38 Foot K'nex Tower

This tower stands 38 feet tall and uses about 3500 pieces (new personal height record). It was built in 4 hours by Austin Granger and Paul Davis, and assembled in 3 hours by Austin Granger, Paul Davis and Simon Olson. It took 5 attempts to get the tower to stand, it collapsed during the first 4. The tower DOES stand on its own, but we added the guy wires to counteract the force of the wind, just to make sure it will last during the night. 400 feet of string was used to make the 4 guy wires.

The completed tower

Close-up of one of the 4 guy wires

Looking up the middle of the tower.
The interior X-shaped supports were added every other level near the bottom, but were used less and less frequently as the tower grew in order to reduce weight and wind resistance.
Here the tower has a slight curve to it as we had not yet tightened the guy wires.

Close-up view showing where the guy wires connect to the tower.

For the two or three of you who care... here's how we did it. We assembled the top 20 feet of the tower on the ground, with the guy wires attached, hanging loosely to the ground. One person pulled on 2 guy wires while 2 people supported the middle of the tower, and we hoisted it up to a vertical position. We then attached it to the base, which is weighted down with about 200 lbs of bricks. Next, 2 people got on ladders on either side of the tower while one person disconnected it from the base. The tower was lifted up 4 feet at a time, and a new section was added in-between. The tower remained free-standing for all of the lifts. When we completed the structure, we each grabbed a guy wire and tied it to 3 bricks, moving the bricks around to straighten out the tower. A total of 36 bricks are used to hold up this tower.