Introduction to Towers

What is a tower? A man-made structure, higher than its diameter, generally used for observation, storage, or electronic transmission Let’s look at some examples

Leaning Tower of Pisa

Eiffel Tower

Lift Bridge Towers

Cell Tower

Tower Supporting an Aerial Cableway

Water Tower

Trusses In architecture, a structural framework of wood or metal based on a triangular system, used to span, reinforce, or support walls, ceilings, piers, or beams. Simple skeletal structure All beams are straight (no rotation forces)

Warren Truss No vertical members for short spans. Simplest of trusses.

Warren Truss Vertical members added for longer spans

Pratt Truss Except for the ends, all diagonals are slanted toward the center of the span Except for near the center, diagonals handle the tension forces, thus can be thinner

Howe Truss All diagonals are slanted toward the outer ends of the span All diagonals handle compressive forces and need to be thicker

Truss Support System

The Competition Each 2-3 person team is to build a tower with the following requirements Criteria Must be 18” ± ½” in height No restriction on width or depth No restriction on shape The top of the tower must be a minimum of 2” per side

The Competition Materials Maximum of 50 drinking straws Tape used only for connecting joints and holding tower to base plate Small paper clips can be used for connecting joints, but must be supplied by the team members.

The Competition Winning The center of the tower must have a ½ inch minimum central channel throughout its height to allow for the load testing device to pass through. Weight will be added to the top of the tower until the structure fails The tower which has the greatest support load to tower weight ratio will be the winner.