ASTM F2533-20

Standard Guide for In-Situ Burning of Oil in Ships or Other Vessels

SIGNIFICANCE AND USE
4.1 This guide is primarily intended to aid decision-makers and spill-responders in contingency planning, spill response, and training.  
4.2 This guide is general and site conditions can change the situation considerably.
SCOPE
1.1 This guide covers the use of in-situ burning directly in derelict ships and other vessels, particularly in remote and inaccessible areas. This guide is not applicable to in-situ burning of oil on sea or land.  
1.2 This guide is applicable to situations in which the vessel and cargo are not salvageable. After the burn, the vessel will never be salvageable. It is intended that the in-situ burning of oil spills in ships be a last resort option.  
1.3 The purpose of this guide is to provide information that will enable spill responders to decide if burning will be used to remove oil from stranded ships or other vessels.  
1.4 This is a general guide only. It is assumed that conditions at the spill site have been assessed and that these conditions are suitable for the burning of oil. It is also assumed that permissions to burn the oil have been obtained. Variations in the behavior of different oil types are not dealt with and may change some of the parameters noted in this guide.  
1.5 This guide is one of several related to in-situ burning.  
1.6 There are many safety concerns associated with in-situ burning of oil in ships. These include the unsafe nature of the wrecked vessel and the use of explosives.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2020
• ICS: 13.020.40 - Pollution, pollution control and conservation
• Technical Committee: F20 - Hazardous Substances and Oil Spill Response
• Drafting Committee: F20.15 - In-Situ Burning

Relations

• Replaces: ASTM F2533-07(2013) - Standard Guide for In-Situ Burning of Oil in Ships or Other Vessels
• Effective Date: 01-Apr-2020
• Refers: ASTM F1788-14 - Standard Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
• Effective Date: 01-Mar-2014
• Refers: ASTM F1990-07(2013) - Standard Guide for In-Situ Burning of Spilled Oil: Ignition Devices
• Effective Date: 01-Apr-2013
• Refers: ASTM F1788-08 - Standard Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
• Effective Date: 15-Sep-2008
• Refers: ASTM F1990-07 - Standard Guide for In-Situ Burning of Spilled Oil: Ignition Devices
• Effective Date: 01-Apr-2007
• Refers: ASTM F1990-99 - Standard Guide for In-Situ Burning of Spilled Oil: Ignition Devices
• Effective Date: 10-Oct-1999
• Refers: ASTM F1788-97 - Standard Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
• Effective Date: 10-May-1997
• Refers: ASTM F1788-97(2003) - Standard Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
• Effective Date: 10-May-1997
• Referred By: ASTM F1788-22 - Standard Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
• Effective Date: 01-Apr-2020
• Referred By: ASTM F2230-19 - Standard Guide for In-situ Burning of Oil Spills on Water: Ice Conditions
• Effective Date: 01-Apr-2020

Overview

ASTM F2533-20: Standard Guide for In-Situ Burning of Oil in Ships or Other Vessels provides guidance for decision-makers and spill responders regarding in-situ burning of oil specifically within ships or other vessels, especially in remote or inaccessible locations. This guide assists with contingency planning, spill response, and training for scenarios where oil spill recovery by conventional means is unfeasible and both vessel and cargo are deemed unsalvageable. Emphasizing situational assessment and regulatory compliance, the standard is part of a toolkit for oil spill response, outlining in-situ burning as a last-resort method.

Key Topics

• Scope and Applicability

  • Pertains exclusively to in-situ burning of oil on or in derelict or stranded vessels - not designed for burning oil on water or land.
  • Intended for non-salvageable vessels in scenarios where recovery is impractical.
  • Assumes site conditions have been assessed as suitable and all necessary permissions have been secured.

• Operational Considerations

  • Need for adequate site ventilation to ensure combustion and minimize coking.
  • Importance of controlling the burn and preventing fire spread to nearby combustibles.
  • Safety risks, including vessel instability, use of explosives, and potential for eruption or break-up.

• Environmental and Health Impact

  • In-situ burning can reduce the environmental hazard by eliminating oil before it is released.
  • Significant decrease in material requiring disposal post-burn.
  • Potential for air emissions and residue management issues.

• Technical Factors and Definitions

  • Burn rate, efficiency, coking, residue, and salvageability are critical considerations.
  • Role of oil type, ventilation percentage, wind speed, and ignition method in burn success.
  • Use of fire-resistant booms for secondary containment.

Applications

ASTM F2533-20 is used primarily by oil spill response professionals, maritime authorities, and emergency planners engaged in:

• Emergency Spill Response:
  Enables rapid oil removal from grounded or abandoned vessels when traditional recovery methods are unavailable, especially in remote areas.
• Contingency Planning:
  Provides a framework to determine whether in-situ burning is an acceptable and effective last resort.
• Training and Preparedness:
  Supports scenario-based training for responders, enhancing readiness for complex oil spill incidents involving vessels.
• Environmental Protection:
  Aims to limit the potential release of oil to marine environments by removing oil at the source.

Note: The guide emphasizes that burning is a highly destructive process, rendering the vessel unsalvageable, and requires careful planning, execution by qualified personnel, and adherence to all safety and environmental regulations.

Related Standards

To inform a comprehensive oil spill response, users should consult these ASTM standards:

• ASTM F1788 - Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
  Addresses considerations for burning oil directly on water surfaces.

• ASTM F1990 - Guide for In-Situ Burning of Spilled Oil: Ignition Devices
  Provides information about devices and methods for safely igniting spilled oil.

Other relevant standards may address complementary oil spill response techniques, equipment, and safety procedures.

---

For more detailed guidance, consult the full ASTM F2533-20 standard and related documents. Always ensure compliance with local regulations and best practices in oil spill response and environmental protection.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2533 − 20
Standard Guide for
In-Situ Burning of Oil in Ships or Other Vessels
This standard is issued under the fixed designation F2533; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This guide covers the use of in-situ burning directly in
F1788 Guide for In-Situ Burning of Oil Spills on Water:
derelict ships and other vessels, particularly in remote and
Environmental and Operational Considerations
inaccessible areas. This guide is not applicable to in-situ
F1990 Guide for In-Situ Burning of Spilled Oil: Ignition
burning of oil on sea or land.
Devices
1.2 This guide is applicable to situations in which the vessel
3. Terminology
and cargo are not salvageable. After the burn, the vessel will
never be salvageable. It is intended that the in-situ burning of
3.1 Definitions:
oil spills in ships be a last resort option.
3.1.1 burn rate, n—the rate at which oil is burned in a given
area.Typically the area is a pool and burn rate is the regression
1.3 The purpose of this guide is to provide information that
rate of the burning liquid, or may be described as a volumetric
will enable spill responders to decide if burning will be used to
rate.
remove oil from stranded ships or other vessels.
3.1.2 burn effıciency, n—the percentage of the oil removed
1.4 This is a general guide only. It is assumed that condi-
from the water by the burning. This is the amount (volume) of
tions at the spill site have been assessed and that these
oil before burning; less the volume remaining as a residue,
conditions are suitable for the burning of oil. It is also assumed
divided by the initial volume of the oil.
that permissions to burn the oil have been obtained. Variations
3.1.3 coking, n—the formation of coke, a hardened
in the behavior of different oil types are not dealt with and may
charcoal-like material. Coke is often formed when a hydrocar-
change some of the parameters noted in this guide.
bon such as oil is heated in the absence of sufficient oxygen to
1.5 This guide is one of several related to in-situ burning.
burn completely.
3.1.4 controlled burning, n—burning when the combustion
1.6 There are many safety concerns associated with in-situ
can be started and stopped by human intervention.
burning of oil in ships. These include the unsafe nature of the
wrecked vessel and the use of explosives.
3.1.5 derelict—a vessel abandoned by its owner with no
intention of returning.
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.1.6 eruption, n—sudden upwelling of boiling oil in a tank
due to specific area heating.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.1.7 fire-resistant booms, n—devices that float on water to
mine the applicability of regulatory limitations prior to use.
restrict the spreading and movement of oil slicks and con-
1.8 This international standard was developed in accor- structed to withstand the high temperatures and heat fluxes of
dance with internationally recognized principles on standard- in-situ burning.
ization established in the Decision on Principles for the
3.1.8 in-situ burning, n—use of burning directly on the
Development of International Standards, Guides and Recom-
water surface. In-situ burning does not include incineration
mendations issued by the World Trade Organization Technical
techniques, whereby oil or oiled debris are placed into an
Barriers to Trade (TBT) Committee.
incinerator.
3.1.9 in-situ burning in ships, n—use of burning on or in a
ship.
This guide is under the jurisdiction of ASTM Committee F20 on Hazardous
Substances and Oil Spill Response and is the direct responsibility of Subcommittee
F20.15 on In-Situ Burning. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2020. Published April 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approvedin2007.Lastpreviouseditionapprovedin2013asF2533–07(2013).DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F2533-20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2533 − 20
3.1.10 residue, n—the material, excluding airborne regulating factor in the burning of oil directly on ships and in
emissions, remaining after the oil stops burning. other confined spaces. The rate of burning is generally calcu-
lated based on the area of ventilation openings in the case of
3.1.11 salvageable, adj—a condition of the vessel such that
low wind situations. Studies have shown that top and side
it is economical and feasible to recover.
openings combined will yield better ventilation than top
3.1.12 seaworthy, adj—a condition of the vessel such that it
openings alone. The presence of two openings allows for air
is fit and safe for sea voyage.
circulationovertheareaoffire.Smallscalestudieshaveshown
3.1.13 stranded—a vessel left aground or ashore.
that a minimum of 10 % ventilation is needed to prevent
extensive coking. The 10 % refers to the area of ventilation
4. Significance and Use
compared to the surface area of oil available to burn. An area
4.1 This guide is primarily intended to aid decision-makers
of more than 20 % ventilation has been shown to result in little
and spill-responders in contingency planning, spill response,
coking during test burns.
and training.
6.3 External Wind Speed—External winds assist in provid-
4.2 This guide is general and site conditions can change the
ing additional ventilation, despite the semi-closed conditions
situation considerably.
that may exist. Burn efficiency increases and prevention of
coking will also be a positive result of higher wind conditions.
5. Background
One study showed a three-fold increase in burn rate with wind
5.1 Overview of Oil Burning—In-situ burning is one of
increase from 0 to 11 m/s.
several oil spill countermeasures available. The thickness of
6.4 Coking—Coking is the formation of a hard, carbona-
the oil is an important factor in the use of in-situ burning (see
ceous material during burning in a low oxygen environment.
Guide F1788). The burning of oil in ships is implemented to
Coking is more prevalent with heavy residual oils. If coking
remove oil from stranded or derelict ships to minimize the
occurs, the burn rate slows considerably as coke itself burns
release of oil.
poorly, if at all, and the coke would prevent the flame from
5.2 Major Advantages and Disadvantages of Burning in contacting oil under it. Coking is prevented by having suffi-
Ships
cient ventilation.
5.2.1 Advantages of In-Situ Burning Include:
6.5 Ability to Ignite—Aconsideration for in-ship burning is
5.2.1.1 May provide a net environmental benefit by quickly
the ability to ignite the oil. There are some oils which are
reducing the potential for oil release into the marine environ-
difficult to ignite and which may not sustain combustion (see
ment;
Guide F1990). Successful ignition will depend on the type of
5.2.1.2 In remote locations it may be the only feasible
oil, degree of ventilation, heat of ignition and length of time
solution;
that ignition must be applied. Heavier oils will require appli-
5.2.1.3 A significant reduction in the amount of material
cation of heat for at least several minutes. Ventilation is
requiring disposal;
required to sustain efficient combustion. The burning of the
5.2.1.4 A significant removal of volatile emission compo-
ignitor will deplete the oxygen in a given area if there is
nents;
insufficient ventilation. Heavy bunker fuels have been success-
5.2.1.5 Removal of oil from the ship.
fully ignited in ships’ holds using diesel fuel as a primer. A
5.2.2 Disadvantages of Burning in Ships Include:
layer of 2 mm of diesel fuel has been shown to be sufficient
5.2.2.1 The fire will weaken the ship hull and the ship could
during test burns.
break up, releasing oil or residue;
6.6 Eruption—During the burn process, some localized oil
5.2.2.2 Creation of a smoke plume;
may become super-heated.When the heating is sufficient, flash
5.2.2.3 Residues of the burn may be problematic;
evaporation of a component of this oil may occur and the
5.2.2.4 The ship may have to be prepared such as by the use
surrounding boiling oil can erupt upwards towards the top
of explosives to ensure that the oil is presented to the burn and
ventilation port. This could result in oil being splashed onto
that there is sufficient ventilation;
other parts of the vessel or sea. This phenomenon has been
5.2.2.5 Thefirecouldspreadtoothercombustiblematerials.
observed in test situations with crude oil.
6. Limitations to Burning in Ships
7. Operational Considerations for Burning in Ships
6.1 Access to Oil—The oil must be accessible to ignition
7.1 Safety Considerations—The safety of the proposed op-
and accessible to air. Explosives are used to allow oil to flow
eration will be the primary consideration.The vessel should be
from tanks to spaces where it will be burned and to increase
stable and relatively stationary during the preparation and burn
ventilation area. This should be conducted by salvage and
phases. The operation should only be contemplated if the
explosiveexperts.Typically,theplannedburnwouldtakeplace
operation will not result in flashback to other sources of fuel.
in the ship’s hold(s) and explosives would be used to open
The fire should be prevented from spreading to other combus-
passagefromlubricationandfueltankstothehold.Lubrication
tible material in the area, including trees, docks, and buildings.
and fuel tanks generally do not have sufficient exposure to the
Situation-specific contingency methods of extinguishing or
air to allow for burning.
protectionshouldbeavailable.Further,escapingoilcouldpose
6.2 Ventilation—Oxygen from air is necessary for burning. a risk. The possibility that burning oil may erupt should be
Studies have shown the area of ventilation is a critical considered.
F2533 − 20
2 2
7.2 EffectsontheShip’sStructure—Preparationofthevessel L/m /day (or 25 gal/ft /day). Burn rate is relatively indepen-
for burning by using explosives and subsequent burning of the dent of physical conditions except for ventilation and high
oil will weaken the ship’s structure. Burning in ships should be winds. In the case of high winds, the burn rate is independent
considered only if there is no potential for future salvage of the of ventilation opening if it is greater than 10 %. With less
vessel or if the trade-off between future salvage potential and ventilation, the rate will be less. Using these values, it is
removing the oil is favorable. The use of explosives and possible to calculate the rate of burning in the ship spaces. The
burning may weaken the structure sufficiently to result in area that is used for the calculation is the area of ventilation
breakup of the vessel. A breakup may result in the release of opening, not the area of the oil surface.
oil. Salvage experts and experts on ship design should be
7.8 Ignition—Oils can be ignited with a variety of devices
consulted before proceeding with the preparation for ignition
which are described in Guide F1990. Enough heat must be
and burn. They should also be consulted after the burn
supplied for a sufficient length of time. Heavy fuel oils
regarding options to deal with the remaining vessel.The vessel
generally require a longer heating time to ignite. Ignition may
may not be seaworthy, towable or even in condition to allow
also occur as a result of the explosives used to prepare the ship
ship-breaking in place.
for burning.
7.3 Oil Thickness—Most oils can be ignited on a water
7.9 Back-up Containment—The operation may release oil
surface if they are a minimum of 2 to 3 mm thick. This is
into the water or shore on which the hull is located. In some
generally not a concern in ships as sufficient oil may be
locations, a fire-resistant boom may be deployed around the
available.
vessel to contain any releases and to protect other combustible
7.4 Oil Type and Condition—Highly weathered oils will materials from the burning oil (see Guide F1788). If oil is
burn, but will require sustained heat during ignition. Oil that is released from the hull, it may be ignited.
emulsified with water may not burn. Guidance on ignition is
7.10 Residue—The residue from efficient burns is a highly
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2533 − 07 (Reapproved 2013) F2533 − 20
Standard Guide for
In-Situ Burning of Oil in Ships or Other Vessels
This standard is issued under the fixed designation F2533; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide covers the use of in-situ burning directly in derelict ships and other vessels. vessels, particularly in remote and
inaccessible areas. This guide is not applicable to in-situ burning of oil on sea or land.
1.2 This guide is applicable to situations in which the vessel and cargo are not salvageable. After the burn, the vessel will never
be salvageable. It is intended that the in-situ burning of oil spills in ships be a last resort option.
1.3 The purpose of this guide is to provide information that will enable spill responders to decide if burning will be used to
remove oil from stranded ships or other vessels.
1.4 This is a general guide only. It is assumed that conditions at the spill site have been assessed and that these conditions are
suitable for the burning of oil. It is also assumed that permissions to burn the oil have been obtained. Variations in the behavior
of different oil types are not dealt with and may change some of the parameters noted in this guide.
1.5 This guide is one of several related to in-situ burning.
1.6 There are many safety concerns associated with in-situ burning of oil in ships. These include the unsafe nature of the
wrecked vessel and the use of explosives.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
F1788 Guide for In-Situ Burning of Oil Spills on Water: Environmental and Operational Considerations
F1990 Guide for In-Situ Burning of Spilled Oil: Ignition Devices
3. Terminology
3.1 Definitions:
3.1.1 burn rate, n—the rate at which oil is burned in a given area. Typically the area is a pool and burn rate is the regression
rate of the burning liquid, or may be described as a volumetric rate.
3.1.2 burn effıciency, n—burn efficiency is the percentage of the oil removed from the water by the burning. This is the amount
(volume) of oil before burning; less the volume remaining as a residue, divided by the initial volume of the oil.
3.1.3 coking, n—coking is the formation of coke, a hardened charcoal-like material. Coke is often formed when a hydrocarbon
such as oil is heated in the absence of sufficient oxygen to burn completely.
3.1.4 contact probability, n—the probability that oil will be contacted by the flame during burning.
3.1.4 controlled burning, n—burning when the combustion can be started and stopped by human intervention.
This guide is under the jurisdiction of ASTM Committee F20 on Hazardous Substances and Oil Spill Response and is the direct responsibility of Subcommittee F20.15
on In-Situ Burning.
Current edition approved April 1, 2013April 1, 2020. Published July 2013April 2020. Originally approved in 2007. Last previous edition approved in 20072013 as
F2533F2533–07(2013).–07. DOI: 10.1520/F2533-07R13.10.1520/F2533-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2533 − 20
3.1.5 derelict—a vessel abandoned by its owner with no intention of returning.
3.1.6 eruption, n—sudden upwelling of boiling oil in a tank due to specific area heating.
3.1.7 fire-resistant booms, n—devices whichthat float on water to restrict the spreading and movement of oil slicks and
constructed to withstand the high temperatures and heat fluxes of in-situ burning.
3.1.8 in-situ burning, n—use of burning directly on the water surface. In-situ burning does not include incineration techniques,
whereby oil or oiled debris are placed into an incinerator.
3.1.9 in-situ burning in ships, n—use of burning on or in a ship.
3.1.10 residue, n—the material, excluding airborne emissions, remaining after the oil stops burning.
3.1.11 salvageable, adj—a condition of the vessel such that it is economical and feasible to recover, refurbish and return to
operation or to re-use portions of the vessel.recover.
3.1.12 seaworthy, adj—a condition of the vessel such that it is fit and safe for sea voyage.
3.1.13 stranded—a vessel left aground or ashore.
4. Significance and Use
4.1 This guide is primarily intended to aid decision-makers and spill-responders in contingency planning, spill response, and
training.
4.2 This guide is general and site conditions can change the situation considerably.
5. Background
5.1 Overview of Oil Burning—In-situ burning is one of several oil spill countermeasures available. The thickness of the oil is
an important factor in the use of in-situ burning (see Guide F1788). The burning of oil in ships is implemented to remove oil from
stranded or derelict ships to minimize the release of oil.
5.2 Major Advantages and Disadvantages of Burning in Ships
5.2.1 Advantages of In-Situ Burning Include:
5.2.1.1 May provide a net environmental benefit by quickly reducing the potential for oil release into the marine environment;
5.2.1.2 In remote locations it may be the only feasible solution;
5.2.1.3 A significant reduction in the amount of material requiring disposal;
5.2.1.4 A significant removal of volatile emission components;
5.2.1.5 Removal of oil from the ship.
5.2.2 Disadvantages of Burning in Ships Include:
5.2.2.1 The fire will weaken the ship hull and the ship could break up, releasing oil or residue;
5.2.2.2 Creation of a smoke plume;
5.2.2.3 Residues of the burn may be problematic;
5.2.2.4 The ship may have to be prepared such as by the use of explosives to ensure that the oil is presented to the burn and
that there is sufficient ventilation;
5.2.2.5 The fire could spread to other combustible materials.
6. Limitations to Burning in Ships
6.1 Access to Oil—The oil must be accessible to ignition and accessible to air. Explosives are used to allow oil to flow from
tanks to spaces where it will be burned and to increase ventilation area. This should be conducted by salvage and explosive experts.
Typically, the planned burn would take place in the ship’s hold(s) and explosives would be used to open passage from lubrication
and fuel tanks to the hold. Lubrication and fuel tanks generally do not have sufficient exposure to the air to allow for burning.
6.2 Ventilation—Oxygen from air is necessary for burning. Studies have shown the area of ventilation is a critical regulating
factor in the burning of oil directly on ships and in other confined spaces. The rate of burning is generally calculated based on the
area of ventilation openings in the case of low wind situations. Studies have shown that top and side openings combined will yield
better ventilation than top openings alone. The presence of two openings allows for air circulation over the area of fire. Small scale
studies have shown that a minimum of 10 % ventilation is needed to prevent extensive coking. The 10 % refers to the area of
ventilation compared to the surface area of oil available to burn. An area of more than 20 % ventilation has been shown to result
in little coking during test burns.
6.3 External Wind Speed—External winds assist in providing additional ventilation, despite the semi-closed conditions that may
exist. Burn efficiency increases and prevention of coking will also be a positive result of higher wind conditions. One study showed
a three-fold increase in burn rate with wind increase from 0 to 11 m/s.
6.4 Coking—Coking is the formation of a hard, carbonaceous material during burning in a low oxygen environment. Coking
is more prevalent with heavy residual oils. If coking occurs, the burn rate slows considerably as coke itself burns poorly, if at all,
and the coke would prevent the flame from contacting oil under it. Coking is prevented by having sufficient ventilation.
F2533 − 20
6.5 Ability to Ignite—A consideration for in-ship burning is the ability to ignite the oil. There are some oils which are difficult
to ignite and which may not sustain combustion (see Guide F1990). Successful ignition will depend on the type of oil, degree of
ventilation, heat of ignition and length of time that ignition must be applied. Heavier oils will require application of heat for at
least several minutes. Ventilation is required to sustain efficient combustion. The burning of the ignitor will deplete the oxygen in
a given area if there is insufficient ventilation. Heavy bunker fuels have been successfully ignited in ships’ holds using diesel fuel
as a primer. A layer of 2 mm of diesel fuel has been shown to be sufficient during test burns.
6.6 Eruption—During the burn process, some localized oil may become super-heated. When the heating is sufficient, flash
evaporation of a component of this oil may occur and the surrounding boiling oil can erupt upwards towards the top ventilation
port. This could result in oil being splashed onto other parts of the vessel or sea. This phenomenon has been observed in test
situations with crude oil.
7. Operational Considerations for Burning in Ships
7.1 Safety Considerations—The safety of the proposed operation will be the primary consideration. The vessel should be stable
and relatively stationary during the preparation and burn phases. The operation should only be contemplated if the operation will
not result in flashback to other sources of fuel. The fire should be prevented from spreading to other combustible material in the
area, including trees, docks, and buildings. Situation-specific contingency methods of extinguishing or protection should be
available. Further, escaping oil could pose a risk. The possibility that burning oil may erupt should be considered.
7.2 Effects on the Ship’s Structure—Preparation of the vessel for burning by using explosives and subsequent burning of the oil
will weaken the ship’s structure. Burning in ships should be considered only if there is no potential for future salvage of the vessel
or if the trade-off between future salvage potential and removing the oil is favorable. The use of explosives and burning may
weaken the structure sufficiently to result in breakup of the vessel. A breakup may result in the release of oil. Salvage experts and
experts on ship design should be consulted where possible, before proceeding with the preparation for ignition and burn. They
should also be consulted after the burn regarding options to deal with the remaining vessel. The vessel may not be seaworthy,
towable or even in condition to allow ship-breaking in place.
7.3 Oil Thickness—Most oils can be ignited on a water surface if they are a minimum of 2 to 3 mm thick. This is generally not
a concern in ships as sufficient oil may be available.
7.4 Oil Type and Condition—Highly weathered oils will burn, but will require sustained heat during ignition. Oil that is
emulsified with water may not burn. Guidance on ignition is given in Guide F1990.
7.5 Wind Conditions—Winds will assist in providing additional ventilation, despite the semi-closed conditions that may exist.
Increased burn efficiency and prevention of coking will also be a positive result of higher wind conditions. Wind direction should
be a concern and local authorities should be consulted about the possibility of smoke plumes (see Guide F1788). At high wind
conditions, the operation may be less safe for reasons including ship movement, getting personnel on decks, applying ignition
devices and secondary fires.
7.6 Burn Effıciency—Burn efficiency in a confined area such as a ship’s hold will vary and has been measured as high as 97 %
for crude oil, but typically may be only 60 %.
7.7 Burn Rate—Most lighter oils burn at the maximum rate of about 3.75 mm/min. This translates to a rate of about 5000
2 2
L/m /day (or 100 gal/ft /day). Testing on heavy oils shows that the burn rate may be lower, as low as 1 mm/min or about 1200
2 2
L/m /day (or 25 gal/ft /day). Burn rate is relatively independent of physical conditions except for ventilation and high winds. In
the case of high winds, the burn rate is independent of ventilation opening if it is greater than 10 %. With less ventilation, the rate
will be less. Using these values, it is possible to calculate the rate of burning in the ship spaces. The area that is used for the
calculation is the area of ventilation opening, not the area of the oil surface.
7.8 Ignition—Oils can be ignited with a variety of devices which are described in Guide F1990. Enough heat must
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