Two ship unloaders at Powergen’s Liverpool Bulk Terminal in the UK have been fitted with a range of components from ABB. The components are part of a system designed by computer process engineer J Merriman & Sons that will ensure the unloaders continue safe operation in the event of a cab travel drive failure.
The two unloaders are capable of lifting five million tonnes of coal a year from panamax ships arriving at the docks. Individually they can unload 1,500t an hour from ships normally holding 65,000t.
Powergen engineering controller Ken Jones explains the role of the bypass control system: ‘The cab travel control system is important since it controls the positioning of the operator’s cab as it travels backwards and forwards along the boom. This ensures that the operator is correctly placed to observe and operate the 30t grab as it moves within the ship’s hold. Should a drive fail during unloading then we are able to continue unabated by switching to the bypass control system, which maintains the smooth starting and stopping essential for the operator’s safety and security. This avoids potential demurrage costs and enables the drive to be repaired or changed after the ship has sailed.’
