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SWCC Self Winding Clock Co. Regulator No.9 Mercury pendulum information needed


New Member
Sep 23, 2016
Hello everyone,
I reside in the UK and have just bought what I believe is a SWCC Regulator No. 9 for restoration, which is an unusual find over here, but although I have the pendulum with it's framework the weights are missing. I understand there should be two weights but would like your help to confirm the clock's model number and identify the details of the missing weights to be able to make some replacements.

If possible I would like to know:

a. What are the weights made of ie. are they mercury, filled or solid faux type etc.
b. If mercury, are they glass vials /jars or metal cylinders.
c. Accurate dimensions of the weights and the materials used in their construction, especially if mercury filled as I understand brass, steel etc. are not suitable.

If someone has this model or similar which uses the same pendulum, I would appreciate some help to enable me to get close to original.

IMG_1845.JPG IMG_1849.JPG


Registered User
NAWCC Member
Aug 21, 2001
The tubes are steel jars nickle plated to match the pendulum connector rods and center rod and filled with mercury originally.
The caps are screwed into the cylinder and use an "O" ring to seal them. I use a little RTV silicone on the threads and gasket to assure a seal.
These dimensions are all close approximations. Over the years there were several production runs of these
pendulums and there are known variances especially in the overall assembled length.
Jar length without caps 9 1/4 inches.
Jar length with caps 9 1/2 inches
Jar diameter 1 1/2 OD.
Wall thickness 0.200 inches.
Cap max OD 1 3/4 inches
Cap top thickness 1/8 inch.
Cap overall height 3/4 inches.



New Member
Sep 23, 2016
Thanks for the response to my information request.
This is more detail than I had hoped for, and your high definition photos show what at first looked like simple cylinders are very well engineered components....very useful. I have also found a scientific supplier here in the UK who are able to supply mercury taking care to meet all the regulations now in force.

I Have discovered that this clock came from the Metropolitan & District Railway M.D.R. formed in London in 1863 and which originally ran steam trains underground prior to later electrification. I understand that the M.D.R. ordered 600 clocks from the SWCC for their network. I wonder how many of these regulators were installed. This has a serial number 50906.

Has anyone got a set of SWCC hands for this 14" dial that they would sell and post to me in the UK?

Many thanks