T4 extension stuff

Just a quick look before I checked back in suggested that there is Hatton X, and a signalling diagram, presumably as was supposed to be built, Hounslow West - Henlys Curve (because it was Henlys Roundabout, Henlys being the long term garage, now it's a M&S foodstore and petrol station) - Cranebank (Crane bridge) - Hatton Cross. JUST CHECKED AGAIN: Hounslow West, Hatton X and Heathrow Central. No T4 it seems, probably as when LT sent me them it was still a hot potato about where the station was going: if LT had not taken up the box in the car park, there was asuggestion that it would have become a warehouse!

There are letters in there about Heathrow Central station, and apparently it was suggested that it be HEATHROW AIRPORT originally, and I assume T4 was to be HEATHROW SOUTH later.

It explains why the T4 station was not built in the terminal, and how the tube link nearly never went ahead because of a GLC-Government funding row. At that time BAA were not over enthusiastic about a Picc link! Also T5 was proposed, and it was hoped that it might open by 1990!!!!!

The two Airports links reports are in there plus memos to the GLC from LT...good stuff all. I wish I had copies of the UN articles after Part 1, as I havea draft of the Part II but there were up to five I think and they set out everything in detail. I am amazed that it I found them as they were my first serious journalistic 'job', 1979ish to 1982ish, 25 years or so before my present-day career.

DH the elder

I'd be genuinely interested in a copy - for fear of being labelled 'geeky': Hatton X signalling was quite a pinnacle in LT signalling history.

EDIT: Though I couldn't immediately give you an answer on the deviation I *might* pull strings that could give you an answer. ;D

The reason for the deviation was that the LONDON TRANSPORT ACT 1967 authorised the Heathrow extension via Hatton X, but the route was only allowed to be moved slightly within certain parameters. When the railway loop had to be moved to accommodate the resiting of the T4 station, a new private Act, the London Transport (No.2) Act (1981??) had to be rushed through Parliament to allow the moving of the curve.

Come on then spill the beans! My maintenance area included South Ealing to Heathrow and I would say there is little to choose in terms of technology at Northfields, Boston manor, Hounslow Central, Hatton Cross or Heathrow T123, in fact the basic signalling with its double cut circuitry and use of Q relays, following the Victoria Line standard up to a point, is the main departure from the rest of the Piccadilly line which in itself is served by technology of at least four other distinctive eras. Is that what you are getting at?
I would divide the rest of the Picc into the East End computer controlled area from just outside Manor House to Cockfosters, then Manor House to Baron's Court , Baron's Court to Hanger Lane Junction and then North Ealing to South Harrow as distinct eras of technology. These latter areas I would seperate by the type of remote control and in the last case by the 33.33Hz AC supply. Of course Ealing Broadway is perhaps a site unto itself in terms of technology and the fact that it controls Hanger Lane Junction.

The train following system is new to me but it is not part of the safety signalling system AFAIK which has remained much the same since it was installed in the 1970s. It will no doubt be part of the non-safety system as are Computers, P/Mcs and Train Describers.

Yes I used to work at Hanger Lane Junction IMR and do the maintenance on 9s Clamplocks there as well. I spent a great deal of time at Ealing Broadway too, the only site I maintained with an N2 converted power frame.

To my mind there was nothing wrong with P/Mcs that proper maintenance would not resolve but over the years a key component , the lamp, was changed probably to save money, younger staff were not trained to properly service them and faults that developed over the last couple of decades went unaddressed in times of cost cutting, the quality of replacements leaving the Signal Overhaul Shop was not what it once was etc etc. There are lots of reasons to gripe about programme machines but it it not the machines themselves that are the problem really! Believe it or not they still do a more competent job of routing trains than computers do because mechanical programming has to be precise unlike computer programming which is subject to the whims and foibles of humans!

Remember that for the most part the railway still relies upon 100+ year old technology for day to day operation and I can't see that changing until trains are freed from the restrictions of running in serial fashion along tracks or other guide !

Old is still beautiful and I do hope that when the railway has decided to finally ditch P/Mcs that someone will save them and keep them in working order, it would be sacrilege for them to be consigned to the scrap heap or to become static exhibits in museums!

i beg to differ programme machines are a pain in the **** but you are right mr railtech maintenance does not exist with them and if they were maintained as they should be (i have the little brown book) they might last abit longer then they do tubylines are in the process of getting rid of them totally as i was speaking to a picc t/o a while ago about them a few weeks ago now but i feel people rely on them too much these days

hats off to the people who designed the circuitly for them though

I know the District P/Mcs are a pain in the derriere and of course it is worse when you know nothing about them but when they are properly looked after and provided with meaningful programme rolls they make music as beautiful as any decent machine! Hang on to the little brown book for a few years and then it'll be worth a few quid on Ebay!

the district sites are staying put as metronet will not pay for them to be taken out this includes places like hammersmith, acton town, ealing common and ealing broadway as these are metronet owned and not tubelines