Tom Benjamin
Iron Mountain Film & Sound Archives
September 29, 1999
Orphans I at the
University of South Carolina
Based on my experience with one of the largest film and document storage
operations in the world, I will discuss some of the opportunities and
challenges of storing motion picture film, in particular storing film
underground. The degree of security
afforded the motion picture films is one of the most important considerations
to be made when choosing a site to store film material, whether it is on-site
or off-site. Nothing else will matter if
something happens to your important material, and a visit of your security
installations could be the most important and best investments you ever make. The American National Standards Institute
proposes that we store black-and-white film at 36 to 45 degrees Farenheidt and
color film even colder than that. Our
company doesn’t specifically recommend environmental conditions to our
clients. That gets risky from a
liability stand point, but this much I can tell you, that in the fourteen years
that I have been there, colder and drier is better. It seems to be getting even colder and drier,
the conditions that film preservation experts and clients want.
I work underground in western Pennsylvania. The majority of the underground facilities
that are located across the country are in mines. Those include iron ore mines and salt mines. Ours is a limestone mine. Underground storage first became attractive
as an indirect result of the Cold War.
The Russians had the bomb. We had
the bomb, and folks were concerned about nuclear attack. The massive underground structures built as
refuges from nuclear fallout are now being retrofitted for new purposes,
including film vaults.
There are a number of opportunities
for underground storage in addition to motion picture film. We store microfilm, microfiche, reels of
computer tape. We have miles and miles
of magnetic media. We have over 2 million cartons of paper records. Underground at our facility we have
approximately 1,000 people working underground in our storage facility. In addition to inactive storage, we have
fully operational data centers located there.
And we have some offices. In the
office locations, a lot of these folks
have their entire business operation needs to be kept safe and secure. This
facility is 220 feet underground. The
main entrance is through a three-ton steel gate.
Why underground? The biggest
advantage has to with the high level of physical security. There is one way in and one way out (that we
advertise and promote). Access is
controlled by an alarmed gate and armed guards 24 hours a day, seven days a week. The underground facilities are virtually
immune from natural and man made disasters –- fire, flood, theft, civil
disorder, hurricanes.
Earthquakes? Let’s talk about
earthquakes. We store assets for five of
the major Hollywood film studios.
Visitors from Hollywood want to talk about earthquakes. So these folks are somewhat preoccupied by
the subject. In selecting an underground
facility, it would be best to choose one that is in a low incident of
earthquakes. We are in Pennsylvania,
right where it says zero, and I work underground everyday, so we have just as
high a likelihood of having an earthquake there as they do in Florida or in
Texas, as you can see.
Another principal reason for underground has to do with maintaining the
proper climate conditions. It is really
very easy for us to maintain the temperature and the relative humidity storage
conditions that are required for the long term preservation of the
material. The first thing we need to do
is to identify the storage conditions that we are shooting for. We segregate the various types of materials
that we would store. Magnetic media –
keeping it separate from paper – and keeping it separate from motion picture
film. For the motion picture film, as I
mentioned before, we selected ANSI
IT. Some of our clients will maintain
their material at 60°F, others will choose 55° and 35% RH. We have space maintained at 45°, 40°, and 33°F, and we are working with a client now for 0° F.
So, it is not difficult for us to maintain those conditions
underground. With standard HVAC
equipment we are able to maintain about 55° to 60° temperature. To get any lower than that, we need to use
refrigeration equipment and obviously, the size of the HVAC equipment depends
on what the moisture and heat loads are.
Factors include the number of people in the facility, the service
activities, service levels. But because
we are underground, we are not subject to seasonal changes.
In our area of the country, the outside temperature can vary by over 100° from summer to winter, and the
relative humidity can vary by more than 50%.
The underground environment is a
constant 58° and 85% relative humidity.
This is
a map of our facility. Just the portion
we have developed is about 133 acres underground, and the entire mine – people
often ask what about when it fills up? – the mine is 1000 acres. So, I am not going to be here when it fills
up. We are occupying about 10% of what
the capacity is. What we able to do is
to segregate the space., the developed space from the undeveloped space by
building separation walls. Mounted in
these walls are huge industrial mine fans.
We circulate about 250,000 cubic feet of air a minute out the
entrance. The entrance is located right
here. So mounted in the exterior walls
are these industrial mine fans. The air
is brought in from the outside and then forced all out that entrance. What we do is to bring the air in from the
opposite side of the mountain, It comes across the 20-50 foot thick rock walls,
and in the summer, the rock walls act as a huge heat sink. It absorbs all of this heat, and by the time the
air gets to the mine fans here, it is at a nice 55°. In the winter the opposite happens. We are pulling in air from the outside, could
be 20°. Once again, we move it
across those rock walls. It then
increases the temperature, and once again, we still get 55° coming in through there. So it is a great system, and it is virtually
free.
In order to get the 85% RH down, we’d need to use desiccant
dehumidification equipment. Once again,
we need to look and see the size of the facility. We have facilities that are the size of this
room. We have others that are the size
of this particular floor of the building.
Our engineers would use psychometric charts to determine the size of the
dehumidifiers needed to insure that they are capable of removing the proper
amount of water vapor.
We use a modular approach to our HVAC equipment. The first approach is to use the cool mine
air that we talked about and a small commercial dehumidifier, such as the one I
have shown. For colder conditions we
would use a regular commercial air conditioning unit, and for still colder, we
might use a small refrigeration unit.
Another advantage to underground has to do with fire protection. This is a picture of a small vault. We use the existing rock walls that you can
see along the back. Wherever possible we
would use an existing rock wall. These
walls are about 20 – 50 feet thick of solid rock, and what we do is to
compartmentalize as best we can these individual vaults. Here is a picture down the hallway, and as
you would just walk down, they look like individual hotel rooms to the left and
to the right.
Fire suppression is also relatively easy.
This is a shot of the ceiling where we have smoke detectors. Many of our facilities would have either dry
pipe or wet pipe sprinkler systems, like this 1301 Halon Fire Suppression
System [Figure #]. We have on-site our
own fire brigade with several fire trucks.
We tested the response times of public fire fighting units, but being in
a rural area, we found them too long.
Another advantage: underground
construction costs are relatively inexpensive.
We start with an area, we looked before at the mine map, we started with
the shell of the building. What we do is
to take some of the rooms. On average
they run about 40 feet wide, about 600-700 feet long, and the ceilings are
about 14-16 feet high. We select a site,
a construction crew goes to work with a pick, and they work for quite a
while. So they will remove as best they
can any loose stone. We will work on the walls, we will work on
the roof to insure there is nothing loose that is left over from the days of
the mining era. Where needed we would
build separation walls. So, if we had a
room this size and perhaps a c???
also some challenges. Even though
you are underground, insulation is always recommended, especially when
commercial refrigeration equipment is installed. It just makes financial sense. The environmental conditions of the
surrounding space, the temperature and the relative humidity need to be
considered, depending on what the temperature and RH is you are shooting for
internally. This drawing is a schematic,
and you should have a copy of that in your packet. It just outlines the concrete block wall, the
phone insulation and wall board on the outside, and depending on how cold you
are looking to design the space, whether it is 1” or 3”. We have some 4” and 6”
insulation.
You also need to consider a vapor barrier.
A good vapor barrier is important if you are hoping to maintain the
proper storage specifications and operate your HVAC system economically. Epoxy paint is important, and also a plastic
barrier is important. You don’t really
want to underestimate the vapor pressure.
It has been known to peel paint off of walls. You need to keep a positive pressure, so within the facility you want to make sure
that you are pumping more air from the outside and conditioning it. The higher pressure inside the room than
outside helps control the dust and also insures that there isn’t a build up of
contaminants within the room itself. We
have used this weather stripping. The
space inside where Bev is standing is about 33°, outside this room is just a small 100 square foot anti-room. The temperature there is about 50°. What we do is take the material
from in the storage vault, bring it out to the anti-room where it will sit for
about a day so it can climatize before we take it out and ship the material
back to the client. So these
environmental door seals are very, very helpful.
Construction and maintenance of all of this equipment can also be a
challenge. We do our own
construction. These fellows are standing
up on a wall. These are two man crews. These are not the fellows you want to arm
wrestle at the company picnic. One
fellow will stand there with a wedge and the other will hit it with a 15 – 20
lb. sledge hammer, and they will do that all day long. So we insure that every single square foot
over head is solid rock. Underground we
allow vehicles. We have at any point and
time 25 –30 vehicles traveling underground.
As far as air quality is concerned, we tell folks it is best to pick a
place that has no air contaminants. We
bill it as ‘remote but accessible’. So
air contamination can be solved by two different methods, dilution or
filtration. We use both. By dilution we mean to move a large volume of
uncontaminated air. We remove any
airborne impurities that are introduced by the storage media themselves. Many clients send us acetate-based
material. Obviously, if they are
interested in storing it at 35°, it will be susceptible to “vinegar syndrome.” We use impregnated charcoal filters to remove
some of the acids from the air and keep those levels low. The best way to insure that you are doing a
good job is to have the air quality tested by a laboratory.
Additionally, at our facility we have five emergency diesel power
generators. Emergency power is critical.
It really puts a lot of stress on the film if you are storing material
at 35°, and all of a sudden you turn
the power off for a week and a half. So
we are able to maintain our own emergency power units. The longest we have ever been without power
is about 18 hours, and the generators certainly were more than capable of
maintaining power for those conditions.
As you can imagine, with 1,000 people underground turning the lights out
is just not an option. •
-- Tom Benjamin