British Cables Company (formerly BT Cables)
Twin Data Link
Interconnecting Cable for SSI Systems
PACW/ PE Insulation/PE Inner Sheath (Belt)/Moisture Barrier / PE Sheath
External Telephone Cable (Complies with BR1932 : 1987)
Network Rail certificate of acceptance – PA05/06234
Twin Data Link Application
The cable is designed primarily for external deployment in railway environments as the interconnecting cable for Solid State Interlocking (SSI) Systems. It is manufactured in accordance with Network Rail Specification BR1932 (Dec 1987). The cable is deployed in troughing or by direct burial. In the latter case, the thickness of the outer sheath is increased.
Construction
The cable core comprises two plain annealed copper conductors, insulated with solid polyethylene and forming a twisted pair with regular lay. The cable core is then covered with a polyester core wrap and a polyethylene inner sheath or bedding. A polymer-coated aluminium tape is applied longitudinally over the cable core wrap acting as a moisture barrier. The moisture barrier is bonded to the polyethylene outer sheath.
A second variant includes a 5 mm outer polyethylene sheath to facilitate direct burial.
Further variants are available including HFFR Sheath and Rodent Resistant outer sheath incorporating a corrugated steel tape bonded to a polymeric sheath.
