The SS Great Britain

The Trustees of the ss. Great Britain decided that drastic action had to be taken if the ship was to be saved from severe corrosion to the 162-year old iron hull.

Brunel’s ss.Great Britain, the world’s first great ocean liner, launched in Bristol in 1843 is laid up in the Great Western Dockyard.

Arup was commissioned to design a glass waterline plate attached to the dock wall, forming a giant dehumidifying chamber so that the relative humidity could be stabilised to 20% and repairs to the hull carried out.

Steel and glass specialist, Space Decks Ltd, prior to commencing on site, built a test rig, simulating the glass plate. The plate was tested for soft and hard body impact and for water ingress.

The waterline plate consists of 170 laminated glass panels supported by steel joists in one direction and in the other by laminated glass beams. The plate is fixed and anchored to the dock wall and to the hull using a watertight flexible joint to allow for any slight movement. The plate is also supported on tubular steel columns from the dock floor, the largest panels are 4.34m x 1.88m, weighing 450kgs.

At either end of the plate there is a weir to keep the water at a constant depth of 50mm whilst it is being circulated and filtered.

Space Decks’ detail design had to ensure that the glass plate was installed to + / - 5mm so that the 50mm of water was evenly distributed, thus forming a ‘sea of glass’. The structure has virtually been ‘scribed’ to fit the varying dimensions of the hull and the stone walls of Brunel’s dry dock.

A full-scale water test was successfully carried out on 7 June with 100m depth of water poured onto the plate. This confirmed the accuracy of Space Decks’ work.

The specification of the glass panels and beams is laminated heat-strengthened clear glass.

The panels are 22m thick and the beams 32mm.

The innovative glass structure provides a stunning effect for visitors to the ship viewing the hull from within the dry dock. Today’s technology is now helping to preserve the world’s first great ocean liner.