Unique Observatory Controlled Transmitter.

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A new video has been uploaded to YouTube of a Gents' Observatory [controlled] Transmitter. The very special [and unusually complicated] Gents' master clock dates back to 1932. Transmitter is a term used for electric master clocks which send out signals to slave clocks and other timing mechanisms. Controlling a distant "master" clock, like this one, would allow observatory clock precision without any of the vital environmental needs: A complete absence of vibration, a massive wall [or bedrock] and very steady temperature control. Caves, dungeons and cellars were all popular to house such precision clocks. [Regulators is the correct horological term.] 



I will attempt to describe the "Transmitter" mechanism as simply as possible: The clock is controlled by the six time pips sent out by the BBC at that time. The pips were timed to a very high level of precision by very precise clocks kept [and constantly checked against the movements of the stars] at astronomical observatories. Apart from astronomical studies, timekeeping was a major part of an observatory's duties. Most observatories at that time had one or more precision clocks.

A see-saw arrangement of two electromagnets is situated at the very top of the master clock mechanism. These electromagnets lift or lower a regulating weight onto a tray on the pendulum.

Another, separate timekeeping mechanism, in the middle of the clock case, decides if the clock is fast or slow compared with the observatory time signal.

Weight regulation of precision clocks has a long history. Normally, small weights are placed or removed manually onto a tray placed near the middle of the pendulum rod. Sometimes tweezers are used to place or remove these weights to ensure the pendulum is never disturbed.

The genius of Gents' engineers was to use electromagnets to place or remove the regulating weight on the pendulum tray. A clock with a weight added will slightly gain. [Go faster] When the weight is lifted free of the pendulum the clock will change to a slower rate.

If only it were that simple to achieve perfect time control from a reference precision clock at a distance. This was cutting edge technology for its time. An added Relay unit accepts the 6 timing pips sent down the telegraph wire from the distant observatory. This in turn passes on a brief signal to further [time checking] units on the transmitter. The seesaw unit will then be triggered to leave the weight alone, lower or raise the weight depending on the exact timing of the pendulum relative to the precise observatory signal.

Towards the end of the video a bell striking mechanism is also controlled by the transmitter via a series of accessory units. These are shown in action during the hourly strike run. All in all, a fascinating display of a whole series of Gent's timekeeping products in excellent, original [or finely restored] condition.

http://pulsynetic.eu/master-clocks/observatory-controlled-transmitter/

All of these fascinating units apply electricity to achieve remarkable results once entirely the domain of centuries of mechanical clocks. The increase in accuracy of timekeeping, reliability and the precise control of dials and bells is the stuff of electrical horology. Where a small number of British firms competed in the first half of the 20th century for the world market in improved timekeeping methods. This led to historical changes in timekeeping for the railways, offices and factories as universal timekeeping could be brought, at relatively low cost to every corner of commerce.

For the first time in history every clock dial could show the same time and required no regular and costly repairs for natural wear and tear. Imagine the effect on a huge factory complex where every clocking-in dial showed the same time. Or vast, multistory, office blocks where every wall dial agreed with every other. Where factory machine, run times and productivity could actually be measured and printed out. All without a single man, with a watch and a salary standing over every one of them.

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Pulsynetic C6 & C7 master clock pendulum and bob.

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Sometimes a Pulsynetic C7 master clock is obtained which lacks a pendulum. In the complete absence of factory spares and as a service to those faced with the construction of a completely new pendulum I offer the following images: The original flat rod would have been Invar with diagonal "scratches" [hatching?] to show its true heritage. The "bronze" finish on the bob was once popular on fireplaces and fittings.

The large rating nut could be turned to make coarse rating adjustments. Smaller changes to slow the clock's rate could be made by adding small weights to the top of the rating nut with tweezers. This avoided stopping the pendulum which often results in an erratic change of the original rate.

Weights could also be added to the top of the pendulum bob to speed up the clock's rate.

The threaded rating screw at the bottom of the pendulum rod is apparently a cycle thread. 5/16" x 26 TPI.

An ordinary, rear bicycle axle could no doubt provide the donor material and save the purchase of a special die to cut the thread on a bare rod.
A cycle wheel fixing nut would do at a pinch in the absence of an original.
 
The cast rating nut has the appearance of a water valve wheel. Here the underside is shown.

The rating nut now fitted but inverted when quickly posed for the photograph.

The slot in the Invar rod where the movement crutch pin fits. A slot provided freedom for vertical adjustment or change in position due to differential expansion without binding. Note the diagonal lines to indicate Invar rather than plain steel.
Invar is a nickel-steel alloy which has almost zero thermal expansion. Changes in temperature should not alter the rate of the clock.

A threaded crossbar [with large washers to trap the suspension spring] normally rests in the cast-in v-grooves in the Pulsynetic master clock movement.


The entire C6/C7 bob. Removing the small screws in the top plate will allow the inner weights to be fitted and removed for examination.

Click on any image for an enlargement.

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WT for sale: Regulator Clock Company. UK

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An interesting example of a later, stepped frame WT has appeared on the Regulator Clock Company [UK] website: The Regulator Clock Company

This C40B[?] WT movement is mounted in/on an exquisite mahogany table and case suitable for the highest standard of furnishing. Though some might argue that the WT never enjoyed such luxurious accommodation, in reality, that is hardly the point. Nobody really wants to place a highly collectible WT in a mock-up of a typical clock chamber with all its [usual] disadvantages of whitewash, squalor and detritus. At least not when that WT is to be housed in a comfortable home or smart office as a fascinating showpiece.

Some work may still be required to run a drive from one of the bevel wheels, via lead-off rods, out through the glass case to a suitable turret clock dial. Which would make it a far more interesting and attractive display for a purist. Drilling glass and polishing the hole is not a difficult task for a skilled glazier. Though making a hole in the glass "envelope" might open it up to the escape of typical WT 'noise.' Which the pretty case may well have helped to dampen somewhat.  WTs and domestic bliss do not [usually] make ideal bed fellows where disinterested partners are concerned. Though this fine example and its cabinet could never be described as "fugly."

The 2-handed pilot dial is also very unusual for a WT but rather attractively done. Most WTs enjoy a simple rotating disk attached to the "front" bevel wheel, with a fixed pointer. This is known as a time setting dial and is usually silvered and clear lacquered. The maker's name, "Pulsynetic" and some reference to patents is usually engraved thereon. Quite how the hands of this dial are driven is impossible to see from the illustrations provided. A mechanical drive from the bevel wheel cluster? Rather like a later, two hand conversion of an elderly, single-handed, 30-hour, long case clock?

Though painted black, as if of the earliest form, the later, stepped movement is usually to be found in battleship grey. Perhaps not to everybody's domestic taste? The eggshell black certainly looks the part against the plated parts typical of a later WT movement. Earlier movements would have had deep, gold lacquered brass or bronze components regardless of frame colour. The bandaged coils to the large, drive electromagnets are also later but still worthy of admiration. Their sheer size and workmanlike finish makes them interesting in their own right.

The large wormwheel indicates a heavy-duty model intended to drive the heavy hands of up to four, large, turret or tower clock dials. It is difficult to identify whether this is a Gent's C40B or C40C but the large bevel wheels and stepped form of the mainframe further confirm a larger model than the [almost] ubiquitous C40A.

One should ask how this WT is driven and controlled? Does it have a robust 24Vpower supply and electronic control unit to provide the vital half-minute, low voltage timekeeping pulse? It will certainly never keep good time nor operate in its typically, hypnotic fashion without some "electrickery."

As this WT is a commercial sale item perhaps I should not have pointed out the cosmetic "difficulties" in quite such a forthright and, shall we say,  'pedantic' manner? I am a clock enthusiast not a buyer of antique furnishing pieces. I see my task as accurately recording and illustrating the history of the components of the Gent's Pulsynetic timekeeping system for posterity.

Surely anyone contemplating the purchase of such a rare and unusual item might be tempted to search online for more information. If some homework is required before burning the plastic: The only known sources of information on Gent's Pulsynetic Waiting Train movements are my own WT blog, the Pulsynetic website and Colin Reynold's excellent books on the Gent's Pulsynetic timekeeping system.

The asking price for this WT and its pretty stand/case is not insubstantial but these things do not come up for auction every week, nor even once in a decade. How does one value such rarity? It is, without doubt, quite beautifully presented. Since I am not in the market for a larger WT at this elevated price level I will leave it at that.  The following link will take you straight back to the WT on offer:

The Regulator Clock Company

Had it been a bare movement, perhaps a rougher example and needing some skilled, TLC, but at only half the asking price, I might have been more than tempted. Let us hope this particular WT finds a comfortable, new home. Where it will be cherished for its true genius in design, hypnotic mechanical details [when working] its long history and its vital importance to 20th century, public timekeeping.

This WT is now SOLD.

Click on any image for an enlargement. 

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Restored C40A Waiting Train movement for sale:

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http://www.thetimeworkshop.uk/gents-c40a-waiting-train-movement-for-sale/

With the permission of the owner I have copied and resized the excellent original images from The Time Workshop website.

It must be remembered that all WT movements were hand built at the Gents factory. Steady improvements were incorporated over time rather than sudden overnight changes. WTs are rarely found for sale and those which have appeared on eBay [for example] have not always been kindly treated. To find a restored and tested example of this age, quality and completeness is very unusual indeed!

The original pendulum is included but not shown in these images. It is visible in the video at the bottom of the page.

This Gents Pulsynetic C40A WT movement, which has been restored by a turret clock expert, is offered for sale. It has been running well on test to ensure reliability.

The details of its many brass components certainly suggest pre-WW2. Possibly early 1930s? There is so little information in the public domain on exact dating that one must seek clues in the shape and materials of its construction and make "educated" comparisons.

There are no plated components which would date it as possibly early 1930s.

The coils lack of later, concealing, protective wax [late 1930s] and even later 'bandages' suggest an early example.

The 'hooked' form of the steel gathering pawl is also early.


While the support boss for the contact assembly is horizontally slotted, for adjustment, so not of the very earliest style.


The pendulum drive armature has a roller rather than the very earliest 'hook' form.    
The sinuous form of the cast mainframe over the electromagnets is definitely a pre-war sign. Later frames had a diagonal slope just here.

It is nice to see a full bevel gear cluster, correctly silvered time setting dial and pointer below the large crown wheel to the motionwork. The Hipp Toggle damper is also present. As is the eccentric depth stop drum and the time setting handle and crank. An unusually complete example.

The lacquering to the brasswork is not well seen in these images but adds a quality touch.

I have no data on when the Gents WTs moved away from the early semi-mat, black finish to the later marine blue-greens. Or even later battleship greys. Though black certainly looks highly appropriate against all the lacquered brasswork highlights. This always reminds me of glittering gold jewellery laid on a black, velvet cushion.  All very desirable in any WT. Even more so on one which could be 85 years old!

Gents' WT design was a very successful, compact and powerful electric turret clock movement. It made weight-driven clocks completely obsolete overnight. What made it even more remarkable was its timekeeping stability, reliability and precision despite constantly changing weather conditions.

When controlled by its master clock's time signals it provided seconds per-week-accuracy to public dials. The WT in larger sizes went on to drive the hands of record breaking sizes of clock dials around the globe. Such dials were completely beyond the ability of any practical or affordable weight driven clocks.

Now add in an end to the need for regular rewinding, its low maintenance and only occasional lubrication. The lack of massive weight chutes allowed a WT installation to be placed where clocks had never previously found a home. Dials appeared on factory chimneys, war memorials and on office blocks and towers where they ran reliably without constant attention. The WT was not only an engineering marvel but an architectural ones as well. Even this very compact C40A movement could manage the hands of exposed 6' dials in all weathers.

For the avid collector the WT offers the enjoyment of watching a real pendulum swing. This is no 'soulless' electric motor. The infamous Hipp toggle is renowned for its hypnotic effect on the fascinated observer. As the toggle rattles quietly across the V-block it almost fell into the notch on that last swing... but then keeps going... and going... until, finally it drops in and closes the contacts. The pendulum is given a push by the huge electromagnetic coils... and so the game begins all over again.

Here is a video of this WT in action.


https://vine.co/v/i1HZUYEJUhB

Sellers website link:

http://www.thetimeworkshop.uk/gents-c40a-waiting-train-movement-for-sale/

Click on any image for an enlargement. 

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