Dear Kristin,
The question of earthquake preparedness on a budget is a thorny
one, especially in light of the recent well founded comments on giving
sound professional advice instead of well meaning hints and folk remedies.
I hope I'm able to give more of the former and less of the latter.
The idea of being able to seismically stabilize a collection
cheaply comes down to an exercise in compromises, dictated by the value and
nature of the collection, directon and intensity of historic and expected
quakes, importance of conservation concerns, site and building
characteristics, and availability and cost of skilled enough labor to
perform the needed work. Doing nothing is obviously the cheapest
alternative in the short run,and may be perfectly appropriate if the site
is located in central Michigan. However, for a Pacific coast museum it will
prove to be an expensive choice overall. The important thing is to analyze
the situation, determine the areas of greatest vulnerability, and try to
implement measures that will reduce risks. The suggestions I will make will
only address physical risks, and do not pertain to the issues of food,
water, medical, etc.. As with conservation advice, each situation is unique
and requires individual consideration. Many of my suggestions may seem
broad and obvious because they are offered not as solutions to specific
problems, but as a framework and starting point for thinking about
earthquke hazards.
When looking at earthquake risks in a museum setting, we need to
divide the subject into three areas: risks to the people at the museum,
risks to the collections in storage, and risks to the collections on
display.
PEOPLE: Obviously, people are the highest priority, so hazards of
flying or falling objects which can injure deserve the most immediate
attention. Large objects and furniture such as shelving or independent
display cases should be anchored to walls or other structures that are
strong enough to remain standing themselves. If an object is diplayed atop
a tall shelf, it needs to be anchored in position, or removed and displayed
more safely or not at all. Lighting fixtures and other objects that hang
from the ceiling need to be checked to see if they will swing wildly and
come loose, or throw off parts. Walk through each room with fresh eyes and
try to notice anything that could become a flying or falling hazard, or
could cut off routes of evacuation from the room or building. It can be an
overwhelming experience to realize how many things could be potential
problems, but the important part is to give priority to those things that
could be the greatest hazards and to act to remedy those first.
STORAGE: Setting up a storage area is mostly a practical matter of
keeping objects from being damaged by falling off of something, being
fallen on by something else, colliding with something, or tipping over. The
analysis must be done in a systematic and comprehensive manner, with an eye
for the weakest link in the chain of support.
Shelving should be examined and extra fasteners inserted to keep
individual shelves from coming disconnected from the main supports, and the
supports anchored to structural building elements. Photos taken by Barbara
Roberts of storage rooms in Kobe showed free standing shelving that had
fallen like dominoes. Once shelves are secure, padding should be provided
under and around objects to restrain motion and cushion impact. Sheets of
thick foam with cavities cut out to receive each object can help define
spacing on a shelf as well as retain the object from tipping. Providing a
lip on shelves, as well as stretching webbing or shock cord across shelf
openings can help keep pieces from falling out.
Support structures can be built to tie large items to. Care must be
taken to avoid tieing an object in such a way that portions are not
supported and restrained, and thus able to accelerate and break free. The
object should act as a single unit. Remember that all systems seek maximum
entropy. Thus, a tall object with a high center of gravity and a narrow
base of support may be best secured horizontally since an object that is
lying on the floor cannot fall to the floor.
Framed works that are hung on storage racks need to undergo the
same sort of examination, and questions asked about the strength of hanging
hardware, and analysis of possible path and range of movement. Restriction
of movement is a good idea.
Storage sites should also be looked at for hazards of bursting
pipes and fire hazards. There's not much use to securing everything, only
to have the area flooded.
A final consideration in storage situations is the issue of
conservation safety. Paddings can have detrimental long term effects on
objects in their vicinity. This is especially a concern in your quest for
low cost options. Much will depend on the age, value, and susceptability of
the objects you are trying to protect, with old metals generally giving the
worst problems. Foams come in a great variety of forms, of greatly varying
stability. Polyethylene foams (Ethafoam, Volara ) are generally regarded as
the safest, but are expensive. Cotton fabrics are a reasonable material
which may be available in the form of old sheets. Newspapers are virtually
no cost, but are high acid papers as well as being dirty and having other
possible reactions from inks. They might be useful for short term padding
on the right type of objects, if used in conjunction with a barrier of
polyethylene film. Just remember that things done as short term solutions
will probably not be redone, and will become long term problems. It's best
to do it right the first time. I don't have a materials list to give you,
but it is worth checking Conservation On Line (CoOL) for one, as well as
looking for the new Materials list that appears to be coming to the net.
DISPLAY: The protection of objects on display is where things
really get difficult, because now, all the aformentioned factors of weight,
position, and stability come into play, but everything must also be done
aesthetically. Even with a large budget, this is a challenge.
The best solution is for each object to have an individual mount
made for it that is appropriately connected to the building structure.
These are generally made of metal (brass, steel, and aluminum), or plastics
such as Plexiglas. They must be designed to provide support for the entire
object to help the piece move as a single unit instead of letting portions
accelerate at different rates, thus causing damage. If an object is tied to
two different structures, such as to a wall and to a separate stand, it can
be damaged by the differential movement of the two bodies. Unity of
movement is a very important concept.
Low cost measures can be effective, but must be appropriate to the
specific situation. Wax (Quake Wax, museum wax, dental wax) can be a good
tool if the object concerned is of appropriate size, material, and
structural soundness. These are not necessarily easy to quantify in print,
but generally I think of using it on non-porous materials such as glass,
glazed high fire ceramics, and metals with good surfaces; reasonably light
weight (<10 lbs.), and having a fairly stable base. Small bits (rice size)
of wax are adhered to the object base at three or four points, and then
firmly pressed to the deck surface. The surface must also be appropriate as
wax can lift, soften or stain wood furniture finishes. Releasing the object
from it's surface can be done by gently rotating and lifting the object, or
by cutting through the wax with dental floss. Although the wax seems
innocuous, it is able to exert a surprising hold that seems to get stronger
over time. I have seen it detach pieces of ceramic, as well as pulling
pieces of gold leaf edging from what appeared to be very sound Decorative
Arts objects. Us wax judiciously, and with common sense.
Another useful tool in a very broad range of applications is the
use of weight to lower the center of gravity of an object. This can be used
to anchor anything from free standing cases to small vases or other closed
vessels. Using dry sand or gravel in thick plastic bags is probably the
simplest and cheapest form, although lead or steel shot give more weight
per volume. Again, common sense must be used to determine if the object is
structurally sound enough to take the extra weight, and if this strategy
will actually help the situation. Extra weight located too high in a tall
narrow footed vessel could actually increase momentum and cause greater
damage.
There are a number of other tools available, each having advantages
and disadvantages. Tieing objects down with monofiliment can be useful, but
mono can be abrasive as well as getting brittle with age and needing
maintenance. Never use it as a sole method of support, it is best as an
unstressed retaining measure. Using padded shims to reduce an objects'
tendency to rock will help it keep from developing momentum. It may even be
appropriate to let an object slide around as long as it won't tip over,
fall off, or crash into anything. This is the theory of decoupling that the
Getty uses in their isolator bases; allowing controlled movement to
dissipate the energy of the shock. However, here we are getting into very
expensive solutions. A practical example of this is that display cases on a
carpeted floor have a greater tendency to tip over than do ones on smooth
floors due to their ability to slide.
This has turned out to be a little longer than I had planned , but
one thing just leads to another. I hope this gives some strategies to
consider when looking at seismic preparedness. There are no sure bets and
there certainly is no such thing as earthquake proofing. There is only the
reduction of risk. Each situation must be individually analyzed and
decisions must be made as to whether any of these techniques may work. The
main thing is to take care of the most vulnerable and hazardous situations,
and work to always consider the potential problems when designing new
exhibits and storage.
Good luck with your research,
Jamie Hascall
Date: Sun, 21 Jan 1996 01:57:17 -0500
From: Kristin Shurley <[log in to unmask]>
Subject: Earthquake Preparedness
I am writing a research paper on earthquake preparedness. It will focus on
small musuems who don't have the budgetary means...
Jamie Hascall
Hascall Museum Services: Seattle, Washington
Mountmaking Services, Seminars and Consulting for
Seismic Mitigation and Presentation Excellence
[log in to unmask] (206) 525-6941
|
