The loading of pig iron was labour intensive and quite primitive. No magnets were permitted for fear of interference with ships’ compasses, so each “pig” was individually handled by dockside labour.
The information can be found in “British Tramp Shipping 1750-1914” by Robin Craig who grew up in Millom close to the pier.
International Maritime History Association,
St John’s, Newfoundland 2003. ISBN 0-9730073-4-6