After Czech floods, a quick-freeze fix

Czech Position

A new exhibition reveals how the Czech National Technical Museum (NTM) rescued their archives from the great flood of 2002

Soaking, stinking paper, books and photos. And a lot of mud. That’s what greeted staff of the Czech National Technical Museum (NTM) on August 16, 2002 when flood waters receded and they were able to get into their depository building in the Prague district of Karlín.

Water levels hit three meters, and the ground floor was flooded to the ceiling. Shelves of archived material were toppled over everywhere, wet and mud-soaked. Could it all be a total loss?

Amazingly, no. Thanks to quick thinking and lots of volunteer help, the NTM was able to save practically all of the flooded material. How they did it is a new exhibition titled “Dosušeno” or “Drying Completed” on now at the museum’s main building in Prague 7.

“It was a mess, devastation in the rooms,” Petr Krajci, the curator of Dosušeno, told Czech Position. “We were lucky because we got permission very early to enter, thanks to the army. The water stayed in Karlín three days before receding and it was during that time we decided to freeze everything,” he said.

More than 200 volunteers assisted museum employees in preparing the material for the deep freeze. Because the material has swelled, workers had to take whole stacks of material off the shelves, spray the mud off and wrap them in polythene film.

Flash Frozen

“The paper must be frozen in a ‘shocked’ way; 22-24 degrees below zero to prevent the crushing of the paper, it’s similar to flash freezing vegetables,” Krajci said. “Maersk came to the rescue with a freezer trailer that could be powered by a diesel engine; there was no electricity in Karlín at that time.”

With about 40 people working per day, everything was frozen by August 26. Freezing everything quickly was essential to prevent an onslaught of mildew and rotting bacteria arising from the summer heat. So everything’s frozen — how do you unfreeze them?

Staff tested a variety of drying techniques for about six months before finally choosing a manual method. “The first idea was defrosting in a vacuum which is very technologically advanced,” Krajci said. “This way was not based on technology but primitive ways of drying archival materials.”

Defrost & Dry

Shown in the exhibition in words and photos are the two methods used: sandwich and vacuum. In both, material is set out to defrost naturally for about 18-20 hours. Then, staff manually disassembles the thawed sheets from the packages.

As there was a mix of materials in each package, this was essential to saving individual documents. Each piece was cleaned and then pressed together in several layers of a blotting material, separated by layers of unwoven textile. The sandwich method was used for bigger pieces; non-woven fabric was layered with absorbent materials and then the entire sandwich was weighted down. Smaller A3 and A4 sized documents were wrapped in newspapers and vacuum-packed sealed. Both methods required the wrapping and rewrapping process to be done two to three times.

“We knew the process would take years so we developed our own in-house department to do it,” Krajci said. “The government guaranteed a special fund to finance the department.” From 2002-2011 costs for rescuing the flood archives have grown to Kc 25.3 million.

“On display you can see defrosted materials,” Krajci said. “Stamps have rubbed off on to other documents, ink is blurred, but it’s readable and it survived.” Paper documents came out relatively well, it was the photos that were the most difficult to save.

“Photos and negatives, they are very fragile, it was a question of hours, not days to save them and we did lose part of the collection,” Krajci said. “Immediately after defrosting we digitalized them. Sometimes the quality was compromised after defrosting and in some cases we are seeing the effects one year later.”

The museum’s hard work paid off: out of 200 cubic meters of archived materials, a loss of only 2-3-percent is estimated.

Seeing is Believing

The exhibition is located in the museum’s Architecture, Engineering and Design wing: Follow the muddy footprints from the elevator. Along the back wall, a photographic chronology has been designed, showing the first days of devastation and the volunteers mucking about trying to save the documents to staff working in the museum separating, cleaning and drying them.

You’ll also see a variety of defrosted items; to the untrained eye, it seems almost impossible they were flooded, frozen and defrosted. Paper and photos weren’t the only things destroyed; there were also cardboard models — you can see reconstructions of them in one of the displays. Open the drawers beneath the exhibit and you’ll see photos of how some of these models looked immediately after the flood and how they were repaired.

The museum is in the process of completing a new archive building located in Celákovice which is set to open at the beginning of next year. Krajci said the three new buildings are specially designed and built to hold archive materials, with heavy walls, a stable interior climate, safe roofs and double doors to regulate temperature levels.

What seems like a tedious process has resulted in the museum’s archives being clean, dry and sorted. And for Krajci and the staff, that is the most important thing. “It’s not like it was before, but the documents are preserved for the future.”