Ballast Tank Refurbishment

The container ship had a requirement for a ballast tank upgrade for over 30,000m². Chemco’s technical manager carried out a pre-dock survey whilst the vessel was at quayside in Gran Canaria. The owners made the decision to utilise Chemco solvent-free systems for the vessel’s imminent dry-docking in Turkey.

Further to discussions with the owners and dockyard personnel, the decision was made to utilise fresh water pressure jet washing @ 800bar to a required WJ3 preparation standard. This method was adopted instead of dry grit blasting in order that as much work as possible could be carried out at the quayside and thus reducing the dry-docking time as well as major cost reduction by eliminating the dry grit-blasting in compliance with IMO and Lloyds’ approval.

High pressure jet wash (800bar) to remove loose rust, loose paint and any contaminants back to a solid substrate prior to application of the coating. The minimum standard of WJ-3/4 was achieved. A primer coat and stripe coat was carried out with Epo-chem™ RS 500P solvent-free, wet & rust tolerant coating @ 100µ DFT followed by the topcoat of Epo-chem™ RA 500M solvent-free wet tolerant coating @ 250µ DFT.

The work programme was successfully supervised by Chemco technical staff and considering it was the first jet washing exercise for the dockyard, all the ballast tanks were completed to class standard and certificated accordingly to the satisfaction of all concerned.

This docking highlighted the flexibility and modern technology of the Chemco solvent-free systems. Utilising low levels of equipment, the jet washing and coating could also be undertaken whilst the vessel was afloat and awaiting dry-dock space, either at anchor or at quayside. This is possible as there are NO restrictions on humidity or dew point with the Chemco systems as well as unlimited over-coating duration. The significant advantage was that 80% of the work was carried out in water (at quayside) before the dry docking was arranged. The obvious advantages to ship owners, ship managers and dry-docks are enormous in organisation of work programmes with no massive loss of downtimes and reduced cost return-to-service quickly.