Rows on MML

For about the third or fourth time, Thameslink can't be extended to Corby - there simply isn't enough rolling stock. It'll almost certain end up with a premium emu fleet (something like the Stansted express units that will be coming off lease is often mooted, although there's a chance of new build as well)

As for the rejigging of stops, there are a few different explanations. The removal of the Wellingborough stops from the long distance services is most likely down to the impending arrival of poorer performing bi modes on the long distance services (following cancellation of the electrification north of Kettering) so they need to miss out stops to keep timings - there's also the fact that the Corby services will have higher capacity trains to serve those stations so why fill the longer distance services with them.

Similarly for the Bedford/Luton stops being removed - a) there is a frequent, high capacity service serving those stations - leave the long distance services for those coming from Nottingham/Derby/Sheffield/Leicester. And b) the Thameslink program - you can't realistically timetable slow accelerating 125mph trains between 100mph quick accelerating trains, and the view of the DfT is that Thameslink is sacred.

Presumably trains could be found to extend Thameslink to Corby with a reduction in service to elsewhere? Given how unpopular the class 700s are proving on Great Northern, this may not be such a bad thing, although of course that issue then just moves from one place to another.

Whilst I take your point about the current general lack of money for public spending, I'm sure I've read somewhere that leasing costs for a brand new train is less than it is for an existing stock.

Right, there is something of a dilemma here - and posters thus far have not really highlighted it.

On the one its true that there are not enough 700 trains on order to allow Thameslink to be extended to Corby, and nor are they really suited to long distance commuting (mind you the same could be said for Brighton, Peterborough and Cambridge).

BUT.....

St Pancras high level only has 4 platforms! It can struggle at times to cope with the current MML service levels and there are serious doubts about its ability to cope with many more trains. Moreover the MML is pretty full south of Bedford too, and is a strategic freight route handling aggregates from the Midlands. Its the lack of enough Infrastructure to support the desirened number of trains (particularly at St Pancras) that is causing the timetable re-writes rather than 'Thameslink' itself

Given the Corby trains will be EMUs (compared to Meridians - which can in theory start as 2 shorter units combined as one train from / to St Pancras then split / join at Kettering) making the service an extension of Thameslink from Bedford does make logistical sense as it provides more train services to Corby but crucially doesn't require any more paths on the congested section south of Bedford

Longer term then maybe a variant of the 800s (which can come as short and long sets) will be the answer as that could split / join at Kettering.

Finally a word on stopping patters, the MML has long suffered from far too many station calls by what should be express services to the East Midlands. This results in a suboptimal solution for nearly everyone - Trains arriving from the north are already full when calling at stations closer to London, long distance journeys are slower than they could be and frequently it is difficult to make journeys between intermediate stations as skip-stop calling patterns are employed to attempt manage overcrowding and avoid delaying 'InterCity' services too much.

This is a legacy of commuter services finishing at Bedford and no other way of serving places north of there. Much the same dilemma occurs on the ECML where the needs of commuters from Grantham, Newark and Retford causes issues with services to Leeds and the North East. As with the MML capacity constraints inwards of Hitchin prevent the ideal solution of a semi-fast London - Doncaster service providing more room for those joining at intermediate stations, better connectivity between the aforementioned stations and speeding up true 'InterCity' services You can also see shades of this problem on the GWML where Pewsey has to be served by 'InterCity type services because stopping services end at Bedwyn (logically Pewsey would mostly be served by ex Bedwyn trains that continue to terminate / start from at Westbury) while the smaller stations of Frome and Castle Cary also interrupt 'InterCity services to / from the West Country.

If capacity constraints allowed, the MML service pattern south of Leicester should see a London - Leicester semi-fast with East Midlands services only calling at a maximum of 2 places (most likely) Kettering and Luton. Similarly on the ECML an ideal situation would be the London - Doncaster semi-fast service, with Leeds / North East trains only calling at One station south of Doncaster (probably Peterborough or Grantham). Meanwhile of the GWML you would see a London - Taunton / Exeter semi fast, the Bedwyn trains extended to Westbury and London - Devon / Cornwall services only calling at one station between Reading and Taunton (Westbury seems logical).

However "we are where we are" as the saying goes and with regards to MML service provision over the next decade something has got to give. Its all very well commuters from Wellingborough Bedford or Luton moaning about losing their 'InterCity' services, or being up in arms over the prospect of a 'basic' EMU being substituted for the current 'InterCity' trains - but to coin a phrase 'life isn't fair - get used to it!' The railway system exists to serve EVERYONE in the country NOT just commuters from selected stations and if it means upsetting them so as to improve the service provision touch larger number of users then the commuters should be told so. "The needs of the many outweigh the needs of the few" comes to mind - particularly as its not as though they are actually seeing an overall reduction in trains, they just might have to change more often.

The turnaround times at St Pancras are generous, to say the least. The fast Nottingham services occupy a platform for an hour or so, whilst the rest of the services (fast and slow Sheffields, slow Nottinghams, and Corbys) are all around half an hour, although these are being tightened up from this May I think.

There is no reason why the meridians can't portion work, other than a lack of stock to do it (assuming that was your point). The problem with being an extension of Thameslink is that the stock through the core has to be identical (for platforming and ATO reasons) so it's 700s or nowt.

For the Corby services, you don't need anything as glamorous as an 800, a fairly ordinary 110mph EMU with a premium interior (2+2 comfy seating, reasonable leg room, etc) is more than enough

Firstly re St Pancras turnarounds - it has long been the case that 'InterCity' services generally need around 40minutes layover at the termini  so that things like toilet tanks can be refilled, buffet / trolleys / kitchens restocked, litter removed, reservations applied, etc on the not unreasonable assumption that if passengers are going to spend a couple of hours or more on the train with things like refreshment facilities, they do have a right to expect them to be fully stocked etc. Yes the shorter the train the less the time needed, and yes at times of disruption turnround times can be cut - but this normally comes at a price as there will not have been sufficient time to properly service the train.

With only 4 platforms and lets say a 30minute turnaround for MML services the brutal truth is St Pancras cannot run many more trains. Even short trains don't help that much as the anything at the buffer stop end will be trapped if another shorter unit is stuck on top of it.

Commuter services generally have had a lower level of on board comfort and facilities - so turnarounds can be quicker. I believe that Charing Cross used to manage with a 6 minute turn round a couple of decades ago in the peaks - but that obviously left zero time to do anything if the incoming train was a mess.

Secondly, my point about coupling is this:-

Two short Meridan trains, one form Leicester and one from Corby can couple at Kettering and only use a single train path down to St Pancras. a 387 EMU (or a 700 for that matter) cannot couple to a Meridan, therefore you now need TWO train paths up to St Pancras rather than one that would be needed if identical trains were used

Similarly if Corby and Leicester (or northwards) services were formed by two shortish class 800 units combining at Kettering then again, only one path is required up to St Pancras.

If the Corby service is a 387 EMU and 800s get ordered to replace the HSTs, then you STILL need two paths up to London as quite evidently a 800 and a 387 cannot work in multiple. Furthermore when you get to St Pancras , if there is a shortage of platforms then those two trains will have to be short ones anyway,  plus one blocks the other in till it leaves, etc.

The big downside to splitting trains at Kettering however is that if the train goes north of Leicester then a short 800 unit probably won't be long enough to cope with demand. This then brings you back to the idea of a St Pancras - Corby / Leicester service calling at all principal stations and splitting at Kettering with services from the likes of Derby running fast from London - Leicester (maybe with a single stop at Luton).

Thirdly, while I do agree with your analysis of the sort of train needed for the Corby run, the bottom line is that high spec, medium spec, trains with armchairs or trains with no seats at all are of no zero use to anyone unless there is a path to run them in and space can be found to terminate them in St Pancras high level. The ONLY reason an extension of Thameslink is being advocated by some is Corby services can use existing Thameslink train paths south of Bedford minimising pathing issues and removing platforming problems at St Pancras High Level. In a way its no different to NR wanting to remove Thameslink from the Wimbledon loop - the decision was based on the infrastructure available and the desire to maximise train throughput (which required some service simplification). As we all know Wimbledon loop users sacrificed 4tph to Blackfriars in favour of 2tph to City Thameslink - and I can see a similar situation developing on the MML. Namely Corby (and East Midlands) users do not get the improvements the electrification and extra track could deliver just so they can keep their existing travel patterns.

All the 700s are spoken for, but there is a glut of electric stock at the moment - the soon-to-be-redundant* class 707s would at least have some compatibility - although if they are to run through the Thameslink core they would need to be adapted to the signalling system . and paths would need to be found for them through the core unless they are to be extensions of the existing Bedford services. You might even be able to multiple-unit a 707 and a 700/0 if thirteen cars will fit any of the platforms.

* can't come soon enough for me: the seating is rock-hard, the announcements irritatingly robotic and the visual displays just plain wrong.