CAN undertook an initial inspection and dimensional survey of roof trusses to Hintze Hall of the Natural History Museum, for evaluation by structural engineers, in preparation for the proposed suspension of the blue whale skeleton.
The skeleton and armature of the whale, weighing approximately 4.5 tonnes, was to be lifted 6m from floor level and suspended on cables anchored to the museum’s roof trusses, and orientated such that the whale skeleton had the appearance of commencing a ‘dive’.
The roof truss rigging and access work required to facilitate the lifting operation, whilst in an historic location, was relatively straightforward. The major risk identified during the project planning phase was the potential to overload the roof trusses during the lifting operation.
To mitigate this risk CAN technicians employed mechanical hand operated Tirfor winches that would allow minute adjustment at each of the 10, individually manned, roof truss lifting locations. The armature anchor points were designed to swivel which enabled the orientation of the skeleton to be adjusted without creating a spike in the loading of an individual roof truss. In addition, load cells were incorporated in each of the lifting rigs which communicated with a control station by Wi-Fi, enabling the load imparted to each roof truss anchor point to be continuously monitored by the CAN Lift Supervisor.
Once the skeleton had been raised and the desired orientation achieved, permanent cables were installed and the lifting equipment de-tensioned and removed.
Link: The Blue Whale – a three year labour of love
Duration: 2 weeks
Client: Natural History Museum
Location: Natural History Museum, London