One of my former employers, a regional LTL Trucking Co., used Abloy locks for trailer security. These beasts were literally bullet - proof, to the extend that the thieves who stole 2 trailers full of Levi's torched around the door latches, rather than try to force open the locks.
I also recall Santa Fe changing switch locks on the Los Angeles Division, in the late 1980's. A very late running SW Chief took the siding @ Kaiser on, on the 2nd District, to clear the Desert Wind, but had to back out of the siding when they found the West siding lock had been replaced & no one aboard had the new key.