‘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?
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.
- 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.
- I made two visits to the route today and it seemed to be performing reliably.
- 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.
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.
Tottenham Hale Station – 9th September 2019
These pictures show the progress on the Underground part of the station.
It will be a big glazed structure.
There was talk of the station being completed this year, but I’d rate it for Sprint 2020.
Landscaping Outside Highbury & Islington Station Is Nearing Completion
I took these pictures outside Highbury & Islington station, this afternoon.
It does appear that this long project is nearing completion.
At least there’s now a large space in front of the station, that leads up towards Upper Street.
Platform 2 At Tottenham Hale Station Was Ready, But The Signs Weren’t
Trains were passing through Platform 2 at Tottenham Hale station today, which obviously was ready and had been signed off by all the relevant authorities.
But look at this picture of the station sign on the platform.
Had someone forgotten to order the signs?
Could A Fourth Track Be Squeezed In At Tottenham Hale Station?
Eventually, when Crossrail 2 is built, there will be four tracks through Tottenham Hale station. It has been anticipated by Network Rail as they have numbered the platforms at the station 2, 3 and 4.
These pictures were taken from the island platform 2/3.
It does appear that another track could be squeezed in, on the other side of the electrification gantries.
Crossrail 2 Four-Tracking
In Crossrail 2 Question Time, I describe a meeting with two Crossrail 2 engineers.
I was told that four tracks on the West Anglia Main Line would be tricky and that the slow Crossrail 2 tracks would be on the East side, with the fast tracks on the West.
In the post, I state that I think, it could be easier to have the Crossrail 2 tracks on the West side, with the Fast tracks on the East.
- If the Crossrail 2 tracks are on the East side, then, this means that a platform will be needed on the fourth track at Tottenham Hale station.
- On the other hand, if the fourth track was a fast line, it might be possible to build it without a platform, which would save space.
Each layout has its benefits and disadvantages.
If nothing else, this illustrates some of the engineering problems of Crossrail.
The Ferry Lane Bridge
One of my pictures, shows the Ferry Lane bridge in the distance. This is the bridge in its glory in close-up.
I feel it will need to be replaced before a fourth track is built.
- Rebuilding the bridge will cause massive disruption to the area.
- It will have a very large cost.
Does this explain why the STAR project to increase capacity on the West Anglia Main Line was only a three-track solution?
At some point in the next few years, after all the current transport improvements are completed and before the construction of Crossrail 2 is started, this bridge will be replaced.
Hopefully, someone will come up with a way of replacing the bridge, that doesn’t cause too much disruption.
Conclusion
As the Crossrail 2 engineer said, four-tracking of the West Anglia Main Line will be tricky.
Do We Need More Bikes Like This?
When I moved back to London in 2010, bikes like this were rare!
Now, you see various bikes every day delivering bread, children, dogd and parcels in the City and East End of London.
It swhould be noted that in a circle of two to three miles from Bank, London is fairly flat and ideal cycling terrain.
But we still need more!
Have we got enough people, prepared to ride them?
The Wrong Kind Of Bleach?
This article on Railnews is entitled 9 September: News In Brief.
It has the following sub-title.
Wrong Bleach Took Caledonian Sleepers Out Of Service
This is the first sentence.
Cleabers who used the wrong specification of bleach in the toilets and shower rooms on Caledonian Sleepers caused significant damage after the chemicals reacted with stainless steel pipes,
To my knowledge stainless steel, especially when it contains increased levels of chromium and some molybdenum, can be very proof to attack from most substances.
Look at this Butler Shba cutlery made in Sheffield from stainless steel with black Delrin plastic handles, which have seen continuous use in my household for fifty years.
Now that’s what I call stainless steel!
Perhaps, the Spanish used the wrong type of stainless steel?
Delrin is a form of polyoxymethylene, which is an engineering plastic.
This plastic has a wide spectrum of usage, including in zips, bagpipes and metered dose inhalers, to name just three of hundreds.
Thoughts On Hounslow Station
These are my thoughts in no particular order.
Step-Free Access
There are only eight railway stations in the London Borough of Hounslow and only Chiswick and Hounslow stations are not step-free and no plans have been published about creating fully-accessible stations.
This is the rather old-fashioned footbridge at Hounslow station.
Current Train Service
The main current Off Peak train service is four trains per hour (tph) using the Hounslow Loop Line, which conveniently pass each other in the station.
There are also two tph between Waterloo and Weybridge, which means the station has a six tph service.
There are also a couple of extra services in the Peak.
Hounslow Track Layout
This map from carto.metro.free.fr shows the track layout at Hounslow station.
The crossovers on either side of the station probably allow trains to be turned back at the station.
A train arriving from London, which is to the North East would do the following.
- Stop in the Southern Platform 2.
- Wait whilst the driver changes ends.
- Return to London using the North Eastern crossover to change to the correct track.
It would probably take between three and four minutes.
West London Orbital
Hounslow station has been proposed to be one of the terminals of the new West London Orbital Railway.
It will have four tph from West Hampstead Thameslink via the Dudding Hill Line.
How will these trains be trains be turned?
Use The Existing Track Layout
There appears to be almost fifteen minutes gaps between trains through the station, so would it be possible to use the existing North-East crossover and the Southern Platform 2 to turn the trains?
When you consider, that London Overground generally allow between five and twelve minutes to turn a train, timing could be tight. Especially, if the driver needed to take a toilet break!
And what would happen, if a train failed or there were several passengers of limited mobility to unload from or load on the train?
I feel, that this current method would only be used as a little-used fallback.
A Turnback Siding
This Google Map shows the station and the track to the South West.
Note that there is probably enough space to put a turnback siding to the South West of the station, with some realignment of the tracks.
This method was used at West Croydon station by services on the East London Line, but recently, the service has started to use the bay platform at the station.
- The train would stop in Platform 2 and unload the passengers.
- It would move to the turnback.
- At the appropriate time it would move into Platform 1 and load passengers.
It would then be ready to start the service to West Hamstead Thameslink.
A Bay Platform
This Google Map shows the North-Eastern (London) end of the station.
There is a road called Whitton Road alongside the station, where a London-facing bay platform would be built. The crossover would need to be rebuilt to allow trains from London to cross into the bay platform.
But operationally, it would be easier.
- Returning trains to West Hampstead Thameslink would not block the Hounslow Loop Line.
- Passengers using the West London Orbital would only cross the line, if they were continuing their journey from Platform 2..
- I doubt many passengers arriving in Platform 2 would want to use the West London Orbital.
- Passengers with reduced mobility changing between the West London Orbital and bus, car or taxi at Hounslow station would have a step-free route between street and train.
- Drivers would have time for a comfort break.
I will be very surprised if a bay platform is not built to handle the West London Orbital.
A Rebuilt Station
If the West London Orbital is built, which I feel would be highly sensible, the station will probably need to be remodelled to incorporate a bay platform to turn trains.
The footbridge at the station will also need to be replaced with a fully-accessible one.
So Hounslow station will probably need to go through a thorough refurbishing, if not a full rebuild.
The Anonymous Widower 