This was originally a covered slipway but is now nicknamed “The BIG Store ” and displays a number of large objects from both the dockyard and the local Royal Engineers Museum.
It was built in 1838 to a design by the shipwright Sir Robert Seppings, at the time it was the largest wide span timber structure in Europe . Those timbers still exist to this day and make an amazing sight when you are standing in the entrance looking up. There are over 400 windows in the roof .It was becoming redundant almost as soon as the first ship made ere was launched with the larger slips 4, 5 and 6 being built in 1848
Slip no 3 was used in the filming of Guy Richie’s First Sherlock Holmes film for a fight sequence but the use of CGI makes it look different and appear to face out not the River Thames.