ISSUE 1 emphasized important viewpoints on preparing tanker ships for green recycling
Expert Insights: Preparing Tanker Ships for Green Recycling & Safety Measures

ISSUE 2 focused on Purging and Gas Freeing Operation for Man Entry
Expert Insights: Purging and Gas Freeing Operation for Man Entry

ISSUE 3
Expert Insights: Man Entry and De-mucking Process

ISSUE 4

GMS Trader Kiran Thorat highlights – Gas Free for Hot Work Certificate

Upon completing the de-mucking process, all collected solid sludge residues are offloaded to the shore reception facility. As part of standard procedure, the tank top is thoroughly mopped to ensure it is cleaned to the required standard.

After confirming that all cargo and slop tanks have been fully cleaned, it is imperative to obtain a Gas Free for Hot Work (GFHW) Certificate from a qualified authority.

Certified Marine Chemist:

A local Certified Marine Chemist (CMC) is authorized to issue the GFHW certificate under specific conditions. The chemist conducts a comprehensive inspection of the vessel, including cargo tanks, slop tanks, and the pump room. This process involves measuring the tank atmosphere for hydrocarbon vapor levels and oxygen content. Additionally, the chemist checks for the presence of toxic gases to ensure compliance with safety standards.

The CMC is also responsible for inspecting piping systems, pumps, void spaces, and adjacent areas to ensure the absence of flammable atmospheres in these spaces. Once satisfied with the conditions of the tanks and associated systems, the CMC issues a certificate specifying the status of the tanks, such as ‘Safe for Man Entry’ or ‘Safe for Hot Work’.

If the tank conditions are deemed unsatisfactory, the CMC will issue a certificate indicating ‘Not Safe for Man Entry’ or ‘Not Safe for Hot Work’. In such cases, a thorough assessment must be conducted to identify the underlying issues. If necessary, additional tank washing and manual de-mucking should be performed. Once the corrective actions are completed, the CMC will re-inspect the tanks before issuing a Safe for Hot Work certificate.

If a CMC is unavailable, the GFHW certificate can be issued by a qualified representative from the port authority.

Gas Free for Hot Work Certificate:

The GFHW certificate contains the following information:

• Vessel Name and IMO Number

• Certificate Number

• Location of vessel: Anchorage / Berth / Name of Port

• Issue Date & Time, Expiry Date & Time

• Tank location and identification – Cargo Tanks, Slop Tanks, Pump Room, Cofferdams Void Spaces & Engine Room

• Tank atmosphere readings – Oxygen, Carbon Monoxide, Hydrogen Sulfide, and Lower Flammable Limit (LFL)

• Safety rules and conditions for certificate validity

• Comments by CMC

The certificate is signed by Marine Chemist, Master/Chief Officer and Supervisor/Foreman.

Validity of GFHW Certificate:

The GFHW certificate outlines specific safety rules and conditions that must be followed to maintain its validity, including:

• Effective mechanical ventilation to be continued throughout the validity of the certificate.

• Continuous Fire Watch must be maintained at each Hot Work Site including at underside / opposite sides of the location by trained personnel.

• Ensure that each Hot Work site is equipped with properly pressurized fire hoses and an adequate number of fire extinguishers. The pressure of the fire hoses should be regularly monitored.

• Rescue Equipment and Approved Breathing Apparatus to be kept ready in the vicinity for immediate use.

• No changes to be made to the status of pipelines, valves, vents, and heating coils etc.

• No changes may be made to the status of ballast or bunker transfer operations, or any other conditions that were in place at the time the certificate was issued.

• Hot work should be prohibited during cargo transfer, Gas Freeing, Purging, Inerting, De-slopping, bunkering operations, and ballast tank cleaning.

• The work area must always be maintained in a clean state, free from combustible materials.

• All guidelines mentioned in the International Safety Guide for Oil Tankers & Terminals (ISGOTT) must be adhered to.

Non-compliance with the safety rules and conditions will render the certificate void.

A copy of the GFHW certificate is maintained in the CCR and displayed in the designated area where hot work is planned. Any man entry into tanks with a GFHW certificate must be supplemented by an Enclosed Space Entry Permit.

Additionally, the port authorities or coast guard may have specific requirements for GFHW (Gas Free Hot Work) certification, which must be fully complied with.

For more information or clarification, please write to bd@gmsinc.net