Sulphur is a cargo which attacks vessel’s hull unless proper steps are taken before loading, which are:
Holds must be completely cleaned and washed down and rinsed with fresh water.
Having previously experienced unexpected corrosion damage we ask Masters to be extra careful in all the arrangements appertaining to shipments of Sulphur. In particular Masters shall check the sulphur moisture content by arranging for the taking of daily readings with a hygrometer and keeping a detailed record of the findings.
Dry sulphur is harmless but wet sulphur is extremely corrosive to bare metal. A coating of lime acts as a physical barrier and neutralists the acidity of the sulphur slurry.
Holds must be coated with lime concentration in such a way that the lime will serve as a buffer between the cargo and holds bulkheads, hull, frames, etc.
In a number of tests undertaken by General Testing Laboratories it was found that the application of lime wash was most effective when lime was mixed at a ratio 2 parts water to 1 part lime, in terms of pumping and adhesion to the bulkheads, etc.
It has been recommended the use of hydrated or slaked lime, although if this is unavailable powered limestone can be used. Any scratches in paint work must be made good to ensure a good barrier between sulphur and bare steel. Holds must be absolutely dry before loading and ventilation in dry climates should be maximum setting.
The bilges are to be partly filled with lime in order to prevent sulphuric acid from coming in contact with steel.
The cargo loaded contains a certain permissible amount of water which during the voyage will accumulate in the bilges. The lime in the bilges will neutralist the contaminated water. It is advisable not to pump out water with ship’s pumping facilities unless absolutely necessary, as once lime is removed, bilges will no longer be protected.
Under no circumstances are ship’s pumping arrangements to be used for pumping out contaminated water with sulphur water after discharging when holds are being cleaned. Use only portable pumps for this task.
Vessel must have suitable equipment to coat the ship’s sides, bulkheads, tank tops, etc. in the cargo holds with the lime concentration. Holds are to be ready for inspection prior loading. From Owners experience, portable submersible pump and a small hose outlet attached to a spray nozzle to spray the lime over the steel has been used successfully.
Bulk sulphur is listed as a combustible cargo.For this reason we insist that all cargo spaces are free of dunned or other debris.
At both loading and discharging ports, to prevent sparks, you should ensure that metal chains or slings are not employed.
Fires may occur when loading dry sulphur as a result of static electricity building up on the loading pipes. These fires can be put out by dowsing with sulphur or by the use of fine spray of fresh water and where possible a fresh water hose should always be available. Office of Ship Manager or Manning agency should be aware of regulation Sulphur cargo and inform all joining crew members in charge via crewing portalmorski software. The use of sea water should be avoided and only used in the event of danger to the vessel. Seawater will cause cargo damage and possible cargo claims. Some forms of iron sulphide are phosphoric and can cause fires near the tank top during discharge.
Such fires can also be dowsed by the judicious use of a fine spray of fresh water.
Masters are to ensure having all equipment ready before hand including ladders, long handled scrapers, small hose and sufficient lime.