Rainford signal box has a single token machine for both Knowsley and Kirkby.
Trains to Kirkby collect the token from the signaller at Rainford and return it on the way back. There's an auxiliary token machine at Dale Lane for trains to Knowsley, so that they can lock-in, and allow the passenger trains access to the single line.
It has in the past been shown as OT(S) in the section appendix, but is now shown as NST. Talking to a colleague who works the box at Rainford, he assures me he definitely exists and operates the line under ETB regulations.