D365
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... And what about the commuting population in between? Our trains have already been messed with enough!
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Welwyn Viaduct section doubling - How?
- Thread starter AlanFry1
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... And what about the commuting population in between? Our trains have already been messed with enough!
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Here's my attempt at posting a timetable.
Please spot for errors and provide feedback.
12.01p = passing time
removed. another attempt coming soon
--- old post above --- --- new post below ---
Attempt 2
Please spot for errors and provide feedback.
12.01p = passing time
removed. another attempt coming soon
--- old post above --- --- new post below ---
Attempt 2
Code:
Destination EDI LDS OA WGSL HNSF CC HNSF WGSL LDS NEW HNSL FS/TL HNSL OA SF/KX LDS WGSL HNSF CC/TL HNSF WGSL EDI SF/TL HNSL FS/KX HNSL
Kings Cross 12.00 12.03 13.06 12.15 12.23 12.30 12.36 12.43 13.00 12.54 13.00
St Pancras TL x x x 12.02 12.30 12.27 12.32 12.45
Moorgate x x x 11.59 12.09 12.12 12.29 12.39 12.42
Old Street x x x 12.01 12.11 12.14 12.31 12.41 12.44
Essex Road x x x 12.04 12.14 12.17 12.34 12.44 12.47
Highbury x x x 12.06 12.16 12.19 12.36 12.46 12.49
Drayton Park x x x 12.08 12.18 12.21 12.38 12.48 12.51
Finsbury Park x x x 12.07 12.11 12.20p 12.22 12.24 12.35 12.32 12.37 12.41 12.50p 12.52 12.59 12.54 13.05
Harringay x x x 12.09 12.24 12.26 12.39 12.54 12.56
Hornsey x x x 12.11 12.26 12.28 12.41 12.56 12.58
Alexandra Plc x x x 12.14 12.16 12.22p 12.29 12.31 13.37 12.44 12.46 12.52p 12.59 12.51
New Southgate x x x 12.32 13.02
Oakleigh Park x x x 12.35 13.05
New Barnet x x x 12.21 12.37 12.51 13.07
Hadley wood x x x 12.40 13.10
Potters Bar x x x 12.27 12.44 12.42 12.57 13.14 13.09
Brookmans Park x x x 12.30 12.47 13.00 13.17
Welham Green x x x 12.32 12.49 13.02 13.19
Hatfield x x x 12.35 12.52 12.48 13.05 13.22 13.15
Welwyn Gdn x x x 12.41 12.58 12.52 13.11 13.28 13.19
Welwyn North 12.16p 12.19p 12.22p 12.39p 12.46p 12.52p 12.55 12.59p 13.16p 13.22
Knebworth x x x 12.59 13.26
Bowes Park x x x 12.33 13.03
Palmers Green x x x 12.20 12.36 12.50 13.06
Winchmore Hill x x x 12.23 12.38 12.53 13.08
Grange Park x x x 12.40 13.10
Enfield Chase x x x 12.27 12.43 12.57 13.13
Gordon Hill (a) x x x 12.30 12.32p 12.45 12.47 13.00 13.02p 13.15 13.17p
Gordon Hill (d) x x x 12.33 12.48 13.03 13.18
Crews Hill x x x 12.51 13.21
Cufley x x x 12.54 13.24
Bayford x x x 12.59 13.29
Hertford North x x x 12.36p 12.37 13.03 13.07 13.22 13.33
Watton at Stone x 12.42 13.12
Stevenage 12.18p 12.21p 13.24p 12.45p 12.50 12.43 12.48p 13.00 13.03 13.20 13.18p 13.30 13.33
Hitchin x x x 12.55 13.05 13.08 13.25 13.35 13.38
Letchworth x x x 12.59 13.09 13.29 13.39
Baldock x x x 13.02 13.12 13.32 13.42
Ashwell x x x 13.06 13.36 13.46
Royston x x x 13.10 13.20 13.40 13.50
Meldreth x x x 13.54
Shepreth x x x 13.57
Foxton x x x 13.59
Cambridge x x x 13.09 13.37 13.39 14.15
Arlesley x x x 13.13 13.43
Biggleswade x x x 13.18 13.48
Sandy x x x 13.22 13.52
St Neots x x x 13.29 13.59
Peterborough 12.44p 12.47p 12.50p 13.11 13.15 13.25p 13.37 13.28 13.44p 14.07
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I've not had chance to read through it in too much detail, so can't make too many comments on the plan as a whole - just a couple of observations on some of the finer points though.
Firstly, the Moorgate branch seems to end up with a rather irregular service - sometimes a 10' interval, but at other times a 17'/3' pattern (reducing to 2' by Finsbury Park - I think the ROTP headway is 5½'!). I'm not sure that'd be too well received!
Secondly (and finally for now), some of the running times on the Hertford Loop look a little bit out. Four minutes to cover nearly ten miles from Gordon Hill to Hertford North is ambitious to say the least! You've also got one train running at a 1' headway behind another, from its extended stop at Gordon Hill to Hertford North - I still maintain that a 3 minute stop isn't enough in that case (inside clear 3' before the fast passes, with a further 2' to then allow the fast to get one signal section beyond, and get the stopper away), but either way there'll be more distance between them by Hertford.
Firstly, the Moorgate branch seems to end up with a rather irregular service - sometimes a 10' interval, but at other times a 17'/3' pattern (reducing to 2' by Finsbury Park - I think the ROTP headway is 5½'!). I'm not sure that'd be too well received!
Secondly (and finally for now), some of the running times on the Hertford Loop look a little bit out. Four minutes to cover nearly ten miles from Gordon Hill to Hertford North is ambitious to say the least! You've also got one train running at a 1' headway behind another, from its extended stop at Gordon Hill to Hertford North - I still maintain that a 3 minute stop isn't enough in that case (inside clear 3' before the fast passes, with a further 2' to then allow the fast to get one signal section beyond, and get the stopper away), but either way there'll be more distance between them by Hertford.
When I used to use the fast KX-CBG services I always thought that stopping at Hitchin would have made sense, rather than forcing everyone to do all stations from Stevenage to Cambridge. Our train was usually pretty empty, and it seemed like it could improve the service to the extremities of the KX commuter services by such things as using a fast Peterborough service to overtake and then catch a previous stopping service to Cambridge, and vice versa, saving some time over waiting for the next fast service. Pre-flyover, I also figured it would help regulate the conflicting movement.
Aictos
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No you misunderstand me, I mean for a alternative service to be provided 30 mins later.
I wasn't aware of the train at 10:54 by the way,
Alternatively, next West Anglia upgrade, put in provision to send them via Bishop's Stortford and Tottenham Hale. Two paths freed up with no loss of service, although it might slow things down a bit.
Peterborough might get plenty of East Coast services, but nowhere else between there and Hitchin gets anything other than a half hourly service (excluding peak-only extras).. Those services that currently stop at Potters Bar etc can sometimes take over 15 minutes more than those that don't, I can't see adding that to all services being popular.
tbtc
Veteran Member
I appreciate that what I'm suggesting wouldn't be popular at the five stations between Peterborough and Hitchin (Huntingdon, St Neots, Sandy, Biggleswade and Arlesey), but I was taking the suggestion of diverting four services an hour via Hertford (to free up spaces over the viaduct) as a starting point...
...since the FCC KX - Cambridge service is the fastest/ main one (whilst Peterborough has alternative faster services) it seemed logical to concentrate on the London - Cambridge market (which, lets face it, is bigger than the London - St Neots/ Biggleswade/ Sandy market).
Giving Cambridge four KX services an hour with a better split of times seems a better use of resources.
tbtc
Veteran Member
Of course.
But (based on the 2011 figures from Wiki)...
- Arlesey - 445,000
- Biggleswade - 740,000
- Sandy - 444,000
- St Neots - 1,091,000
- Huntingdon - 1,630,000
...vs...
- Cambridge - 8,240,000
Obviously not all of the journeys from each station are just to Kings Cross, but I don't have anything more specific to use. It does kind of put things in a little perspective though.
I don't pretend to understand the whole thing, so a question. I probably have the terminology wrong as well.
Does your plan either allow for, or eliminate:
* Trains which use the bay platform at Gordon Hill and need to cross the up line on arrival.
* Trains which use the bay platform at Hertford North and need to cross the down line on departure.
Although those numbers are largely considered to be inaccurate.. however, I'd like to point out that Cambridge also has services to Liverpool Street - passengers are more than welcome to use that route.
Taking in to account the far larger number of destinations available from Cambridge than somewhere like Arlesey the figures above are even further skewed.. that 8m is likely to end up far closer to those 5 stations put together.
transmanche
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- 27 Feb 2011
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Although they take, what, 30-40 minutes longer than FCC's non-stop?
tbtc
Veteran Member
If those figures are inaccurate then I'd be interested if you could provide me with some accurate ones.
There are other places you can get to from Cambridge (including some slow services to Liverpool Street) but London is a much bigger market than the alternatives.
Am not suggesting removing any services from the five stations between Peterborough and Hitchin, just giving them the same stopping pattern south of Hitchin (so that the bigger market of Cambridge to London can be better served.
The Cambridge non-stops are often 8 car and full during the daytime off-peak on weekdays and most of the weekend- it really isn't uncommon to get a Saturday mid-morning service and find it full and standing. Adding stops to full and standing services is, um, foolish.
There are no trains terminating at Gordon Hill. Each arrives in the loop platform, waits for a fast to pass, then follows it to either Hertford or Royston.
2 trains per hour would reverse at Hertford and need to cross from the down side to the upside. There are only 6 trains per hour so a path would be straight forward to find.
tbtc
Veteran Member
Presumably partly because at the moment the Cambridge traffic is skewed towards the one fast train each hour, rather than the badly spaced other services (one of which gets overtaken)?
Four fairly evenly spaced services each hour should manage that demand better.
There are two fast services to Cambridge per hour. One continues through to King's Lynn and the other terminates at Cambridge.
tbtc
Veteran Member
jopsuk was talking about the non-stop one though, which I was answering about. There is another "fast" service, albeit stopping en route (and is therefore a little slower).
Both the Cambridge-Kings Cross only and the Kings Lynn-Cambridge-Kings Cross service, spaced half an hour apart, are very busy services. The semi-fast, which doesn't get overtaken, is pretty busy. The Liverpool Street trains are quiet leaving Cambridge as despite being cheaper they're much slower (especially the xx21). Sending the Cambridge-Kings Cross non-stops to Liverpool Street would drastically slow them down; even with special conditions for a record run they weren't able to match the Kings Cros timing. There's also not really any spare capacity through Clapton.
No, both services I am referring to are fast to Cambridge. There are two non-stop trains per hour to Cambridge with one continueing to King's Lynn.
tbtc
Veteran Member
At least some of the xx:50s from Cambridge stop en route - not all though, apologies.
That's only in the morning peak and up to 11:00 and only in the Cambridge to London direction. Off peak it's xx:15 and xx:45 from Cambridge both non-stop to London. In the evening peak the reverse situation applies with 2 tph non-stop from Cambridge to London but not from London to Cambridge.
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OK. You threw me a bit by putting the assumptions after the plan.
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Sorry.
If you read the thread from the start all the 'plans' are discussed. The timetable was more a method to see if it works.
Most of the times come from the existing timetable and/or are based on my experiences of doing the journies. So not very scientific?!?
It's more to generate debate rather then being seen as the finshed article. It can be updated or improved as required.
You'll see that I have made some assumptions about the new Thameslink services. These may very well be wrong.
Don't forget, the idea is to free as many paths across the viaduct as possible.
At present I have 5EC, 2OA and 2FCC each hour.
Chris125
Established Member
I was just reading the East Coast Main Line 2016 Capacity Review and it's take on the whole issue is worth reading.
"The four-tracking of the Welwyn viaduct is not expected to resolve the capacity constraints on the southern end of the route. Four-tracking would allow the trains calling at Welwyn North to use the slow lines, providing an approximate two to three trains per hour increase in fast line capacity. Any other trains using the slow lines would either need to run along the slow lines from Finsbury Park (incurring significant pathing time) or weave to the slow lines north of Potters Bar.
Weaving at Potters Bar (assuming an upgraded fast – slow crossover is provided) would result in capacity issues on the slow lines and extension of journey times unless the linespeed on the slow lines was increased. Weaving at Welwyn Garden City (assuming an upgraded crossover is provided) would be possible; however, the running time differential between LDHS and outer suburban services between Welwyn Garden City and Woolmer Green Junction is only 30 seconds and thus only a minimal capacity gain would result.
Therefore, the total capacity gains from fourtracking Welwyn Viaduct would likely be too small to offset the significant cost. A more cost-effective
solution would be to reduce signalling headways over the section."
Chris
"The four-tracking of the Welwyn viaduct is not expected to resolve the capacity constraints on the southern end of the route. Four-tracking would allow the trains calling at Welwyn North to use the slow lines, providing an approximate two to three trains per hour increase in fast line capacity. Any other trains using the slow lines would either need to run along the slow lines from Finsbury Park (incurring significant pathing time) or weave to the slow lines north of Potters Bar.
Weaving at Potters Bar (assuming an upgraded fast – slow crossover is provided) would result in capacity issues on the slow lines and extension of journey times unless the linespeed on the slow lines was increased. Weaving at Welwyn Garden City (assuming an upgraded crossover is provided) would be possible; however, the running time differential between LDHS and outer suburban services between Welwyn Garden City and Woolmer Green Junction is only 30 seconds and thus only a minimal capacity gain would result.
Therefore, the total capacity gains from fourtracking Welwyn Viaduct would likely be too small to offset the significant cost. A more cost-effective
solution would be to reduce signalling headways over the section."
Chris
Speaking of increasing capacity on that section...one thing that occurred to me when I used to travel that section was that there didn't seem any great obstacles to 6-tracking out to WGC from AAP, enabling the stopping metro services to operate segregated (and thus more frequently) from the suburban (i.e. Thameslink) services, which could then just run FPK, WGC, then all-stations to Peterborough/Cambridge.
In most cases the only obstacles would be the tunnels, and these could be handled quite simply by just widening out the single bores added when the line was quadrupled to give three double bores.
In most cases the only obstacles would be the tunnels, and these could be handled quite simply by just widening out the single bores added when the line was quadrupled to give three double bores.
Although you could leave some/all of the tunnels as they are and not have too much in the way of capacity constraints.
That's an equally important issue. The whole route between Woolmer Green and Bounds Green needs work. It hasn't been upgraded since electrification. To take full advantage of a four-track Welwyn, we need 100 mph slows, 125 mph fasts (if possible) and full ERTMS. This suggests a complete route upgrade, of which the viaduct would only be one part. However, there are probably other priorities at the moment, and the ECML has to take its place at the back of the queue.
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The tricky ones would be Hadley South, Hadley North and Potter's Bar, which are two double-track tunnels. There, you would need a third bore and slew the line over (not sure if there's room, though).
BTW, the Cambridge slows are more to serve intermediate stations south of Stevenage, and tend to be single units, while the semi-fasts are pairs. This works fine from a North Herts perspective.
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