GPO Insulator No ? - UK Vintage Radio Repair and Restoration Discussion Forum

Pellseinydd · 5th May 2023, 12:26 pm

Does anyone know the GPO description number for this insulator?

I've searched for years without luck. I know what the following insulators are as per attached list. This insulator was replaced c1914 by an Insulator No 20 - the small black composition insulator - used in areas subject to 'stone throwing' .
So I assume it had a lower number - not listed in attached list i.e. No 12, 15 or 18?

This is the only one of this type I've ever seen.

davidw · 6th May 2023, 9:21 am

Not one I remember from my linesman days but as a thought maybe a railway trackside type perhaps?

Granitehill · 6th May 2023, 5:33 pm

Quote:

Originally Posted by Pellseinydd

Does anyone know the GPO description number for this insulator?

I've searched for years without luck. I know what the following insulators are as per attached list. This insulator was replaced c1914 by an Insulator No 20 - the small black composition insulator - used in areas subject to 'stone throwing' .
So I assume it had a lower number - not listed in attached list i.e. No 12, 15 or 18?
This is the only one of this type I've ever seen.

I'm fairly sure it's an Insulator No.12 which is the small variety of two groove terminal insulator. There's also the large which is the No.7.
Information from my 1930 edition of T.E. Herbert's "Telegraphy".

Pellseinydd · 6th May 2023, 10:12 pm

Quote:

Originally Posted by Granitehill

Quote:

Originally Posted by Pellseinydd

Does anyone know the GPO description number for this insulator?

I've searched for years without luck. I know what the following insulators are as per attached list. This insulator was replaced c1914 by an Insulator No 20 - the small black composition insulator - used in areas subject to 'stone throwing' .
So I assume it had a lower number - not listed in attached list i.e. No 12, 15 or 18?
This is the only one of this type I've ever seen.

I'm fairly sure it's an Insulator No.12 which is the small variety of two groove terminal insulator. There's also the large which is the No.7.
Information from my 1930 edition of T.E. Herbert's "Telegraphy".

Hi John

The No 7 is listed in the Vocabulary of Engineering Stores for eary 1940's as 'Large, Terminal White or Brown' (terminal indicates two grooves - one to terminate the span on either side). No mention of the metal outer. The No 12 is listed as a 'small two groove white' which indicates a pot one in an earlier extracte replaced c1914 as the later black compisition No 20 two groove small insulator.

I can find no mention of metal coated insulators - the one I have has a white pot insulator the size of a No 2 inside the metal coating.

Ian J

5th May 2023, 12:26 pm	#1
Pellseinydd Heptode Join Date: Jul 2007 Location: Flintshire, UK. Posts: 703	GPO Insulator No ? Does anyone know the GPO description number for this insulator? I've searched for years without luck. I know what the following insulators are as per attached list. This insulator was replaced c1914 by an Insulator No 20 - the small black composition insulator - used in areas subject to 'stone throwing' . So I assume it had a lower number - not listed in attached list i.e. No 12, 15 or 18? This is the only one of this type I've ever seen. Attached Thumbnails

6th May 2023, 9:21 am	#2
davidw Heptode Join Date: Sep 2006 Location: Woodbridge, Suffolk, UK. Posts: 630	Re: GPO Insulator No ? Not one I remember from my linesman days but as a thought maybe a railway trackside type perhaps? __________________ Dave G1AGK. My perception is my reality!