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,
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
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
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.