Category:Ways to transport chemicals at sea

This chapter lists the most common ways chemicals are transported at sea. For responders to oil and chemical spills, it is important to have insight into the various ship types. When making a risk assessment, it is important to know the amounts and the types of substances that a certain ship type can carry.

Substances in bulk are transported by oil tanker, chemical tanker, (liquefied) gas tanker or bulk carrier. These types of ships can carry large amounts of unpackaged cargo.

Oil tankers are designed to carry oil and have a double hull to protect the cargo in case of a distress situation.

Substances likely to present an environmental and/or safety hazard are transported with more caution. Type 2 and type 1 chemical tankers have more space between the outer hull of the ship and the cargo tanks so the cargo is protected in case of a collision or grounding. In type 1 tankers this spacing is the largest, these tankers therefore being allowed to transport the most hazardous substances. Moderately hazardous substances are transported in type 2 chemical tankers in which double hull, spacing is less than for type 1 while in type 3 the outer hull is also the side of the cargo tank, these tankers being allowed to transport only the least hazardous substances.

Liquefied gas carriers transport gases in bulk, by compression or refrigeration. In a manner essentially the same as chemical tankers, though rapid evaporation of liquefied gases can pose extra danger to the environment. As with chemical tankers, there are different types of gas carriers from type 1G to type 3G that carry decreasingly hazardous substances.

Bulk carriers carry loose solids such as coal, grain iron ore ect..

Packaged goods are transported in container vessels, Ro-Ro vessels, general cargo vessels or barges. Container vessels only carry containers; Ro-Ro vessels carry containers, trucks and cars. General cargo vessels can carry either containers or smaller packages. Freight containers are easy to handle because of their standardized sizes.

Most common ship & package types are listed in the tables below, with their cargo types and tank sizes. Table 1 Ship type versus cargo type and tank size

Ship		Cargo type	Max cargo (per tank)	Max cargo (total)
Oil Tanker	General purpose tanker	Liquid bulk goods	Wing tank 30.000 DWT Centre tank 50.000 DWT	25.000	DWT
	Medium range tanker	Liquid bulk goods	50.000	DWT
	Large range 1	Liquid bulk goods		80.000	DWT
	Large range 2	Liquid bulk goods		160.000	DWT
	Very Large Crude Carrier	Liquid bulk goods		320.000	DWT
	Ultra Large Crude Carrier	Liquid bulk goods		550.000	DWT
Chemical tanker	Type 1 tank	Liquid bulk goods (high risk)	1250 m3	40.000	DWT
	Type 2 tank	Liquid bulk goods (moderate risk)	3000 m3	40.000	DWT
	Type 3 tank	Liquid bulk goods (low risk)	Unlimited	40.000	DWT
Bulk carrier	Handy size	Solid bulk goods		30.000	DWT
	Handymax	Solid bulk goods		50.000	DWT
	Panamax	Solid bulk goods		80.000	DWT
	Cape Size	Solid bulk goods		250.000	DWT
Liquefied gas tanker	Fully pressurized	Liquefied gas		1.000	m3
	Semi pressurized	Liquefied gas		12.000	m3
	Fully refrigerated	Liquefied gas		100.000	m3
	Ethylene tanker	Liquefied gas		12.000	m3
	LNG tanker	Liquefied gas		135.000	m3
Container vessel		Containers	Package size	15.000	TEU
Ro-Ro ship		Containers / trucks	Package size	52.000	DWT
General cargo vessel		Packaged goods/ containers	Package size	20.000	DWT
Barge		Packaged goods	Package size	3.000	DWT

Table 2 Sizes and weight of packages

Package		Cargo type	Max cargo
Container	40 foot		68 m3	27 T
	20 foot (1 TEU)		33 m3	22 T
Tank container	20 foot	Liquid	25 m3	32 T
	20 foot	Gases	25 m3	15 T
Drum	Steel/iron	Liquid/solids	< 1 m3
	HDPE	Liquid/solids	< 1 m3
	Kraft drums	Solids	< 1 m3
IBC’s		Liquid/solids	1,2	m3
Bulk bags		Solids	1.200	kg