Complex sentence: In 1665, plans were first laid by the Navy Board for Sheerness Dockyard where warships might be provisioned and repaired, a site favoured by Samuel Pepys, then Clerk of the Acts of the navy, for shipbuilding over Chatham.
Split into simpler sentences: In 1665, plans were first laid by the Navy Board for Sheerness Dockyard, a facility where warships might be provisioned and repaired. The site was favoured by Samuel Pepys, then Clerk of the Acts of the navy, for shipbuilding over Chatham.