Hertford Loop RUS Improvements

[Aictos]

I'm currently reading though the RUS for the ECML specifically the sections which concern FCC services, now NR discuss capacity improvements to the line to be completed in 2011/2012.

The enhancements to capacity on the Hertford Loop, recommended in the RUS, will provide the ability to divert more trains when the main line via Welwyn is closed for engineering work. Against the background of continuing growth on outer suburban and long distance services an increased level of diverted services will be necessary to deal with passenger numbers. The scheme will also allow more trains to be diverted on an unplanned basis in times of disruption which will help bring performance benefit.

So what outer suburban and long distance services could they be?

Could we see a hourly service alterating between Cambridge and Peterborough via Hertford? So the 1207 ex Hertford is to Cambridge then the 1307 ex Hertford goes to Peterborough for example...

Keeping the current xx39 as a service to Letchworth or terminate at Stevenage if platform layout supports it.

I know in NSE days, there was a Peterborough service calling Kings Cross, Finsbury Park? Hertford North, Stevenage then all stations to Peterborough.

Hertford Loop capacity enhancements

provision of improved signalling headways north of Gordon Hill, passing loops or enhanced turn-back facilities at Gordon Hill and additional S&C at Stevenage to provide improved access to/from the ECML, to enable more frequent trains to operate.

Improved capacity and performance 2011/12

Now I know from photographs that the now uplifted line which used to use Platform 4 at Gordon Hill used to meet the Down line north of the station so bearing in mind the station uses a pair of island platforms converting Platform 1 (currently the Up Bay platform) and reinstating Platform 4 to though platforms should be feasible.

As to passing loops, the places I can think which has the room available are at Crews Hill, Cuffley, Bayford and Watton at Stone.

Not sure what they mean by additional S&C at Stevenage though?

What other capacity improvements could NR do to the line?

Would it be possible for NR to raise the linespeed to 90mph where possible for all services from the current 75mph which may well be possible with the improvements plus signalling upgrades.

 

[Tomnick]

Assuming your xx07 is an existing stopping service from Moorgate, I wouldn't have thought that'd be a serious candidate for extension - stopping at every shack between Hertford and London isn't an attractive prospect for someone travelling from Cambridge or Peterborough on an outer-suburban! I think the former NSE pattern is more likely - additional semi-fast services, on top of the stopping service pattern.

I'm not sure passing loops are the right option though - a stopping service 'put inside' can expect to wait 8 minutes (assuming a 4 minute headway, which I can't confirm at the moment) for a single train to pass. Hopefully being 'looped' once would be sufficient to allow an extra fast 'per stopper', but even that's a significant extension to the journey time of the stopper, plus of course the increased potential for it all to go horribly wrong! If it's not possible for additional fasts to fit between stoppers without catching the previous train up, perhaps terminating stoppers at Gordon Hill (with more provision for them to do so more conveniently than at present!), and serving the remaining stations to Hertford with the new outer-suburban service, or introducing a new regular service between Moorgate and Hertford, running fast between Alexandra Palace and Gordon Hill. I reckon that might just work without having to loop anything.

 

[yorkie]

Not sure what they mean by additional S&C at Stevenage though?
.

Allowing trains to get from Platform 2 to the Loop, I'd imagine!

 

[Aictos]

Assuming your xx07 is an existing stopping service from Moorgate, I wouldn't have thought that'd be a serious candidate for extension - stopping at every shack between Hertford and London isn't an attractive prospect for someone travelling from Cambridge or Peterborough on an outer-suburban! I think the former NSE pattern is more likely - additional semi-fast services, on top of the stopping service pattern.

I was thinking if the capacity was there to keep the xx39 as originating from Moorgate and the xx07 service going over to being a outer suburban service originating from Kings Cross.

The proposed outer suburban services could call Hertford North, Stevenage then all stations to either Cambridge or Peterborough with the xx07 being used with the existing Hertford terminators to provide the all shacks service.

There are two similar services provided at the moment which is the 0325 ex Peterborough and the 0106 ex Kings Cross both of which call at selected stations including Hertford North.

Would mean extending the platforms at Hertford to take 8 cars unless the services were using 4 car trains only.

Allowing trains to get from Platform 2 to the Loop, I'd imagine!

Or even allow trains to come off the Loop to use Platform 3 as trains are currently restricted to use just Platforms 1 and 4.

 

[yorkie]

They may as well do both really!

There's enough space for an extra line, and another platform on the west side of the station (with perhaps the loss of a few car parking spaces), and that would really make a big difference.

 

[philjo]

I would imagine that new fast/slow crossovers south of Stevenage to allow all platforms to access the Loop would be beneficial - on days when everything is diverted at short notice they can queue up at Stevenage as they all tend to call. Allowing one to arrive/depart on one platform while a train calls at the other would speed things up a bit & allow more flexibilty.

A semi-fast Hertford service to Kings Cross would give them a bit more parity with the Welwyn line & more regular connections at Stevenage. Presumbaly would call at Hertford North & Enfield as a minimum on the loop.

When the Hitchin flyover is completed there will be more capacity there so extending some of the Hertford services to Letchworth sidings would not have the same adverse impact it does at the moment as timetabling the northbound services over the flat crossing at Cambridge junction would not be a factor.
The case for additional platforms at Stevenage may get a boost depending on the outcome of the East-West route decision & exactly where they were planning to route it.

 

[Lee_Again]

I would put the loops back in at Gordon Hill so that stoppers can get out of the way and allow the existing semi fasts to Cambridge and Peterborough pass by unhindered. This would free up paths accross the Welwyn Viaduct.
New points south of Stevenage to allow access from/to the loop from the fast lines would also help.
And all this would be quite cheap. Far cheaper than building a new viadut and tunnels at Welwyn.