IBM UK Master clock 25-7 serial 17656

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Can anyone date this clock. It had been in continues use in a Victorian building where I worked until the building was vacated and the clock given to me.
 

jkfabulos

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Aug 21, 2001
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Photos and or a more detailed description including the serial number if available will be required to help you date your clock.
 
P

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Originally posted by jkfabulos:
Photos and or a more detailed description including the serial number if available will be required to help you date your clock.
2 Pictures


Discussion Topic IBM UK Master clock 25-7 serial 17656
 
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eskmill

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Your IBM model 25-7 master clock is typical of those we see here in the US that were made after 1936. The style of the case, a quasi Art-Deco motif, was used on many IBM model 25 magnet wound and model 35 motor wound (weight driven) master clocks after 1936.

Yours appears to have the invar temperature compensated pendulum, a medium priced feature bested by a mercury compensated pendulum or the standard wood-stick cast zinc lenticular bob.

Some models require an external 24 volt DC source to control slave or secondary clocks while other model 25's have an internal 125 Watt transformer and rectifier to provide the control voltage needed for slave clocks.

Where specified for school campus classroom signaling or factory work schedule, most have a large metal disk 4, 6 or 8 level programming device. Your case has no evidence of ever having the programmer mounted inside the case.

You might have a more accurate date on your clock if you could determine when the postal address format used on the build plate was implemented in GB. In the US, various postal address formats have been implemented over the years each with an implementation date.

US made IBM clocks always have an identification plate with model designation, serial and a date code which is well documented but for US domestic production only.
 

eskmill

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The pictures have either vanished into the ether or were censored.
 

eskmill

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Your most recent photo of the master clock movement and wiring reveals little except the wiring from the movement toward the top of the case where external connections are made.

Barely discernable in the dark at the right of the movement there appears to be a very small transformer and a small selenium rectifier. Doubtful that the transformer and rectifier could supply enough current for more than the master movement and a few slave or secondary dials.

Too, it appears that the movement has duration contacts used to control the period that annunciators or bells are energized. However, there is no evidence of there ever was a bell programmer in the case.

There is nothing in the photos to help estimate the year of manufacture except for the postal address on the build plate shown in the previous photos.
 

Edwardo

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After much research into my own IBM master clock I have now gathered a large amount of information.

The IBM logo on your pendulum scale plate was use between 1926 and 1946.
Some plates were used after this date

The serial number you have given is typical of the one found on the movement

There should be another serial number on the inside left of the case and maybe some letters as well.

Are the connections at the top large screw down knobs that can be tightened by hand or a terminal strip that you need a screwdriver to do up?

Are these terminals labelled “D,D,1,2,3,4,A,B,C”?

If you can post this information here I may be able to date your clock more accurately
Regards
 

StephanG

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Edwardo said:
After much research into my own IBM master clock I have now gathered a large amount of information.

The IBM logo on your pendulum scale plate was use between 1926 and 1946.
Some plates were used after this date

The serial number you have given is typical of the one found on the movement

There should be another serial number on the inside left of the case and maybe some letters as well.

Are the connections at the top large screw down knobs that can be tightened by hand or a terminal strip that you need a screwdriver to do up?

Are these terminals labelled “D,D,1,2,3,4,A,B,C”?

If you can post this information here I may be able to date your clock more accurately
Regards
Hello, I noticed your post regarding IBM master clocks and was wondering if you could help to date mine. Mine has a serial number on a silver tag screwed to the inside of the case on the left hand side. The number is 18867 2035. It has IBM in silver letters on the cross timber just below the dial. It has a silver scale just below the pendulem that measure the swing and this is also marked IBM. Pendulem appears chrome plated and rod is metal with adjusting screw on end. A silver dial with dark brown letters for the hours and dots only on the seconds dial. None of the movement is visable. Clock operates on the 1 min magnetic puls system which winds a spring. The entire front of the case is covered by a single glass door which has a lock at the top and another at the bottom.
Thanks
Steve
 

harold bain

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Steve, welcome to the message board. Does your clock have a serial number tag that says where it was made? This will affect the dating of your clock, as each source factory had its own dating system. It will also tell you what the model number is.
 

StephanG

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Hello Harold,
If you tell me where to look I will try to find some other numbers. The number I gave is on a silver label screwed to the inside of the case about half way up on the left side. There is nothing else on the plate. To look at the movement or anything on the upper part of the case I will have to remove the dial which completly covers that section. The clock is currently mounted on the wall and has been running for about 6 years. Case is 19 ins wide by 8 ins deep by 61 ins high. It hangs in a cast steel bracket which you bolt to the wall first. Took 2 people to hang the clock.
The previous owner has added a small power supply to run the clock. I think it was from an electric train set. It is mounted behind the dial at the top where it can not be seen. When I first got the clock going I found it very noisy to live with and it took a while to find ways to quieten it down. You can still here it but it is now much better than it was.

Steve
 

StephanG

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My work for the day evaporated due to bad weather so I had some time to devote to this matter. Took the dial of and found some more information. Clock front plate is marked International. Made in England and a serial number of E18867. There is some extra parts attached to the bottom of the clock movement which appears to be some kind of switching device. This is also marked International Made in England with a number 2035. 3716.jpg
 

eskmill

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The device attached to the lower end of your IBM master clock movement is called an "accumulator."

The attachment keeps track of minutes passed if and when no electrical power is available to control slave (secondary or daughter) clocks. When electrical power is restored to the system, slave dials are corrected to agree with the master clock.

The device is actually a mechanical counter that increments from zero only when no electrical power is present. Once power is restored and stable, the counter decrements to provide correcting impulses to the slave dials.

The feature was attractive in locations where electrical service was not sufficiently reliable for an ordinary master-slave system.

Your original query which should have originated a new thread, asking for dating your master clock, remains unanswered because, to my knowledge, IBM US domestic archive data does not include data on IBM's foreign businesses. Although IBM US sold their domestic "Time Equipment Division" to Simplex in 1958, IBM companies outside the US continued to provide timekeeping sales and service.
 

harold bain

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Steve, I don't know of any reference to dating from British serial numbers. Maybe someone across the pond might be familiar with IBM in England.
Your movement looks clean and well looked after.
 

harold bain

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Edd, if you could post your dating info here, it would be helpful for future questions on British IBM clocks. Thanks.
 

StephanG

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Edwardo said:
Hi Steve
Your clock looks to be exactly the same as my one
I got my one from country Victoria OZ
Can you post a photo of the face
Where in Oz are You?
I have dates of most UK clocks
Best Edd
Hello Edwardo,
Here is a picture of my clock. I believe it came from a building in the Melbourne CBD that was the head office for an insurance company. Alas the person who saved it is no longer with us so I can not find out any more. I believe he had it for some time before he passed it on to me.
The little bear was attached by my youngest daughter who helped me install the clock. Just for fun I decided to leave it there and adjust things to suit.
Steve
[edit=6557=1183071284][/edit] 3750.jpg
 

Edwardo

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Hi Steve,
This is exactly the same as my clock, except for the bear and the "IBM" written across the trim under the face
Your clock seems to be in very good condition.
Date of manufacture would be approximately May 1950
However it may not have been originally installed until the late 50’s
NB I live in the eastern suburbs of Melbourne

Hi Harold,
A lot of my info is fragmented across old computer HDD’s, emails and filing cabinets, both in Australia and the UK
However I do intend to collate this information and publish it to a web page when I have the time
Once I start doing this I will post a link here

Cheers Edd
 

StephanG

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Thanks Edd. It is nice to have some idea how old the clock is.
I have a few questions about the way the clock works. Not sure to add them here or start a new thread. What do you think?
Steve

PS. I am in the Southers Suburbs of Melbourne so not far away.
 

eskmill

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Please Steamcar, do start another thread with a fresh subject line.
 

BrianScott

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Jan 19, 2012
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After much research into my own IBM master clock I have now gathered a large amount of information.

The IBM logo on your pendulum scale plate was use between 1926 and 1946.
Some plates were used after this date

The serial number you have given is typical of the one found on the movement

There should be another serial number on the inside left of the case and maybe some letters as well.

Are the connections at the top large screw down knobs that can be tightened by hand or a terminal strip that you need a screwdriver to do up?

Are these terminals labelled “D,D,1,2,3,4,A,B,C”?

If you can post this information here I may be able to date your clock more accurately
Regards
Hi Edwardo - I recently purchased a weight driven IBM clock in Melbourne and I was wondering if you had any information on ones of this type.
Looks like it may have been assembled in Australia but I am pretty sure it is US origin in Manufacture.

Brian
I have enclosed a few h3194 Une horloge à moitié électrique.JPG h3197 Une horloge à moitié électrique.JPG h3210 Une horloge à moitié électrique.JPG h3216 Une horloge à moitié électrique.JPG h3220 Une horloge à moitié électrique.JPG h3225 Une horloge à moitié électrique.JPG h3232 Une horloge à moitié électrique.JPG pictures
 

Edwardo

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Hi Brian
Nice find!!

I serviced one of these last year
It was made in England

If you remove the face the country of manufacturer will be stamped on the front plate
I have never seen an ITR or IBM that had been assembled in Australia but I have seen their movements used in other manufacturer's clocks
Hope this helps
Edd
 

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