AS feats of civil engineering and industrial performance go, even now there are few to surpass that which Lancashire witnessed 60 years ago - the building of a mammoth factory the size of a small town in just three years and it employing 35,000 people on round-the-clock production.

Yet, this was the achievement of the Royal Ordnance Factory at Chorley, commemorated in a new book* published this month.

Throughout the story, told by authors Mike Nevell, John Roberts and former employee Jack Smith, superlatives and staggering statistics are sprayed like machine-gun bullets as truly tremendous resources that went into making ROF Chorley not only the greatest building project of its time but also the world's largest ammunition filling plant.

Covering 928 acres at Euxton and comprising 1,500 buildings and its own railway, the factory was begun in January 1937.

By the time it was complete at the end of 1939, it had employed 14,000 construction workers and the three million cubic yards of earth excavated on the site had consumed more than 30 million bricks and one million cubic yards of concrete - for which the world's largest mixer was made.

Estimated at £2.1 million in 1934 when the Nazis rise to power in Germany triggered Britain's race to re-arm, the factory's cost had by January 1940, by when the feared war with Hitler had become a four-month old reality, risen to almost £11.5 million - equal to nearly £286 million now. But what was ultimately incalculable was the contribution the works made to Britain's victory as night and day, non-stop it put the bang into countless numbers of shells and bombs - everything from small calibre round to 12,000lb "blockbusters." So vast was that undertaking that an army of workers had to be recruited - among the 35,000 on the factory's wartime payroll were many from East Lancashire who had formerly worked in the region's textile mills whose supply of raw materials had been hit by the war.

Their work at the ROF was painstaking as during the war years every shell was filled by pouring in the molten explosive mixture by hand from special "kettles" and bombs were topped up in the same way.

The logistics of employing so many people were also immense. Some 40 trains a day arrived at the factory's own railway station bringing workers from all parts of Lancashire.

Peacetime brought sharp reductions in the payroll - by 1957 falling demand and automation had reduced it to 3,300.

Sold to British Aerospace in 1987, Royal Ordnance - an empire of more than 50 factories in 1945 - now has its headquarters at ROF Chorley.

A History of Royal Ordnance Factory, Chorley by Mike Nevell, John Roberts and Jack Smith (Carnegie Publishing), £17.

Converted for the new archive on 14 July 2000. Some images and formatting may have been lost in the conversion.