Tank Cleaning


OTM-7.17	Oil Tanker Manual OTM Tank Cleaning	Doc No.: OTM 7.17 Revision: 01 Date: 15 Oct 2024 Issued by: DPA Approved by: MD

This document applies to Oil Tanker vessels managed by Company.

To specify standard requirements for Tank cleaning on oil tankers.

Master:
- Review & approve each tank cleaning plan prepared by chief officer.
- Send at least one tank cleaning plan per month for office review, when applicable.
Chief officer:
- Prepare tank cleaning plan, supervise the operation and ensure compliance with MARPOL requirement.
- Prepare tanks for loading next cargo
Deck officers: Responsible officers to assist chief officer
Watch Keepers: Assist as required

Carry out tank cleaning only when necessary to prevent:
- Bunker consumption
- Impact on environment
- Water in tanks, which may cause cargo contamination
Use fixed or portable machines or both
Cleaning standards as required by charterers
Use Inert gas, when fitted and ensure following:
- Oxygen <8% by volume at all times
- Monitor oxygen level at regular intervals
When washing with hot water ensure:
- Temperature not higher than permitted
- Consult coating manufacturers, if required
Ensure following when third party contractors engaged for cleaning:
- Carry out safety briefing prior start of work
- Include information regarding hazards of cargo, stowage plan, emergency procedures etc. in safety briefing
- Escorted & supervised by ship’s crew
- Final responsibility remains with ship staff

• Prepare tank cleaning plan using “TNK-11 - Tank Cleaning Plan”

Use following reference for preparing tank cleaning plans:

Coution:

To avoid contamination of sensitive cargoes where tank cleaning operations involve change of grade or tank mopping prior loading next cargo and where physical/visual inspection of cargo tanks is required/requested.
All cargo line drains / valves, all manifolds drains / valves, venting system drains/valves and cargo pump filter/separator valves (as applicable) shall be left open until cargo surveyor have completed the tank inspection & have certified the tanks to suitable for loading next nominated cargo.
Prior loading operation, the line-up & securing of drains / valves must be verified by two (2) separate officers & shall be duly recorded in Port log book.

Note:

Tank washing is carried out under two conditions:

For inert condition washing verify following at regular intervals:

Note:

Refer to OTM-7.15 - Tank washing atmospheres for washing under:

Note:

Coution:

Refer to OTM 7.16 Appendix 2