Typical Bell transformer with a difference. This is got a very large output. Capable of driving quite a large amount of bells . As it’s got a low voltage output chances are the bells would not of been a long distance away from the transformer. Probably controlled through a relay in conjunction with a contact maker . One other use I have seen in the past for the lower output version is a warning bell on waste treatment Systems
Interesting point as it’s a high output ,it has 3 Slydlok fuses for protection and not the usual cartridge fuses . Andy