We overcame the unusual challenge of building a structure on a ship and helped bring The Royal Yacht Britannia back to something of her former glory with the addition of a new events space on her top deck. The historic vessel has a permanent mooring in Edinburgh’s Western Harbour and the new space is known as Royal Deck Tea Room.
The new function suite sits on the teak deck, its design reminiscent of the temporary candy-striped canopy that was erected on the Yacht in the 1960s when her former owners, the British Royal Family, and their guests were in the Caribbean.
The new permanent steel portal-frame structure is, however, designed for Edinburgh’s climate, with a double-skin roof of lightweight steel and tensile fabric to ensure no leaks. The need for cross-bracing has been avoided through the strength of the circular hollow section steel frame members. The walls are fully glazed. Access to the State Rooms below was limited and fire restrictions on deck precluded welding, so hollo bolts have been used to secure the frame.
Although Britannia is now generally a stationary visitor attraction, she does move to dry dock for refurbishment. Weight distribution design was critical for the maintenance of the Yacht's stability and buoyancy. Careful records were kept of the weight of all items joining and leaving the ship. Major structural loadings, such as the function suite's column base plates, are supported directly by the hull's stiffening ribs. The Royal Yacht tilts one degree off vertical so the new structure is designed to tilt similarly.
Space for services was tight, necessitating the conversion of the Yacht's funnel into a new plant room and extended lift shaft.