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Pleasley Pit Dosco Roadheader. Picture Source: Paul Fillingham.

Stage 4

Dosco Roadheader

There were three production stages in the coal-mining lifecycle: Development, Production, and Salvage, taking place concurrently in different parts of the mine, to ensure there was no gap in production between one coalface becoming exhausted and new one starting.

  1. Development – creating roadways and tunnels to access working areas
  2. Production – cutting the coal
  3. Salvage – recovering equipment from working areas that are exhausted

So-called, ‘development headings’ were sometimes made in order to access deeper coal seams. When a heading was being driven, there was only one entrance, restricting the number of men who could work there. This work was undertaken by a machine called a ‘Roadheader’.


A Brief History of Development Work

Development heading in the 1970’s with a Dosco Mk2 Roadheader. Picture Source: The Coal Authority.

Before mechanisation, development headings and roadways were constructed using picks. Mineworkers would than hand-load the rock and coal into tubs (small underground narrow gauge railway trucks) ready to transport to the surface.

Coalminer using a borer to drill into the coalface.

This slow and laborious process was eliminated after explosives were introduced. The early 1900’s saw the arrival of large percussive power drills, these were eventually superseded by heavy-duty electric drills called borers. These were much larger than the power drills that are used for home DIY use.


The use of explosive charges operated over three cyclical phases:
  1. Drill, charge and blast-down the rock and coal
  2. Load-out the debris
  3. Erect steel supports and advance services


Headers setting steel junction supports at Annesley Colliery in 1985.

Eventually, the loading process of these boring and firing development headings became mechanised by the introduction of bucket loading machines. The men who worked on development work were knowen as headers.

Bucket loading machine used in borer and fired development headings.

Eimco bucket loading machines in a development heading at Annesley Colliery in the 1970’s. Picture Source: The Coal Authority.

Dosco Mk2 Roadheading Machine

The Dosco Mk2 was a type of mechanised road-heading machine introduced in the late 1960’s. They cut the face of the heading and loaded out the debris simultaneously, speeding-up the process of development work underground from the older method of boring and firing.

Dosco road heading machine. Picture Source: The Coal Authority.

Diagram of Dosco Roadheader in a development heading.

The Dosco Mk2 Roadheader consists of a cutting boom containing the drive motor and controls, and the whole machine resting on twin caterpillar tracks.

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