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Steel

Metal muscles

By Lynn Stanley

Steel underpinnings shore up Ark Encounter

June 2017 - Faith is defined as the evidence of things not seen. That was Noah’s lot when he was instructed to prepare for a global flood—an unheard of event— by building something no one had seen before—a mammoth-sized ark. “Noah had to have a lot of faith,” muses LeRoy Troyer, founder and chair of Troyer Group.  Operating on faith is something with which the architect has firsthand experience.  In 2013, his Mishawaka, Indiana-based firm was asked to pull a blueprint from the pages of Genesis and build a life-size replica of Noah’s ark.

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A $72 million wood structure, Ark Encounter rests atop 102 concrete piers 15 ft. high in a Williamstown, Kentucky, field. The Ark is part of an 800-acre Biblical theme park and one of two attractions [the Creation Museum], operated by Answers in Genesis. From the first book of the Old Testament, instructions stated, “the length of the ark shall be 300 cubits, its breadth 50 cubits, and its height 30 cubits.” 

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“A cubit by English definition is the distance from the elbow to the tip of the finger,” says Troyer. “We used the Hebrew interpretation of a [long] cubit which is 20.4 inches.” The ark, at 15,800 tons, is the length of nearly two football fields and the height of a five-story building. Its’ 3.3 million board feet of timber, 290,000 board feet of bamboo flooring and 64 logs measuring up to 3 1/2 ft. in diameter and 50 ft. long have garnered headlines, but Troyer says “metal had a big role to play.”

The original ark was made of gopher wood and coated with pitch. The architect considered use of wood pegs but the Ark’s sheer size, designed for wind loads and reactions, prohibited use of that fastening method. “The Ark has the capacity to hold 10,000 visitors at one time,” notes Troyer. “Strength and wind pressure requirements dictated use of metal for the wood connection. From an authenticity perspective, we felt that was appropriate. Genesis 4:22 says, ‘…Tubal-cain; he was the forger of all [cutting] instruments of bronze and iron.’”

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To meet engineering requirements and building codes, Ark construction required more than 5,500 steel connection plates to fasten logs and timbers. Steel connections weighing up to 900 lbs. were used to brace vertical, longitudinal and cross sectional loads. 

“We had to build masonry towers first to support wind pressure from horizontal air flow,” Troyer says. “We used  steel rods 1 in. in diameter on each level to anchor the Ark to the tower walls.” A shear wall is typically composed of braced panels engineered to counter the effects of lateral loads like wind and seismic activity. 

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Timber frame construction was milled and supplied by Colorado Timberframe in Lafayette, Colorado. On-site crews included Amish craftsmen from Ohio, Kentucky, Illinois, Wisconsin, Georgia, Tennessee, Pennsylvania and Southern and Northern Indiana. Properly -sized heavy timber columns 20 in. by 20 in. square by 32 ft. long were machined for joints, slot cuts, and recesses. To accommodate steel plates, 67,467 holes were drilled into wood beams and steel connections. 

“Solid wood floor joists were 16 in. wide and 18 in. wide,” says Troyer. “Every 6 ft. we had to tie the joists together with steel knife plates that were 14 in. high and 5/8 in. thick. Some of the plates were up to 11 ½ ft. long. The knife plates had to match up perfectly with the holes drilled in the wood to accommodate the bolts.”

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Construction of the Ark’s three floors consumed 300,000 screws, 50,000 pegs and bolts and 500,000 self-tapping screws 7 in. long for wood floor decking. Galvanized bolts were 1 in. in diameter. Bolt lengths ranged from 10 in. to 36 in.  

Steel also shored up a total of 32 bents, the large framework sections that formed the Ark’s shape.  One half bent, every 8 ft. on center for the length, weighed 35,000 lbs. Steel plates and connectors used on the structure totaled 95 tons.

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“The Ark’s architecture is all about connections,” says Troyer. “These steel connections had to support tremendous pressures. We were dealing with huge forces.”

Timber and wood erection for Ark Encounter took a total of 14 months and was completed July 7, 2016. FFJ

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