Key distinguishing points
- Held in situ via a centre pin to top and bottom straps.
- Telegraph usage shackles are usually white.
- Single or double wire ridges.
- Design attributed to Sir C.T.Bright in 1858.
These insulators are mainly found in power applications such as street lighting and in the brown variant, see the Electrical Porcelain page, however where this requirement was on railway land / property older installations used white. They are exceptionally strong in tension due to the top and bottom fixing, however this very fixing made them poor insulators in wet weather.
This design has remained virtually unchanged from 1858 until the present day.
Two common sizes existed for railway telegraph useage. A small variant for 8/11 gauge wire and a larger variant for 4 gauge wire. A much larger wire grooved version is used for power applications.
The conductor is bound to the insulator with soft copper wire as shown
Above - Three views of a white porcelain shackle by as yet unknown manufacturer, but most likely Bullers, a variant of model No. E.I. 358. This type has a smaller than average pin fixing hole of 5/8" compared to the usual 3/4" / 21/32" sized hole, and was possibly for lighter gauge wire, ie lighter duties.
Bullers Ltd 1938
Above - Three views of a white porcelain shackle by Bullers LTD, dated 1938 with hand logo prominent on the top face. There is plenty of soot left on the undersides, even after vigorous cleaning, a true railway insulator.
Above - Three views of a white porcelain shackle probably by Bullers LTD, stamped 'Made in England' on the top face and of distinct mushroom shape.
Above - Three views of a white porcelain shackle, similar to one one of the others shown, except larger and with a straighter bottom skirt, probably a Bullers model, No. E.I.395.
W.M.Warden & Co. Westminster
These next three images are from the only fragment of insulator within the collection marked as from W.M.Warden & Co. Westminster. It does not look different from a normal shackle type insulator except for various styling changes including a much narrower neck than most others and a small wire ridge.
Who are Saunders of Cardiff and why is their name printed on this insulator?
'Price Bristol 58'
This next shackle looks very similar to example No. 8 except for a smaller spindle hole and they may be from the same manufacturer.
Price, Bristol - Is this the retailer, customer or manufacturer? No details of this company has yet come to light. 58 - Does this represent 1958?
J & P LTD 1.1003
Only recovered on 06/11/04, this basic shackle is clearly stamped J & P LTD 1.1003.The number probably is a pattern id.
It was recovered from a felled power pole between a railway line, transformer station and a redundant steel works, along with a further 2 examples, (1 of which didn't make it whoops!!).
You just never know what's going to turn up ! On a trip to a favorite insulator hunting ground I spied some new poles lying near a small electrical sub station. Now if there are new poles about then there must old ones as well. A hop over a gate and voila, laid out infront of me was a plethora of electric power transmission poles. Now you may be thinking why am I talking about high voltage stuff on a page connected to Telegraph shackles. Well amongst all this was an old telegraph pole with 4 Black Composite shackles, 2 in perfect condition and 2 slightly damaged.
Many assumptions can be made about who made what but at the end of the day a stamped example is the only real proof
This nearly complete shackle has a lovely printed description, J.B.Saunders & Co. TAUNTON. I have so far been unable to find any reference to this company in Taunton but I have found a J.B.Saunders & Co in Westminster London and Cardiff ( see earlier image)
Other than the underglaze text the only marking is a 'X' stamped underneath near the root of the lower shed, probably an individual makers mark.
Read my theory in the markings page on these letter stamps