‘Other Helmets’  by Siebe, Gorman & Co. Part II ‘The Small Plate helmet’


the scrapbook of diving history

A small Siebe, Gorman & Co 12 bolt helmet

The shape of the breastplate looks much like a 'modern' Siebe, Gorman & Co Ltd breastplate, the older 'Patent stamped' breastplates were usually wider in shape. But the bolts and nuts on this breastplate were of a much older style: as small as on A.Siebe or early Siebe & Gorman helmets. One brail, left front, is younger and has larger holes, 2 larger bolts were built in the breastplate to keep this brail in the right position. The copper of the breastplate clearly shows the company name stamped directly in the copper: 'Siebe, Gorman & Co Patent'. This company markings would usually be found on a helmet with a number in the 3000 range, in this breastplate however there is the number '9' stamped inside 'in the neck' / back of the ring. And at the same place in the ring of the bonnet a locking bolt is passing through and there is no trace of a serial number. When the bonnet had a number then it would have been a single digit number because the rest of a larger number would have been visible. I think that the number was drilled away when the locking bolt was installed. The three original brails are also stamped with number 9. And since both the helmet and the breastplate are different in style from a standard Siebe, Gorman & Co. helmet from that era, and both have the same 'Small Plate' markings in white wax pencil on them, I am convinced that it is a matching helmet. Except for the faceplate. The faceplate which came with the helmet was a much younger one and in very bad shape. So I found another faceplate for it, also with a higher serial number but with its grill it looks great on the helmet 

After having found out that the helmet has a much smaller breastplate some more oddities were discovered: 

The studs holding the weights seem to have been built onto it at later date. They are smaller then standard SG weight studs and the mounting was done in a rather rough way (different from the rest of the helmet) But there are no traces (like patched rivet holes) of full size studs it once could have had. So the helmet seems to have left the factory without studs at all. Maybe its entire volume is smaller and it would have needed smaller weights anyway(?)

The helmet has a locking device at the back which is copied from Heinke, there are no traces of a standard Siebe Gorman locking device

The side windows are placed more towards the front on the helmet and come very close to the faceplate

The exhaust valve assembly has also been positioned more towards the front on the side of the helmet

PS: the text here above is part of a larger article which I wrote for the Journal of Diving History #82.