I wrote one about my Grandfather who was a foreman coremaker. Legend has it he cast parts for the Sydney Harbour bridge, and when I looked around it finally found a series of blocks between the forged hinge and the dressed stone that sat above the bedrock. Each layer was bigger to spread the load that the bedrock could withstand.
The reason his foundary cast the blocks is because they specialised in bridge work and they cast quality blocks that didn't have voids or fissures.
The song is Push on the Shovel (look for the title) but it doesn't say much about foundary work per se.