Session	Disaster Avoidance and Recovery of Magnetic Tapes Key Findings From a 20-Year Study
Presenter	Peter Brothers Specs Bros, LLC
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ABSTRACT

In recent years, many archives and repositories have been threatened or damaged by severe flooding, earthquakes and acts of terrorism. The effects of these disasters can seriously compromise records stored at these repositories.

Over the past half century, an enormous amount of data has been archived on magnetic tape and, when disasters strike, whether natural or man-made, this data is at risk. In order to protect valuable economic and cultural records, it is necessary to have a basic understanding of what happens to magnetic tape in various disaster scenarios and what steps have been successful in minimizing losses.

For over two decades, an ongoing study has been examining thousands of tapes from multiple disaster sites around the world. Recurring exposure patterns have been identified and the effects of various disaster scenarios on the media have been analyzed. Numerous recovery procedures have been tested and methods of restoring tapes to usable condition have been developed, refined and successfully applied. Observations have also been made on the mishandling of compromised tape material and the negative effects that can result from the application of inappropriate protocols.

This paper will provide an overview of findings on what has and has not proven successful in protecting and recovering magnetic tapes from actual disasters. It is based on the examination of tapes recovered from a wide variety of disaster sites. It will discuss general damage patterns observed and highlight a few key damage avoidance measures that proved highly effective at protecting materials and minimizing loss at the disaster sites where they were employed. It will also review handling techniques and recovery protocols that have repeatedly proven successful at maximizing the recovery of compromised tapes and which protocols may not be appropriate with some formats.

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PRESENTATION

In recent years, many archives and repositories have been threatened or damaged by severe flooding, earthquakes and acts of terrorism. Records stored at these repositories can be seriously compromised by the effects of these disasters.

During the past half century, an enormous amount of data has been archived on magnetic tape. When disasters strike, whether natural or man-made, this data is at risk. In order to protect valuable economic and cultural records, it is necessary to have a basic understanding of what happens to magnetic tape in various disaster scenarios and what steps have been successful in minimizing losses. Such understanding can also assist archivists in evaluating the continued viability of magnetic tape as a storage or back-up medium.

Over the past two decades, SPECS BROS., LLC has examined hundreds of thousands of magnetic tapes from various parts of the world that have been exposed to a wide variety of environments and disasters. We have examined and tested tapes that have been burned, melted, crushed, and immersed in liquids ranging from water to chemical spills and maliciously applied solvents. These tapes have been recovered from out of damaged buildings, from the bottoms of lakes and oceans, from war zones and crime scenes and literally from out of the jaws of children, pets and, in one instance, crocodiles.

Our experience has highlighted a number of key issues concerning the effects of disasters on magnetic tape. First and foremost, polyester-base magnetic tape is highly resistant to short-term exposure to most disasters. Our results show that over 95% of the tapes recovered from disaster scenarios can be returned to playable condition if they are recovered intact and treated within a few days. Of those tapes that are not fully recoverable, more than half of the recorded data can be recovered from an additional 95%. This means that less than 1/4 of 1% of the tapes are compromised to the point that the majority of the recording can not be retrieved.

The primary reason for this high recovery rate is that short-term exposure to most disasters does not affect the signal recorded on the tape. Tapes recovered from disasters are compromised such that the signal cannot be retrieved but the signal still exists. This allows for successful recovery procedures to be employed that focus directly on the physical structure of the medium.

When recovery personnel handle compromised tapes so as to avoid additional damage, and damage mitigation procedures are applied in a timely fashion, the vast majority of loss can be averted. In fact, most of the losses we see are not the direct result of the initial disaster exposure but are actually caused by mishandling and delay in treatment. Observed effects of exposure clearly indicate that the two most critical times to mitigate damage to magnetic tape and insure effective recovery are during a disaster and during the first 72 hours immediately following a disaster.

It is this final point, the initial actions taken, that is truly the difference between successful recovery and unnecessary loss. As such, some disaster planning to direct those actions is extremely important. We have found, however, that it is often the simple, direct plans that have been most effective. After 9/11, many organizations began to implement fairly complex and inclusive disaster plans. Unfortunately, complexity in directing a disaster response can be as much of a hindrance to the recovery of archival materials as no plan at all.

I do not intend to investigate the development of disaster plans at this time but do wish to point out a few crucial components that have repeatedly proven to have a major impact on the successful recovery of magnetic tapes.

To start with there must be clear, simple directions for the initial response. Complexity during or directly following a disaster leads to confusion. A good first reaction makes later clean-up and recovery more efficient.

It is also essential to identify one person who has both the responsibility and the authority to act immediately. Too often, complex bureaucratic plans place lower level employees in the position of being responsible for areas of reaction but give them no authority to actually perform what is needed. Additionally, 10-15% of the time, the individual in charge of initiating recovery does not know what formats of tape are in their collections, or even whether the media are tape or film! Needless to say, in such circumstances, recovery efforts are seriously hampered.

In accordance with Murphy’s Law, disasters frequently occur when the person tasked with oversight responsibility is absent. Disasters have a propensity for striking after hours, on weekends and during holiday periods. Therefore, a back-up person must be identified and the off-site contact information for both people must be readily available.

While a disaster is actually in progress, should personnel be able to enter the archive safely to perform damage control, by far the most effective tool has repeatedly proven to be plastic tarps. While simplistic to the point of absurdity, the use of plastic tarps to divert contamination from direct contact with materials has done more to protect tapes in actual disaster sites we have investigated than any other single activity.

Another key issue that has a major impact on recovery, but is frequently overlooked, is the identification and allocation of an immediate source of funds that can be tapped to cover initial costs. When a disaster strikes, there isn’t time to hold a board meeting, a fund raiser or wait for a check from the insurance company before starting damage control on magnetic tapes.

Finally, if in-house experts don’t exist, identification and pre-approval of recovery experts who are experienced at handling tape materials is essential. Like in-house personnel, contact information for recovery experts needs to be readily available. Even from a remote location, restoration experts can begin directing recovery activities so that materials are handled properly.

With these few things in place, and at a cost of less than $50 US, one can have the basis of a response with a proven track record of success in recovering magnetic tapes. Consider the difference having these provisions makes in a couple of actual disasters:

• In the New York area, firemen respond to an alarm in the middle of the night. Following procedure, they cut a hole through the roof of a facility to evacuate smoke before entering. During this process, they realize they have targeted the wrong building. The fire crew relocates without informing anyone that they have left a 20 by 20 foot hole in the building’s ceiling.

• Early the same morning, there is a heavy rain and water begins to pour through the roof into a facility holding over one million audio and visual documents.

• The staff immediately calls the manager (at home), and the approved recovery experts; in this case, SPECS BROS. The manager contacts the roofer to effect repairs and a recovery specialist gives the staff “first response” orders before heading to the facility. Plastic tarps, already on hand, are used to cover materials under the falling water while other tarps are formed into funnels and attached to the ceiling to catch and divert the water away from sensitive materials. Mops and buckets are used to control the water level in the facility until larger equipment can arrive.

• Within a few hours, the roof is patched, materials are triaged and damage control commences on all materials that actually got wet. Within 24 hours, the roof is fully repaired and the archival environment is stabilized.

• While full recovery takes some time, a quick, decisive disaster response results in only a single tape, out of over a million elements, receiving serious damage.

On the other hand, consider what happens when effective reaction is delayed. As in the first case, this disaster is started by something outside the facility’s control.

• In Florida, while testing a local flood control system, county technicians mistakenly close some out-flow valves. When the system is flooded, the blow-back sends fountains of water into a facility through the floor drains.

• No reaction supplies are on-hand and virtually all of the materials near the drains are soaked with water. No experts or support personnel are either called in or consulted. The heavily contaminated materials are simply removed from the facility and stacked in piles to dry on a covered loading dock. These actions result in hydrolytic decay, infestation by vermin and fungal growth.

• Damage control and material recovery is not begun until money is received from the insurance company nearly 60 days later. By this time, some of the material is severely damaged by fungus and decay and can’t effectively be restored. Additionally, the “time and treasury” required to treat the salvageable materials is more than doubled.

These are just two out of a great number of sites we examined where the basic precautions listed made the difference in the initial response and were the major mitigating factors in both the amount of damage done to the materials and the percentage of materials that could be easily restored.

In addition to basic planning, there are a number of simple actions that can be taken with tape materials before a disaster occurs that have a substantial effect on potential recovery. As in the case of planning, I do not intend to cover pre-disaster precautions extensively. I only intend to highlight a few, simple actions that our examinations have shown to be both effective and easy to implement.

First, all cassette formats have an erase lock-out device. Some are tabs, some slides and some are buttons on the cassettes. Two thirds of the recorded cassettes we examine from networks, libraries, museums and production facilities are in the active record or erase mode. While this doesn’t relate directly to large scale disasters, every master tape left in the erase or record mode is a disaster waiting to happen. We receive multiple calls every week from individuals, both private collectors and professionals, who have erased or recorded over irreplaceable data. It is a simple matter to active the erase lock-out on cassettes and, with current technology, most data on tapes that is erased or overwritten cannot be recovered.

Nearly one half of the cassettes we examine are not rewound. In a disaster, the portion of the tape that receives the greatest exposure is that portion that is on the outside of the wrap or between reels in a cassette. On a wound tape, both the reel and the outer wraps of the tape give added protection to the inner wraps. In most instances, even when the outer wraps are melted, the inner wraps can be restored to playable condition. When the tape is rewound, the exposed section is frequently leader or bars and tone which can accept damage without any loss of recorded programming. Unfortunately, when a tape is stopped in the middle, there is often a reason. Too often that reason is that the place where the tape is stopped contains the most important section of recording, thus exposing to damage the one section one most wants to protect.

Another effective precaution is to store tapes in plastic cases. Cardboard or cellulose-based tape boxes provide virtually no protection against crushing or piercing damage in a disaster. Should the disaster also involve water, cellulose-based containers retain moisture and promote fungal growth. Once fungus has established itself on the box, it will spread to the tape. Fungus can be removed from tape but, over time, fungus will do permanent damage that is not correctable.

Even should plastic cases be used, the positioning of the case on the shelf can be important in protecting material during a disaster. Plastic cassette cases should be stored on-edge, spine-up to provide optimal protection. In this position, falling water is diverted away from the tape. Standard cassette cases stored in the usual upright position, with the spine outwards, actually catch falling water and divert it into the case and onto the tape inside. In a number of archives where tapes are stored in both positions, after a disaster, cassettes stored on shelves spine-up in the area of water incursion showed virtually no direct contamination. Tapes stored in the same areas but in the conventional position showed over an 80% incidence of contamination on the tape surface.

On final precautionary measure is to make sure that no tapes are left directly on the floor at any time. Tapes left on the floor will invariably suffer during a disaster; especially should the disaster involve water. While most archives are good about following this precaution in general practice, we have examined very few collections where it is not abused at some time. Even if tapes are placed on the floor only temporarily, it should be remembered that disasters do not announce themselves or abide by set schedules. One clear example of this occurred in an archive in the Southeast where all materials are consistently shelved off the floor. The only exception to this practice happened on a single afternoon when a collection of new masters was arranged on the floor to be sorted and inventoried. That, of course, is when the archive experienced its one and only flood.

While a few simple precautions can reduce the eventual impact of a disaster on magnetic tape, disasters do happen and, unfortunately, disasters can happen to anyone, at any time. All too often it is assumed that disasters are rare outside of known flood zones and areas frequented by severe weather. In actuality, most of the disasters that impact magnetic tape are the result of failing technology, not the weather. Most relevant fires are due to electrical shorts and, by far the greatest numbers of disasters that affect magnetic tape are the result of flooding due to broken pipes.

Once a disaster has struck, the primary thing that must be remembered is that, no matter how bad it looks, most tapes can be saved if treated properly. The greatest losses are actually due to tapes being discarded without any attempt at recovery being made. Most of these tapes are discarded on the basis of superficial contamination that can be removed using standard cleaning procedures. The second greatest number of losses is due to mishandling during recovery attempts. Often tapes are damaged or lost when inappropriate recovery procedures are applied or when recovery of the recording is attempted by simple playback of the compromised tape without the application of any remedial processing.

With this in mind, one of the first prohibitions is: Do not play contaminated tapes.

Minute amounts of debris can interfere with signal retrieval resulting in inferior copies or excessive error concealment. During playback, some debris can also result in serious head damage, abrasion to the tape surface and ripped tapes.

The signal loss from debris can almost always be corrected by proper decontamination. Even if the debris has slightly deformed the tape, some resizing can be done. On the other hand, if the spacing loss represents part of the recording surface that has been scraped off or deeply scored by debris during playback, the damage done during playback can’t be corrected.

If the tape is wet or retains a high moisture content, the tape will also warp and stretch. Since water seriously compromises the elasticity of the tape, this deformation cannot be treated with resizing. Another complication is the tendency of wet tape to adhere to itself and to the interior of a cassette. Playback of tapes before these adhesions are treated will result in tape shearing and/or sections of the recording layer tearing from the base.

To avoid causing additional damage when handling tapes retrieved from a disaster site, the first thing that must be determined is the severity of exposure. Unless damage control is going to be initiated, this can generally be done by examining the outsides of the cases. No standard tape case is either air-tight or water-tight. If the outside of the case is contaminated, the inside will be as well.

At this time it is also necessary to identify if the contamination is dry or involves liquids. Most dry particulates will not chemically interact with magnetic tape. As such, dry contamination is not time sensitive and treatment can be delayed without additional damage to the tapes.

Wet contamination, on the other hand, is extremely time sensitive. Any delay in treatment will increase the difficulty of recovery, the cost and the potential to lose some or all of the recording. Recovery of wet materials is most effective when experts are able to begin processing the tapes right away, while they are still wet from the original exposure.

When first examining tapes it is important to reduce the spread of debris and isolate contaminated materials. In this process, tapes that are dry should always be separated from tapes that are wet. In addition, if the contamination is dry, it should not be cleaned using water. Applying water can activate chemical reactions with dry debris that otherwise would be harmless to the tape.

Tapes should also be removed from the disaster site to reduce extended exposure to the negative environment. The physical structure of the tape may be compromised after exposure and they must be handled very gently during this and all other procedures.

Extreme care must be exercised in allowing access to tapes by any commercial cleaning crews that come in to deal with the physical plant. Many of the chemicals they use are harmful to magnetic tape and can do more damage to the tape than the disaster itself. A classic example of this occurred at one disaster site we visited in the Northeast. In this instance, the simple task of removing smoke residue from tapes was seriously complicated by the actions of a fire restoration crew. Tape which should have been easy to restore was seriously damaged when the crew washed the tapes with the same high-chlorine-content cleanser they use to remove visible soot from walls.

If tapes are wet and they cannot be treated by experts right away, some damage control must be done on-site by existing personnel. To start with, all paper inserts and cardboard boxes need to be removed from the vicinity of the tapes. Fungus will grow on tape but fungal growth will usually start on the cellulose and then transfer to the tape surface.

If wet tapes have been contaminated with water containing salt, sewage, a high concentration of metal ions or chlorine, these contaminants must be removed as soon as possible. The danger of having someone not experienced in tape recovery do this has to be weighed against the certainty that leaving these contaminants on the tapes will cause serious damage over a short period of time. When rinsing water-soluble contaminants off magnetic tape, only cool distilled water should be used. A common mistake made by untrained personnel during this process is to use presumably clean tap or drinking water to rinse tapes. Unfortunately, much of the drinking water in the United States and elsewhere is chlorinated and rinsing tapes in chlorinated tap water can cause substantial damage.

Another mistake that is often made at this point in handling is the practice of keeping wet tapes submerged in cold water until such time as they can be treated. This procedure can and does work well with polyester-base magnetic tapes that have ferric oxide recording pigments, such as ¼” audio, 1” Helical and VHS. However, many new tape formulations, including most digital formats, use active metal particle recording pigments that can oxidize. These particles are sensitive enough that a ceramic coating is added to seal them from the environment. The ceramic armor seems to work well against atmospheric moisture but often fails catastrophically when submerged. When active metal particles are exposed to water and oxidize, they lose their magnetic properties and can start a cascade effect that damages surrounding areas of the tape.

This problem will appear more often as the current trends toward digitalization and higher data densities on media result in more data being stored on mediums that are less chemically stable. With active metal particle tapes, even short submersion times can result in serious damage. Recovery processing of these materials is substantially more difficult and attempts to mitigate damage in-house without expert help is less effective. Unless treated immediately by experienced personnel, expected recovery rates on these new materials is reduced and three times as many tapes are likely to suffer some permanent damage as compared to ferric oxide tapes.

Rinsing and removal of contaminants, when done by experts, usually involves removal of the tape from its cassette and/or reel to be most effective. This procedure greatly increases the recovery rates that can be achieved but is not recommended to be attempted by inexperienced personnel. Consider that a small D-2 cassette, not including the basic shell, door, hubs posts and the tape itself; contains 20 moving parts, half of which are metal springs. If the tape is wet, it may also be adhering to the interior of the cassette. While trained technicians can remove tapes from cassettes and reels safely, many tapes we examine that were taken apart by untrained personnel show damage from the procedure. This is particularly true with wet tapes and many newer tapes with small widths and thicknesses.

The reduction is size of many of the new digital formats is another trend that will seriously impact the success and degree of recovery possible in the future. Simply compare the dimensions of a 1970 era 2” analog tape and a 2004 era 6 mm digital tape. A relatively small section of damage that may or may not produce some signal distortion on a 2” tape can be large enough to exceed the full width of a 6mm tape. In addition, damage that may only scratch the surface of the 2” tape will penetrate entirely through the new, thinner format. Exposure during a disaster can be expected to cause twice as much damage to extremely small formats than to larger, more robust tapes. Should a format with very small dimensions and an active metal particle formulation be submerged, recovery rates can be reduced by both limiting factors. This makes expected recovery a basic 50/50 proposition unless immediate damage control is performed by a restoration specialist.

The highest rates of recovery may require a number of steps be taken depending on the type and severity of the expose the tape has received. These can include chemical decontamination to remove non-water-soluble contaminants, desiccation of tapes to stop hydrolysis and stabilize the structure, resizing of deformed tapes, solvent or mechanical breaking of adhesions and one or more types of machine or hand cleaning. Once these procedures have been applied however, our testing shows that a remarkably high percentage of the tapes recovered from disasters can be restored. Unfortunately, our testing also shows that the combined trends toward, digitization, high data density on the recording medium, less stable formulations and reduction in media size have a cumulative and negative effect on recovery.

As collections on older tapes are being transferred to modern formats, there is another potentially disastrous trend. This is the practice in some collections to dispose of obsolete originals after remastering or digitization. Our studies do not suggest in any way that modernization of records be halted or reversed. What our studies clearly do show is that polyester-base tape, particularly many of the older formats, have well developed techniques for and a proven track record of content recovery from disasters. These results provide a strong case for the retention of the original tape materials, even after migration, until such time as similar recovery rates can be consistently demonstrated for the newer mediums. Should high recovery rates not be obtainable for some of the new mediums, after a disaster, recovery of data from the old originals may be the only viable alternative available.

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SPEAKER BIO

Peter Brothers
Peter Brothers is CEO of SPECS BROS., LLC, a magnetic tape restoration and disaster recovery facility. Over the last twenty years SPECS BROS has processed hundreds of thousands of tapes from all corners of the world. In addition to restoring aging and compromised magnetic tapes, they have recovered tapes from a wide variety of disasters including floods, fires, shipwrecks, earthquakes and plane crashes.

An internationally recognized expert, Mr. Brothers has given presentations to numerous organizations on tape preservation and disaster recovery including AMIA, FIAF, The Library of Congress, The National Archives, The International Television Association and The International Teleproduction Society. Mr. Brothers is an active member in the committees and working groups of AES, ANSI, ISO and SMPTE that draft standards and recommended practices associated with magnetic tape preservation. He is one of the primary authors of the new ISO standard on Magnetic Tape- Care and Handling for Long-Term Usage.