The Geo-Globe and the Deck-Cetra interlocked units aren't as obvious.
A self-contained water coolant supply is fully interlocked to prevent furnace operation without coolant flow.
The junction is currently controlled by ground frame electrically interlocked from Wareham signal box.
In free-barrel cranes the lifting barrel is connected to the revolving shaft by a powerful friction clutch; this, when interlocked with the brake and controller, renders electric cranes exceedingly rapid in working, as the barrel can be detached and lowering performed at a very high speed, without waiting for the lifting motor to come to rest in order to be reversed.
The symbol, known as Vesica Piscis, depicts a sword dividing two interlocked circles and foliage to symbolize the Glastonbury Holy Thorn.
