A Signalling SystemA series of electrical, electronic, electro-mechanical units brought together to form a system which controls the safe movement of trains. used on Single Lines controlled by the use of physical
Tokens, only one of which can be released from the instruments for a
Section at any one time. The released TokenAny Single Line Token, Staff or Tablet. is the prime authority to enter
the Token SectionA Block Section or designated section of running line controlled by Token..