Plans of signal boxes from the Stratford District showing alterations to withstand attack. File list includes signal boxes at: Angel Road, Barking, Bethnal Green, Bow, Brentwood, Brimsdown, Bromley, Broxbourne, Chadwell Heath, Campbell Road, Channelsea, Chingford, Cheshunt, Clapton, Copper Mill Junction, East Ham, Enfield, Forest Gate, Gas Factory Junction, Gidea Park, Goodmayes, Harringay Park, Hackney Downs, High Meads, Ilford, Lea Bridge, Little Ilford, Liverpool Street, Lower Edmonton, Mile End, North Woolwich, Northumberland Park, Picketts Lock, Pitsea, Plaistow, Ponders End, Ripple Lane, Romford, Seven Sisters, Shenfield, Shoeburyness, Silvertown, South Tottenham, Southend, Spitalfields, Stanford Le Hope, Stepney East, Stratford, Thames Wharf Junction, Tilbury, Temple Mills, Tottenham, Upminster, West Ham, Wickford, Wood Grange and Wood Street.