gibson's cut was bought for £840, but in order to entend it to join the main line at tattershall, part of the terminal warehouse had to be demolished, as it obstructed the line of the extension. sir joseph expected jessop to oversee the work, but he was too busy and suggested william cawley from cheshire as engineer. cawley was engaged in april 1793, and work started immediately, but workmanship was poor. the lock at tattershall collapsed when first filled with water, and cawley was dismissed in october, to be followed by a series of other engineers, none of whom lasted for very long. pressure was put on the builders of the locks at tattershall and tumby and the bridge at butts road in coningsby, and they agreed to rebuild them, rather than lose contracts for other parts of the canal.