Good morning!

Back in the late 1800's, Elgin decided to move from a slow train to a quick train movement in their 18s watches. What was the advantage of making this change?

I have examples of both, one dated 1877 and the other 1882, both fully COA'd and in equal tip top condition. You can definitely hear the difference in speed of the two movements as they run. I just wondered what the advantage was. Both watches keep perfect time in a 24 hour period, so I'm a bit puzzled as to their reasoning to the change of mechanical design.

I'm sure this is as basic a question as there is to a well seasoned horologist we have in these hallowed hallways, so please excuse this inquiry, but between first and second cup of morning coffee, it was a question that rattled through my brain that I thought others at my collection level may find the answer of common interest.

Inquiring minds want to know.

Regards! Mark

It is a simple matter of division. The more times you can divide a second, the more accuracy you can attain. Modern mechanical wristwatches can attain a bph rate as high as 36,000. Quartz is dividing a SECOND higher than that. And then of course there is the Atomic Clock.

That is a great question and I will be elated to see the responses especially from our many qualified watch makers on site !!

From a laymen prospective and from someone who has never taken a watch apart, I always believed that the reason for going from a slow/coarse train to a fast/fine train was all about accuracy and economics.

I believe that when the fast train was incorporated that the beats per hour [bph] increased from around 15000 to 18000. As mechanical watches have evolved even till today we find that some of the manufacturers have actually increased the bph up to double that on some mechanical watches.

Putting this last sentence another way, it is possible to obtain a given level of accuracy cheaper with a fast-beat watch than it is with a slower-beating timepiece.


This is from an On-Line Article written by Walt Arnstein posted at timezone.com and I quote the following...

"OK, so faster is better, up to a point. So why doesn’t the mechanical watch industry boost the beat rate of all watches to at least 10 bps? Or, for that matter, why don’t we keep raising the beat rate, to 16 bps, say, or try for 20? It turns out that a fast beat is not without its technological problems. The most significant of these is lubrication. To keep a layer of lubricant between critical moving surfaces at that rate takes some very sophisticated materials. Fast-beat Rolexes, for example, use dry lubricants (made with bismuth compounds) in the escapement. The method of applying them is very exacting.

Then there is the problem of supplying the proper power to run these escapements. The energy needed to operate a movement varies approximately as the square of the beat rate (approximately because the losses due to friction and air resistance are nonlinear), so the mainspring tension and forces acting on the gear train’s components grow accordingly. Most important, the consequences of loss of lubrication are far more serious in a fast-beat watch than they are for a 5 bps movement. Walt Odets, for example, wrote about a friend’s watch that had gone without an overhaul for 15 years or so, I seem to recall. It was probably a 5 bps or 6 bps watch. A watch designed to operate at 10 bps would probably have suffered a serious amount of permanent damage if it had been allowed to run that long without an overhaul. In short, given 10 bps watches as presents, a large portion of our consumer population would through neglect allow these fine instruments to literally beat themselves to death.

Also, there are other considerations in comparing various watches. For example, the phenomenally accurate pocket watches designed for railroad use by Hamilton, Elgin, Waltham, Ball, etc. (and now, sadly, no longer made) all had frequencies of 2.5 Hz (5 bps). Why, then, were they so accurate? To begin with, they were adjusted to an unusually high degree of precision. Also, they were generally kept in the wearer’s pocket in a 12-up position* most of the time and carefully protected from external disturbances. Equally important is that fact that their balance wheels were very massive compared to the tiny components of a typical wrist watch. It therefore took a strong disturbance indeed to cause a noticeable reaction on the part of the movement.

Finally, we should keep in mind that response to mechanical disturbances is not the only source of error in a watch. There can be poor adjustment for isochronism, sensitivity to temperature, friction in the gear train, etc. How else to explain the fact that Rolexes, Omegas, and other fine watches of the 1930s and 1940s routinely passed COSC tests with flying colors despite their low (5 bps) beat rate? Or the fact that a sizable number of modern watches (notably models by PP, IWC, Minerva, etc.) still continue to exhibit outstanding performance with a beat rate of 5 bps? The answer lies in precision and individual attention to detail.

No, beat rate is not the only factor affecting potential for outstanding performance. But given everything equal, the properly designed fast-beat watch does have a leg up on its slower cousin."

As Mr. Arnstein summerized...

"Conclusion? The higher the beat frequency of the escapement the lower its sensitivity to external mechanical disturbances. Hence, the better its achievable accuracy"


With all of this taken into consideration and put into proper perspective, what you see above, in quotes, is an authoritative take from a recognized expert, let's welcome others !!

regards,
bb

*or pendant-up position

Do I detect a little plagiarism?

Timezone.com article by Walt Arnstein

Excellent explanations! Thank you!

That said, one would wonder if this was something the horologist was/is after, as to a layman like myself, if a coarse train ran slower and yet kept the same time as the fast train example, logic would also say that there should probably be more wear on the fast train due to it having to work at the increased rate.

So, to a man on the street who is simply pulling his slow train watch out of his pocket to check his time, and finds his watch to hold the same time as the fast train, what has been accomplished for this man? What has the watch company changed to make his life any different?

This sentence offers me a great answer: "The higher the beat frequency of the escapement the lower its sensitivity to external mechanical disturbances."

I understand the 'what' (thank you Roger/Buster). I'm just trying to understand the 'why' when it came to the consumer.

Please continue. I'm on a learning curve today.

Regards! Mark

In short, the quick train was used to increase accuracy in rough service (such as a railroad man compared to a doctor).
My thoughts; due to the higher inertia of the balance and/or pallet fork it would not be disturbed as easily .

Roger,

I have always considered Mr Arnstein to be one of my mentors whose well versed writings I don't mind sharing with the members.. I could only wish I knew .05% as much. Perhaps you did not read my opening that I stated I have never taken a watch apart. Then you should realize I am here to help with the questions that members present...... Of which if I don't know the answer, I then rely upon and research the experts......

Have a great day !!

regards,
bb

Well Buster, If you are going to quote your mentor, then maybe it would be appropriate to at least put quotes around his material and give proper reference to it. The last sentence in your post "That has always been my take....." certainly makes it seem like you are the author of the material above it. If you can't take some constructive criticism, I'm sorry.

Roger

For future reference, so no soul is confused Mr Nolfe, and so that others won't think I am some self appointed guru or genius, let me state for the record; I am not an expert anything, but I usually know just a bit about a little, sometimes, perhaps, hopefully........

Most of my given and shared information to do with mechanics of moving parts and asteroids will generally come from experts, such as yourself and others, whom I research first and post to answer our members questions and to be a helpful participant in our forums.

I'm a firm believer that if we aren't part of the solution, then we are part of the problem, and I don't intend to ever be part of the problem.....

Thanks for your help and criticism when constructively used without animosity........

regards,
bb

Thank you all for your input. My question has been answered to my full satisfaction.

Regards! Mark

Changing the mechanism from 4.5 Beats Per Second to 5.0 B.P.S. would make more sense to everything from an "even count/Second" to designing the ratios of the wheel train to managing the mass and accuracy of the Hairspring and Balance wheel.

I appreciate all this accumulated data being pulled in to one post.

I wish there was a mechanism or process in place to take clear and concise post like these, clean up all the fluff and personal banter.. and place them in a library of sorts for us to be able to find in the future.

What always amazes me when I think about it, The intelligence of the early watch pioneers. Just the simple temp compensating balance, safety pinion, quick train, The list go's on. It all took years to accomplish, but those guys were really thinking with not much to fall back on.

Question - Was there an improvement in mainsprings (and hairsprings) allowing for the switch from slow train to fast train?

This will be the last I have to say about this subject and I apologize to Mark for interrupting his thread.

Mr. Beck...There is no animosity. I posted a link to the author's very informative article so that he would get proper credit for his work. You got extremely defensive about this instead of just looking at your own post and admitting your mistake. You apparently see no problem with just copying and pasting someones work on a public forum and posting it in such a way that it appears to be your own words. Sharing information you find is one thing, but failing to recognize the author or expert as you put it is plagiarism plain and simple.

If you want to be part of a solution, then don't create problems. I'm not the one who plagiarized this mans work. You did.

Update: I am happy to see that Buster Beck has now given proper credit to the author of the text with a bold print note, quotes and italicizing. Thank You.