Any kind of signalling that requires some remote equipment at Okehampton will need an appropriate communications link to Crediton for control and supervision. Traditional dedicated railway cable routes have long since disappeared along the route concerned and would be ruinously expensive to recreate today, but some new products can use other means, such as Park Signalling's Digital Block Controller (DiBloC). This is a modern recreation of the traditional key token system that can communicate securely over any IP based digital medium, potentially including public internet services and custom wireless links.
Watch the traincrew/signaller familiarisation video here
DiBloC
Park Signalling has developed a Digital Block Controller to allow a section of single line railway to be controlled without the need for end to end cabling or on-board equipment. The product shares many of the same operational and safety concepts with traditional electric key token machines...
www.park-signalling.co.uk