Ayrshire, 1921 Boiler Makers and Iron and Steel Ship Builders, 1921: Ardrossan Boiler Makers and Iron and Steel Ship Builders, 1921: Ayr Boiler Makers and Iron and Steel Ship Builders, 1921: Irvine Boiler Makers and Iron and Steel Ship Builders, 1921: Kilmarnock Boiler Makers and Iron and Steel Ship Builders, 1921: Troon