At Glenhuntly on Melbournes Frankston line the boom gate barriers are hinged to clear the wires of the Carnegie tram line, Suburban trains & a tram are seen in this presentation. There are 3 rail tracks at this location.
When the boom gates were first installed, replacing the old manual gates years ago now, the Glenhuntly fire station fire engine used to go in and out of the boom gates if travelling to a call out. Technically, they were not supposed to do it, but because they could see any city trains stopped on the up line at the platform, and any train travelling towards Frankston that crossed the up train, (which would only happen in the peak at Gelnhuntly), would be travelling very slow to cross the tram tracks, it was never an issue. Also, the driver of a city bound train would also indicate to the firies that it was safe for them to "navigate" the boom gates from wrong side of the road. As a kid at school I used to wonder how they worked the boom gates out for safety, and after a while I noticed the firies only did it when the up city trains were stopped at the station, and the train driver would even get out of the train and wave them through from the end of the platform, as nothing was coming the other way. They even did it for police cars and ambulances. That would never be done with workplace health and safety today, and back then, it did not happen all that often anyway.
A part of the signalling the signalman switches out the 1500 V Dc train overhead and switches to 600 V Dc for the trams linked in with the train and tram signals. Other RU-vid vids explain this aspect. Search RU-vid for Glenhuntly rail square.
Why this crossing does even have half-gates? Double-gates would do better justice than half-gates, especially if there's so much traffic that sometimes vehicles would circumvent around the gates!
I have watched too many videos of cars trapped by double gates. When they were hand operated there was a safety process. With booms there appears to be zero safety at all. which violates one of the first principles of railways.