NOTICE TO VESSELS ARRIVING AT THE PORT OF VANCOUVER, CANADA TO LOAD BULK FORMED SULPHUR

1. INTRODUCTION

This notice is delivered to provide information and to assist the Master and the Vessel Owner in the safe delivery of uncontaminated cargo. It is issued to protect the interest of the sulfur supplier and Sultran, acting on behalf of the sulfur supplier, and is not to be regarded as a code or as a limitation of the vessel’s responsibilities for taking preventative measures for the protection of the cargo and the vessel.
 

2. VESSEL INSPECTION

As a service to the sulfur supplier and/or customers, marine surveyors have been appointed to inspect vessels arriving at Vancouver to load sulfur. Upon completion of the inspection an inspection certificate will be issued and will be made available to the Master and to the vessel agent through Sultran either approving the vessel for loading or rejection it, and detailing the reasons for rejection. Neither approval of the surveyors nor actual loading of the vessel shall relieve the ship owners of the obligation for ensuring that the vessel is fit, and remains fit, for the carriage of sulfur, nor from the further responsibility for taking appropriate steps to protect the vessel from any effects of interaction with the sulfur cargo.
 

3. CLEANLINESS AND CARGO PURITY

Sulfur shipped from the Port of Vancouver is generally described as “Canadian bright yellow formed sulfur”. The sulfur suppliers warrant strict purity specifications to their customers and so are concerned at the risk of contamination. Loose rust/scale and residues of previous cargoes easily contaminate this product. To facilitate the issuance of an inspection certificate, vessel owners should be aware of the following:

·       All receiving holds are to be in a “grain clean” condition.

·       All residues of previous cargoes are to be completely removed. This includes residue  from the underside of hatch covers.

·       All loose rust and scale are to be removed from all metal surfaces in the holds,  including  the underside of hatch covers.

·       All receiving holds are to be washed down with fresh water.

4. POSSIBLE HAZARDS

(a) CORROSION

Sulfur, water and steel in the holds of vessels that have not been properly prepared for the receipt and carriage of a sulfur cargo may form a corrosive system, which can lead to contamination of the cargo and damage to the vessel. Sulfur shipped from Vancouver is normally stored in uncovered stockpiles exposed to all weather conditions, resulting in moisture content. It is also sometimes sprayed with fresh water prior to loading, if required, and is loaded wet. If a corrosion product occurs, it can contaminate the cargo. Higher temperatures can increase such corrosion and prolonged residence of the cargo in the hold due to unscheduled delays in carriage or in discharge.

i) Preventing Corrosion

The Code of Safe Practice for Solid Bulk Cargoes as amended April 1988 and adopted by the Maritime Safety Committee of IMO (London) (‘the Code”) states, in part ”9.3.1.10 Materials which present corrosive hazards of such intensity as to affect either human tissue or the ship’s structure should only be loaded after adequate precautions and protecting measures have been taken.”

 Vessel owners should, therefore, be aware of the following … The reaction between sulfur, water and steel can be substantially reduced by a physical barrier between the cargo and the vessel. Paint and lime wash have been used for this purpose in the past. Experts have recommended that a mixture of approximately 60 kilograms of lime to 200  litres of fresh, water should  be applied to all surfaces which may come to contact with  sulfur. Lime wash contractors are available in the Port of Vancouver. If the Owners or Charterers of the vessel specify lime washing, the holds should be prepared as described in paragraph 3 prior to the lime wash.
 
Studies have been shown that the reaction between steel and sulfur can continue if sulfur residues remain in the hold after discharge. The Code referred to above further states…“9.31.1.12 After discharge of materials, a  close inspection should be made for any residue, which should then be removed  before the ship is presented for other cargo; such an inspection is particularly important  when materials having corrosive properties have been transported.”

ii) Chlorides

The presence of chloride salts such as sodium and potassium chlorides can hasten the interaction between moist elemental sulfur and ship’s steel. Sodium chloride, for example, is a major constituent of saltcake and of materials dissolved in seawater, and potassium chloride (potash) is regularly handled by bulk terminals in Vancouver. The  faster effect can be more important if the ship’s holds have not been properly prepared to  receive sulfur. As a normal precaution of preventative maintenance, it is strongly  recommended that all cargo compartments be thoroughly washed down with fresh water,  prior to final preparation for receiving sulfur. Additionally, ingress of seawater during  carriage must be avoided.

iii) Moisture Levels

Increased moisture content enhances the corrosive interaction between sulfur and steel. Sulfur is loaded wet. During carriage, however, drainage of some of this   moisture may occur. In order to minimize moisture content at tank top levels, bilge-pumping efficiency should be assured.

b) GAS EMISSIONS

i) Hydrogen Sulphide

There are circumstances during cargo carriage and after discharge in which bulk sulfur can emit small but measurable quantities of hydrogen sulfide gas. All areas in which sulfur is stored or used, or which require the presence of personnel, should be thoroughly ventilated.

ii) Sulfur Dioxide

Masters should also be aware of possible generation of sulfur dioxide due to burning when repairs involving heating are affected in compartments previously exposed to sulfur. Appropriate safety precautions should be taken.

5. FLAMMABILITY

A research report on the properties of formed sulfur was produced in 1989 by Alberta Sulfur Research Limited, a scientific research organization. The report focused on   whether Formed Sulfur was a flammable solid within the meaning of the regulations issued by IMO’s International Maritime Dangerous Good Code, Class 4.1 - Flammable solids, UN No. 1350 definition.
The result of tests included in the report led to the following declaration from the Canadian Coast Guard on August 7, 1989 that: “Based upon the results of the tests, as submitted, it is  agreed that formed sulfur does not meet the criteria for classification in  Class 4.1”.

6. MATERIAL SAFETY DATA SHEET

To provide further information regarding the properties and characteristics of the sulfur cargo a copy of a Material Safety Data Sheet and related technical information is  available on request.

7. RESPONSIBILITES

Sultran and the sulfur supplier hereby notify the Master of carrying vessels of the  above properties. They do not undertake any responsibility for defining, devising, or advising upon the measures necessary to protect the vessel or the cargo. It is the  responsibility of the Vessel Owners and the Masters to acquaint themselves with the characteristics of sulfur, the hazards that these might present to their vessels, and the appropriate methods of carriage as recommended by national and international authorities.