Huhm, don't quote me on this (unless I'm right ;D) but I think the show ID button would come in handy nonetheless. You see, you can use it in conjuncture with a formatted hint-radio call. I think it might go bananas and start adding "scalarboolarraystring0xfffff" or something like that towards the end, but when I tested it, it gave me the proper name nonetheless (some time ago, haven't got OFP here, as per usual).
*ahem* Make trigger, activated by radio Alpha, in the On Activation field write:
hint format ["%1", object xxxxxx]
object xxxxx being the ID of the bridge. Now, I think this should maybe work. A shot in the dark if it doesn't, make it ["%1", name object xxxxx] instead.
My other suggestion would be that you'd download the appropriate editor addon, add the bridge in an empty desert island test map thing, and then open up the mission.sqm and just check what the Vehicle name is.
good luck :thumbsup:
Wolfrug out.