Complex sentence: At this point in the strike there were 477 naval ratings attached to 22 collieries including New Monckton a few days earlier after 3 & 4 miners stormed it.
Split into simpler sentences: At this point in the strike there were 477 naval ratings attached to 22 collieries. Including New Monckton a few days earlier after 3 & 4 miners stormed it.