Been out of the loop for a while, and just found my old C.P.R. lock and key, what do they use to lock switches today? They still don’t use the old style system now do they?
I can answer that by saying that I live within a couple blocks of a portion of the BNSF’s yard here in Sioux Falls, South Dakota, and they keep the switch at the yard lead locked with a modern, heavy duty lock, where you would need a key to open it.
Adlake, Sargent & Greenleaf(sp?) and American style locks are still in use. Very common.
I believe that for certain especially safety-critical or vandalism-prone locations, a more heavy-duty and secure lock is used instead of the older styles. - Paul North.
Both are in use. Low security switch locks, which is the older Adlake and Keline versions, are common, while many roads are switching to High Security locks.