the proceedure that was fallowed on the s.p., i don't have the book of rules in front of me, is that at the whistle post you start the long long short long, and then just hold the last long, keep it going until actually entering the grade crossing. where there were multiple crossing like that the proceedure would be to use the bell and just keep that going untill you cleared the last one.
whether you held the horn through all of them probably depended somewhat on local politics. but you deffinately had the bell going. also on the s.p. anything that moved had to have some sort of lights on at all times it was moving or going to, and everything that moved on rails 'displaying markers' was considered a train for purposes of the book of rules, that included a pickup truck running on highrailers, those hydraulicly raised and lowered rr wheels that can be mounted on highway vehicules to let them run on rails.
i'm not sure what you did for a bell with a highrailler or a track motor car, parobably just leaned on the horn.
one of the truck mounted backhoes i was on had highrailers and when we ran on the track the same rules applied as if we were any other train.
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