In a method known as all-in, all-out production, a barn that houses a group of hogs sent to slaughter is washed before another group of hogs enters.

WSJ: What China Can Learn From America's Hot Dogs

It claims Mr Taft recruited the other men and also another man from Dublin, who is still at large, to help build the bombs at a barn on his farm.

BBC: Staffordshire bombing: 'Nail bombs built in barn'