Shown are my 13 "whole" Locke ST-3524 specimens. This includes 10 unrepaired examples, and 3 repaired examples. In addition, I have 3 more specimens in the process of being repaired.

All of these insulators were found by yours truly, on several expeditions along an early New England transmission line.

Due to flaws in design, these insulators were prone to premature failure. Additionally, the tall inner-most skirt made inserting and removing the connecting pins difficult without breaking the porcelain. In my experience, the inner-most skirt is almost always found broken.

Thanks to info from Elton Gish, I know a few more details about these insulators. They were introduced in the early 1910s, and are shown as catalog no. 2335 in Locke's 1912 catalog. By 1916 Locke changed designs and no longer cataloged these suspensions. They are apparently quite rare.

Condition seems to vary as much as the glaze! Some have flashover and puncture damage, some are missing extensive portions of the inner skirt, some have nearly flawless caps and pins, others are badly pitted and eaten by rust.

I don't know of many online resources for suspension insulator collecting, and what I have found is very limited. The "All Insulators" web page displays at least one Locke ST-3524, but erroneously labels it as an Ohio Brass product- I know this site is far from a complete, comprehensive depiction of all known insulator styles, colors, makes, and markings known to the hobby. That said, there are only two variations on the Locke ST-3524 listed here.

Between the insulators in my collection so far, and incomplete broken insulator remains I have found but not taken home, I have identified at least 5 different embossing/marking variations, and (depending how you slice it) at least 3-5 distinct glaze variations (some of which, so far, seem to correspond with certain glazes). At least one of these marking variations was not previously known to the hobby.

See [id=698103622] for a view of the undersides of these insulators!