However, they do come at a cost: while a synthetic wig costs from £80 to £200, a human-hair wig costs between £250 and £1,000.
Maggie Flisher, 26, and husband Gavin, 30, from Maidstone in Kent, have not worked since the birth of their first child in 2005.
The workers appear tiny when overshadowed by the monolothic machines being used to drill 26 miles of tunnels beneath the capital for the new Crossrail route.
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