Bourn Windmill: Historic mill's timber support successfully removed

Bourn Windmill in Cambridgeshire had to be supported with scaffold to remove the rotten timbers from underneath

Teams restoring one of England's oldest windmills at risk of collapse say they are "extremely relieved" work to remove the rotten timbers has been successful.

Bourn Mill in Cambridgeshire is a Grade I listed ancient monument dating from the 1600s but faced collapse due to its rotting central support beams.

The decay was spotted in a routine inspection two years ago.

The main post of the mill is thought to be from a tree felled at some point after 1515.

Unlike a fixed windmill, Bourn Mill is a postmill which can be manually rotated on a central wooden post - allowing the sails to be turned directly into the wind.

Cement repairs 35 years ago allowed rainwater into the timbers

James Littlewood, from the Cambridge Past, Present, Future (CPPF) heritage group, said the beams that needed replacing were 140 years old.

"We discovered that they were rotten and therefore if they collapsed or failed the whole windmill would fall over," he said.

"Now that we've taken the timbers out and had a look at them, we totally did the right thing.

"And the guys who operated the mill normally said, 'oh my god, I can't believe we were turning the mill around with these rotten beams in place'."

Heart 'thumping'

Site manager, Dave Mott, said he was surprised by the level of decay.

"Everything was coated in this black bitumin material," he said.

"My concern was whether there was enough strength in the timbers, because we had to jack the whole windmill up, whether they would hold the extra loading."

The engineers discovered a resin concrete material had been poured into the timbers in the 1980s to strengthen it - but instead caused more damage as the material allowed moisture and damp in.

Mr Mott said it took "a lot of conversation and planning" to lift the windmill up from its base.

Five bottle jacks placed underneath the building had to be operated simultaneously to move the structure away from the rotten timbers.

"The heart was thumping a bit," said Mr Mott.

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The restoration has cost in the region of £250,000.

About £140,000 has come from the Heritage Lottery Fund, £56,000 from Historic England, and CPPF providing £12,000.

The Cambridge group now needs to raise a further £10,000 towards the project.

New timbers will be fitted by September with the windmill expected to open again to the public in spring.

The post mill was last restored to working order in 1932

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