36 – Antique and Vintage Mechanical Clocks

I am currently working on a mantel clock from the Hamburg American Clock Company. This is Part II in a two-part series. For Part I go here.

The Hamburg American Clock Company is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU and in many parts of the world, it is simply known as HAC.

In Part I, I described the steps taken so far which are disassembly, inspection, cleaning of the parts, and polishing of all pivots. The next steps are bushing work, reassembly, oiling (the mainsprings were oiled in a previous step), and finally, testing.

I believe this is the No. 36 movement by HAC.

The wheels that spin the fastest typically show the most bushing wear, but wear can also appear in other areas, such as the main wheels, which endure significant torque. For instance, I observed punch marks on the cap side of each mainspring barrel. While punching around any bushing hole is generally poor practice, it appears this was done at some point in the clock’s history and can’t be reversed. Nonetheless, the repair seems to have held up well.

Bushing Work

I have seen similar movements with much more wear than this one, but I felt that some bushing work was necessary to extend the clock’s lifespan.

Six Bergeon brass bushings were installed in total. For the time side (T), bushings were placed at T1 (front and back) and T3 (back). For the strike side (S), bushings were installed at S3 (back), S2 (front), and S4 (front). The numbers indicate the wheel location in the train beginning from the bottom. A couple of pivot holes were borderline, but I decided to leave them as they are.

Reassembly

It pays to be patient and methodical during reassembly. Rushing can lead to mistakes, such as missing steps or improperly aligning parts, which could cause malfunctions or even damage later. Taking the time to carefully double-check the placement of parts, and ensure everything is in its correct place will help ensure the reassembly is smooth and successful.

_{An older HAC movement, without the barrel cutouts}

Once the wheels are in place the lever and there is only one multi-arm ever that resides between the plates. Position it such that the long arm rests in one of the deep slots of the count wheel while a short arm is placed in the cut out of the cam wheel (as above).

Positioning the pivots is a delicate process, and any forceful handling can result in a bent or broken pivot. In this, as in all cases when aligning pivots, a pivot locator is your best tool.

My usual practice is to position all the wheels and the lever(s) on the plate with the movement posts, first. Once the wheels are correctly located, I lower the front plate onto the back plate. I secure two nuts to the mainspring end which prevents the movement plates from coming apart as I position the upper wheels in the train.

The pin-wheel, which is uppermost and one wheel removed from the fly on the strike side, is placed in approximately the 12 o’clock position, the warning position. At the same time the hammer paddle is positioned between two of the points on the star wheel. More than once I have had to go back in to make minor adjustments when the paddle hangs up on one of the star points. It looks like this one is also a candidate for that very adjustment.

_{A Timetrax machine is used to adjust the beat and the rate of the movement.}

The movement has been placed on a test stand and the time side Is in beat and running as it should according to my Timetrax machine. Curiously, the Timetrax manual lists only one HAU/HAC movement, a three-train one but this one is likely similar to Junghans bracket clock movements which runs at 164 bpm. Junghans is mentioned for comparison because, by 1930, the company had successfully taken full control of HAC.

Testing

The testing phase is crucial in the process of servicing a clock, often taking the most time because it ensures that the clock is functioning properly before it is reunited with its case.

During this phase, the clock is put through various operational checks to simulate real-time performance, which helps in identifying any issues that may not have been apparent during the initial servicing or cleaning process. Issues such over-tightened or loose components can present themselves as well as problems with the escapement mechanism.

The testing phase serves as an important diagnostic step to identify what further repairs or adjustments may be needed.

This concludes the servicing of an 8-day HAU/HAC movement. If you have any comments or feedback on any of the steps in the process, please feel free to share!

This article traces the historical journey of a significant German clock manufacturer, ultimately absorbed by the Junghans Clock and Watch Company in the late 1920s. After providing a brief overview of its history, the article will delve into the specifics of the clock movement that is next on my workbench.

Among clock collectors and admirers, the Hamburg American Clock Company is a well-known German company. It is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU and in many parts of the world, it is simply known as HAC or HAU.

The company was formed in Germany in 1873 by Paul Landenberger and Phillipp Lang. Originally called Landenberger and Lang, it became the Hamburg Amerikanische Uhrenfabrik in 1891. The company was very active from 1885 onward, became a cooperative in the mid-1920s, and eventually merged with Junghans, one of the world’s largest clock companies, in 1930.

_{HAC 14 day time and strike, a relative’s clock}

Original investors insisted that “American” be in the company name but “American” also refers to the manufacturing system adopted from America. The name of the company adds confusion to the novice repair person who might assume that what they are working on is an American-made clock.

HAC trademark, crossed arrows — _{HAC trademark}

HAU adopted the cross arrows as their trademark in 1892, and it became synonymous with the brand.

In 1925, a few years before its merger with Junghans, the company had a workforce of 2,200 individuals. Junghans remains a successful and thriving company today, specializing in the production of high-end wristwatches.

Before I embark on servicing a clock from my collection, I make an effort to gather information about the clock’s history. If details about the clock prove elusive, my fallback is to delve into the broader history of the company behind it.

Two Hamburg Amerikanische Uhrenfabrik clocks

The two HAC clocks in my collection are mantel or shelf clocks.

The clock pictured above was acquired several years ago.

It has an earlier version of a HAC production movement because of the solid front and backplates. It is quite possible that this clock was made in or around 1900 or a little later.

_{HAC clock movement with solid front plate}

Now, turning our attention to the second HAC clock in my collection, the one I will be working on next. The clock was acquired about two years ago from a clock collector in Ottawa, Ontario. The previous owner knew nothing about the clock but a plaque on the clock case gives a glimpse into the clock’s history.

This clock is a later production model because of the construction of the plates which I will explain further.

HAC clock number #2, model unknown, a later production — _{HAC clock number #2, model unknown, with a dedication plaque}

While the wheel positions, levers, and movement size remain identical, there exists a noticeable difference between the two clock movements as can be seen by the solid front and back plates on the first clock movement and the various cutouts in the front and the back of the second movement.

_{Open plate, a later production movement}

The use of open plates typically indicates a cost-saving decision made by the company. This choice is often driven by the aim to reduce manufacturing expenses by minimizing the amount of brass used in a movement.

HAC clock #2, #36 movement — _{HAC #2 movement}

Aside from the four brass mounting straps and the slight difference in the positioning of one “V” shaped lever springs, HAC movement #2 has all the characteristics of the #36 movement pictured below.

_{No. 36 HAC time and strike clock movement}

The story of two clocks made at different times in the company’s history is both captivating and compelling.

And finally, who is The Rev. J.H. Cox? A search online reveals nothing at this point.

Before concluding that the clock was manufactured in 1926, it’s important to note that relying solely on plaques for dating may not always be accurate. The clock might have spent time on a retailer’s shelf, or it could have been acquired second-hand, introducing questions as to its actual production date. However, there is a 5,25 number on the upper left of the back plate which might be a date code. HAC was known to have begun dating their movements in the 1920s.

Now, on to servicing the clock movement the details of which will be covered in a forthcoming post.

Tag: 36

Hamburg Amerikanische Uhrenfabrik | Servicing an 8-day Countwheel Strike Movement – Part II

Bushing Work

Reassembly

Testing

Hamburg Amerikanische Uhrenfabrik: The Clock Company with an Alias

Bushing Work

Reassembly

Testing

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