MILLTOWN, DE – Pennoni Associates, an award-winning consulting engineering firm, assisted Delaware’s Red Clay School District in building the tallest Lego structure ever assembled. A representative with Guinness World Records certified the district’s 112 foot, 11 ¾ inch high tower as the tallest tower constructed of interlocking toy bricks, defeating the previous the record of 106 feet, 7 inches, held by Prague in the Czech Republic.
“When it comes to a tower this tall, Lego bricks are much more than child’s play and we were fortunate to have professionals, including Pennoni Associates, to make sure the tower was safe and successful,” said the district’s Assistant Superintendent Ted Ammann.
In preparation for setting the new record, Pennoni structural engineers volunteered to design the internal steel mast that would provide the lateral support required to prevent the tower from toppling over. The tower, constructed of Legos, was required to be freestanding and therefore could not be supported vertically from the steel mast. However, lateral support of the tower was required due to the forces from wind gusts that could easily cause the tower to collapse. The steel mast was designed as a series of steel pipes ranging in size from a six-inch diameter at the base, to a three-inch diameter at the top of the tower. The steel pipes were built in 20-foot sections and were engineered to slide into one another to make erection and disassembly easier. At each section of pipe, a quarter-inch diameter tensioned guy-wire was attached to a gusset plate welded to the steel pipe to provide support for the steel pipe itself.
Six guy-wires were installed in each cardinal direction to brace the steel pipe for wind loads in any direction for a total of 24 guy-wires in all. Four large concrete mass anchors were cast into the ground 60 feet from the tower base in each direction to anchor the guy-wires to the ground. A large concrete foundation was also cast at the base of the tower to support both the steel mast and the Lego tower itself. The theory behind the design is that the steel mast and guy-wire assembly is a self-supporting stable structure. The Lego tower was built in sections and placed around the steel mast, with careful consideration and planning so that the tower did not touch the mast at any location. Voids were left in the tower at the gusset plate locations to allow the guy-wires to connect to the steel mast without touching the Lego tower itself. As wind blows on the Lego tower, the structure will deflect until it makes contact with the steel pipe inside the tower, which will resist the loads caused by the wind, and prevent the tower from toppling. As the wind calms, the tower will restore to its original shape.
“The Red Clay School District thanks Pennoni Associates for their assistance in helping us make it into the Guinness World Records,” added Dr. Ammann. “They were an integral part of the team that helped us accomplish this goal.”