Letter: Underground army

Sir: Robert Nelson (letter, 8 November) remarks on overmanning in London's Tube system compared with New York's. It could be that he didn't recognise many of the people working on New York's system, as some of them are plain-clothed, particularly the police officers with the rather large T-shirts to allow them to carry a gun in the waistband.

PHILIP BRITTON

Whitley Bay, Tyne & Wear