Binary programme machine clock

[Deleted]

Whilst trawling through u.t.l. I came across a fascinating thread about the binary 24hr clock connected to the supervisor programme machine in the Archway (NN) IMR.

A picture can be seen here.

Are there any more of these clocks to be found in other IMRs?

[Tom]

Quite possibly - got a link?

[Deleted]

A link to what? I have a URL to a photo of NN IMR's binary clock in my OP.

A link to the relevant u.t.l. post, made by a Northern Line T/Op by the name of romic, can be found here.

[q8]

I see the clock is wired to the electric supply in typical underground fashion. I.E a taped joint. I have seen electricians on the tube pull a joint like that into a pipe so it can't be seen. I wonder what HSE would find if they had a thorough investigation of wirng in the tube.

[citysig]

There used to be a lot of that sort of thing (the dodgy wiring) but it's mostly been replaced.

Besides, you never know what's inside the tape, and providing it is secure and unlikely to cause shock, arcing, short-circuiting and the like, HSE would not have a problem with it. Even certain suitable connectors should be covered to avoid someone touching an exposed part.

[Tom]

I've seen those clocks in other places - Acton Town East IMR for one.

From my notes on programme machines, it looks like the clock gives the time input to the time co-incidence unit, which compares the true time and the time of the programme machine's next move.

[q8]

I seem to rmemeber somewhere years ago that programme machine time was co-ordinated by a central atomic cock somewhere or other. This was a private circuitand maintaned millisecond accuracy throught the combine.

[Deleted]

the master clock for the district is fed from earl's court behind the t/o's (aet) depot i sends either a 50v or 100v pulse every 30 seconds the clock in earl's court programme machine room can be seen here

aetearlscourt.fotopic.net/p15106328.html

also you can see the machines and the electronic cards which control them

aetearlscourt.fotopic.net/p15106342.html

in case of a power loss the time co-incidence units are also fed with a 13v battery feed.

i got no idea why the clocks were there and the t/o's at earls court now (well last night) have no idea either

High St Ken,Hammersmith,Earl's Ct,Parsons Green still have the clocks installed but none of them work anymore and Parsons Green itself as a programme machine site does not work either in Programme Only mode

[Deleted]

Does that mean that most of the other SSL IMRs with functioning programme machines have working clocks?

What do ED, WD, EC and WF use instead of the clocks?

[Tom]

At a guess, time machines, as they are amongst the earlier sites. I'm sure AETEarlsCourt will correct me though.

[Deleted]

Putney Bridge is the only one with a Timing machine, the other sites excluding south ken,gloucester road, tower hill and mansion house have there time fed from the time co-incidence which gets a pulse every 30 secs so it adds 30 secs to the time we initially set the time up manaully then after that the co-incidence unit does the rest.

south ken,gloucester road the machines do not have the time stamped onto the roll as the signalman does not book trains at either station so aslong as the train as the right number and the t/d is correct the machine will route in programme only

mansion house and tower hill have atomic clock units installed (rugby clock) as when they re-furbed aldgate station the line was cut for the clock pulse leaving aldgate and due to bad cabling (old age) there is not enough voltage coming from earls court to even get to mansion house

and just for some info parsons green and putney bridge were the first sites on the district to have programme machines installed west ken was the last to be installed but that site dont work either