Good evening, some single track museum railways in the United Kingdom are still operated with staff or token blocks although all their stations are equipped not only with home signals but also with departure signals (generally "railway semaphore signals" with arms positioned at 45º in the dial lower or in the upper quadrant to communicate to the driver that the way is clear). It is therefore not clear to me the need to have a staff or token block in the presence of starting signals. In other words, the signals that authorize the sending of trains in the opposite direction along the single track section could not be interconnected with each other in order to avoid head-on collisions as well as pile-ups as happens on double-track lines equipped with "Absolute block" ? If I remember correctly, the intermediate railway stations of the lines operated with the "Radio Electronic Token Block" do not have departure signals, except the "Stop Board". Grateful for the attention given to me, I would like to take this opportunity to extend cordial and sincere regards
Thanks for commenting, the staff or token comes into its own if there are intermediate sidings between the signal boxes on the single line sections as. They being usually unmanned ground frames are locked by a physical lock upon the lever which can only be released by the staff or token. In essence the staff or token is both the permission to enter the section and a reminder in hand to the driver but also the means of unlocking intermediate sidings where usually no power is provided for any electrical means of release and the sidings are in the middle of nowhere
Thank you for uploading this rare insight into the day to day workings of a rapidly disappearing world. Perhaps a silly question, but on the locking table, what does "LCC" stand for?
Lock. Checking contact. Proves the lever lock is not energised , lever bands prove the position of the lever but you could still have a false feed energising the electric lock so being as locking is both mechanical and electrical if that were to occur youve already lost half of your safety, thus lccs prove no electric lock is falsely powered up or energised at the time, the notch into which the lock drops technically also proves the lever is the correct way. So you could say if the notch was in normal that to make the contact the lever has to be both normal and not energised to make the lcc contacts
The king lever releases the opposing interlocking between signals in opposite directions. So normally when a Signalbox is open you wouldn’t have signals reading against one another off at the same time, but when the box is closed you may wish to have all the signals on the through line off, in both directions so trains pass the box and don’t stop, to do that a king lever is used, in essence when operated it disconnects (puts a gap) in the interlocking so mechanically you can pull opposing signals against one another or electrically releases opposing signals
