1. SCIENCE OLYMPIAD Elevated Bridge Div. B - C 2008-09 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. General Parameters B & C Cont’d 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

5. General Parameters B & C Cont’d Entire structure must be made of wood pieces no larger that ¼ x ¼ inch in cross-section Dowels must not exceed ¼ in diameter Must accommodate a loading block that is 5.0cm x 5.0cm x 2.0cm w/a ¼ inch diameter hole in the center

6. Construction Parameters 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

7. Construction 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

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 – 10.0 cm long x 10.0 cm high Div. C – 25.0 cm long x 7.5 cm high

9. Testing B & C 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 materials & construction will be ranked by their structural efficiency

15. Scoring TiersB & C 2 nd tier Structure does not meet all specifications under materials & construction 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