U.S. Army M2 Message Center Clock Chelsea 12E Movement

[SGM (ret.)]

So, after being totally motivated by the recent threads about Message Center Clocks, I took a deep dive into the clock collecting world to try to track one down for my militaria collection.  After some research, I decided to take a chance on one that was in less than perfect condition, but which was priced "right."

The clock I got had the glass broken out of it, the hands were bent into the dial-face, it wasn't running (reason unspecified by the seller), and it was missing the wooden transportation box.  Nothing wrong here!  LOL!  I figured if I couldn't restore it, then I could always get my money back out of it to put towards a better, more complete example.  The fun was in the research and challenge.  As it was, this resto has kept me busy for several months now, so it was, IMO, money well spent.

My first challenge was to see if I could research how to disassemble the clock to do what I could to bring it back to life.  I eventually found a couple of different .pdf versions of the US Navy Department, Bureau of Ships, NAVSHIPS 250-624-8 "Manual for Overhaul, Repair and Handling of U.S. Navy Mechanical Boat and Deck Clocks Chelsea Type."  Just Google this title and free to download copies will pop up.  If you have any mechanical skills and some few tools for doing fine work, with these instructions you can easily do almost anything to the Chelsea 12E (and 17E) Movement and Escapement to properly disassemble, clean and lubricate one of these clocks.  With some additional research, you can also learn how to do a number of other more complicated repairs.  I'm not going to lie to you and say that "it's so easy even a caveman can do it."  However, if you have the enabling skills, knowledge and ability to do fine, detailed mechanical work and the research needed to learn what to do, it is doable.

I' won't try to detail all of my work, but I will leave you with one bit of advice that took me a while to discover: DO NOT CLEAN THE ESCAPEMENT WITH ANY SORT OF CELLUOSE BASED SOLVENT - ALCOHOL, ACETONE, or LACQUER THINNER.  PERIOD!  Any of these solvents will dissolve the shellac that is used to glue the pallet stones and the impulse stone to their respective parts of the escapement.  You will ruin these parts, and if you don't lose the stones (which are not much bigger than grains of salt or sugar), you will have to find a real (a REAL!) clock maker to reset them for you.  Before attempting to even clean the movement and escapement, do your due diligence and research!

If you're not up to all this, do not despair.  Chelsea Clock made the 12E movement, used in the M2 (also used in US Navy Deck, US Lighthouse Service, and US Government clocks) to be sturdy and repairable.  Finding a clock maker who can work on one of these should be no problem.

After learning how to correctly disassemble the clock, I had to figure out why the clock wouldn't run.  I was hoping that it was something simple like a broken mainspring.  (Note, I have learned that "my clock doesn't work because the spring was 'over wound'" is a complete myth.  Either the spring will break, or it won't, but if it's fully wound, no matter how hard, it will just run unless there's something else wrong.)  In my case, the problem was the pivots on both ends of the balance wheel staff were broken off.  Because the Chelsea clock was produced in such numbers for decades, finding parts is not impossible.  I managed to source another escapement on eBay and used it to source a replacement balance wheel assembly.  (The staff can be replaced by a competent clock maker.)  The first picture shows my broken balance wheel in the platform escapement with the movement partially disassembled.

After fixing this, all the rest of the movement work was mostly simple disassembly, cleaning, proper lubrication, and reassembly.  Since the balance wheel assembly (which includes the hairspring) was replaced, I did have to do some work to regulate the time.  Again, learning how to do this (starting with the timing screws on the balance wheel) can be learned from online resources.

The next photo shows the condition of the hands and the clock face - dial after some preliminary straightening of the hands.  You can see where some of the paint had chipped from the hands in different places, and how the face of the clock was dirty.  However, there was no real damage to the finish of the face (no chipped or scratched black paint), so adding a new piece of glass, straightening the hands and touching up the chipped paint, and, finally, cleaning the face and refilling the etched markings with lacquer tinted to match the paint on the hands (not fresh pure white) was pretty straight forward.

The next two photos show the clock restored to running condition with the replaced bezel glass and hands and face freshened up.  At this stage, I was working on regulating the running speed.  Eventually, I was able to get the clock running well within the specified +/- 30 seconds per day (this clock now runs about -5 seconds per day or roughly -1/2 minute per week).

Once I had the clock running and keeping good time, I decided that it was worth the time and effort to make a reproduction wooden transportation box for it.

Continued research turned Whitney's book, "Military Timepieces" in which he included a chapter on the US Army's message center clocks.  That chapter (also printed as an article in the Horological Times magazine that can be found online for download) included a dimensioned external drawing of the M2 Message Center Clock transportation box.  With those dimensions, dimensions taken from the actual clock case, and a couple of dozen photos of original clocks in their boxes, I was able to "reverse engineer" the box and draft up a set of working plans for one.  The original specifications for the transportation box called for it to be made from hardwood with all of the parts for any given box made from the same species.  Based on photos of original boxes, the early ones would appear to be made from Mahogony while the later ones would appear to be made from white oak.  I guessing that US Navy demands on Mahogony for naval construction placed that wood in the "strategic" materials category (with the Navy having priority) so the US Army boxes were mostly made from oak.  The actual wood species and this variation is all based on nothing more than my personal observations and interpretations.  In the end, I elected to make my repro box from 1/2" thick white oak.

Hardware was another challenge.  The original hardware maker was Eagle Lock Co. in Connecticut which went out of business in the early 1970s.  In other words, original hardware is for all intents and purposes, impossible to find.  (In all of my searching, I was only ever able to find a single original wooden transportation box without a clock, and the clock collector who owns it would not even talk about selling it, much less entertain an offer to buy.)  In the end, I had to source a hinge, latches, screws, etc. from various sources.  The Chelsea Clock Co. is still in business, though, and I obtained an OEM leather strap handle from them, along with an OEM brass winding key.

The remaining photos show my reproduction transport box in various stages.  Finishing the box was done in accordance with the standards and specifications spelled out in a 1927 version of the US Department of Commerce for industries and vendors supplying the US government with products made from wood (again found online in a free .pdf).  It covers everything from paper to railroad ties and all in between.  The standards and specifications for finishing furniture and other fine wooden products called for stain, filler, shellac and spar varnish, so that's what I did with my repro box.

I'm pretty happy with the overall result.  It was a fun and educational project.  Clocks, timekeeping, celestial navigation and the history of the US Naval Observatory were all fascinating subjects, along with the mechanics of clock movements and escapements.  Even if you only have a passing interest in the clocks, themselves, I highly recommend Marvin E. Whitney's book, "Military Timepieces" from AWI Press.  In the modern world, we never really think about the complexity of timekeeping and the problems of long-distance precision navigation, but a century ago, all of this was really the high-tech GPS of its day and just as critical to national defense.



 

 

 

[VMI88]

Very impressive work!

[River Rat 1]

Nice job on that box. I have one with original box and if they were side by side, I could not tell what one was original.

[SGM (ret.)]

I appreciate the kind words, gentlemen!

[SGM (ret.)]

So, a local fellow militaria collector and friend asked me to take a look at his M2 clock and give him an assessment on the scope of work that it might take to get it running again.

 

It was one that he'd had for a number of years, purchased, I believe, from an "antique" (aka "junk") store for a very modest price.  It was in overall pretty sad shape - not working, the hour hand subassembly dynamically blown apart (the washer that goes between the hour and red time zone hands was "taco'ed" and both hands were off their ferrule), the minute and second hands were bent and chipped.  At some time in the past (before my buddy bought it water had infiltrated (through the winding hole, it would seem) and rusted up the mainspring, creating rust stains and some rust formation on a few other parts.

My buddy had used it as a "static" display type item mounted on a rough stand made from a couple pieces of wood rattle-can spray painted OD and screwed on with short deck screws.

At any rate, I blew it apart and found that the movement was nasty, covered in "gak" and rust stains.

I am happy to say, though, that after about 20 hours of work cleaning (and re-cleaning and then cleaning the clean parts again!), I managed to bring it back to life.  Replacing the mainspring was easier than I anticipated.  The main challenge was to free up the minute hand clutch spring mechanism.  This took quite a bit of work, but it's good now.  The cosmetic work on then hands was straightforward.  I left the face/dial alone.  I was tempted to refinish the scratches, but they were only a small few and once the face was cleaned, they looked about right for the age and use.

I did "reprofile" my buddy's homemade stand and replaced  the mounting screws with the correct, blackened slotted, brass #6 x 5/8 wood screws.

The clock's now running great and keeping very good time.  Although not in a correct wooden transport box, the display stand looks pretty good and seems appropriate for an Army Message Center Clock.  You could easily imagine it on some commander's desk in his garrison office.

[SGM (ret.)]

I forgot to add the picture of the repaired hands and cleaned dial/face.

One thing that really convinced me to leave the dial alone was that the luminous dots, triangle and square next to the numbers still glowed in the dark.  The luminous material on the hands was covered with black mold and mildew spots, but I was able to match the original color and repaint those areas with modern luminous paint (no radium, LOL!).  I was glad to see this, though, since I now have a very accurate color match for the original luminous paint.  (Which I'll use to touch up the hands and dots on my own clock at some time in the future.)

Anyways, these clocks have a very "brutish" and industrial look to them, but this one is still quite attractive.