Workers seal off Kellingley Colliery's main shaft

When the last of Kellingley Colliery's miners went down the pit for the final time in February, it marked the end of the British coal mining industry. They cut the ropes to the lift that used to carry up to 500 men a day below ground.

Now, that very same shaft has been blocked with a concrete plug.

About 50 cubic metres of concrete were used to make a cap that will seal off the shaft. Below that is a steel platform and below that, a 740 metre drop and right at the bottom, around 30 million tonnes of British coal, now out of reach for good.

The cap is put in place for safety reasons - to stop trespassers falling in and to keep methane getting out.

Once it is completely sealed that methane will be extracted through a pipe that runs through the centre of the cap, and will be used to make electricity.

The site will eventually be cleared with plans for a housing development, or an energy from waste plant.

• Click below to watch Adam Fowler's report: