The Chemical tankers are specialised tankers to carry chemicals in bulk from place to place. These ships are dedicated to carry industrial chemicals around the world.
The International Convention for the Prevention of Pollution from Ships (MARPOL)describes a Chemical tanker as “a ship constructed or adapted for the carriage in bulk of any liquid product listed in chapter 17 of theInternational Bulk Chemical Code”.
Carriage of chemicals in tankersare governed by the regulations in SOLAS (Safety of Life at Sea) and MARPO. To safeguard the ship crew, ship and marineenvironment, SOLAS and MARPOL conventions have demanded all the tankers builtafter 1st July 1986 to adhere to the International Code for theConstruction and Equipment of Ships carrying Dangerous Chemicals in Bulk (IBCCode). All the chemical tankers built prior 1st July 1986should comply with the “Construction and Equipment of Ships Carrying DangerousChemicals in Bulk” (BCH Code).
Chemical cargo are extremelydangerous in nature as these cargo could be flammables or toxics. So, thechemical tankers. Hence, according to the nature of hazard of the cargo, IBCCode categorises chemical tankers into 3 groups as ST1, ST2, and ST3. The ST1chemical tankers are designed to transport the highest dangerous products.These chemical tankers are bound to make maximum preventive measures topreclude an escape of such cargo. ST2 or Type 2 chemical tankers are to carry cargowhich requires significant preventive measures and type 3 (ST3) requiresmoderate preventive measures.
Other than to the mentionedprecautionary measures as per the caring cargo type every tanker should becertified as mentioned in chapter 14 of IBS codes prior transporting chemicals.The chemical tankers which fulfil the requirements of IBC code will be grantedwith the “International Certificate of Fitness for the Carriage of Dangerous Chemicals in Bulk”.
Same as the industrial chemicalsand clean petroleum products, Chemical tankers also use to carry cargo such aspalm oil, vegetable oils, tallow, caustic soda, and methanol.
Unlike in most of the tankers, chemical tankers have separate pipes connected to each tanks for cargo loading and discharging. These separate pipes help to avoid contamination of cargo which could lead to distress situations. Other than to the storage tanks in deck holes, there are chemical tankers with Cylindrical tanks on deck to store air which use for blowing of pipeline.
The tanks of these ships are designed with extra care. In most of the cases, vessel is built after deciding, which chemicals will be carried onboard due to the hazard precautionary measurements. The coating of the tanks are done to prevent reactions to the chemicals. Some tanks are coated with stainless steel.
Once cargo discharged, it is mandatory to clean the cargo tanks prior loading another type of cargo. Did you know? Once the cleaning is done, inside the tanks are not even touched by palm as it will cause expiration of chemicals. Most importantly the tank cleaned water cannot be release to the sea and should be treated properly to minimise its impact to the environment. Plus, when the water discharge at port, it should be recorded in ship’s garbage record book to make sure water is not released to the sea.
Have a clear look when you see a chemical tanker again. They are small in size than product tankers. And painted in Green and Orange colors to identify easily.
The funny fact on chemical tankers is now almost every company in the world follow a dry ship policy. Which means no alcohol onboard!
The crew of chemical tankers is bound to wear PPE (Personnel Protective Equipment) every time while they work. And the accommodation units of chemical tankers are built with Positive pressure inside. This helps air to flow from inside the accommodations to the outside instead letting outside air flow inside the ship. This mechanism is using to make sure no chemical contaminated air flow inside the vessel. So, when the ship is at port, they generally do not allow natural air to flow and only use internal air to circulate inside the ship. Once the vessel leaves the port, natural air circulation is allowed as there is no chemical contaminated air in the mid of the sea.
IMO and other governing bodies are taking every measure to make sure the safe operation of chemical tankers.