My thoughts... The lamps on the track diagram are block occupancy. The lamps centered between the tracks on the street crossings show which gate circuits have been activated.
Typical of these later systems for gate towers, the gates come down automatically. That way, there is NO chance of a train coming through the crossing without the gates going down, should the tower be unmanned for whatever reason, bathroom break, run to store for smokes, etc.
The buttons are overrides so the gateman can raise the gates as soon as the train clears, even if it's still in the circuit. Note the buttons are marked "Raise No. 1 Track" and "Raise No. 2 Track". The toggle switch is just labeled "Raise." I suspect the gateman flipped the switch to RAISE, then pushed the button for the track that was occupied, and that overrode the automatic circuit ON THAT TRACK ONLY. If a train entered the circuit on the other track, the gates would start back down.
This is the way I recall Winneconne Ave. in Neenah on the Soo Line working, the tower that is now at Mid-Continent, but I don't know if the signal equipment was saved. That was a simpler installation in that it only governed one street, which was crossed by a main track and a parallel track that was the drill track for the yard. When the yard job pulled out, the gates would start down automatically. The gateman would make a judgement if they were going to cross the street or not, and kill the gate circuit if they would stay clear. Meanwhile, if a road train would approach on the parallel main track, the gates would automatically go down again, even if the gateman had killed the circuit on the drill track. The whole purpose was to NOT have the gates down all the time there was equipment in the circuit, since the gates would be permanently down while they were switching the yard, and this was the main street through town. The gate circuits were still automatic, and the gateman used his judgement to override them.
The eventual solution was a bridge.
|