Doulton 10.75 inch open profile porcelain suspension.

Doulton insulators goes back to 1840s and only closed in 1999.

. While digging thought this pile, [id=228155729] saw this one white 10.5 inch disc in a string of 10. The other nine are all brown CP. This sting was still in the shipping crate and probably was never installed. Half of the suspensions in this picture appear as unused, still in their crates. The wood in the crates has rotted away - all that is left of the crates is miles of twisted wire. Having spent three afternoons digging through this pile, I figure I have examined less than half. Deciding I'm too old for this much exercise, I've recruited a local soon to be suspension collector to continue digging through this pile in the future.

The underside is a slightly different profile than most other suspensions, having only one slightly protruding ring. The metal cap is marked HF over 8320 as can be seen in the picture slightly to the right of the inkstamp on the porcelain.

Lee Southern has contributed this link which tells some of the company's history. Since links die I have included the information below.

http://www.alliedinsulators.com/content/view/37/71/

In 1842 Captain J Buller and J Devett purchased the Folly Pottery, in Bovey Tracy, Devon and started in business as the Bovey Tracy Pottery Company. Using Cornish clay and coal from Staffordshire and Somerset, they produced a wide range of ware including bed knobs and door furniture. As the business grew, it suffered increasingly from the cost of transporting coal to Devon, and so the owners decided to move the company to the Potteries to be at the centre of the pottery industry. By 1862 W W Buller & Co were trading in Joiners Square, Hanley and by 1865 the pottery had three bottle ovens. Bullers were one of the first companies to explore the new markets created by electrical power, and by 1868 they were supplying porcelain Insulators complete with Ironwork in large quantities. Many government contracts followed, and Insulators were produced for Australia, Africa, India, Canada and Hungary.

Much of this earlier work was involved with telegraph Insulators, but Bullers were also able to supply Insulators for the Metropolitan Railway, for London County Council Tramways, and for many other transport systems.

In 1883 the Buller-Harris partnership was established, and in 1890 the company became Bullers Ltd. Expansion continued, and so the Hanley site soon became inadequate. From this, the decision was taken to build a new factory at Milton, then in the countryside outside the Potteries. Work started in 1917 and the factory was fully operational by 1920. Electrical porcelain was the mainstay of both factories. This continued until 1959 when there was an agreement between Bullers Ltd and Taylor Tunnicliff to form Allied Insulators, sharing technical and sales expertise, whilst operating under there own names. This remained the same until 1972 when Taylor Tunnicliff Eastwood, Hanley closed, causing the amalgamation between Bullers and Taylor Tunnicliff to become Allied Insulators Ltd with factories at both Milton and Stone. The amalgamation enabled knowledge of over 100 years to be shared, with the result that the new company was well equipped to meet the demands for future business both at home and worldwide markets.

It was a fitting merger for both companies until the early 1980's when Allied Insulators became part of the Fairey group and took on the Doulton division, from this the company was operating as Allied Doulton Insulators. In the early 1990's Allied/Doulton Insulators become part of the Beauford group.

Management buyout in the late 1990's saw Allied Insulators purchased along with Wade Ceramics to form the Wade Allied Group. The Milton manufacturing site was closed in 2001, Allied Insulators now operates from the Stone factory and supplies the Insulator market via strategic partnerships with some of the worlds finest Insulator manufacturers.