ECML capacity improvements

[YorkshireBear]

I just wanted to query the progress, if any, on a few plans to increase capacity on ECML
Shaftholme junction north of doncaster, Hitchin flyover, removal or flat crossing north of newark, extra platforms.

Any new appreciated

 

[philjo]

Hitchin flyover is awaiting formal planning approval from The Government. The public enquiry was earlier this year- I think the decision is due early 2011.
Platform 2 at Royston is due to be extended to 12-car in the near future.

 

[swt_passenger]

There are no current plans for Newark flat crossing. Although it is known to be a major timetabling constraint, even the very recent ECML 2016 capacity review doesn't suggest its removal...

Shaftholme grade separation is going through design procedures at the moment, target completion is not until March 2014

 

[DaveNewcastle]

There's also the upgrade to Holgate junction. (The fourth line between Holgate jn and York Station).
That removes a lot of pressure on the southern approach to York.

 

[Sir_Clagalot]

I had heard that they were looking into a flyover for the flat crossing, with the ECML staying put and the Lincoln line going over the top.
Another major bottleneck is Welwyn Garden City to Knebworth over the viaduct and through Welwyn North. Would take some radical thinking to get round that one!

 

[TGV]

I was just about to mention Welwyn as the biggest problem. Realistically, the only way round it is a sodding great bridge and another tunnel. But there are several thousand NIMBY's in that valley that'll create god knows how many leaflet campaigns to make sure no new bridges are built there.

How about... if the fast lines started climbing up immediately after WGC station, then by the start of the bridge they're high enough to route the slow lines underneath, then over the bridge (which would need major structural modifications, but at least it would fit in the same space) it would be a double-decked bridge, all the way over Welwyn North (fast lines on top - they never stop at the station anyway) and then the fast lines would split to one side and dive through the hills in their own tunnel and re-join the current route at Woolmer Green - possibly with a flyover.

OK - it's pretty radical, but looking at the scale of that bottle neck - I just can't see another bridge that size being allowed - and at any rate, you'll need a new tunnel, so you may as well route it where you want.

 

[Sir_Clagalot]

With some ingenious engineering I dare say the viaduct could be widened to four tracks, fairly unobtrusively. Though it would require the mother of all engineering blockades and diversions!! No several weekends on the trot, more like a few months!

 

[YorkshireBear]

Well i've just started a civil engineering degree so i'll see what i can do

 

[ainsworth74]

Well i've just started a civil engineering degree so i'll see what i can do

We'll be waiting

 

[Peter Mugridge]

That would mean a huge cantilevered deck combined with all sorts of re-inforcement for balance wouldn't it? In which case I'd think it would have to be a total blockade for 5 - 6 months, not just a large number of weekend blocks.

TGV's suggestion of double decking the bridge is probably the most practical suggestion short of buying off all the NIMBYs. Might need to widen the pillars a bit to take the extra load generated by the upper deck, to avoid passing those stresses through the existing structure ( thinking in terms of avoiding the risk of harmonic vibrations developing as you could potentially have two trains in the same direction at the same time on the structure ), but that would be a lot less than the re-inforcement needed for a doubled width decking.

 

[GingerSte]

With some ingenious engineering I dare say the viaduct could be widened to four tracks, fairly unobtrusively. Though it would require the mother of all engineering blockades and diversions!! No several weekends on the trot, more like a few months!

What are you thinking? Cantilevering a deck out with big juicy beams every 3 metres or so? Put in some trimmer beams, a GRP deck, some parapets, ballast and track and the job's a good 'un! You'd need to check your foundations though, as you'd be doubling your live load.

Double-decking might also be a good option, but I'm reserving that for the viadict between Leeds station and Neville Hill.

 

[stut]

Alternatively, how practical would it be to shadow (or even travel over) the A1(M) from Stanborough to Knebworth? I know there's some bits that are pretty tight there (Ayot St Peter, for example).

 

[MidnightFlyer]

Comment deleted

 

[Sir_Clagalot]

Was thinking Monster beams over each pillar, with ironwork 'arches' that fan out to support the widened deck (with 'hammer beams' underneath that stretched down into the pillars). The transverse beams would be tied together with longitudinal ones that were also anchored into the embankments at both ends, sort of building a 'bridge within a bridge', as I believe they did with the Forth Road Bridge... The exposed metalwork would have designs that enhance the viaduct and that don't have a detrimental effect on the ground below.
OK, it would take months to do but would be well worth it in the end! Welwyn North would have to be moved outwards and either one double bore or two single bores on both North and South tunnels would be required too.
There is another viaduct (Robbery Lane) between the North tunnel and Woolmer Green Jn, but I cannot remember if it would need widening or not?

 

[swt_passenger]

I had heard that they were looking into a flyover for the flat crossing, with the ECML staying put and the Lincoln line going over the top.

I've found more info - the possibility of the flyover IS mentioned in the MML RUS. Maybe the theory is that the ECML services take precedence, and therefore the MML services fit in around them,so if there is a need to improve/change the East Midlands service pattern, whether freight or passenger, that is what would drive the change, not the ECML.

Still, it's odd that the latest ECML stuff doesnt even mention it in passing...

 

[YorkshireBear]

I'd never even seen the viaduct before, but i can see what the problem is, old historic viaduct like that must be very diffucult (or expensive to improve)

Adding another deck would be extrmely difficult and would probably need alot of external refurbishment strengthening.

i'll just invent something that will fix it


Also just learnt about the OHLE being poor north of york ie 92's 86's can't go? This realistically needs reweiring as soon as possible doesn't it? because that is limiting the electric freight network

 

[sprinterguy]

86s and 92s can and have worked north of York on the ECML, all the way to Millerhill, so there isn't a problem there, but it's true that there's no denying that the standard of the OHLE is poor on the northern section of the route.

GNERs' "White Rose" Eurostar sets were banned from working north of York, but that's probaby because there was never any reason to clear them further north on the ECML as well as overhead line tension issues.

The Welwyn bottleneck poses quite a major problem to surmount. Whilst it is possible to add catenary masts to the superstructure of a viaduct, adding a whacking great upper deck or wider single deck must surely put some major stresses on the existing structure that would perhaps mean that a detrimental speed limit would have to be imposed on it. I think the only feasible way to circumvent the problem would be a second viaduct, but with the number of NIMBYs' in the area, as mentioned above, that would be unlikely. I'm all for ingenious viaduct widening plans though!

 

[TGV]

373's weren't "banned" from running up there - they had gauging issues for one thing. Mainly though, the commercial argument for them that far North was slim.

 

[Peter Mugridge]

You could double deck Welwyn more easily if the upper deck was actually a second viaduct built around the present one without actually putting any extra loading on it.

Think about it; pillars on either side of each existing arch, carefully disguised with old style brick facades over concrete cores, supporting a new deck, also visually disguised, above the existing one but structurally independent of it...

 

[YorkshireBear]

I think anything would have to be struturally independant, i can't see a way increasing load on viaduct is going to work. But this is 21st century there must be a way.

 

[stut]

The viaduct is one thing, what about the tunnels afterwards? There's not an awful lot of space to play with around Digswell...

 

[Failed Unit]

Thinking out the box, I wonder if a totally new alingment would be the answer maybe bypassing Welwyn Garden City and Stevenage altogether. May trains don't stop at Stevenage and removing them altogether from this section would remove the problem, if it went to the East it could rejoin the Cambridge line as well. (could remove need for Hitchin Viaduct)

Could be not feasible but was thinking of a simular idea to the Selby bypass of the 1980's and what is proposed on the WCML

 

[YorkshireBear]

Whats proposed on WCML ?

 

[philjo]

The viaduct at Welwyn is Grade 1 listed & I understand that English Heritage had indicated when a scheme was mooted by Railtrack that they would block any permission which altered the "classic" view of the viaduct across the Mimram valley, so double decking is very unlikely to be permitted by EH.

With the 2 tunnels as well it would be extremely expensive as would an alternative scheme to tunnel from Hatfield on a new section of line.
it might be possible to incorporate 2 new tracks from Stanborough to Stevenage built alongside the A1(M) alignment if & when that is widended to 3 lanes (the A1M also has a bottleneck in this section) - but that would need joined up thinking by Dft so will never happen !!

I think the money would probably be better spent towards a parallel HS line running to the east, which would have spurs into Stansted & cambridge & rejoining ECML north of peterborough.
The bulk of the Cambridge traffic would then be removed from Welwyn, with the remaining through cambridge services having more capacity for the intermediate Hertfordshire ECML stations.

 

[jopsuk]

Rather than go through Welwynb, would it be easier to four-track and straighten up the Herford loop line instead? Major work would have to be done at the junctions at Stevenage and Bounds Green Yes- and I guess the North London stretches may be rather tricky?

 

[DaveNewcastle]

You could double deck Welwyn more easily if the upper deck was actually a second viaduct built around the present one without actually putting any extra loading on it.

Think about it; pillars on either side of each existing arch, carefully disguised with old style brick facades over concrete cores, supporting a new deck, also visually disguised, above the existing one but structurally independent of it...

Now I'm no civil engineer, but one thing aout such a structure jumps out at me - its all very well proposing a "structurally independent" viaduct which envelops the original, but they cease being independent at the ground! The footings of the original and the new 'outer' viaduct will present their weights onto overlapping surface areas of the valley slopes and flatlands below.
Some of the "new" weight would still be bearing down on the "old" piers' foundations.

(and anyway, some nice new cladding trying to look old will probably look awful far sooner than old things look awful!)

 

[YorkshireBear]

Now I'm no civil engineer, but one thing aout such a structure jumps out at me - its all very well proposing a "structurally independent" viaduct which envelops the original, but they cease being independent at the ground! The footings of the original and the new 'outer' viaduct will present their weights onto overlapping surface areas of the valley slopes and flatlands below.
Some of the "new" weight would still be bearing down on the "old" piers' foundations.

(and anyway, some nice new cladding trying to look old will probably look awful far sooner than old things look awful!)

Yeah your right there actually, lets face it it looks pretty impossible in my eye's

all i can think of is a completely different route serperate, but you'd have to go away for quite a while as any new viduct would obscure current viaduct...

 

[Aictos]

Rather than go through Welwynb, would it be easier to four-track and straighten up the Herford loop line instead? Major work would have to be done at the junctions at Stevenage and Bounds Green Yes- and I guess the North London stretches may be rather tricky?

As much as you've just made yourself your very own No.1 fan and I would like to see such works take place, they would be major works with platforms at all but two stations needing replacing, new track and OHL to be put in, bridges etc...

This is where the LNER and later BR missed out on when they carried out the 4 tracking at Potters Bar, they should have got the Loop done as well, just think of the pathing improvements!

 

[swt_passenger]

Yeah your right there actually, lets face it it looks pretty impossible in my eye's

all i can think of is a completely different route serperate, but you'd have to go away for quite a while as any new viduct would obscure current viaduct...

Once the current government abolish all the quangos like English Heritage, NR will be allowed to build a duplicate viaduct any time they like, but unfortunately there won't be any money...

 

[Failed Unit]

Whats proposed on WCML ?

A bypass of Stafford to reduce the bottle neck, don't think it was ever approved but it considered the best way of increasing capacity in the area as the Birmingham line crossings are done on the flat.