SSI (Wikipedia ) can refer to both a generic term for interlocking that uses microprocessors (i.e. computer based interlocking, or CBI), and also a specific "brand" of interlocking widely in use in the UK and several other countries.
The first application of SSI was at Leamington Spa in 1985.
Last edited by GeoffM on 15/09/2016 at 03:01