DESCRIPTION: The objective of this event is to design and build the lightest tower, with the highest structural efficiency, capable of supporting a load of up to 15 kg. Each team may enter only one tower that they have built prior to the competition.

MATERIALS:

1. The tower is to be a single structure, constructed of wood and bonded by glue. No other materials shall be used.
2. Particleboard, plywood, beaverboard, any other composite wood products, bamboo or paper may not be used.
3. The entire tower (including gussets) must be constructed from wood pieces no larger than 1/4 inch x 1/4 inch in cross-section. If dowels are used, they may not have a diameter greater than 1/4 inch. There is no limit on the length of individual wood pieces.

CONSTRUCTION:

1. Sound engineering and construction practices such as trusses, mitered joints/corners, gussets and lamination (layers of wood glued together) are encouraged.
2. Unlimited lamination by the students is allowed, however, commercially laminated wood is not allowed. Wood laminations may be any size provided the individual pieces used to make them comply with materials listed above.
3. The tower must support a square loading block, 5.0 cm long x 5.0 cm wide x 2.0 cm thick, at its top. All parts of the loading block must be minimum of 60.0 cm above the testing platform before the load is applied. There is no maximum height.
4. The loading block must be supported so that a 1/4 inch diameter loading rod/chain suspended from its center, is within 2.5 cm of the center of the opening in the testing platform. The loading rod/chain may not contact the tower at any point.
5. The portion of the tower more than 30.0 cm above the testing platform must be able to pass through an 8.0 cm diameter round hole.
6. No portion of the tower may extend below the top surface of the testing platform.

TESTING:

1. The teacher will provide all equipment, except for eye protection, used for testing. Students must bring and wear approved impact resistant eye protection.
2. The testing platform will be a flat surface with a 20.0 cm x 20.0 cm square opening in its center.
3. The students will place the tower on the testing platform so that the loading rod/chain will pass within 2.5 cm of the center of the opening in the test platform.
4. The loading block will be placed on the top of the tower by the students.
5. Students will use the rod/chain to suspend a 5-gallon bucket, approximately 30 cm in diameter, below the testing platform.
6. The students will add sand to the bucket until failure occurs or the maximum load of 15 kg is supported. If the loading rod/chain comes into contact with the tower, loading will stop at that point and the Load Supported at that time will be used to calculate the structural efficiency.
7. The mass of the loading block, eyebolt, washer, wing nut, bucket, and sand are included in the Load Supported
8. Sand added after failure will be removed.

SCORING:

1.  The Score will be determined by the Structural Efficiency equation: Structural Efficiency = Load Supported (grams) / Mass of Tower (grams)
2. Towers that hold more than 15 kg will be scored using 15 kg as the load supported.

DESIGN PROCESS & TESTING REQUIREMENTS:

1. Your procedure must not involve any sort of safety hazard. Your procedure must not involve any safety hazard. Goggles must be worn during testing. Goggles and adult supervision are required while tools are being used.
2. A project proposal must be approved and signed by the teacher before construction begins.
3. Quantitative tests (strength of materials, strength of joints, etc.) must be used to inform decisions made (choice of materials, assembly, etc.) during the design process. These must be documented in the report.
4. Unless all testing data and the final evaluation are perfect (not likely), evidence must be shown that design changes were made based on quantitative tests.

REPORT:

Reports will be evaluated according to the following criteria:

Presentation of Physical Concepts

· Introduced the relevant physical principles (and historical background when appropriate) completely and clearly

· Kinematics and dynamics accurately represented throughout (symbols, graphs, text, data, equations)

· Accurately described/defined relevant quantities (d, v, a, F, etc.)

Design Process and Analysis

· Demonstrated careful and thorough planning

· Quantitative tests conducted during the design process

· Quantitative tests used to inform decisions made during the design process

· Used a logical method to effectively manipulate materials during design/construction

· Used a logical method to effectively manipulate materials and instruments during testing

· Interpreted/analyzed data logically and correctly

Communication

· Submitted a formal report containing all the required sections

· Submitted an attractively formatted, completely word-processed lab report

· Electronically inserted a picture or diagram into the report

· Presented and organized data in table (and graph, where appropriate) form

· Data collection/reporting was accurate and complete

· Showed complete quantities with units

· Presented information and analysis in an easy-to-follow format and writing style

· Gave a clear interpretation/analysis of test and data

· Clearly states the purpose of the work

· Proposed an appropriate and succinct concluding evaluation

· Followed rules of grammar, sentence construction, and punctuation; minimum of spelling errors

Teamwork and Cooperation

· Met intermediate deadlines set by the teacher; came to class prepared, used class time effectively

· All members were helpful and respectful to each other

· All members participated and made a significant input