Background information about MV Derbyshire
Detail from the capacity plan of MV Liverpool Bridge, the original name of MV Derbyshire.
Copyright HMSO, reproduced by kind permission.
- 95% of world trade is carried by sea
- bulk commodities do not move by air and have to be carried by sea
Bulk carriers and oil tankers
Before 1960 two different types of ship were used to transport commodities depending on the type of cargo.
Oil tankers carried liquid cargoes including:
- crude oil
- fuel oil
- diesel oil
- liquid caustic
Bulk carriers transported a variety of solid cargoes including:
- iron ore
- steel products
Oil/bulk/ore ships (OBOs)
In the mid 1960s a new type of ship, the OBO (oil/bulk/ore), was introduced. OBOs offer greater flexibility, being designed to carry both solid and liquid cargoes in bulk. The Derbyshire was such a vessel and on different occasions in her short life of four years she carried coal, crude oil, iron ore and tapioca pellets.
As with other OBOs the design of Derbyshire was more complicated than a tanker or a bulk carrier but, potentially, they would earn more. These ships also had to be built very strongly because of the high concentrations of weight when loading and carrying heavy iron ore cargoes, which caused tremendous stresses.
The limited number of loading gantries at the loading berth meant that only one or two holds could be loaded at a time. This caused high sheer forces and bending moments between loaded and empty holds.
When carrying iron ore not all the holds would be used because the ore is so heavy. On her final voyage the Derbyshire sailed with holds 2 and 6 empty.
Facts and figures
MV Derbyshire was:
- 294 metres (1000 feet) long – almost three times the length of a football pitch
- 44 metres (150 feet) wide – as wide as a six lane motorway, wider even than the Titanic
- she could carry about 160,000 tons of cargo (this is about the same weight as 15,000 double decker buses.