2nd Gen Driver:
Hello PETE SMITH my owd man used to drive for HKR TRANSPORT in the 50s /60s and when he was on the Octopus after a while the gaffer fitted one of those “SPIES IN THE CAB” my owd man used a less subtle method of interfering with the workins of the machine than a boot to the back of the cab he just kept a wet rag hung over it to rust the insides up.
Well I drove a Dodge with one of these Servis Recorder clocks as they were called in those days, They were hand wounded & ran for 9 days before a rewind, Now did the wet rag work 
, Regards Larry.