Accidental Formation of Flammable Gas from Chemical Waste on a Ship
During the shipments of incinerator bottom ash, flammable gasses including hydrogen generated and caused two explosions. The first explosion was in the forecastle store and the second in the cargo hold.The vessel was loaded with a cargo of 2333 tonnes of unprocessed incinerator bottom ash. The chief engineer, who was inside the forecastle store at the time, suffered second degree burns and was airlifted to a nearby hospital.
Event Date
January 13, 2017
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The investigation established that the explosions were caused by the ignition of hydrogen gas released from the cargo. Laboratory tests carried out during the investigation have established that hydrogen gas was the only flammable gas released by the load on board. The presence of 2.6% non-ferrous metals including aluminum, the alkalinity of the cargo, and an increased moisture content due to heavy rain during loading led to the generation of hydrogen.A sufficient quantity of hydrogen could have been released to form an explosive atmosphere. The ignition source for the hydrogen air mixture was most likely to have been electrical arcing between the contactors in the switch gear in the emergency free pump starter panel when the chief engineer stopped the pump.The investigation also found that the testing protocols in place for assessing if the waste was capable of producing flammable gases were inappropriate and inadequate.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Cargo ship, transportation of incinerator bottom ash
Storage/Process Medium
Location Type
Location description
Harbor and/or Ship
Operational Condition
Pre-event Summary
Prior to the accident, there had been 34 similar shipments of incinerator bottom ash. In all these cases no step had been taken to seek approval from the competent authorities for its carriage and its potential risks.
Property Loss (onsite)
No damages in any component, nor of the SOFC module nor of the BoP.
Lessons Learned
Lessons Learned
The investigation found that the testing protocols in place for assessing if the waste was capable of producing flammable gases were inappropriate and inadequate.It also found that no step had been taken to seek approval from the competent authorities for its carriage and its potential risks, despite it not being listed in the International Maritime Solid Bulk Cargoes (IMSBC) Code. CORRECTIVE ACTIONSFollowing the accident, the MAIB (UKs Marine Accident Investigation Branch) has published a safety flyer to disseminate the lessons from this accident and improve awareness of the IMSBC (International Maritime Solid Bulk Cargoes) Code.The ship owner has been recommended to review its safety management system to reflect the requirements of the code. The Maritime and Coastguard Agency has set up tripartite agreements between the UK, the Netherlands and several other administrations for the safe carriage of incinerator bottom ash and proposed its inclusion in the code.The agency has been recommended to update the Merchant Shipping (Carriage of Cargoes) Regulations to refer to the IMSBC Code and to work with the Environment Agency to ensure that test protocols for the classification of cargoes are fit for purpose.
Event Nature
Emergency Action
Unknown
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References