Somebody asked a similar question on the NYMR unofficial forum.
This is the reply that 80135 gave:-
On both Train Staff and Ticket (the system we currently use between Goathland and New Bridge, via Levisham) and Electric Token Block (the system currently used between Grosmont and Goathland, but hopefully through the whole line from New Bridge to Grosmont by next year), where there are 3 signal boxes with 2 single line sections in between, the signalling can be installed so that the middle box can be "locked out" - i.e. taken out of use, to produce one, "Long Section". (thus reducing by 1 the number of Signalmen required).
This can be done when there is no need to pass trains at the central box or the gap between trains is such that the box does not need to be opened. The current Train Staff and Ticket System means that a "Train Staff" (a large key) has either to be carried by a train or the train has a brass "ticket" and the driver has to see the staff before he enters section. This means that the staff must be at the station from which the next train will depart. (Under Electric Token, a Single Line Token can be obtained from either end of a section at any time that a token is not already out of the Token Machines and in use).
To Close out Levsiham Signal Box, the eventual position is that the points are set for trains in both directions to use the Down (usually Grosmont bound) Platform. The Two Section Staffs for Goathland to Levisham and New Bridge to Levisham are inserted into levers in the Signal Box and turned. This allows those two leavers to be reversed and then a third leaver which has the Long Section Staff in it can be returned to normal and the staff released. This then allows the signals to be cleared in both directions at once for the Down Platform. The Long Section Staff is then given to the train, which proceeds - in tonight's case to New Bridge. As the next train was the 17:30 from Whitby and this needed to enter the Long Section at Goathland, JRW (the Footplate Superintendent) was waiting at New Bridge to transfer the Staff back by road to Goathland.
In the morning, Levisham Box will switch back in with the 10:00 from Pickering, the Long Section Staff will be returned to the frame and the 10:00 (10:20 from Levisham) will progress using the Levisham to Goathland short section staff. The New Bridge to Levisham Short Section Staff will be conveyed by road to New Bridge for the 11:00 ex Pickering, whilst the 10:30 ex Grosmont will return from Goathland on the Staff for that section to pass the 11:00 ex Pickering.
