London Overground 9XXX headcodes

[First class]

London Overground seem to be using Class 9 headcodes, i.e.

They either have 9Axx, 9Bxx, 9Cxx, 9Dxx, 9Exx, 9Fxx HC allocations.

I was under the impression that a 9xxx headcode indicated an International service, (Eurostar), or an inter-regional express that the signaller would treat higher than a class 1 express.

Any reason known why an intensive, stopping service commuter network is using these headcodes?

Anyone else think the way they are allocated (across the country) needs to be reviewed?

 

[ralphchadkirk]

I gather it's to differentiate between Southern and SET services easily. Out of London Bridge there are hardly any 2x headcodes left.

 

[First class]

I'd use the following classification:

Class 0 - Rail Replacement Bus/ Shipping service
Class 1 - Intercity Express
Class 2 - Regional Express
Class 3 - Local stopping/ Regional stopping
Class 4-7 Various Freight/worksite allocations
Class 8 - Empty Coaching Stock
Class 9 - International Services

 

[ralphchadkirk]

Light engines?

 

[First class]

Light engines?

Classes 4-7 or 8

 

[ralphchadkirk]

If it ain't broke, don't fix it.

What's wrong with the current system? It's worked fine for years.

 

[First class]

It is broke if they're having to give inter-regional express headcodes to local stopping services because they're running out!

 

[ralphchadkirk]

Yes, but the trains are local to the region, the signallers, drivers and other operational staff know that they have 9x headcodes, so there isn't a problem is there?

 

[Dreadnought]

Classes 4-7 or 8

Light engines run as Class 0!

My understanding is that the other Classes are as follows

Class 1 is for express passenger services
Class 2 is for local / stopping passenger services
Class 3 is for guaranteed ECS / certain passenger services / RHTT / test trains
Class 4 is a 75mph timed freight
Class 5 is an ECS move
Class 6 is a 60mph timed freight
Class 7 is a 45mph timed freight
Class 8 is a 35mph or slower timed freight
Class 9 is for international passenger services, although has been used by Cross Country and now by LOROL as well.

 

[Tomnick]

9 is something like 'nominated passenger service' now, isn't it? In that case, it'd fit ELL services as well as it fitted XC services. Apart from the lack of a suitable range to dedicate to ELL services, the use of 9 does give an obvious differentiation between ELL services and the rest towards London Bridge at the crucial point on the Southern where a wrong route would cause untold chaos.

The current system does seem a little broken when it comes to semi-fast regional services that are slower than Intercity services but faster than the stoppers in the suburbs. Changing the classifications would require some extensive changes to the long-established signalling regs (bell signals, if nothing else!).

 

[thefab444]

Perhaps a better system would be:

0 - Light Engine (also 0B00 - bus, 0S00 - ferry)
1 - Express/Intercity Passenger
2 - Semi-fast/Regional Passenger
3 - Stopping/Local Passenger
4 - Empty Coaching Stock
5 - 75mph Freight
6 - 60mph Freight
7 - 45mph Frieght
8 - 35mph or slower Freight
9 - International services, also Priority ECS, Test Trains, MPV Sandite, Weedkiller or Spraying workings etc.

Class 3 currently is a bit of a waste of time. I'm not sure that it is ever used for passenger services; I was under the impression that it was only used for priority ECSes, and RHTT workings. Test trains are nearly always Class 1 or Class 4. Given that International services are pretty much split from the rest of the network there's no reason why Class 9 couldn't be used as a general headcode for 'out of the ordinary' workings, allowing there to be more passenger headcodes which is where the shortage currently lies.

 

[Tomnick]

Using Class 3 as a passenger classification seems the most sensible approach, if the lack of passenger classifications is the problem! Not sure it's worth exchanging 4 and 5 though - I know it'd 'flow' better, but it'd be a lot of hassle (presumably 4 and 5 are in that order because a 75mph freight or Freightliner would often be run ahead of an ECS returning 'home'?)

 

[me123]

I don't know the area well, but from what I've heard the class 9 headcodes are in place to help distinguish ELL services from other services at New Cross Gate. Given the high service frequency there, it's pretty understandable that Class 2 headcodes are at a premium. The high frequency also means that wrong routes would be catastrophic, so in addition it helps prevent this. Might be useful in other areas methinks...

This is just my understanding of the situation based on what I've read elsewhere. I may be wrong as I don't know the area.

Asides from Eurostar trains, I can't think of any services that would otherwise use a 9xxx headcode nowadays. Given that CrossCountry trains have reverted to their standard 1xxx headcodes now.

 

[Class377/5]

I gather it's to differentiate between Southern and SET services easily. Out of London Bridge there are hardly any 2x headcodes left.

Add in the FCC services which combined with the engineering works at the weekend can mean all the south of thames FCC trains use the BML from London Bridge and you have a serious lack of spare headcodes.

9 is something like 'nominated passenger service' now, isn't it? In that case, it'd fit ELL services as well as it fitted XC services. Apart from the lack of a suitable range to dedicate to ELL services, the use of 9 does give an obvious differentiation between ELL services and the rest towards London Bridge at the crucial point on the Southern where a wrong route would cause untold chaos.

Simply put, this is the reason for it. Quick and easy as the lines are very busy and a signaller can know straight away that this is a LO service as the others aren't. The faster you can id a service that needs to be treated differently, the safer it becomes as you react before any possible problem arises.