This 585-foot Montana tower ended a deadly rain of 20 tons of arsenic per day

Building the World’s Tallest Brick Stack in 142 Days

The Anaconda Smelter Stack rose from need, not pride.

Back in 1918, the old 300-foot stack dumped 20 tons of arsenic daily, killing farm animals across Deer Lodge Valley. So the copper company went big—really big.

On May 23, smelter boss Frederick Laist laid the first brick of what would soon stand 585 feet tall. In only 142 working days during World War I, they built the world’s tallest brick structure.

Just 12 bricklayers per shift did the work, using 2.4 million special radial bricks and wood from 10,000 trees.

Today, this massive monument to American industry still towers over Anaconda, Montana.

Toxic Smoke Forced Anaconda to Build a Giant Stack

The old 300-foot Washoe Smelter stack pumped 20 tons of arsenic daily into Deer Lodge Valley. Farmers watched their livestock die and crops wither from the poison cloud.

Anaconda Copper Mining Company faced growing anger from locals about the toxic fumes, even as World War I needed top copper production.

Company bosses knew they needed to fix this fast. Their answer?

Build the world’s tallest smokestack to shoot the pollution higher into the sky where it would spread out and harm less.

Concrete Foundation Used Materials by the Trainload

Workers poured a huge concrete base in May 1918. The foundation stood 30 feet high and weighed 9,000 tons.

Building it took 20,891 bags of cement, 50 train cars of sand, and 118 cars of crushed rock.

Crews shaped it into an eight-sided base measuring 99.5 feet across at the bottom, getting smaller to 89 feet at the top.

They picked a spot on a hillside near Anaconda, placing it to connect with the smelter’s maze of flues.

The Boss Got His Hands Dirty with the First Brick

On May 23, 1918, smelter boss Frederick Laist rolled up his sleeves and laid the first brick himself. His brick marked the start of America’s biggest masonry project.

The Bricklayers and Masons Union made such a big deal about this that they named Laist an honorary life member right then and there.

The gesture brought bosses and workers together during a time when the war effort needed everyone working together.

German Engineering Know-How Built America’s Tallest Stack

The stack needed special bricks created by German engineer Alphons Custodis. These weren’t normal building bricks.

Each one came shaped like a wedge to make perfect circles as the stack grew taller. Workers placed 2,464,672 of these custom bricks, equal to over 6.6 million regular bricks.

The Alphons Custodis Chimney Construction Company from New York ran the job under boss W.C. Capron. Brick makers in Anaconda made the special blocks right near the building site.

Just 12 Bricklayers Built the Whole Massive Structure

Most big building projects use huge crews working day and night, but not this one.

The stack went up with only about 12 skilled bricklayers per shift, working just one 8-hour shift each day.

These craftsmen had to learn how to lay wedge-shaped bricks that created smaller circles as the stack grew taller.

They started with the tricky eight-sided base before moving to the round main section. Their steady pace kept the project moving despite its huge size.

Forests Became Scaffolding Inside the Growing Tower

The stack used up 305,000 board feet of lumber, about 10,000 trees, just for the scaffolding inside.

Workers built this wooden frame higher as the brick walls rose toward the sky. The scaffolding let bricklayers reach their work and held materials being hauled up.

As Montana winds blew around them at greater heights, the wooden structure had to stay solid. Safety gear was basic, making the job more dangerous with every foot they climbed.

Wind Resistance Made the Stack Super Strong

Montana’s strong winds could knock down a normal chimney this tall. Engineers designed this one to handle wind pressure up to 33 pounds per square foot.

The stack got smaller from 76 feet inside width at the bottom to 60 feet at the top, giving it better wind strength.

The special wedge bricks created fewer joints where wind could push through.

Steel rods ran through the round part, tying everything together. This careful design kept the stack standing through decades of Montana’s worst weather.

Workers Finished in Record Time Despite Wartime Challenges

The last brick went into place on November 30, 1918, exactly 142 working days after the first one. This speed seemed impossible for such a massive structure during wartime shortages.

The bricklayers kept a steady pace even as they worked at more dangerous heights. By the time they finished, they had created the tallest brick structure on earth.

The project wrapped up just 19 days after World War I ended.

Hidden Technology Inside Made the Stack Work Better

The finished stack looked simple from outside but had complex systems inside. Workers hung 111 miles of electrified chains to catch particles from the exhaust gases.

The system handled 3. 5 million cubic feet of gas every minute from the smelter furnaces below. Complex flues connected dozens of furnaces to the single chimney.

Two large openings in the eight-sided base let the toxic gases flow in before starting their journey upward.

Smoke Finally Flowed Through the Finished Marvel

The big moment came on May 5, 1919, when smoke first poured from the 585-foot stack.

People watched from miles around as dark clouds billowed from what was now the world’s tallest free-standing masonry structure.

Travelers on Interstate 90 could spot it from far away. The stack served the Washoe Smelter faithfully for 61 years until operations stopped in 1980.

Today it still stands as a monument to American engineering.

Visiting Anaconda, Montana

You can visit the 585-foot Anaconda Smelter Stack at the junction of Park Street and Monroe Street.

The free 12-acre viewing area at Anaconda Smoke Stack State Park lets you see this 1918 engineering marvel built with over 2.4 million locally-made bricks.

Check out the replica brick circle showing the stack’s massive size and explore original smelting pot artifacts big enough to walk inside for photos.

This article was created with AI assistance and human editing.

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