The Anonymous Widower

‘Digital Twin’ To Support More Robust Timetable Planning

The title of this post is the same as that of this article on Railway Gazette.

When I saw the title of this post, I was surprised that it was a newsworthy story.

I have been doing scheduling of people, machines and other resources since the late 1960s and creating print outs and graphs to help people to manage businesses from the early 1970s.

In so many cases, I’ve found digital models have given a great insight into the interactions between factors affecting the system.

So I would have expected train companies to all have a digital twin from at least 1980, especially as I know BT and other phone companies had digital models of their networks by that time.

If they don’t have a digital model of their network, how do train companies plan their timetables?

By trial and error!

Or do they start with marketing ideas like four trains per hour and then fit the timetable together like a jigsaw?

September 10, 2019 Posted by | Computing, Transport | , | Leave a comment

Shuttling Between Stratford And Meridian Water Stations

The shuttle between Stratford and Meridian Water stations started today with a frequency of two trains per hour (tph).

As a driver said to me, it’s more of a Z, than a shuttle, as it has this pattern.

  • Bishops Stortford to Stratford. – 56 or 53 minute +turnaound of six minutes
  • Stratford to Meridian Water – 15 minutes + turnround of seven minutes
  • Meridian Water to Stratford – 15 minutes + turnround of seven minutes
  • Stratford to Bishops Stortford – 53 or 55 minutes + turnround of 19-24 minutes

As I said in Meridian Water Station Is To Be Upgraded, the diagram takes three and a half hours and it would need seven trains.

Note.

  1. Most of the trains today, seemed to have been formed of two four-car Class 317 trains, although there was at least one train working as a four-car train.
  2. I made two visits to the route today and it seemed to be performing reliably.
  3. One train was cancelled due to a shortage of crew.

These are some pictures, I took throughout the day.

A few thoughts on what I saw and deduced.

The Timetable Works

The timetable seems to have worked well today and the driver who described the timetable as a Z, didn’t say it was crazy or ridiculous.

Passengers didn’t seem to be running around like headless chickens, so they were probably getting the hang of it.

Greater Anglia and Network Rail should be very pleased.

The Stations Have Long Platforms

The stations on the route; Stratford, Lea Bridge, Tottenham Hale, Northumberland Park and Meridian Water, all seem to have long platforms, which can certainly accommodate eight-car trains, which are 160 metres long.

Tottenham Hale’s platforms can handle twelve-car trains and are 240 metres long.

Do Greater Anglia’s Trains Fit the Platforms?

Greater Anglia’s new Class 720 trains come in two lengths.

  • Five-car trains are 122 metres long.
  • Ten-car trains are 243 metres long.

Only the five-car trains will fit the platforms at Lea Bridge, Northumberland Park and Meridian Water and the ten-car trains will only fit Stratford and Tottenham Hale.

It certainly looks to me, that only five-car trains will be able work the Z-shaped service between Stratford, Meridian Water and Bishops Stortford stations.

But this is not a problem.

In Greater Anglia Are Replacing Eight-Car Class 317 Trains With Five-Car Class 320 Trains , I explained how the new five-car train has almost the same capacity as the old eight-car train.

There Are Now Three tph Between Stratford and Northumberland Park 

This is probably only an interim timetable, but it still has tripled the frequency of trains between Stratford and Northumberland Park.

This means that the base frequency for events at Tottenham Hotspur’s new stadium has tripled.

So those going to events at the stadium, will have increased train  capacity from Stratford, Lea Bridge and Tottenham Hale.

As only one train of the two tph between Stratford and Bishops Stortford stops at Northumberland Park, it would be easy to up the frequency to four tph, by getting the second service to stop.

This Timetable Can Easily Be Increased To Four tph Between Stratford And Meridian Water

Currently, the two tph between Stratford and Bishops Stortford, stop as follows.

  • 1 tph – Lea Bridge, Tottenham Hale, Waltham Cross, Cheshunt, Broxbourne, Harlow Town and Sawbridgeworth
  • 1 tph – Lea Bridge, Tottenham Hale, Northumberland Park, Enfield Lock, Cheshunt, Broxbourne, Roydon, Harlow Town, Harlow Mill and Sawbridgeworth

The four tph between Stratford and Meridian Water, that was promised in the STAR project, could be arranged by stopping both trains at Lea Bridge, Tottenham Hale, Northumberland Park and Meridian Water in both directions.

The only extra stops at Northumberland Park and Meridian Water would be as follows.

  • Southbound in Platform 3
  • Northbound in Platform 4

These are the same platforms current services use at Tottenham Hale.

The Proposed Fourth Track Between Meridian Water And Tottenham Hale

How does the now-implemented Z-shaped service fit with the proposed fourth track, I discussed in Meridian Water Station Is To Be Upgraded.

The upgrade is described in the Wiukipedia entry for Meridian Water station, where this is said.

In August 2019, it was announced that funding had been approved for construction of a fourth platform and a new section of track between Tottenham Hale and Meridian Water to enable up to 8 trains per hour to serve the station at peak times.

This must be the earliest upgrade in history, after a new station has opened.

In the related report, I came to the conclusion, that the fourth track would.

  • Leave the Southbound West Anglia Main Line, just to the North of Meridian Water station.
  • Go through the new Platform 1 at the station.
  • Continue through Northumberland Park station.
  • Join the new third track, between Northumberland Park and Tottenham Hale.

This would allow Stratford and Liverpool Street trains to take separate routes to their respective terminals.

In the Meridian Water Station To Be Upgraded post, I said this.

Eight trains per hour (tph) in both directions calling at the station could be as follows.

  • Platform 1 – Two tph from Bishops Stortford to Stratford
  • Platform 2 – Two tph Meridian Water to Stratford
  • Platform 3 – Two tph from Hertford East to Liverpool Street
  • Platform 3 – One tph from Cambridge to Liverpool Street
  • Platform 3 – One tph from Cambridge North to Liverpool Street
  • Platform 4 – Two tph from Stratford to Bishops Stortford
  • Platform 4 – Two tph from Liverpool Street to Hertford East
  • Platform 4 – One tph from Liverpool Street to Cambridge
  • Platform 4 – One tph from Liverpool Street to Cambridge North

Four tph go to and from each of Stratford and Liverpool Street.

At Tottenham Hale, platforms would be as follows.

  • Platform 2 – Southbound Services to Stratford and two tph to Meridian Water.
  • Platform 3 – Southbound Services to Liverpool Street
  • Platform 4 – Northbound services going further than Meridian Water.

I am assuming that the missing Platform 1 and the fourth track through Tottenham Hale station will not be built in the short term, as doing this, would blow the available budget.

Conclusion

The shuttle is working and it will get better, with the addition of a fourth track between Meridian Water and Tottenham Hale.

 

September 10, 2019 Posted by | Transport | , , , , , , , , | 1 Comment

Greater Anglia Are Replacing Eight-Car Class 317 Trains With Five-Car Class 320 Trains

At first sight eight into five won’t go, but here’s how it will be done.

Greater Anglia’s new Class 720 trains come in two lengths.

  • Five-car trains are 122 metres long.
  • Ten-car trains are 243 metres long.

Compare this length with that of an eight-car Class 317 train, which is just under 160 metres long.

Several platforms on the Greater Anglia network, such as Hertford East, can only take one five-car train, as I wrote about in Greater Anglia’s Class 720 Trains.

So how does the capacity of this train compare with an eight-car Class 317 train?

Using Wikipedia, the capacity of a five-car fie-car Class 720 train is 540 seated and 145 standing or 685 in total

  • Eight-car Class 317 train – 396 seated and 171 standing – 738 total – from Angel Trains web site.

The new five-car train has a capacity of 92.8% of that of the old eight-car train, but it has thirty-six percent more seats.

This plate was on the end of a Class 317/1 train.

This says that a four-car unit has 292 seats, so an eight-car Class 317 train would have 584 seats.

The new five-car Class 720 train has 92.4% of the seats of an old eight-car Class 317 train.

I suspect this is all down to modern train interior design.

Conclusion

An eight-car Class 317 train can be replaced with a five-car Class 320 train.

September 10, 2019 Posted by | Transport | , , | 1 Comment