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Hermle

Hermle (pronounced "Herm-lee") was founded by Franz Hermle in Württemberg in Germany in 1922. His sons oversaw expansion into the large US market and the firm became the biggest maker of clock movements in the world but in recent years the business has suffered several financial setbacks and the number of lines reduced considerably. Very little is actually manufactured in Germany these days thanks to cheap Far East labour.

Their clock movements are easily identifiable by the rows and columns of light counterpunch marks on the brass plates. Most have the name Hermle on them but on earlier examples you'll see the initials FHS (for Franz Hermle and Son) instead. Some URGOS movements are so similar that I'm sure the two makers have cross-ties.

The three most common spring-driven movements with Westminster quarter-chiming are the 340 series, which has a floating balance suitable for medium-size mantel clocks (see Image 1), and the 341 series (Image 2), which has a pendulum hanger (Image 3) suitable for wall clocks.They also produce a range of weight-driven movements (Image 4) for longcase clocks. Small striking clocks often have a 130 Series movement with circular plates and floating balance (Image 5).

Dating Hermle movements is easy if you look closely at the back plate . Up until 1987, they simply added the last two numbers of the year of make - so 77 indicates 1977. But rumour has it that retailers complained about the system because their customers could quickly spot old stock lines. So in 1988 Hermle adopted a letter code starting with A (see the table below right), so the letter 'O' denotes 2002, and so on, restarting in 2014 with AA. It's not infallible however; in 2012, I bought a new movement with the date letter denoting 2001 so I suspect Hermle were using up old stock to clear it. Nothing wrong with that as they're unused and since production shifted to China in around 2010, it might even be better.

Being cost-conscious, Hermle's brass plates are thinner than those found in some older clocks and this sometimes leads to pivot holes wearing more quickly, especially in clocks that are not oiled every three years. Worn pivot holes can be re-bushed but in some movements the pivot holes are so close to the edge of the plates that re-bushing is not safe. Also, mainsprings seem to be less durable so a frequent complaint is that after ten years, a Hermle clock will only run for four of five days instead of the usual eight, and that the strike and chime sound sluggish after a few days from winding or stop altogether.

Fortunately, however, because of the efficiencies of large scale production, it often costs no more to replace a Hermle movement than to strip, clean, rebush, reassemble and oil the existing one. And if yours has mainsprings that need changing, replacement will actually be cheaper! The springs themselves add around £35 each to the cost of a service (£185). So a new three train movement will typically cost £250 to supply and fit, whereas the cost of servicing your existing one might be £290. Small striking mantle clocks are also cheaper to replace, typically £200 (as opposed to £220 for a service and two new mainsprings). The existing dial, hands and gongs are all re-used so the clock still looks and sounds the same. And of course it's quicker so you can have your clock back in a fortnight or less.

If these costs exceed what you can afford, there is a cheaper alternative, which is to remove, soak, wash, rinse and dry the movement without first dismantling it. You cannot immerse the mainsprings in the cleaning solution because they will oxidise (rust) and the clock will quickly stop. But like most German movements, the Hermle design allows the mainspring barrels to be removed without separating the clock plates. This is helpful because stripping and rebuilding a clock is time-consuming and therefore expensive, so it can be avoided. At just £100, it all adds up to much less than a fully stripped service, though the guarantee is shorter (3 months) because even in an ultrasonic tank with the best cleaning fluids, a fully assembled clean cannot remove every trace of dirt. And of course it won't help if the mainsprings are worn out or if any pivot holes are worn because re-bushing requires dismantling.

In case you're wondering, a three train version is more expensive than a two train even for a fully assembled clean because the underslung chime assembly has to be removed to get the Going barrel out and that means you're faced with the setting up of the chime sequence after you put it back again.

Incidentally, for any repairers reading this, I've found that the simplest way to reset the chime on the underslung unit is first to prise off the circlip holding the lower of the two four-spoke wheels of the chiming train on the outside of the backplate (see third photo opposite); then slide the wheel off a little so that it disengages from the two smaller wheels above and below it. Next, turn the loose bottom wheel until you see a run of four hammer movements in sequential order (1, 2, 3, 4) and stop - the chime train has now run the 'quarter past' position. Now run the going train by turning the centre arbor until it strikes the hour (any hour), and then rotate it through another another 90 degrees until one more chime activation, and stop. Finally, without moving either of the two smaller wheels, refit the four-spoke wheel to re-engage the chiming train again and refit its circlip.

Overall, Hermle movements aren't the easiest to work on but given the price they are decently made and will last 25/30 years if checked and oiled periodically. If you don't maintain them, however, you will probably have to replace them after 15 years.

For more, check out the Hermle website.


2 and 3 train movements

  • Behind the dial of many modern quarter-chiming mantle clocks is a Hermle 340-020 8-day spring-driven 3-train movement
  • Hermle 341-020
  • Hermle underslung chiming hammers
  • Hermle 2 weight movement
  • Hermle 130-070

 


Dating your Hermle clock

On the brass backplate of your Hermle clock movement you will find either two numbers (pre-1988) or a capital letter (post 1988) which denote the year of make:

85
1985
86
1986
87
1987
A
1988
B
1989
C
1990
D
1991
E
1992
F
1993
G
1994
H
1995
I
1996
J
1997
K
1998
L
1999
M
2000
N
2001
O
2002
P
2003
Q
2004
R
2005
S
5006
T
2007
U
2008
V
2009
W
2010
X
2011
Y
2012
Z
2013
AA
2014
BB
2015
CC
2016