The traditional turnback point was New Barnet, right through to electrification, mostly because the line was double track through the Hadley tunnels before the 1950s. N2s used to run into the down slow (I think) to run round and head back. Despite quadrupling, this continued right up until the line was electrified in the 70s, when they built the Welwyn flyover.
That would be nice. 313s ran alongside Deltics (literally in some cases) and so they have seen two new generations of East Coast traction. It's high time we had something new, and 378s are certainly tunnel compatible. Only question is whether they should be 2X3-car or 6-car. The higher speed would not see much use, but would give better recovery margins between stops, so I'd imagine it would be useful. The toilets would be good for the longer runs to Letchworth, which take up to an hour.
Other useful things would be four-aspect signalling on the Hertford Loop, 100 mph running for diverted trains, loops at Gordon Hill, full loops rather than just a turnback at Hertford North, or at least a second turnback, lookps at Letchworth and ideally a passenger connection from Canonbury and the ELL. Even better would be rebuilding of the Palace Gates branch so that Hertford Loop freight can run to Stratford without going via Finsbury Park.
As for EMU cascades, new outer-suburban stock would make the Networkers available for elsewhere, either a West Yorkshire electrification or the Paddington suburban routes. If we're having 378s, then how about a load of 379s? Best make it enough for twelve-car services in the peak.
1. ) If 378s with the specification I discussed above were to replace the 313s then rather then being restricted to 3 car trains as they are at the moment, I'm of the belief that they ought to be 6 car trains but enough ought to be ordered to be able to run all existing services as 6 car trains and also introduce more services.
2.) I believe the Hertford Loop already has 4 aspect signalling but only between London and Crews Hill, it's 3 aspect signalling the rest of the line but as to your point on the 4 aspects, yes that would be good but what would be better is if Network Rail shorten some of the signalling sections as the signalling sections between Langley Junction and Hertford are far too long as a result, diverted services often are right up each other's behinds.
3.) 100mph, well I would be happy with increasing the freight linespeeds to allow freights to run at 75mph the whole length of the line but feel 80mph is more reasonable then 100mph.
4.) By resignalling Gordon Hill, reinstating Platform 4 and carrying out the trackwork needed, you could loop services at Gordon Hill.
5.) Hertford North was actually designed to take 4 platforms, the unused platform face on the opposite side of Platform 1 is hidden by overgrowth.
I rather a 8 car headshunt was put in running from the Up Yard along the old platform face which would mean not having to block the main lines for periods of time when having to shunt trains.
6.) Equally they could rebuilt the road bridge and do the same work at Hertford that they could do at Gordon Hill.
7.) Seeing as FCC already has experience with 377s, it would make sense to order enough to run a lot more 12 car services instead of bidding with the NXEMUs after all, having two fleets of 377/5s and 378s would be much more effective operationally, both fleets would be dual voltage capable with the 378s on Inners and 377s on the Outers.
I know the 379s are the last of the Electrostar build but surely it would be more value for money to go for a tried and tested design after all, it's not like we're discussing a 70s or 80s design but rather a 00s design which is far newer.
8.) I wouldn't say no to having the 365s on the Oxfords,
