Reminds me of something that happened over 10 years ago. I arranged a trial of a radio communication system, (noisy factory, hearing protection mandatory, with main production line over 100 meters long and operators communicating by sign language). The supplier had various case studies and testimonials. After a couple of hours, when the operators realised that its range covered the whole factory, they started to have a bit of fun with it. It culminated with the factory joker going to the vending machine and asking each crew member in turn how they wanted their tea/coffee. Midway through this a voice came over asking who he was and where he was. He entered into a conversation with them, telling them his name and where he worked only to be told he should not be using this frequency, as it was an emergency frequency and that the other person was the foreman of a quarry about 2 miles away, where they were blasting. 10 mins later the police turned up and confiscated the equipment. I then rang the supplier and told them where to pick their equipment up from. We didn't buy the system, while the supplier claimed their system was fully licenced to use the frequency and that the quarry were using the wrong frequency. Ileft it for them to sort out.

There are lots of potential safety issues associated with poor radio protocol. They include misunderstanding or misinterpreting messages, the wrong people acting on information and failure to respond or feedback following a message. I don't have a TBT, but you may find something useful at http://toolboxes.flexibl.../msapmsup102a/index.htm. In particular the section on Telephone and two-way radio protocol at http://toolboxes.flexibl...phone-radio-protocol.htm