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NO 5 Pressure Switchs
- Thread starter jvollenberg
- Start date
Thanks Tom and Darryl. The manufacturers of the No 5 Switch is proving to be more interesting than expected. During the prototype stage of development at Station XII G.H. Gladhill and Sons were invited to consider manufacturing methods for the switch and they made certain recommendations, the chief one being the use of die-casting for the bodies rather than machining out of solid and cast brass. Gladhills received their first order in October 1941. Skipping a few details it became necessary to give some components of the switch a Dichromate treatment before assembly and in order to do this Gladhills held a licence from National Alloys Ltd, Avonmouth, who owned the process.
Gladhills manufactured 502,000 No 5 Switches up to December 1944. The switches are unmarked but the primary packing (a tin holding 10 switches in 5 cardboard cartons) shows the manufacturer as LG which as you know is the SOE firms code for GladhilL.
So Gladhills made the switches for SOE (some of which were supplied to the Army).
The interesting bit is that GHG made No 5 Switches in the fifties (also 1984) but by this time GHG was Garland & Co. What are the chances of two companies with the same initials being contracted to manufacture the same devices, albeit a decade apart?
Gladhills manufactured 502,000 No 5 Switches up to December 1944. The switches are unmarked but the primary packing (a tin holding 10 switches in 5 cardboard cartons) shows the manufacturer as LG which as you know is the SOE firms code for GladhilL.
So Gladhills made the switches for SOE (some of which were supplied to the Army).
The interesting bit is that GHG made No 5 Switches in the fifties (also 1984) but by this time GHG was Garland & Co. What are the chances of two companies with the same initials being contracted to manufacture the same devices, albeit a decade apart?
The No 5 Switch was designed primarily to initiate a railway demolition charge. In laying the charge the switch had to be carefully fitted under a rail (or a sleeper) and an adjustable extension rod was provided for this purpose. The flexing of the track beneath the wheels of a train was sufficient to to fire the switch.
Setting the switch under a rail could take some time and it would likely take longer in the dark. Station IX personnel devised a self-adjusting extension rod which required the minimum of operator involvement to set. The last modification involved adding a time delay mechanism to the self-adjusting extension rod thus providing a delay to arming function. The delay mechanism used was from the Time Pencil (No 10 Switch).
Although acceptance trials were passed, it is doubtful that many were issued to the field.
The photograph shows the three configurations [Service, Self-adjusting, Delayed self-adjusting]
Hope it is of interest.
Setting the switch under a rail could take some time and it would likely take longer in the dark. Station IX personnel devised a self-adjusting extension rod which required the minimum of operator involvement to set. The last modification involved adding a time delay mechanism to the self-adjusting extension rod thus providing a delay to arming function. The delay mechanism used was from the Time Pencil (No 10 Switch).
Although acceptance trials were passed, it is doubtful that many were issued to the field.
The photograph shows the three configurations [Service, Self-adjusting, Delayed self-adjusting]
Hope it is of interest.
Interesting. I have never seen the different configurations before. Bonnex but your box was full.
Joe
Joe