Troubleshooting A Strike Issue on a HAC/HAU Movement

The maker of the movement is HAU or HAC. The familiar cross arrows trademark of the maker is stamped on the movement, in the middle of the backplate.

HAC was formed in Germany in 1873 by Paul Landenberger and Phillipp Lang and was originally called Landenberger & Lang Uhrenfabrik. The company changed its name to Hamburg Amerikanische Uhrenfabrik (HAU)/Hamburg American Clock Company (HAC) in 1883. The famous crossed-arrows became their trademark in 1892. In 1926 the company went into a cooperative with Junghans and in 1930 they finally merged with Junghans.

HAC/HAU clocks can be difficult to date prior to Junghans acquisition of HAC/HAU in 1930. Once Junghans and HAC began their collaboration in 1926 some of the movements were date coded.

Now on to the adjustment of the movement that is the subject of this article.

Strike Adjustment Required

Earlier in the fall this time and strike mantel clock was serviced. During the servicing six new bushings were installed, all components were cleaned, the mainsprings serviced and the clock reassembled and tested.

_{The movement has been cleaned and serviced}

However, during testing, the movement did not strike correctly. While there can be several causes, the most common of which is a misalignment of the hammer tail with the star points on the star wheel. This issue frequently arises during the reassembly of this type of clock movement.

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. Once the wheels are in place 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.

My usual practice is to position all the wheels and the lever(s) on the plate that has 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 moving around as I position the upper wheels and their pivots in the train.

Setting up the strike side can be tricky. The wheels and levers must be set up correctly or the strike will not function. For instance, the width of the slots on the count wheel tells us that there is no “passing strike” on this movement. In some count wheel movements, for example, in many American-made movements, the half-hour is actuated by a cam on the centre arbour.

The pin-wheel, which is uppermost and one wheel removed from the fly on the strike side, is placed in approximately the 10 to 12 o’clock position, called the “warning” position. This allows for a half-turn to set up the strike.

To make the adjustment of the star wheel there is no need to completely disassemble the movement. Loosen the nuts on the strike side and gently lift the plate taking care not to dislodge the wheels on the time side. Disengage the star wheel from the adjacent wheel and rotate it slightly so that the hammer tail is in the middle of two of the star tips.

_{Tail and star point (arrows), in this photo, the tail is almost resting on the star point which is not the optimal position}

The adjustment was made. On the test stand, the hammer tail isn’t perfectly centered between two of the star points, but it should function adequately.

If the hammer tail is in contact with the star point at the end of the strike sequence, it will hold in the raised position and the strike may not function at all from that point onward. While you are making this adjustment, ensure that the strike lever spring (which is a straight wire) is on the outside of the strike arbour.

In Sum

Adjusting the strike mechanism on an HAC movement requires patience, precision, and attention to detail. By carefully aligning the hammer paddle, star wheel, and other components, you can restore the clock’s striking functionality and ensure reliable performance. While challenges such as this are common when reassembling these movements, a systematic approach and an understanding of the mechanism’s function can make the process smoother.

January 28, 2025 0

Hamburg Amerikanische Uhrenfabrik: The Clock Company with an Alias

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.

_{HAC clock movement, with solid backplate}

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.

March 22, 2024

HAC mantel clock – it came without a crown – FIXED

I knew when I first laid eyes on the clock that it was missing something, the crown.

It’s too bad because it is very attractive Hamburg American Company or HAC 8-day time and strike mantel or parlour clock.

The little plaque on the base references 1926 the year it was presented to a pastor in England presumably for years of faithful service. I think the clock was made a few years earlier. Back in those days clocks like this might have sat on a Merchant’s shelf for years.

The chap I bought it from said it was an English clock but I knew right away that it was German. It has that distinctive German look and style of a clock made after 1900. Since he was a clock collector he should have known by looking at the trademark on the back of the movement. Oh well!

Okay, back to the crown. I have another HAC time and strike with a crown.

I am willing to bet that the crown on my new acquisition was either very similar or exactly like the one on a HAC I bought a year ago. It fits exactly into the slot on the top.

A crown makes a difference. You can see that adding a crown transforms the clock. It made be subtle but there is a difference. The problem I have now is, should I leave on this clock or the other?

June 27, 2022

Dating a Hamburg Amerikanische Uhrenfabrik (HAU) shelf clock

During the Christmas season, we split our time between Calgary, Alberta, and Ottawa, Ontario to see our 2 daughters. While in Calgary my wife spotted an interesting item on an Ottawa Facebook Marketplace, an English time and strike clock.

She showed me the photo and I said, “that does not look like any English clock I am familiar with. The style is definitely German”. There is a commemorative plaque on the front base section which references an English church so, I am assuming the seller thought it was English.

When we picked it up from his home outside Ottawa I was surprised to learn that the seller is a clock collector and had no idea the clock he was selling was German. Occasionally I sell clocks to manage my collection and when advertising one for sale I make it a point to know the maker.

But, no matter, it was in very good condition and in working order.

_{The movement showing the single strike rod and pendulum bob}

The maker is HAU or HAC. The familiar cross arrows trademark of the maker is stamped on the movement, in the middle of the backplate.

became their trademark in 1892. In 1926 the company went into a cooperative with Junghans and in 1930 they finally merged with Junghans.

The date on the plaque says 1926. However, HAC/HAU clocks are difficult to date prior to Junghans acquisition of HAC/HAU in 1930. Once Junghans and HAC began their collaboration in 1926 some of the movements were date coded.

Plaques are a good but not foolproof method of dating a clock. A clock purchased as a gift in 1926 could very well have been sitting on the retailer’s shelf for two or more years.

Catalogs are another good but hardly foolproof method of dating a clock. A catalog confirms that a model was made in a particular year, but that same model was probably offered 5 years +/- from the year of the catalog.

I will probably not determine a more reliable date for my new clock than circa 1926. The movement, compared to an earlier model (below), also has many cutouts and additional holes that indicate that it was a late production model and confirms that is closer to the 1926 date.

The clock runs for a while and stops. It is in need of a service but I expected to clean it as many of these old clocks have rarely seen the inside of a clockmakers’ shop.

February 4, 2022

HAC mantel clock – refreshing the case

Servicing the movement is complete. Next is the case.

For those unfamiliar with the HAC acronym, it stands for Hamburg American Clock Company, a well-known German company that was acquired by Junghans in the late 1920s. I have a number of German clocks including Junghans, Mauthe, Hermle, Jauch, Gufa, and Gustav Becker but this is the first HAC clock in my collection. This clock dates to somewhere between 1900 and 1908.

Here is the auction photo of the clock.

Bracket clock — HAC mantel clock (reproduced with permission)

As you can see there is some wear as expected from a 100+-year-old clock. The dial is especially grimy.

I focused on the dial first, managing to remove most of the grime while retaining its patina. Plus I touched up the numbers and chapter ring. There were numerous scratch marks on the dial surround and I did my best to clean it up and make it more presentable but it is what it is. Check out this article for more information on cleaning the dial.

HAC clock is attractive but the dial needs a lot of work — HAC clock is attractive but the dial required a lot of work

Stripping a case is always the last resort in my view. There is visible wear on the bottom corners, the lower part of the columns, and column capitals but not enough to justify removing the finish.

I cleaned the case with Murphy’s soap, applied 2 coats of shellac using 4X0 steel wool between coats followed by a coat of Minwax finishing wax.

Better but not perfect but perfect was never my goal. Now, where to put it?

May 31, 2021

Hamburg American Clock Co. – shelf clock, first look

This clock was an estate auction buy in early 2021. Since my wife and I were unable to bid in person we placed an online bid. So many estate auction houses are taking this very route that the days of people packing an auction house and bidding feverishly may be behind us. It was described as an unknown clock but I’d seen enough photos online to know that I had likely won a Hamburg American Clock Co. shelf clock. And, for a small shipping fee the clock was delivered to us a few days later by courier.

HAC was a well-known German company that was founded in 1883 and made clocks for a number of years before they were acquired by Gebr Junghans Uhrenfabrik or Junghans for short, in the late 1920s. I have a number of German clocks but this is the first HAC clock in my collection.

When I opened the box I inspected the clock for damage (there was none) and proceeded to look for the familiar cross arrows trademark on the backplate of the movement. I could see how it would have been easily missed by the auction house since the trademark was “hidden” behind the pendulum leader. Many HAC clocks have a trademark on the gong block, this one does not.

The case is a little tired and worn, especially the dial, but there is nothing amiss, no parts missing. The movement works but I am not sure what to do with a very tired looking dial face.

I pulled the movement out of the case to examine it more closely, inspect for any immediate issues, and proceeded to photograph it from different angles.

Like other German movements, it is robust, well-engineered and has a certain industrialized look, even crude in some respects. The front and backplates are solid indicating that it was probably an early version of this movement. There are no “extra” holes in the plates that are often found in many other German movements, holes that are made for various functions for other styles of cases. Compared this to the #36 movement (below right) from HAC. At 8.7 cms by 10.9 cms this one is almost the exact size.

The plates are almost 2 mm thick, suggesting a well engineered movement.

Movements on German mantel and shelf clocks from other manufacturers are typically bolted to a seat-board. On this clock, brackets on all 4 corners attach the movement to the inside front panel which is very American!

Numbers in the top left corner of the backplate,164, 42, and 130 tell the beats per minute, the number of escape wheel teeth, and pendulum length.

I am anxious to take the movement apart and look at ways to revitalize the case and dial.

This is an excellent winter project.

March 27, 2021

Strike Adjustment Required

In Sum

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