With many new buildings in major shipyards now under IMO PSPC Ballast Tank rules, part of the standard calls for only power tooling to St 3.0 for the remaining erection joints. Though under the rule, the shipyard is permitted for this kind of treatment considering that the damages in a particular tank do not exceed maximum 2% when compared to the whole area.
Power tooling to St 3.0 for the remaining erection joints considering that the damages in a particular tank do not exceed maximum 2% when compared to the whole area. New building construction stage is very important when it comes to quality and its impact when the ship finally goes into service. Hence, careful review of the standard is a must during construction period.
As we have seen at in-service ships, most corrosions are likely to occur many times on the erection joints and welding seams. So a viable way to avoid this condition would be to have a delicate balance during new building stage of the vessel between power tooling and keeping the anchor profile on the erection joints. Though for some really good shipyards, they have used a particularly handy nozzle and blasting equipment to treat the erection joints.