trunk Sub system
The Trunk sub, as in subscriber, system was an expensive way of making a call from one trunk sub number (Wattisham tower was IIRC Ipswich TS2) being directly connected to another trunk sub. The (expensive) calls had to be logged in a notebook next to the trunk sub phone, an ordinary black bakelite model. I seem to remember having to get an urgent message to ATC at Stornoway in 69/70 and called Stornoway TS1 and asked for Air traffic control only to be to told by an early sounding Scottish lady that, 'he was away to lunch"
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