Train carriages used to go ca-chunk-ca-chunk, ca-chunk-ca-chunk, ca-chunk-ca-chunk. Each carriage has two bogies and each bogie has two pairs of wheels on axels

Train carriages used to go ca-chunk-ca-chunk, ca-chunk-ca-chunk, ca-chunk-ca-chunk. Each carriage has two bogies and each bogie has two pairs of wheels on axels; the first ca-chunk pair was the forward bogie, the second the rearward bogie. It was as recent as the 1980s in Ireland, I remember the sound when travelling by train as a kid.