Saturday, 29 March 2014

Waltham Colonial Riverside, 21J, 1936

Another excellent size 12 Waltham, this time a "Colonial Riverside" with 21 Jewels including the mainspring barrel.

The Swiss Lever escapement has a Breguet Sprung screwed balance with double roller, the hairspring appears to be elenvar to reduce temperature variation and the movement is adjusted for temperature. The serial number dates it to 1936.

The Colonial movement is particularly slim and in its case is only 0.4" / 1cm thick.

A perfect watch to wear with evening dress or military mess dress but equally suitable for day to day wear.

Tuesday, 25 March 2014

J.W. Benson "Ludgate" 1886, which had an interesting repair.

The is the top grade watch made by J.W. Benson at their Ludgate Hill factory in London, hence the branding "The Ludgate".

It was in a sorry state when it arrived and needed quite a bit of TLC to get it back into good condition including  fitting a new mainspring,  finding and fitting a replacement setting arbor (the time could not be set), a few adjustments, a lot of cleaning and the removal of a previous repair which is the subject of this post.

The movement has a true English Lever escapement with an over-sprung cut-compensating balance and 13 jewels. From the picture you can see the patented ring that sits between the case and the movement and which hold the dust cover.

After opening it up I found that some serious damage had occurred
in the past. The picture to the right shows the under-dial as it is now, after I removed and made good the previous repair.

Notice the large gear too the right is pinned to its "shaft" which is in fact the mainspring arbor, the winding key is applied to the other end of the small gear wheel which turns the larger gear which winds the spring, this is done so that the watch can be wound anti-clockwise as was normal for the Fusee watches still then in production (just).

At some point in its career, probably pre war by the condition of the watch,  the mainspring winding arbor had broken, probably by a watch repairer trying to lever off the gearwheel when the retaining pin had stuck in - that will work with the brass pins most people use but not with a steel pin, finding one of those is bad news as they will rust and jamb.

To rescue the watch he then had a lot of work to do, probably to avoid a difficult conversation with his customer! And its because of this sort of potential problem that I do not do work on other peoples watches.

After grinding the broken end of the arbour flat but leaving just enough of the square shoulder to locate the gear on the arbor, he drilled into the end of the  arbor - a tricky operations as the small hole is over half the diameter of the arbour, tapped it and then screwed the gear to the arbour as shown.

I was very tempted to leave this repair but the attachment was a little precarious and as I had a spare arbor from a scrapped "Ludgate" which would fit, not as common an occurrence as you might think, I replaced the arbour and gear wheel.

Saturday, 22 March 2014

A very rare Waltham 1894-Riverside Maximus, 21J 1903/4

In a previous post I described the Waltham S16 Riverside Maximus and mentioned that the grade name was also used on premium grades in other sizes. Here is one in size 12 and it is pretty rare.

The Waltham production records show that about three and a quarter million 1894 models were made of which about 83 thousand were "Riverside" grades but only 10,063 Riverside Maximus grades were made of all types - and that number will include rejects and movements planned to be made but not.

Of these only 2,801 were recorded as Open Faced 21Jewel movements the rest being Hunters or of different jewel count.

The general design is very close to the larger 1899 & 1908 models which followed and has moved away from the captive winding stem of the 1888 model. It has a Swiss Lever escapement with a Breguet  sprung cut compensating balance.

This grade also has a double roller, micro adjuster and steel escape wheel as found in railroad grade watches of the period.

Apart from the escape wheel the train wheels are gold and the top plate jewels are screw set in gold mountings. There are diamond cap jewels on the escape wheel and the Balance.

This example has a rare dial signed by Bailey, Banks, Biddle Co. Philadelphia - a very prestigious jewellery maker and retailer.

The case is by the Illinois Watch Case Company of Elgin and is rolled gold.

More pictures can be found via this page of my web site.

Friday, 21 March 2014

Waltham 1908-Royal Lever Set Variant.

My previous post was on the 1899 & 1908 Royal Grade, this is a rare Lever Set version from 1919.

A total of around seventy-five thousand 1899 & 1908 Royal grade movements were made but they are normally pendant set. The production records show that only five production runs totalling 4,000 movements included some open faced lever set variants, what the proportion was is not known, all are 1908 models dating from 1919 or later.

Apart from the lever setting the movement is the same as the 1908 pendant set version.

Tuesday, 18 March 2014

Waltham 1899-Royal & 1908-Royal

This is one of a series of posts illustrating the main grades of Waltham size 16 watches, primarily the 1899 & 1908 models. Note that specifications did change over time, the description below being typical.

The 1899 and 1908 versions are essentially the same and so can be treated together.

These were one of the highest grades before getting to the Railroad grades and their "civilianised" variants. The damascened nickel movement has 17 Jewels, a Swiss lever escapement with a Breguet Sprung cut compensating balance with micro adjuster and is adjusted for temperature and three positions. The top jewels are screw set in gold mountings and it has a gold centre wheel.

The example shown, which has just been restored, has an unusual 3 piece plain dial and which probably originally had a retailers name applied, (see related posts on watch face construction and on  blank dials).

Tuesday, 11 March 2014

“Summer” Office Hours.

The upper reaches of the river Test
near Whitchurch
With the Salmon fishing season now underway in Wales and the Chalk Stream trout season opening in mid-April I will no longer be working 6 or 7 days a week at watches but 4 or 5 instead. So until early October:

Shipping: I will only be able to ship watches on Monday, Tuesday, Thursday and either Friday or Saturday, usually alternating week by week.

Order processing and queries: On non-shipping days I will usually be able to answer queries and process orders late in the evening, if not then they will be dealt with first thing the next day. Orders will be processed in the order that they are received.

A Fake "Saleman's" watch case.

Occasionally in the USA you find watches advertised as being in a "Salesman's" or "Display" watch case that has has a transparent back so that you can see the movement working.

I am a little suspicious that these were not actually for salesmen but I should have been more suspicious of the American watch with such a case I bought in UK where these cases are very rare and never seen on English watches - at least I don't recall seeing one - not least because English watch case construction does not generally lend itself to the form.

Here are the front and back of the case in question side by side.

If you look at the enlarged version of the picture, by clicking on the image,  you can see more clearly see that the front bezel on the right has a very worn pattern on it whereas the one on the left does not. What has almost certainly happened is that someone had a watch with a damaged screw-on back and they found an almost matching front bezel that fitted the back and we suddenly have a more valuable display case.

The main body of the watch has a different pattern on it so it is even possible that the case was constructed from three different cases!

I must try and study the pictures more carefully but it's difficult when you are looking at several hundred in a sitting.

Friday, 7 March 2014

Geneva Stop Gear on a 19J Rotherham, 1902

Geneva Stop Gear.
Click on an image for a larger version.
In my last post on isochronism I mentioned the Geneva Stop Gear, the next watch I opened up for restoration was a very nice size 12, 19 jewel Rotherham from 1902 – the first I have had in for months – and it not only has Geneva gear but it is fully function rather than broken or removed to give a longer run time.

So, here is a picture of it (Top) and I will attempt to explain how it works.
The mainspring is in the barrel with the gear teeth on its top edge and that powers the watch via the centre wheel pinion, it rotates around the arbor (axel). One end of the mainspring it attached to the inside of the outer wall of the barrel and the other end is attached to the arbor. To allow the spring to be wound, the arbor has a longish extension on the other side that goes through the face plate and is pinned to one of the winding gears (the left most gear in the second picture).
The 12 Rotherham 19J Keyless, 1902.
On the other side of the barrel (shown) there is a collar fitted to a squared off section of the arbor which has a small “nib” protruding (at 5 o’clock to the centre in this picture). This nib engages the cut out in the Geneva gear. In this picture the spring has been pre tensioned just over one turn and is as it will be with the watch fully wound down, if you look at the piece of the gear clockwise from the nib you can see that it is locked against the collar having a convex profile so it cannot lose that pre-tension.

The segment anticlockwise however is concave as are the next 3 segments and when the watch is wound the “nib” moves anti-clockwise pushing the Genva gear a little clockwise and after one full circle it will engage in the next cut out, this cycle can be repeated three more times until the nib reaches the next convex section of the gear at which point it will be locked in a similar way to the position shown thus preventing the spring being wound further.
The arbor is prevented from turning backwards by the “click” or ratchet operating on the winding gear, bottom left of the pinned winding gear in the second picture.
As the watch runs the barrel rotates around the arbour until it comes back to the state shown in the picture and the watch will stop. But during those four revolutions the spring will not have the very weak power from a fully wound down spring, because of the pre-tension, and will not have the maximum power of a fully wound up spring because of the four turn limit.

One more method of making a watch more accurate but see also my post Does non-functional geneva gear matter?

Thursday, 6 March 2014

How come my 30 hour watch runs for > 40 hours? Or: Management of Isochronism in watches.

Waltham 1899-Vanguard 23J
click on the images for a larger view
This post was inspired by a query from a customer who was surprised that his newly acquired 23J Waltham 1899-Vanguard featured in my post  anatomy of 1899 vanguard was still running 14 hours after he received it after c24 hours in transit.

Firstly what is isochronism in a watch? In brief it is the ability of a watch to run at the same rate as the mainspring unwinds and that is critical for the accurate running of a watch and is a required "adjustment" in a railroad grade watch. So what has this to do with how long a watch runs?

Most pocket watches are designed to run for 30 hours (some are designed to run for 8 days but I am ignoring those for this discussion), to achieve this the mainspring will have to be of sufficient strength to operate the escapement and to have sufficient length and space in the spring barrel for 30 hours operation.

There is then a major problems to overcome, a mainspring of consistent thickness will provide more power when fully wound than when it is almost run down and although careful design of the escapement can make it less susceptible to varying power input it is unlikely to be completely immune so will run fast when fully wound, slower when partially wound and then faster and less reliably when almost wound down due to a weak (short) balance action.

Historically there have been a number of design features built into a watch to overcome these problems including:
  • An English Fusee movement
    showing the chain drive from the
     Fusee (right) with its spiral path for
    the chain, to the mainspring
    barrel (left) 
    The Fusee chain drive which gave a continuously variable gearing and had a high gear at full wind  reducing linearly to a low gear as it ran down. This meant that the torque delivered to the gear train was more consistent. It also reduced the minimum and maximum power delivered by the spring in the same way as...
  • The Geneva stop gear used by the English and Swiss in the late 19th and early 20th centuries but like the Fusee not adopted by the American industry. This limited the winding of the spring from a pre-tensioned state to four complete turns of the mainspring arbore (not the winding gear). This meant that the mainspring was never at maximum or minimum tension and delivered power in a more linier fashion over a narrower range. But it also limited the run time of a watch, particularly one not in tip-top condition.
  • Introduction of more jewelling to reduce friction requiring less mainspring power (see below) and more accurate fitting of the components to reduce friction and other inefficiencies.
  • In later years, as metallurgy and manufacturing processes improved, mainsprings were made of varying thickness through their length to provide more consistent power as they wound down, this technology was not however effective around the turn of the century when the Waltham 1899 & 1908 models were designed.
So why did the Vanguard run for so long?
Waltham 1899-Vanguard 23J
mainspring & barrel assembly

Highly jewelled variants of a movement can run for long periods because of the low friction enabled by so many jewels and in particular the jewelled spring barrel, this means that a weaker spring than the lower jewelled variant is often used (apart from other reasons the movement may otherwise run too hard and break the impulse jewel). A weaker spring is thinner so can be longer and still fit into the usually optimum outer 33% of the diameter of the barrel before winding. So it runs for longer but time keeping will be affected as it runs down.
But as watches are regulated for 24 hours (with a 30 hours maximum) this is one of the ways Isochronism is managed, if the watch runs for say 40 hours then the pressure exerted by the spring will be more consistent over the first 24 hours than if it only ran for 30. 
So a 23 jewel Waltham Vanguard and similar movements in good condition, with a good escapement and a weak main-spring (perhaps 0.15mm thick in the case in point) of the correct length (25.5") will run for considerably longer than a 7 jewel Traveler with its need for more power to overcome friction and a thicker (0.19mm) and shorter (21.3") spring. And because of the extended run time, the Vanguard over the first 24 hours of running, will not suffer the same reduction of power in the later stages than the Taveler and, even before other design factors come into force, will deliver more constant performance.
Length matters!


Tuesday, 4 March 2014

The Waltham Traveler

This is one of a series of posts illustrating the main grades of Waltham size 16 watches, primarily the 1899 & 1908 models. Note that specifications did change over time, the description below being typical.
Made in large quantities over an extended period the Traveler (yes with one "T") was a very successful movement and for good reason. Again the 1899 and 1908 models are essentially the same but the 1908 version came in one of the two plate designs as illustrated here. Hunter and open faced versions were produced, all are pendant set.

The 1899 model was as the design of the lower movement shown. Some late 1908 Travelers were made in nickel but the majority are Gilt.

Over six hundred and seventy thousand 7 jewel Travelers were produced in total, with more being made as special order or with other branding. Almost eight thousand 11 & 15 jewel versions were also made, see also the entry for the Marquis model. The movement normally has 7 Jewels, a Swiss lever escapement with a Breguet sprung cut compensating balance. It is unadjusted and has a single roller.

The top movement shown is from 1918, the lower from 1917, both are 1908 open faced models.