Poles Battle to Preserve Historic Salt Mine : Wieliczka: The pit is a United Nations World Heritage site and a major tourist attraction. Artists have turned hollowed-out chambers into chapels, underground lakes and exhibition halls.

When an unprofitable salt mine outlives its expected life and is threatened daily by tectonic pressure, water seepage and flooding, isn’t it time to seal the shafts and let it die?

Under ordinary circumstances, yes. But the Wieliczka mine, 8.5 miles south of Krakow, is an original United Nations World Heritage site and one of Poland’s principal tourist attractions.

Since the 17th Century, miners have carved statuary in Europe’s oldest saltworks, which dates back a thousand years.

The self-taught artists have created altars, biblical bas-reliefs and statues of saints and heroes. They have converted hollowed-out chambers into chapels, underground lakes and exhibition halls.

Polish miners first burrowed into the dark, salt-laden mudstone in 1290. They carved out 262.5 million cubic feet of tunnels, passages, chambers and pitheads that plunge to a depth of nearly 2,000 feet and extend 180 miles on nine levels.

By 1772, visitors were allowed into 20% of this magical underworld. During World War II, the Germans built an aircraft-engine factory in one chamber.

Today, the mine’s legends and history attract some 600,000 visitors a year.

To preserve the historic portion, 1,400 employees wage a never-ending battle against nature.

Tectonic plates underlying the nearby Carpathian Mountains exert a relentless south to north pressure, geologist Aleksander Garlicki of Krakow’s University of Mining and Metallurgy explains.

“The movement can be measured in fractions of millimeters and brings tangential pressure which destroys every area of the mine,” he said.

And 700 years of burrowing have taken their toll. “The ground is like Swiss cheese,” Garlicki said.

The true miner’s art, says Aleksander Majer, who came to Wieliczka from another mine 14 years ago, isn’t the salt sculpture but the intricate network of whitewashed wooden beams erected 100 years ago to add support. In places, the foot-wide beams have snapped under pressure.

To better counteract these forces, Zarebski Zbigniew, general director of the mine, is overseeing a program designed to buttress chambers and reinforce the surrounding rock.

To support tunnels and chambers at risk, workers are filling selected areas with sand.

The 177-foot-long Chapel of Blessed Kinga, dedicated to a fabled Polish queen, contains an elaborate carved altar, bas-reliefs and salt-crystal chandeliers. Part of it now rests on a sand foundation.

In the 66-foot-tall Drozdowice Chamber, excavated in the 17th Century but currently closed to the public, miner Klawak Kosk supervises the insertion of synthetic fiber rods into the rock.

“Nobody can stop the movement of mountains,” Kosk said. He estimates that the chamber will reopen in two years and that the rods may last as long as 200 years. “I’m an optimist,” he admitted.

Majer, however, thinks the rods’ effectiveness will be short-lived. “Nature abhors a vacuum,” he said.

No less debatable is how best to prevent a repeat of the sudden flooding that threatened to collapse the 198 feet of earth separating the mine from the town of Wieliczka (population 18,000) three years ago.

As Majer leads a knee-wobbling descent to the fourth level, 530 feet underground, he recounts “the unhappy calamity” that closed the mine twice, from September, 1992, until January, 1993, and for a few days last summer.

It all started about 80 years ago, when miners inadvertently punched through an impermeable layer of clay. Immediately, water started to seep into the passageway. Alarmed, they resealed it and gave it a name: “Mina,” the land mine.

In 1992, as part of an effort to control the 8.75 million cubic feet of ground water that flows into the mine yearly from more than 300 sources, workmen again drilled into the clay barrier.

Mina exploded, gushing as much as 5,200 gallons of water a minute, pouring debris into the gallery where the miners were working, and causing some small chambers to cave in.

Eight arduous months and more than $4 million later, Mina was harnessed, and a control valve now channels the water into pipes.

Garlicki favors this response for the long term, but Zbigniew wants to cap Mina. “If we leave it open,” he argues, “we do not know where the water might flow in the future.”

The present arrangement allows workers to regulate outflow rates and take daily samples to comply with environmental laws.

Like other ground water in the mine, Mina’s is uncontaminated but too salty to pour into the nearby Wiska River.

Instead, the water is pumped into one of a dozen chambers and left there long enough to raise its salt level. Then it’s pumped to the desalination plant, where Wieliczka produces 150,000 tons of salt annually.

In the Middle Ages, one-fourth of Poland’s income came from the mine. Today’s salt sales, combined with revenue from tourism, generate enough money to cover about 75% of the mine’s operating costs.

The remainder, and money for long-term projects, comes from government grants and subsidies.

Other underground chambers include a mining museum, a recreation hall, a restaurant and a sanatorium for asthma sufferers.

Zbigniew is confident that the mine is in no danger of collapsing, that it will survive centuries longer as both a World Heritage site and a source of salt.

Someday, he hopes to invite the public to the areas he most loves--the undeveloped, dark tunnels where people can experience the mine’s “special smell, the traces of generations past--and the power of nature.”