IMO SHIP TYPES- CHEMICAL TANKERS
All 3 types are meant to carry chapter 17 cargoes of IBC code.
Type I ships must be able to survive assumed damage anywhere in their length. Cargo tanks for the most dangerous products should be located outside the extent of the assumed damage and at least 760mm from the ship's shell.
IMO type 1, 2 and 3. Other cargoes, which present a lesser hazard may be carried in tanks next to the hull- ( incl diluted slops after tank washings ) See layout below--
Some of the chemicals carried on type one ships are Chlorosulphonic acid, Dodecyl phenol, Phosphorous yellow/ white, Tricresyl Phosphate (>1% ortho-isomer), Trixylyl Phosphate.
Maximum tank size is 1250 M3.
Double side width B/5 or 11.5 mtrs which ever is less.
DB depth B/15 or 6 mtrs at centre line, but not < 760mm .
Auto ignition temperature of cargoes <65 deg C.
Explosive range >50% by volume in air.
Type 1 offers highest limit of containment.
Type II ships, if more than 150m in length, must be able to survive assumed damage anywhere in their length; if less than 150m, the ship should survive assumed damage anywhere except when it involves either of the bulkheads bounding machinery spaces located aft. Tanks for Type II cargoes should be located at least 760mm from the ship's shell and outside the extent of assumed grounding damage.
Maximum tank size is 3000 M3.
Capable of stripping tanks <100 litres.
Auto ignition temp of cargoes <200 deg C.
Explosive range >40% by volume in air.
Type III ships, if more than 125m in length, should be capable of surviving assumed damage anywhere in their length except when it involves either of the bulkheads bounding the machinery space. If less than 125m in length, they should be capable of surviving damage anywhere unless it involves machinery spaces. There is no special requirement for cargo tank location. No limit for size of tank.
Capable of stripping tanks <300 litres with tolerance of 50 litres.
Length > 125 m but < 225 m damage anywhere in length except including ER bulkheads
Length <125 m damage anywhere in length except machinery space
After 1 January 2007 vegetable oils have to be carried in chemical tankers complying with the revised IBC Code as a Ship Type-2 (double hull) with COF as Cat Y.
-------CAPT AJIT VADAKAYIL(29 YEARS IN COMMAND )