New clocks

[fabieng]

Dear all,

I have a question and you may be able to answer.

There are many different clocks in the stations. When these clocks are too old, broken, and need to be replaced, are they nowadays replaced by the same one single model of clock? If yes, which brand is it? Is it possible for an individual to buy one?

In the LT museum shop they only sell small clocks, and I tried to contact LT and never recieved any answer.

I imagine it maybe black or silver, with red digit, like this one maybe?:
(chromus newgate large wall clock)
www.onlinereality.co.uk/prod/28721/chromus-newgate-large-wall-clock
But Newgate told me they were not the official LT clock supplier, and on their own website they don't even sell this.

I have seen pictures of London tube stations clocks having a roundel logo, but these clocks seem relatively old to me.

It is well known that the brand Mondaine is the official Swiss railway clock, and it's possible to buy them.
The London transport tube and its is roundel is so world famous that I am surprised that I can't see an official clock of the London Tube to buy anywhere.

Thanks for your answers.

Fabien

[Tom]

Westerstrand supplied a few clocks to LT over the years - try here.

[Chris L]

Most if not all the clocks on the Underground are controlled from a central clock. I'm not sure they would be much use to you.

Many years ago every clock had to reset twice a year by teams visiting the stations. A major exercise.

[stapler]

In the trade, they are called "slave dials"....

[brigham]

Is there anything to stop a third party from marketing a domestic clock in the style of an 'official' LT one?

[Chris L]

Jan 18, 2021 8:46:31 GMT brigham said:

Is there anything to stop a third party from marketing a domestic clock in the style of an 'official' LT one?

The roundel is a protected trade mark.

[Tom]

But many 'official' clocks don't feature roundels - only a minority.

[Chris M]

The design of those clocks may be trademarked and/or copyrighted by their designers or TfL

[fabieng]

Thank you for your answers.

I'll have a look at Westerstrand.

I understand all clocks must be centrally controlled, I imagine indeed the time it would take if all the LU clocks were working with a simple common battery and needed to be time-checked twice a year!
But, as I explained with my example, the Swiss rail Mondaine clocks, that work with the same central system, have produced a commercial model for people to buy.

I was not specifically expecting the old clock with the roundel replacing the numbers, I don't know what is the common replacement clock nowadays in the LU as I don't live in England.
Maybe when a clock nowadays is removed it is not replaced by another, maybe it's just by digital numbers in the lightbox?

[zbang]

Jan 16, 2021 18:18:48 GMT Chris L said:

Most if not all the clocks on the Underground are controlled from a central clock. I'm not sure they would be much use to you.

Virtually all mechanical "slave" clocks operate perfectly well on their own, the Master signal usually serves to reset the clock to a specific time* (often 12:00:00, 00:00:00, or xx:00:00), for some gory details see Electrical Timekeeping (F. Hope-Jones**, www.abebooks.com/book-search/title/electrical-timekeeping/), which is ahem, rather dense, technically.

*The Western Union clocks worked that way

**Brother of Robert Hope-Jones, the organist and organ designer

Digital clocks come in two flavors- simple display repeaters which have no internal timing source (often used in broadcast stations and control rooms) and full-on clocks which use the external source to either set the display time or to adjust their rate, those will usually operate without a master signal.

[class411]

Jan 22, 2021 17:05:54 GMT zbang said:

Jan 16, 2021 18:18:48 GMT Chris L said:

Most if not all the clocks on the Underground are controlled from a central clock. I'm not sure they would be much use to you.

Virtually all mechanical "slave" clocks operate perfectly well on their own, the Master signal usually serves to reset the clock to a specific time* (often 12:00:00, 00:00:00, or xx:00:00), for some gory details see Electrical Timekeeping (F. Hope-Jones**, www.abebooks.com/book-search/title/electrical-timekeeping/), which is ahem, rather dense, technically.

*The Western Union clocks worked that way

**Brother of Robert Hope-Jones, the organist and organ designer

Digital clocks come in two flavors- simple display repeaters which have no internal timing source (often used in broadcast stations and control rooms) and full-on clocks which use the external source to either set the display time or to adjust their rate, those will usually operate without a master signal.

Thanks for that.

I'd been wondering how they avoided losing pulses over the hundreds of clocks on the system - having assumed that they were being sent a pulse per second.

A bit daft of me, really, as I should have realised that they'd employ the same system as atomic synched clocks.

(Note for pedants: They do actually transmit a pulse per second as well as coded time stamps, but every clock and watch that I've looked at the specs of uses the 'once a day' method).

[zbang]

I should have mentioned that there is an over-the-air source of precision time, known as the "NPL", "MSF" or "Rugby" clock, but being a radio signal it doesn't work too well underground. If any kind of Internet Protocol connectivity is available, precise time can be distributed via Network Time Protocol (NTP) but I'd only expect that for display boards that would have a connection for the other information. My assumption is that telegraphic connections were used if there wasn't someone riding around with a precision watch to check them.

(Now I'm going to go down the rat-hole of time distribution....)

[rincew1nd]

Jan 23, 2021 7:14:47 GMT zbang said:

I should have mentioned that there is an over-the-air source of precision time, known as the "NPL", "MSF" or "Rugby" clock....

(Now I'm going to go down the rat-hole of time distribution....)

Isn't the MSF signal now broadcast from Cumbria?

Edit to add: yes www.npl.co.uk/msf-signal

[class411]

It moved in 2007, and, annoyingly, in some areas (including mine), the signal is weaker from the Anthorn station than it was from Rugby.

[brigham]

Not ONE of the 'slave' clocks I've ever come across has had ANY timekeeping capability whatsoever.
They have ALL moved one position (usually ½ minute) per pulse.
Some electric clocks have a spring-driven reserve, in case of interruptions of the electric supply, though.

[class411]

Jan 23, 2021 15:35:54 GMT brigham said:

Not ONE of the 'slave' clocks I've ever come across has had ANY timekeeping capability whatsoever.
They have ALL moved one position (usually ½ minute) per pulse.
Some electric clocks have a spring-driven reserve, in case of interruptions of the electric supply, though.

But were they slave clocks that were operating a a considerable distance (i.e. miles) from the master?

Within a building it's perfectly reasonable to expect every pulse to get were it's supposed to. Over a railway network, not so much.

[zbang]

Jan 23, 2021 15:35:54 GMT brigham said:

Not ONE of the 'slave' clocks I've ever come across has had ANY timekeeping capability whatsoever.
They have ALL moved one position (usually ½ minute) per pulse.
Some electric clocks have a spring-driven reserve, in case of interruptions of the electric supply, though.

I guess that becomes a matter of terminology- many people would say a unit without a timing element isn't really a clock, it's a display or a repeater. PPM-driven displays certainly work in a single facility when driven from a local timing source, but that source would either have to get some sort of master resync from elsewhere or run wild and be manually reset from a precision watch.

There are references to clocks made by the "Self Winding Clock Company", which invented the "reset to the hour" mechanism, at Acton Town, Chalk Farm, Colindale, Earl's Court, and a few others. Electrical Timekeeping mentions "A somewhat similar arrangement [ref to the previous page] is adopted by the Self-winding Clock Company of New York, and an installation of the clocks is still in use on the underground railways of London, controlled by a master clock at Lots Road Generating Station."

I also found what ought to be a very interesting piece at Timekeeping on the London Underground by David Burton although the actual article is members-only and I'm not (and at $80/yr, probably won't be).

BTW, one of the references I saw mentioned that because of the early adoption of block signaling in the UK and especially on the London lines [and I extend that all of the various train control systems devised], the railways there weren't nearly as time-centric for operations as in other countries. Make of that what you will.

Edit- correct punctuation.

[Chris M]

Jan 23, 2021 18:13:53 GMT zbang said:

I also found what ought to be a very interesting piece at Timekeeping on the London Underground by David Burton although the actual article is members-only and I'm not (and at $80/yr, probably won't be).

[/div][/quote]

There is a copy at the Science Museum, Wroughton smg.koha-ptfs.co.uk/cgi-bin/koha/opac-detail.pl?biblionumber=76184
There is a David Burton who works at TfL (LinkedIn), who may be the author and if so may be able to help you if asked.

When looking for an online copy I did find docplayer.net/90293103-Journal-of-the-national-association-of-watch-clock-collectors.html which includes "The Clocks of the London Underground part 2" by David J Boullin (search in the page for Underground) which may be of interest. I've not found part 1 available online, but it too is available at Wroughton smg.koha-ptfs.co.uk/cgi-bin/koha/opac-detail.pl?biblionumber=65401

[Tom]

Jan 23, 2021 19:47:05 GMT Chris M said:

There is a David Burton who works at TfL (LinkedIn), who may be the author and if so may be able to help you if asked.

It's the same individual. He gave a talk to the London Underground Railway Society about the evolution of station lighting a couple of years ago.

[brigham]

Jan 23, 2021 17:56:57 GMT class411 said:

Jan 23, 2021 15:35:54 GMT brigham said:

Not ONE of the 'slave' clocks I've ever come across has had ANY timekeeping capability whatsoever.
They have ALL moved one position (usually ½ minute) per pulse.
Some electric clocks have a spring-driven reserve, in case of interruptions of the electric supply, though.

But were they slave clocks that were operating a a considerable distance (i.e. miles) from the master?

Within a building it's perfectly reasonable to expect every pulse to get were it's supposed to. Over a railway network, not so much.

I'll know more when my copy of Electrical Timekeeping (F. Hope-Jones) arrives.

Meanwhile, I've just remembered the Waiting Train movement. The clock runs over 30 seconds on the dial in about 29 seconds, then waits for the pulse to set it away for the next spasm.

The 'waiting train', of course, is a train of gears, and nothing to do with railways.

[fabieng]

Thank you for your answers, interesting to read.

But so, it seems you don't know everything about the tube ?!  

I'll keep searching then.

[fabieng]

I finally recieved an answer from LT:

“Regrettably there isn’t an ‘official’ supplier of clocks to Transport for London, like for example Gents of Leicester from bygone days. This is a thing of the past, an era that’s gone now. In terms of our surviving old clocks in some of our mainline stations, the mechanisms for these are almost infinitely replaceable so are unlikely to need full replacement. If they do, then we would opt for digital signs that provide more information than just the time.” Alex C.

Thank you again.

Keep up the good job with the forum and enjoy London/England you lucky people.