Number 3 Dry Dock

No. 3 Dry Dock is a dry dock located at Chatham Dockyard, built between 1816 and 1821 by Sir John Rennie Snr. It is constructed from granite ashlar and features a round-ended design with stepped sides divided into two sections by a walkway. There are stair flights at the end and four additional stair flights on each side, along with stone slides for goods. The inner timber gates fit into recesses in the sides, while an outer caisson is located at the west river entrance.

Historically, this was the first stone dry dock built at Chatham, drained by steam-powered pumps from a nearby dock pumping station. It is the earliest of three uncovered dry docks and includes capstans and former cannon bollards. The engineering of this dock represents a transition between Bentham's dry docks at Portsmouth and Rennie's later docks at Sheerness, which featured iron gates and caissons. The docks are crucial to the operations of the Yard, influencing the scope and scale of its work. No. 3 Dry Dock marked a significant advancement for Chatham and played an important role in the evolution of modern dry docks, particularly at Sheerness.