ROF Risley was known as Filling Factory No.6, and used in World War II for filling munitions, including the Grand Slam bomb.
With the advent of the Second World War, 927 acres (3.8 km²) of agricultural land, known as Risley village, between Leigh and Warrington in Lancashire, was compulsorily purchased and built up into a massive Royal Ordnance Factory. The location was chosen because the low lying mist and cloud helped to camouflage the factory from the air.
According to a local builder, “It was very lonely and misty at night, and that’s why the factory was constructed there… it was usually covered with a mist or cloud. It was hard to see it in the day time, you know”. Construction began in August 1939. It took 18 months to complete, but bombs were produced from September 1940. Around 22,000 people worked there.
A number of bunkers were also built to house the munitions, to protect them from potential bombing, and also to segregate the site and reduce the consequences of any accidental explosions during manufacture or storage. Although these bunkers are on the surface, they are covered with soil and turf and so give the impression of being underground. You can still see some of them in Birchwood Forest Park. Area 6 was where the detonators were filled with explosive powder. Gorse Covert housing estate is now built on this land.
However, after the war the factory no longer had a purpose, other than as a storage depot, and so, in 1956, the north west section of the factory was sold to UKAEA, with the entire disused area being put on the market in 1963. No buyer was found for it until 1968, when the Warrington and Runcorn Development Corporation purchased the site and turned it into the district of Birchwood. Birchwood Forest Park is in the centre, in which the old bunkers from the factory form part of the landscape.
The photo shows part of the sluice mechanism for the ROF site in the Walled Garden at Birchwood Forest Park in Oakwood.
Read more about the area in the Birchwood Forest Park section of Warrington Green.
Some information from Wikipedia