110mph EMUs on the Corby line, which would probably free up 4-5 Class 222s to strengthen current operations on the Nottingham/Sheffield routes, lets say that provides replacements for 2 HSTs, leaving a need for 10 Mk4 rakes to maintain current capacity.
EMT do run doubled up 222s, but in my experience, these are limited to a few services only in the morning and evening peaks.
Not only that but why would it not be possible to order 8 car EMU's?
It's possible, but the economics look very weak - you wouldn't be able to use them until 2022 at the earliest, the HST sets would need extensive work to get them past 2020, then in 2026, there will be a huge recast of WCML services that will free up dozens of 9/11 car Class 390s and a handful of 221s, that still have a decade or more of useful live in them. Not only that, but the civil engineering works fit better too, you would struggle to fit 8 car EMUs in at the Sheffield terminus currently, so something has to be done there to allow them to be turned around, I've seen units sat in platforms 5, 6 & 8 for well over half an hour at times (not at the same time). That, coupled with NT plans to increase frequency and length of trains, plus TPE looking to run six car 185s through the day makes Sheffield look a lot busier.
Who's to say that no one can make the economics of EMU's work given that sooner or later those cascaded trains would have to be replaced. Unless you live close to Toton (i.e. the western suBurbs of Nottingham) then HS2 will be of no use nor ornament to those living in the East Midlands. The DfT / Network Rail have already stated that MML timetable will stay as it is and so there is no reason to suggest that you couldn't get 30 years life out of a 125 mph EMU.
Where has that been stated ? There will of course be a demand for Sheffield to Derby/Nottingham/Leicester services, but given we are talking a point roughly 16 years from now, following two major recasts of the mainline timetables, I'm having serious difficulties believing that will be the case. Growth on these intermediate routes will eventually bring passenger numbers up on the MML, which will work very well with the release of some 390s in 2026, more units once HS2 reaches Crewe and dozens of released AT300s past 2032 once HS2 reaches York and beyond.
The figures were quoted in Railway Magazine a while a go and I think you'll find that my estimates are pretty close to the actual speed limits. Given that Network Rail have spent millions in recent years upgrading the line to 125 mph would it not be madness to not make full use of it? And as a regular user of the route it doesn't take rocket science to work out how fast you're going.
Given that I use the line on a regular basis, I'm originally from the East Midlands and I know many people who regularly use the route I think I'm in a good position to know how the media / local population will react.
I think you'll find that Thameslink make use of all four lines with the limited stop services running on the 'fasts' where they can. In fact I know this for certain. And so if there is a mixture of 125 mph and 100 mph running at the moment why should that change with 110 mph units?
All that this statement does is reinforce the reason why 125mph running isn't always possible on the MML, I've asked if there is any information on actual speeds of services along the MML, clearly some services will run at slightly different speeds depending on delay at stations, but all we have is a headline - yes, there's 125mph line in place - yeah great, but what's the actual speed of services.