Hot work is any work that involves sources of ignition or temperatures high enough to ignite a flammable gas or liquid or material. This includes but is not limited to:
- Welding (electric arc or gas)
- Cutting, burning, gouging (electric arc or gas)
- Heating (blow torch or heat gun)
- Soldering (electric or blow torch)
Use of following temporary/ portable equipment in a hazardous area should be classified as hot work:
- Power tools (electric or electric power tools)
- Non-intrinsically safe electronic equipment
- Internal combustion engines (driving air compressors, pumps, pressure washers, etc.)
Due to the inherent risk of this task, all possible alternative means of performing this task must be explored. Hot work must be chosen only if the other means are not feasible. If possible, the hot work shall be deferred to the dry docking of the vessel.
Hot work shall NOT be carried out when following operations are in progress:
- Loading / discharging operations.
- Gas freeing / purging of cargo tanks.
- Inerting of Cargo tanks.
- Tank Cleaning.
- Bunkering.
PRECAUTIONS
- All equipment intended for use should be inspected and tested before work commencing. Faulty equipment should be repaired or replaced and the work should not be commenced before all equipment are in a satisfactory condition.
- Personal Protective Equipment complying with the relevant standard specifications or their equivalent must be worn by the Operator performing the Hot Work and as appropriate by those assisting with the Operator to protect themselves.
- Adequate Fire Fighting Equipment must be laid out and ready for immediate use. Effective means of containing and extinguishing welding sparks and molten slag must be established.
- The site of hot work must be kept clean and clear of all dangerous & combustible material such as aerosols, rags, papers, flammable solvents, etc. Flammable solvents must not be present, even for use in cleaning tools.
- The work area must be adequately and continuously ventilated. Periodic gas measurements should be carried out while the hot work is in progress and before the resumption after a break.
- Immediately before hot work is undertaken the compartment where the work is to be executed should be:
- Ventilated until tests with a combustible gas indicator gives reading of not more than 1% LFL.
- All sludge, scale & sediment should be removed from an area of at least 10 metres around the area of hot work, including reverse side of frames, bulkheads, etc.
- Other areas that may be affected by hot work should also be cleaned, e.g. the area immediately below the place where the work is being undertaken.
- Hot work inside the main machinery space, when associated with tank or pipeline containing flammable liquid(Fuel, lube, etc), must:
- Take into account the possible presence of hydrocarbon vapours in the atmosphere and the existence of potential ignition sources.
- NO HOT WORK should be carried out on bulkheads, pipes and associated fittings of bunker tanks, or within 500mm of such bulkheads, unless the tank is cleaned to hot work standard (as per point 5 above).
- All pipelines to a tank being worked on should be:
- Isolated and adjacent tanks and spaces should be rendered safe by gas freeing, inerting or filling with water.
- An adjacent bunker tank containing fuel may be considered safe as long as tests on ullage space with a combustible gas indicator give a reading of not more than 1% LFL.
- Checks should be made to ensure that there is no ingress of flammable gases or liquids, toxic gas or inert gas from adjacent tanks or spaces by leakage.
- Hot work on pipelines and valves should only be permitted when:
- The appropriate section has been detached from the system by cold work and the open-ended sections of the remaining system have been sealed off.
- The section of pipe to be worked on should be gas free to a safe hot work standard.
- Heating coils should be flushed and opened to ensure that they are gas free.
- A written plan for undertaking the work should be completed, agreed and discussed by everybody. The plan should define the preparations needed before work starts, procedure to carry out the work, use of other associated permits such as Isolation Permit, Enclosed Space Permit, etc., and associated safety precautions. The plan should also identify the person authorizing the work and the personnel responsible for carrying out the specified tasks, including contractors. A designated Responsible Officer not directly involved in the hot work should ensure that the plan is followed.
RISK ASSESSMENT AND HOT WORK PERMIT
When Hot Work is to be carried out other than in the “designated area”, work can only commence after:
- A risk assessment has been carried out to fully appreciate the hazards arising out of the Hot Work and other simultaneous operations and appropriate mitigating measures have been put in place.
- Some Company’s will require written permission and should be obtained for hot work.
- A “Hot Work Permit has been issued duly signed by the Chief Officer / Second Engineer, Safety officer and countersigned by the Master.
- Vessel should notify office on Positive start of hot work and upon completion.
The period of validity for such permission will be 8-12 hours provided all the conditions mentioned in the Hot Work Permit remain unchanged, during the entire period.
If for any reason, conditions which form the basis for issuing Hot Work permit change during the work, e.g. unplanned opening of valves etc, or if the hot work is re-scheduled, the Permit stands cancelled, hot work should cease, and not be restarted until all safety precautions have been re-checked and a new Hot Work Permit has been issued.
After the hot work permit has been issued and while the work is in progress, the responsible officer, shall remain in the immediate area to maintain control until work has been completed.
The responsible officer is usually the Chief Officer on deck & the 2nd Engineer in the Engine Room. However, if required, another officer nominated by the Master may take this responsibility.
Irrespective of the area of hot work, Fire watch procedures must be established for the area of hot work and adjacent areas must be regularly checked.
The Operator performing the hot work should be competent in the process, familiar with the equipment to be used and instructed where special precautions need to be taken. Fire watchman should be in attendance in the compartment while any hot work is in progress. Fire watchman is to be fully familiarised with the dangers involved and the mitigation measures, for the hot work being carried out.
HOT WORK ON BOARD TANKERS
Masters shall also be guided by the following additional requirements for carrying out hot work on tank vessels:
1. On Oil Tankers – Refer to concerned section in the ISGOTT for other details and precautions to be taken.
2. On Chemical Tankers – Refer concerned section in the ISGOTT and ICS Tanker Safety Guide (Chemicals) for other details and precautions to be taken.
3. On Liquefied Gas Tankers – Refer concerned section in the ISGOTT and ICS Tanker Safety Guide (Liquefied Gas) for other details and precautions to be taken.
a. No hot work should be undertaken on the open deck of Liquefied Gas Tankers, unless the area is free from flammable vapour and all compartments, including deck tanks, within radius of at least 30 metres around the working area have been:
i. washed and freed of flammable vapour and/ or
ii. inerted.
b. On Gas tankers of smaller length, even the gas safe area/ poop deck could come within the 30 meter radius of aft cargo tanks due to which the hot work may not be feasible in poop decks.
HOT WORK ON THE CARGO DECK AREA
Hazardous area on tanker’s deck effectively means an area slightly larger than tank deck, which includes cargo tanks and pump rooms, and the atmospheric space around and above them.
Hot work in hazardous area should only be carried out when ship is in ballast.
a) In cargo tanks:
Work area to be cleaned, all sludge, cargo-impregnated scale, sediment or other material likely to give off flammable vapour should be removed. The extent of the cleaned area should be established following a risk assessment of the particular work to be carried out.
Below table provides guidance on the minimum safe distance (radius) for areas to be cleaned in preparation for hot work in tanks:
| Height of Work area | Operator’s side | Opposite side | ||||
| Gas Cut | Welding | Gouging | Gas Cut | Welding | Gouging | |
| 0 – 5 metres | 1.5 m | 5.0 m | 5.0 m | 7.5 m | 2.0 m | 2.0 m |
| 5 -10 metres | 1.5 m | 5.0 m | 5.0 m | 10.0 m | 2.0 m | 2.0 m |
| 10 – 15 metres | 1.5 m | 5.0 m | 7.5 m | 15.0 m | 2.0 m | 2.0 m |
| >15 metres | 1.5 m | 5.0 m | 10.0 m | 20.0 m | 2.0 m | 2.0 m |
All interconnecting pipelines to other compartments should be flushed through with water, drained, vented, and isolated from the compartment where Hot Work will take place.
Heating coils should be flushed or blown through with steam and proved clear of hydrocarbons.
The vapour space of adjacent bunker tank should be tested to ensure a reading of less than 1% LFL and it is to be ensured that no heat transfer through the bulkhead of the bunker tank will be caused by the Hot Work.
Inerted Ships:
1. The compartment in which the Hot Work is to be carried out should be cleaned, gas freed to Hot Work standard and be continuously ventilated.
2. Adjacent cargo tanks, including diagonally positioned cargo tanks, should either be:
- Cleaned and gas freed, with hydrocarbon vapour content reduced to not more than 1% LFL and maintained at that level; OR
- Emptied, purged and the hydrocarbon vapour content reduced to less than 2% by volume and inerted; OR
- Completely filled with water.
3. When Hot Work is to be carried out on the cargo tank bulkhead or within 500 mm of cargo tank bulkhead, then the space on the other side should also be cleaned to Hot Work standard
4. All other cargo tanks should be inerted and their deck openings closed.
5. All slops should be securely isolated and kept in a non-adjacent tank at least 30 meters from the Hot Work location.
6. Cargo piping and Inert gas lines to the compartment should be purged with inert gas to not more than 2% hydrocarbon by volume and isolated.
7. Inert gas pressure should be reduced for the duration of the hot work to prevent incontrolled venting.
8. Non-adjacent slop tanks should kept closed, securely isolated from the Inert Gas main line and isolated from the piping system for the duration of hot work.
Non-inerted Ships:
1. The compartment in which the Hot Work is to be carried out should be cleaned, gas freed to Hot Work and be continuously ventilated.
2. Adjacent cargo tanks and diagonally positioned cargo tanks, should either have been cleaned and gas freed to Hot Work standard or completely filled with water.
3. All slops should be either removed from the ship or securely isolated in a closed, non-adjacent tank at least 30 meters away from the Hot Work location. For this purpose, tanks located diagonally should be regarded as adjacent tanks. A non-inerted slop tank should be kept closed, securely isolated from the vent main and isolated from the piping system for the duration of hot work.
4. Vapour or vent lines to the compartment should also be ventilated to not more than 1% LFL and isolated.
5. The possibility of using an external source of Inert Gas should be considered.
b) On tank deck and up to a height of 500 mm above the tank deck:
It is classed as hot work within that tank and appropriate safety measures as mentioned above for cargo tanks are to be complied with.
c) On tank deck at a height of more than 500 mm above the tank deck:
1. Hot work on the tank deck higher than 500mm shall be undertaken only if cargo and slop tanks within a radius of at least 30 meters around and working area shall either be:
- Cleaned and gas freed to hot work standards; OR
- Emptied, purged and HC vapour content reduced to < 2% by volume and inerted; OR
- The cargo tanks shall be completely filled with water.
2. All other cargo tanks must be inerted with openings closed.
3. All slops should be either removed from the ship or isolated in a non-adjacent tank at least 30 meters away from the Hot Work location.
d) Non-Inerted Ships: Hot work on tank deck at a height of more than 500 mm above the tank deck:
1. All cargo tanks within 30m of the hot work location, including those positioned diagonally, should be either cleaned and gas freed to hot work standard or completely filled with water.
2. All slops should be either removed from the ship or securely isolated in the furthest tank at least 30 meters away from the Hot Work location. The vapour or vent lines to the compartment should be ventilated to not more than 1% LFL and then isolated.
3. The possibility of using an external source of IG should be considered.
Hot Work Permit
M.T. _______________________ Reference number : __________
This permit to work relates to any work involving temperature conditions which are likely to be of sufficient intensity to cause ignition of combustible gases, vapour or liquids in or adjacent to the area involved. Before completing this form, refer to the accompanying guidance notes, and to I.S.G.O.T.T.
- GENERAL
This section to be completed by the Master
This permit is valid from ………………………………hrs Date ………………………………………..
to ……………………….hrs Date ……………………………….
Location of hot work …………………………………………………………………………………………………………..
………………………………………………………………………………………………………….………………………………
Has an enclosed space entry permit been issued ? (Reference Nr. …………..) Yes / No
Reason if `No’ …………………………………………………………………………………………………………………
Description of hot work …………………………………………………………………………………………………….
……………………………………………………………………………………………………………………………………….
Responsible Officer …….……………………………………………………………………………………………..
Hot work team leader : …………………………………………………………………………………….
- SECTION 1
This section to be completed jointly by Responsible Officer and by Hot work team leader
1.1 Has the hot work area been checked with a combustible gas indicator for
hydrocarbon vapours ? YES; NO Time …………………….
1.2 Has the surrounding area been made safe ? YES; NO Time …………………….
Date / Time _____________________ Responsible Officer Signature : _________________________
Hot Work Team Leader Signature : _________________________
- SECTION 2
This section to be completed by the Master
2.1 Has the work area been checked with combustible gas indicator for hydrocarbon
vapours ? YES; NO Time …………………….
- Has the equipment or pipeline been gas freed ? YES; NO Time …………………….
- Has the equipment or pipeline been blanked ? YES; NO Time …………………….
- Is the equipment or pipeline free of liquid ? YES; NO Time …………………….
- Is the equipment isolated electrically ? YES; NO Time …………………….
- Is the surrounding area safe ? YES; NO Time …………………….
- Is additional fire protection available ? YES; NO Time …………………….
- Special condition / precaution ……………………………………………………………….…
…………………………………………………………………………………………………..
- SECTION 3
Authorization
In the circumstances noted it is considered safe to proceed with hot work.
Date / Time ________________________ Master Signature : _______________________________
- SECTION 4
The work has been completed and all persons under my supervision, materials and equipment have been withdrawn.
Date / Time ________________________ Responsible Officer Signature : _____________________
Master’s Signature : ______________________________
GUIDANCE NOTE FOR HOT WORK PERMIT
GENERAL
- Starting / finishing time must not exceed the Authorized Signatories’ / Responsible Officer’s working hours.
- Specific location of hot work should be given.
- Description of hot work to include type of equipment to be used.
SECTION 1:
Applies to all hazardous work not involving naked flame or continuous spark production, and would include use of electrical equipment, use of air driven rotary equipment, sand or grit blasting, hammering and mechanical chipping and movement of equipment or materials over or near to machinery that is operating.
SECTION 2:
Applies to all hot work involving high temperature, open flame, electric arc or continuous source of sparks etc. this type of work includes but is not limited to welding, burning and grinding.
TEST FOR COMBUSTIBLE GAS SHOULD BE CARRIED OUT IMMEDIATELY BEFORE COMMENCEMENT OF HOT WORK AND AT FREQUENT INTERVALS AS LONG AS THE WORK IS IN PROGRESS.