Fred Locke

Multipart Porcelain Insulators

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M-4321 (Locke catalog #)

Production date: 

 

M-4325 (Locke catalog #)

Production date: 

The M-4325 was first produced by Fred Locke in 1903 specimens had markings 6-1 or 7-1 an initial order of 3000 was placed in 1903 for the 55kV Electra-Seattle, WA transmission line.  The insulator was a custom design by the Stone and Webster engineering firm for this line. The insulator became known as the Stone and Webster insulator in engineering circles of the time.  An Journal article from 1917 was located which was written by an engineer for Puget Sound Power Light and Traction Company indicated 90% of these original Locke insulators had failed in service do to cement expansion cracking of the thin top skirts by the time the article was written. They used identical design insulators of more modern manufacture to replace the Locke units and had no trouble with those. 

Only parts of these insulators have been found and no whole specimens or kits have been recovered to date this insulator is interesting in that it was the FIRST lily-shell design multipart as well as the first four skirt cemented multipart known to have been manufactured. This would be a highly desirable historic insulator if one is ever found.

 

 

M-4384 (Locke catalog #)

Production date: 

The M-4384 was introduced in late 1903 or early 1904. It was designed by engineers of the California Gas and Electric Co (later PG&E) for use in the upgrading of the original Colgate and Electra lines to 60 kV the basic design seems to have been derived from the M-3725 by adding a fourth recessed inner skirt. The insulator was fabulously successful and thousands were put into service in northern California.  Many survived to modern times fatefully doing their job insulating PG&E's older 60 kV lines mainly in the central valley of California, a few remain in service as of this writing including some that may be marked with Fred Locke markings.  Two variations of this insulator exist One made in a three part mold which are likely the earlier production and some made by green trimming which have no mold line visible both variations come with or without marking #7-1 the colors tend to be very pretty medium to light tan sometimes verging on blond. Overall, these were the most successful and long lasting insulators that Fred Locke produced.

M-4384's were also used to replace M-2795's on the Bay Counties and Standard Electric lines.  It has a recessed 4th skirt.  Some specimens have the #7-1 marking, but many are unmarked.

M-4384 with #7-1 marking.

 

 

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