SSR Resignalling

Regardless of when you do it (and you almost certainly couldn't do it at the same time as other works in the area for logistical reasons), it would be massively expensive in terms of both direct costs and the associated costs from disruption. I can't imagine that any gains from track realignment would come even remotely close to justifying the outlay at a time when TfL was rolling in money let alone the current financial situation.

The simple answer is no - there is no plan to remove the tripcocks from any of the S7 trains. The main reason that comes to my mind is that there is no benefit in creating a sub-fleet which makes allocation more difficult - if one was created they couldn't be reformed onto a District, as you say, and would have to be maintained at Upminster rather than Ealing Common. It's more hassle than it's worth!

In theory a train with a defective or no tripcock could be left on the Circle line all day, but at the moment there's still a Tripcock Tester at East Ham which makes operation on the C&H more difficult. In practice, I doubt it would be allowed to stay in service.

Indeed so, and my understanding is that the East Ham tester is removed once SMA7 is commissioned.

Longer term I think the plan is for the four Earl's Court testers to remain, and the one at Barons Court WB to be removed and replaced by one just entering the tripcock area at Stamford Brook.

From memory, there are testers on both roads at Upminster Bridge at the moment.

4LM's migration boundaries were deliberately chosen to be away from interlocking areas, if at all possible. Naturally this wasn't always possible (e.g. SMA2/8 boundary at Finchley Road) but where posible it was done that way.

Tripcock Testers are a bit more hit-and-miss. Unlike, I believe, on the Jubilee and Northern resignalling (and definitely unlike the Central line which had several Tripcock Testers at various stages), no new Tripcock Tester locations were introduced, though the Barbican installation was converted from temporary (switched in as required) to permanent, though they were in their permanent state for less time than they ever were in their temporary one! Finchley Road and Barons Court are both good examples of where there is a tester and a boundary.

As and when a migration area is commissioned the testing requirement changes, so for example:
SMA0.5 - No change. Trains tested shortly after/before leaving the CBTC area at Ladbroke Grove.
SMA 1 & 2 - No change. Trains tested at Euston Square migration boundary.
SMA3 - Ladbroke Grove testers removed (not replaced), Euston Square removed (replaced by conversion of Barbican to permanent)
SMA4 - No change. (There were no testers on the south side of the Circle line).
SMA5 - No change. Earl's Court testers modified to work in CBTC. Barons Court tester alarmed to South Kensington control room instead of Earl's Court.
SMA6 - Bayswater, Barbican, Upney, and East Ham WB testers removed.

Good question, 2006 or 2007 I think. I'll check and confirm when I'm at work next (on leave at the moment).

How many of the Tripcock Testers will stay once the 4LM is complete and where will they be on the SSR network?

Did trial of SMA9 include operation of the new colour light signals provided for Chiltern trains? Do they show red, yellow, green? Is a trainstop provided at these locations?

The report on a signal passed at danger and subsequent near miss at Chalfont & Latimer station on 21 June 2020 details three signalling safety systems fitted to Chiltern trains for use on Network Rail managed lines, apart from the LU tripcock system. I presume that when resignalling is completed on the Metropolitan Line, the S8 stock can have their tripcocks removed. They would only need them fitted for an unlikely trip to Ealing Depot. It seems to me that if Chiltern provided for the installation of one of the three other systems their trains use on the Met, they could remove tripcocks from their fitted trains to reduce maintenance costs and improve fleet flexibility by allowing others of their trains to also work on these lines when required. This would allow LU to remove lineside air mains, compressors, etc with a saving in maintenance. The Uxbridge branch will need to retain trainstops for a few years, at least until current Piccadilly Line trains are replaced by the new trains on order, and probably until new signalling is funded for that line.

No ETCS currently planned. Chiltern trains will continue to be tripcock fitted for running on the LUL section and they will continue to be controlled by lineside signals with trainstops.

(Quote subsequently added for context - Tom)

This is not a statement, it is a question.

Can you enlighten me as to how, for example, the 1938TS and SS will get from any depot to the tripcock section to "ply that route" ?

AIUI the tripcock retained section is limited to those tracks used by Chiltern : the fast lines only between Harrow and Moorpark, thence Amersham.

So for example, Neasden depot is in the CBTC area and has no connection anything but CBTC (or TBTC) tracks. How will the heritage trains get from there to, say, Harrow On Hill ? They will have to come from /somewhere/ since they won't reside in Amersham or Rickmansworth sidings.

Empty or in service, anything over CBTC only tracks need to be CBTC; non communicating trains verboten.

Unless I've missed something blindingly obvious, I do not see how what you say can be done short of using CBTC fitted battery locos piloting to/from depots - and I dread to think what the technical and coupling details of that would be, never mind the actual uncoupling and shunting once in the CBTC area, and recoupling to leave it. And the crewing expense involved. Assuming the engineers have spare battery locos at weekends, the time they are most intensively required for, funny enough, engineers trains.

Not saying anything is impossible. Just sceptical.

Or has something passed me by here ?

I'm inclined to agree with d7666. The only places heritage stock could be moved to is Rickmansworth or Amersham sidings and it would have to be done during Cancelled Engineering Hours as an Incompatible Train Movement. Doing it with Battery locos in Traffic Hours wouldn't be feasible - CBTC really dislikes uncoupling and the 'cleaning up' of train positions isn't quick.

If you think tickets are expensive now, may I offer you a Ronald Reagan quote: "You ain't seen nothing, yet".

when a brand new all-singing all-dancing signalling system cannot handle things that were possible previously I start to wonder if (to coin a phrase that uses our four legged friends) the tail is now wagging the dog


what if there is a daytime need to take a maintenance train (eg: several ballast wagons / hoppers) and leave them in a siding somewhere for a few days?

'no can do'??


btw, can the signalling system cope with the rescue of a failed train (eg: power collection shoes damaged, need replacing) by attaching another train to it - without shutting down services on the whole of the SSR?

I don't disagree they have not allowed for this type of non standard move.

You can not go into every last possible if and but and maybe to do everything you can do on your Hornby train set.

First, rescuing by attaching one train (S stock) to another train (of S stock) is allowed for - it ain't easy, but it is allowed for. So you can eliminate that one from your objection.

Are you aware of the costs of some of this stuff. The root of this present sub-debate is about heritage trains. Are you aware that the costs of developing testing and approving CBTC to any vehicle type is in excess of £1m ? And that was the figure mid 2010s. That is £1m for SS, £1m for 38 stock, £1m for 60 stock, and so on. That is the main reason they ain't fitted.

Now, take your example of ballast hoppers. How many times can you count you have known ballast hoppers have been taken, during traffic hours, to one location and left there sans locomotive with the locos returning light ? I bet you can't get can't above your count of thumbs, not fingers.

Yes, outberthing, it is done with kit like ballast tampers - but they are CBTC fitted. Yes it is done with complete trains, but they left berthed with their battery locos in situ at both ends.

The case of doing that, or the same with positioning heritage stock, is no way like your example of one unit assisting another.

Once you start to consider splitting trains into 3 parts (lead loco / load / trail loco), shunting that non standard length load somewhere, detaching locos from both ends, and then coupling them together, then to go light somewhere, in a yet different length of departing movement to one that arrives, you have created a huge huge amount of software and hardware to address that. And, you would surely whine if limited locations for that, for it to be of value it would be needed everywhere. It is a massive massive amount of effort for something that might never be needed.

Sorry but trainspotters annual fixes of having SS or 1938 one weekend a year, or someone needs one wagon to be moved from A to B, have to take their place in the queue of value for money. Heritage trains are marginal as it is, and will never never cover the cost of Seltrac software variations. Odd Engineers vehicles movements have no revenue generation at all.

I'm not sure what sort of commercial IT you work with 35b, but this is a highly specialist system of which the software is just one element.

I don't like the idea of being locked in to one supplier either, but it's the nature of the beast in this sort of application; once you've selected your supplier you are tied in to them for the next 25+ years, something that we never had a problem with then it was relay-based!