Built in 1838, the immense No. 3 Covered Slip at The Historic Dockyard Chatham was, when built, the largest wide span timber structure in Europe. Today it is home to a vast array of epic objects and vehicles from both the Chatham Historic Dockyard Trust and Royal Engineers Museum, Library and Archive collections. No.3 Slip stands at the cusp of technological change, its amazing cantilever roof was built to the design of shipwright Sir Robert Seppings. It stands next to roofs made of cast iron constructed under Captain Bandreth of the Royal Engineers less than 10 years later.