Vibration

We have just gotten into our brand new museum of Australian art
building which is part of a complex of several buildings built
across a street from, and over the railroad tracks of, the main
downtown suburban commuter train station.  We experience no
noticeable vibration from the many electric commuter trains running
all day, but I'm now told by staff now beginning working in the
building that there are occasionally much heavier diesel trains that
do cause noticeable vibration.  It was suggested there are many of
these heavy trains overnight and it is a possibility that there is
much more vibration than the small number of staff currently working
in there are experiencing. I am currently trying to get a schedule
of the heavy trains from the rail authority so I can feel walls as
the trains go by to try to determine if there is a problem, and if
so, how severe.

Sections of our previous building vibrated from large trucks on a
road on one side, trams rattled showcases in certain locations on
the other side, and I had to deal with an out of balance fan in the
HVAC system that shook violently and transmitted enough vibration
through air ducts to cause noticeable movement of a large painting on
a wall. Over many years we found, mostly from observant installers,
that there were certain walls and display locations which vibrated
and we avoided these, displayed invulnerable items there, and/or
used wax to secure items as was most appropriate.  In most cases it
was not a practical option to eliminate the cause of the vibration,
so knowing where the problems were was critically important.

Having a new building without a known history of vibration I don't
know if there is a real threat to vulnerable works of art due to
vibration from the diesel trains or any other source or not. I'm
looking for ways to determine if any display walls, showcase
locations or floor areas have enough vibration to damage a work of
art.  It would be nice to have a device I could leave for a day or
two in a display space and then read and have a record of vibration.
There needs to be a quantifier in order to know if the vibration is
enough, for example, to endanger a pastel drawing or that metal
items might shake enough to move along a shelf in a display case. We
recently trialled a Tinytag Plus Vibration Logger TGP-0650, but it
flatlined and was not sensitive enough to register any vibration of
the building, though it showed the vibration of being handled and
transported perfectly well.

I would appreciate any ideas on equipment or methodology for
determining and quantifying vibration and its relation to display of
works of art in a new building.

Tom Dixon
Chief Conservator
National Gallery of Victoria
Melbourne Australia


                                  ***
                  Conservation DistList Instance 16:26
                Distributed: Wednesday, October 9, 2002
                       Message Id: cdl-16-26-016
                                  ***