CeAnn Chalker ceann@chalker.org Towers B & C – 2010-11 CeAnn Chalker ceann@chalker.org

Disclaimer This presentation was prepared using draft rules. There may be some changes in the final copy of the rules. The rules which will be in your Coaches Manual and Student Manuals will be the official rules.

Towers Students will design and build the lightest structure holding the greatest amount of weight.

General Rules Only 1 structure entered per team No Impound Testing maximum load 15 kg Students must wear goggles Towers must be marked by team so judges can identify them Tower is a single structure (no separate or detachable pieces)

Towers Construction Towers must be made of only wood and bonding glue (any type of glue) No particle board, plywood, beaverboard, or other composite wood are allowed (this includes bamboo and paper) Unlimited laminations by students is allowed No limit on the cross section size of individual pieces of wood

Towers Parameters Must accommodate a loading block that is 5.0cm x 5.0cm x 2.0cm w/a ¼ inch diameter hole in the center Height – All parts of the loading block must be a minimum 50.0 cm above the platform (no max.) The base of the Tower must span the testing platform which has a 20.0 cm x 20.0 cm square opening

Towers Parameters No portion of the Tower may extend below the top surface of the testing platform The Tower may not be braced against the edge of the Test Base After set up, the Tower may only contact the Loading Block and the Test Base

Towers Parameters Division B Parameters Division C Parameters The portion of the tower more than 30.0 cm above the test base must pass through an 8.0 cm diameter hole or opening Division C Parameters The portion of the tower more than15 cm above the test base must pass through an 8.0 cm diameter hole or opening

Towers Testing A chain and bucket will be suspended from the loading block Structures will be tested by loading sand into the bucket up to 15 kg. Students will be the only ones to handle their structures

Towers Testing cont’d Students may adjust the tower until they begin loading the sand Teams are given 10 minutes to load the sand into the bucket

Towers Testing cont’d Sand loading stops – When failure of the tower occurs When maximum load is supported (15 kg) When the chain comes in contact with the tower When any part of the tower extends below the top surface of the Test Base

Towers Testing cont’d Load Supported includes – Loading block Eyebolt Washer Wing nut Bucket Sand

Towers Scoring Formula Score= Load Supported (grams)2/Mass of Tower(grams) Highest Score wins Tie Breaker Ties will be broken in favor of the lighter structure

Towers Tiers 1st Tier 2nd Tier Tower meets all Construction Parameters Tower does not meet one or more Construction Parameters

Towers Tiers cont’d 3rd Tier Structure can not be tested for any reason will be ranked by the lowest mass