1. SCIENCE OLYMPIAD Elevated Bridge Div. B - C 2009-10 CeAnn Chalker ceann@chalker.orgceann@chalker.org

2. Elevated Bridge Students will design and build the lightest structure with the highest structural efficiency

3. General Parameters B & C Testing maximum load 15 kg. Only 1 structure entered per team No Impound Teams maintain a log containing data for future improvement

4. Wood Parameters B & C Structures must be of only wood and bonded 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 size limitation of dimension of wood

5. Construction Bridge Maximum & Minimum Span Lengths Bridge Span Minimum Div. B – 35.0 cm Div. C – 45.0 cm Bridge Span Maximum – 5.0 cm beyond Minimum Bridge Span Div. B – 40.0 cm Div. C – 50.0 cm

6. Construction – Span Length Parameters cont’d Bridge may not touch the surface of the Test Base within the clear span boundary at any time Bridges may not extend below the top of the Test Base Bridges may not be braced against any edge of the Test Base for lateral support

7. Construction – Bridge Height & Width Maximum height of both B & C bridges 20.0 cm No maximum or minimum width of the bridges

8. Construction – Clearance Under Bridge Center Portion of Bridge must be raised above the level of the Test Base to the underside of the bridge to the following clearances Div. B – 15.0 cm long x 15.0 cm high Div. C – 30.0 cm long x 12.5 cm high

9. Testing B & C Must accommodate a loading block that is 5.0cm x 5.0cm x 2.0cm w/a ¼ inch diameter hole in the center 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

10. Testing B & C cont’d Students must wear goggles Students may adjust the structure until they begin loading the sand Teams are given 10 minutes to load the sand into the bucket Structures must be marked by team so judges can identify them

11. Testing B & C cont’d Sand loading stops – When failure of the structure occurs When maximum load is supported (15 kg) When the chain comes in contact with the structure When the bridge or loading block touches the Test Base between the span boundary lines or the bucket touches the floor

12. Testing B & C cont’d Load Supported includes – Loading block Eyebolt Washer Wing nut Bucket Sand

13. Scoring B & C Structural Efficiency = Load Supported (grams) / Mass of the Structure (grams)

14. Scoring 3 Tiers B & C 1 st tier Structure meets all specifications under Event Parameters will be ranked by their structural efficiency

15. Scoring Tiers B & C 2 nd tier Structure does not meet all specifications under Event Parameters but can be tested will be ranked by their structural efficiency

16. Scoring Tiers B & C 3 rd Tier Structure can not be tested for any reason will be ranked by the lighter mass

17. Scoring Tie Breakers Ties will be broken in favor of the lighter structure 2 nd tie breaker will be the lowest overall bridge height

18. National Bridge Examples Placing the bridge on the tester board.

19. National Bridge Examples Placing the loading block on the bridge. Note the red knobbed lever for the sand hopper.

20. National Bridge Examples Loading block on top of bridge.

21. National Bridge Examples Loading block on the top of the bridge. Red knobbed lever for sand hopper.

22. National Bridge Examples Loading block on top of bridge.

23. National Bridge Examples Loading block below the top of the bridge.

24. National Bridge Examples Attaching the bucket to the hook suspended from the loading block.

25. National Bridge Examples Starting the flow of sand from the sand hopper by moving the lever.

26. Additional Information Elevated Bridge Event Commentary The National Event Supervisor has provided us with a 9 page commentary including the Test Base setups for B & C along with the score sheets for B & C. The commentary is included on the Summer Institute CD and will be posted online.