Vibrations may have given the Beach Boys excitations but in a Museum vibrations can give curators and conservators serious concern.
The movement of vibrations can put objects at risk of harm and potential damage. Vibrations can be created by a number of things, for example a busy road outside or foot falls on a springy floor. More conspicuous vibrations, such as those caused by heavy construction, are potentially harmful to both objects and the museum building.
The structural demolition and excavations required to create the Europe 1600-1800 Galleries stimulated the need for a number of ‘vibration controls’ needed to be included in the project’s construction plan. It is not possible to completely eliminate the vibrations but systems are put in place to reduce them and their effect as much as possible.
There are of course no museum objects currently in the Europe galleries, but vibrations from such major construction affects the physical structure of the Museum and put any objects displayed or stored in nearby areas of the building at potential risk. It is crucial for the curators responsible for affected areas to be kept informed of exactly what work contractors will be undertaking for the duration of the project, so that they can understand and prepare for the risk of any vibration issues arising.
The British Galleries run along above the Europe Galleries and so particular attention was given to ensuring the protection of objects on display there.
Curators and conservators identified vulnerable objects in the galleries and decided on the most effective precautions to take. The main danger is that objects could ‘creep’ – like cups of hot tea that judder across tables on train journeys. ‘Creeping’ may make them bump into other pieces or ultimately fall from the shelf. One way to prevent ‘creeping’ is to place something beneath the object to give it extra grip. In the British Galleries we have used Plastizote, which is a stable and non-reactive foam, commonly used in the storage of museum objects. Delicate ceramic objects were amongst those most obviously at risk
Other objects were stabilised by being laid on their side and placed in wads of acid-free tissue paper.
Some objects with loose or detachable parts were partly dismantled to ensure that the pieces didn’t knock against and possibly damage other.
If you have visited the British Galleries in recent weeks you will probably have been very much aware of the sound and vibrations caused by the construction work below. It may have seemed a bit disconcerting as you looked at cases of fragile objects but reassuringly the levels of vibration that humans can perceive are much lower than the recommended limits for displaying museum objects. Vibrations in the galleries may sometimes be noticeable to visitors (predominantly by the noise they can create) whilst not being at a level that risks damage to objects.
We don’t rely solely on human perception to keep track of the intensity of vibrations in the galleries. A number of sensors have been secreted around the British Galleries to record levels of movement. At this stage in the project, the key areas being monitored are those around the Norfolk House Music Room.
If the agreed limit is exceeded these sensors send out an alarm to inform curators and those overseeing the construction work. In the event of a ‘red’ alarm all work ceases and can only commence again once the relevant curator has checked that objects in the British Galleries are safe and secure and gives the ‘all clear’.