It is frequently the case that timecharterers need to know the capacity of a vessel’s bunker tanks, so they can accurately estimate maximum times between replenishment of bunkers and plan voyage strategy. Because of the likelihood of damage to a main engine caused by burning the wrong fuel type, most charter parties will stipulate a grade in accordance with the internationally accepted standard for marine fuels ISO 8217. Some owners may go beyond this demand and require any fuel to be tested free of contaminants. This is the result of unscrupulous bunker suppliers using marine fuels as a method of disposing of waste chemicals. In 2001 Singapore suffered a spate of incidents caused by suppliers adding dry-cleaning chemicals to fuel resulting in several cases of severe engine damage as oil seals in the engine disintegrated. Those concerned with dry cargo chartering should aim to have a complete knowledge of the physical characteristics, carriage requirements and trade routes of those commodities with which they are closely involved, as well as a good, working acquaintance with other dry goods. It is important too, to keep up to date with events in the real world. As countries try to make more of their natural resources some trade patterns may well change. As an example, rather than transporting coal and iron ore to Europe for steel manufacture and exporting the finished product around the world there is a valid political and economic argument for transferring steel production nearer to the sources of coal and iron ore and only transporting what steel is required for European consumption long distances.