Essex, 1921 Boiler Makers and Iron and Steel Ship Builders, 1921: Colchester Boiler Makers and Iron and Steel Ship Builders, 1921: East Ham Boiler Makers and Iron and Steel Ship Builders, 1921: Harwich Boiler Makers and Iron and Steel Ship Builders, 1921: Plaistow Boiler Makers and Iron and Steel Ship Builders, 1921: Wivenhoe