By John Morris
The same disaster can, and does,
strike a business office, a museum, an architect’s office from time to
time. The lowest level collects the water and suddenly comes the realization
that you have 50 or 100 file cabinets loaded with important records and
legal papers, all swimming in dirty water; something has to be done quickly,
These water emergencies are the business of the drying contractor. He flies to the scene, assembles a work force, and hustles everything into cold storage. Freezing stabilizes the damage, prevents mold from forming, and buys time to get the drying operation set up. This may take days or weeks, or even longer. In Los Angeles, after the fire of April 29, 1986, 700,000 books went into the freezer warehouse and stayed there for 2 1/2 years. This was the background for the drying job that set new standards, using a new process that takes half the time and produces a better result.
Late in January, 1989 a load of books was delivered to the Los Angeles Public Library processing center, marking the end of the largest book drying job ever undertaken. In 4 months 560,000 books water-damaged in the 1986 fires were processed in a sophisticated vacuum freeze-drying operation at Saugus, California. Commencing in late September, 1988, 4 days every week a load of books went from the freezer warehouses to Saugus, and 4 loads of dried books went from Saugus back to the library. The driers ran day and night, and the job was finished well within the 6 months time stipulated in the contract.
The 560,000 books represented 80 per cent of the total number of books wet in the 1986 fires. The major share of the lot went to Document Reporcessors of San Francisco, while Airdex of Houston contracted for the remaining 20 per cent. The wet books had been blast-frozen immediately after the fires and placed in warehouses normally used for shrimp and other perishable food items. When the library was finally able to locate processing and storage space, the Los Angeles City Council set aside $2,800,000.00 for the restoration of the books.
For several years vacuum freeze-drying has been considered the preferred method of restoring wet books that have been kept frozen to stabilize damage and prevent mold from forming following a fire or water emergency. The ice-covered books are placed in a vacuum chamber and subjected to vacuum and vapor form (sublimation) and is collected on chilled panels in the form of ice.
Eric Lundquist, founder and president of Document Reprocessors and his associate, Robert Ritchie, have lately refined this conventional drying routine with advances in both technique and equipment and have given the name THERMALINE to the new process. It shortens the typical drying cycle for heavily water-damaged materials, and eliminated the need for refreezing water vapor on cold surfaces within the vacuum chamber. What formerly required 10-15 days can now be done in a 4-8 day period. The new method also provides a mechanism for straightening boards and text blocks during the drying cycle, minimizing the distortion previously encountered during the drying, and useful also for reprocessing books which were dried previously, but are still in need of straightening.
Other refinements provide for enhanced distribution of low heat uniformly to the books in the vacuum chamber. Lundquist has found that when the inside of a frozen book is warmed only slightly above freezing temperature it tends to return easier and in a shorter time to its original alinement, and with less stress to the materials. The effect achieved is somewhat like the benefits of annelaing in working with metals, and is referred to by this term by Lundquist and Ritchie. This method is one of several in the process of patenting.
Having bid on a contract for drying 700,000 books, more or less, in 6 months, Document Reprocessors leased an industrial building in Saugus, 33 miles from central Los Angeles. They installed 5 vacuum chambers, 3 of which are semi-trailer mounted cylindrical tanks, 8 1/2 ft. across and 45 ft. long. The other two are smaller stationary units.
A typical journey for the books began at 7 AM with the loading of palletized books into a refrigerated truck at the freezer warehouse. There were 50,000 boxes of books to be moved eventually, each box containing 15 books, more or less. A single truck would carry 8,000 to 10,000 books. Within an hour after leaving the warehouse the truck was unloaded at Saugus. The books were unpacked, categorized according to the degree of wetness, and prepared for the vacuum chambers. Workers at tables placed books of uniform size spine-down in aluminum tray, 10-15 books in a tray 18 inches long and easily handled. They then placed rigid aluminum plates between books at close intervals, and around the lot wound two or more wraps of elastic “bungie cord” under tension. Each tray was then loaded on a metal cart roughly 6ft. by 4ft. and 6 tiers high, and the carts were then positioned in the vacuum chambers.
Inside the chambers workers connected the warm water circulating system to metal tubing secured to the underside of the metal shelves of each cart. The vacuum pumps were activated to reduce the internal pressure. The warm water began circulating, and the heat was conducted from tubing to shelves, from shelves to trays, and from trays through the aluminum plates into the damp books. The water temperature was monitored and controlled to limit the book temperature to approzimately 100 F. As the books dry, shrinkage occurs, usually 10 per cent to 20 per cent, and the binding of elastic cord contracts, applying constant pressure toward one end of the tray, combining with the rigid aluminum plates to help straighten any distorted covers or text blocks.
When the drying cycle was complete the racks were removed from the vacuum chambers, the books inspected for humidity (7 per cent maximum) and packed in new boxes for the return trip to the library. Boxes were placed on pallets, shrink wrapped for protection during shipping and handling, and loaded into the truck. When unloaded at the library’s processing center in Los Angeles they would be put through cleaning, evaluation and inventory, then be moved along to the temporary location of the Central Library.
Eric Lundquist and Robert Ritchie are graduate mechanical engineers. Mr. Lungquist founded Document Reprocessors in 1979. He had seen the need for improved drying methods when he worked as an insurance claims adjuster. His first major contribution to the science of book drying was probably designing a vacuum chamber on wheels and making it available wherever there was a major water disaster involving books, fine arts, documents or business records. Document Reprocessors acted as consultants to the library staff during the emergency removal of wet books after the fire disaster of April 29, 1986 at the Los Angeles Central Library.
On behalf of himself and Robert Ritchie, Eric Lundquist has applied for patent rights to be assigned to Document Reprocessors for several innovations of the THERMALINE process in the drying of wet books and materials, specifically claiming the following:
1. A method of applying uniform heat and controling the temperature throughout the pressure/time cycle for drying wet books and materials.
2. A method of providing nearly constant compression force on wet books, such that, as shrinkage occurs during the drying cycle, the cover boards, text block and other materials are provided a rigid and straight surface to conform.
3. A method to straighten books that, when previously dried, exhibited severe distortion (but) can be recycled in the described equipment and restored to a near original straightness.
4. A method which is suitable for a very high rate, mass drying of books. The fundamental equipment and process beyond one tray is identical. Only the capacity of the heat sources and vacuum pump(s) needs enlarging.
With their vacuum chambers on wheels Document Reprocessors have been able to move promptly to any part of North America to respond to water emergencies. In 1985 they went to Dalhousie University in Halifax, Nova Scotia to dry 90,000 books wet in a fire in the Law Library. In November of that year, when a disastrous flood left Roanoke, Virginia under 14 ft. of water they were able to save millions of documents and business records. And when an arson fire struck the records of the Supreme Court of New Jersey, and the drying had to be done on site, Eric Lundquist took his Arctic 550 freeze drier across the country in a 747 aircraft and dried the documents. In addition to the western base at Saugus, California he has an eastern base at Middlesex, N.Y. and two seagoing driers.
References on salvage of wet books and materials:
An Ounce of Prevention - A Handbook on Disaster Contingency Planning for Archives, Libraries and Record Center, Toronto, John Barton and Johanna Weilheiser, 1985;
Salvage of Water-damaged Books, Documents, Micrographic and Magnetic Media, San Francisco, Eric G. Lundquist, 1986;
Salvage of Water-damaged Materials, Washington D.C., Library of Congress, Peter Waters, 1975;
Planning Manual for Disaster Control in Scottish Libraries
and Record Offices, Edinburgh, National Library of Scotland, Hazel Anderson
and John McIntyre, 1985.
Written by John Morris, Professional Services in Loss Control.
This article adapted from Vol. 2 No. 4, p. 12.
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