The underground tunnels of the Central Line played a vital part during the Second World War, as SAM ADAMS discovers

FEW of the thousands of Redbridge commuters who use the Central Line each day could possibly imagine the vital role played by its miles of underground tunnels during the Second World War.

The three-mile stretch of line between Leytonstone and Wanstead was packed with thousands of industrial workers making tons of military components for the war effort long before any trains hurtled down its tracks.

Work to extend the line to Gants Hill was halted by the outbreak of war, with Ilford-based engineering firm Plessey commandeering the empty tunnels in 1941 to use as bomb-proof production lines.

The subterranean factory was staffed almost entirely by women and operated 24 hours a day, producing parts for Lancaster bombers, gear levers for armoured vehicles, shell fuses and cartridge cases.

Plessey won permission to move tons of production equipment into the tunnel after its factory in Vicarage Lane was badly damaged during the Blitz.

More than 2,000 of its workers used a series of specially constructed lifts and escalators to access the underground factory, which was the biggest of its kind in Britain.

A huge number of modifications were made to the 300,000 square feet of tunnels, with accommodation blocks built to house the huge workforce and ventilation shafts dug to provide fresh air.

The factory was so vast that a small train had to be installed to move parts and people from one end to the other.

Secrecy surrounding the site was so intense that few local people were ever aware of its existence, with the only exterior signs being a handful of windowless factory buildings and a shed used by workers to store their bicycles.

The workforce required special security clearance to work in the factory, with guards on constant alert for attempts at industrial sabotage.

Former employee Dennis Barron recalls working on the vast production line as a 16-year-old in 1942.

He said: "It was strange really, like working in a mine only you could hear the bombing overhead - a terrific bang, and all the lights would shake.

"Men and women worked side by side. We all liked it because there was such a good group of people working together.

"We took our work seriously, arrived at 7.30 in the morning and worked until past dinner time, and on Saturdays, with no overtime pay."

Fellow worker Leonard Brown was less impressed with conditions in the tunnels.

He said: "It was horrible. In winter it was very cold, with no heating at all.

"Bombs dropped close enough to blow drawings off tables. So strong was the pressure wave.

"There was also a certain amount of water seepage dripping down my neck."

Despite these shortcomings, production at the underground workshops went uninterupted throughout the war, though it suffered a couple of near misses.

On separate nights in March 1944, two German bombers crash landed close to the tunnels, with the engine block from one Junker aircraft nearly penetrating one of the subway entrances.

The workers celebrated news of the D-Day landings by singing a tearful rendition of hymn Abide with Me, which echoed along the length of the factory floor.

Workmen took more than a year to convert the tunnels back to their original use after Plessey closed the plant down in 1945.

Removal of thousands of tons of concrete flooring alone took seven months to complete.

The temporary factory entrances at Wanstead, Redbridge and Gants Hill were demolished and replaced with the art deco-style booking halls that stand there today.

The stations were the last to be designed by the famous 1930s architect Charles Holden, but fell foul of post-war funding shortages with Wanstead being built in concrete, rather than brick, as intended.