Usual bell code, send call attention, wait for the acknowledgement, send is line clear. The other end would acknowledge the is line clear, and on the last beat would hold the bell key while continuing to crank. You would lift a staff into the throat of the instrument. This lifted a crank inside the machine that operated a contact directing the incoming current away from the bell to the lock. As you continued to lift the staff, this lifted a second crank that lifted the electric lock and, if the polarity was correct, the mechanical lock that secured the drums. The staff could then be pulled through the circular path which rotated the drums a quarter turn and reversed the commutator. All this time the signaller at the other end would be holding the bell key down while cranking like mad. At your end you turned the cutoff switch at the top left of the instrument and held it hard over against a spring. This opened the line wire, causing the galvos on both instruments to assume the vertical position. This indicated to the signaller at the other end you had the staff and they could stop cranking (phew). The cutoff switch could then be released from the spring, but it would be left turned a quarter turn (indicating 'staff out'), but this was simply a reminder and had no mechanical or electrical significance. The other end was supposed to turn their cutout switch to show that a staff was out. Train departure would then be sent and received.
More complex galvos existed (and I think were used in Ireland) that had subsidiary indicators marking if the section was clear, or if an up or down train was in the section. In Ireland, there was also the section signal release key. This was mechanically released by removing the staff, and, once released could be used to free the starting signal.
I think the reason why there was no direct electrical signal release may have been because the block line belongs to Telecom Eireann, rather than Irish Rail.
JRB wrote:The GPO and successors had for many years a legal monopoly of telegraphs, so having the railway ones was not a voluntary decision. Policy & timing diverged with Irish independence.
madscientist wrote:does that mean that initially the signaller , looking to release the staff, operated his magneto , merely to ring the remote bell, then the remote signaller , also operated his magneto to provide answering bells , then held his key down and continuing to operate his magneto, until he saw his galvanometer swing vertical ?
madscientist wrote:The reason I was asking this , is Im thinking of building a working version to add to a model railway , but as the staff wont actually go anywhere , I may have to invent a compromise instrument
madscientist wrote:PS : all these machines had little brass knobs on the to of them , what was that for ?
Did cabins have different bells for each machine , I ve seen some pictures where there was a magneto per machine with a bell on top , and equally some with no obvious bells, was the bell inside the machine ???
Heres the actual ones Im interested in this box had five at one time ??, ( including two full size originally , Then four miniature on a shelf near the stove with two magnetos , ) the bells must be in the instruments??
I've never heard of a ES machine with the bell inside - to be honest there is absolutely no room inside for anything like that. In Australia the bells were normally mounted on the wall above the machine.
There is another approach to this problem you could consider, as used in Richard Pike's simulation of the Ely Dock Jn to Soham section (albeit using EKT rather than ETS). Ely Dock has a token instrument, and the signalman operates it in the usual way, but in instead of handing the token to the driver, he immediately inserts it into an auxiliary instrument, as he actually would at that location since the train stops a good distance past the box. In reality the driver would take the token from another auxiliary instrument near the signal. In the simulation however, that other auxiliary is at the Soham end of the section, adjacent to the main instrument which had accepted the train. After the train is deemed to have travelled through the section, the signalman transfers a token from his auxiliary instrument to his main instrument putting it back in phase. The same process works in other direction too of course, so the need to rebalance tokens isn't unduly frequent.
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