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SSBC Rules and Clarifications

2019 Official Rules

Download the Official Rules for the 2019 Student Steel Bridge Competition.

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2019 Official Clarifications

Clarifications are based on the Student Steel Bridge Competition 2019 Official Rules.
All clarifications have been reviewed and approved by the Rules Committee.

Full Index of Clarifications

Click on each section below to read the posted clarifications.

SSBC Clarifications

1. Mission and Summary

There are no clarifications for Section 1 at this time.

2. Introduction

There are no clarifications for Section 2 at this time.

3. Problem Statement

There are no clarifications for Section 3 at this time.

4. Eligibility

There are no clarifications for Section 4 at this time.

5. Safety

There are no clarifications for Section 5 at this time.

6. Scoring

There are no clarifications for Section 6 at this time.

7. Schedule of Competition

There are no clarifications for Section 7 at this time.

8. Material and Component Specifications

Q8.1. Does an externally threaded part need to be a bolt or a nut welded to a member? Sébastien Lépine-Lacroix, Université de Sherbrooke

A. No, an externally threaded part does not need to be a bolt or a nut. An externally threaded part is any threaded piece that is welded to a member and has continuous threads around its full circumference.  [8.2.2.1, 8.2.2.3, 9.4.1, 9.4.2, 9.5]


Q8.2. Can steel cable be used in a bridge? Adam Iturria, Missouri State University

A. No, members that make up the constructed portion of the bridge shall not have flexible parts. [8.2.2.1]


Q8.3. May a member purposefully be designed such that it will not fit within a right rectangular prism of dimensions of 3’-6” x 6” x 4” while accepting the weight penalty associated with Section 8.2? Ben Meseroll, Virginia Polytechnic Institute and State University

A. No. Section 3 states that any attempt to gain an advantage by circumventing the intent of the competition as expressed by the rules will be grounds for disqualifying a bridge. [3, 8.2, 8.2.2.2]


Q8.4. Are plates that are used to hold other members together considered members provided they remain rigid? Erin Nebel, University of Colorado - Boulder

A. Yes. A plate or multiple plates welded together constitute a separate member if they are made out of steel, are rigid with no moving parts and are not welded to another member. As such, they are governed by all specifications and regulations pertaining to members. However if the plates are not part of the final constructed bridge, then they are considered tools and are governed by all specifications and regulations pertaining to tools. [Glossary, 8.1, 8.2.2.1, 9.4.1, 10.2.4, 10.3.7, 10.4.2, 10.4.3]


Q8.5. What type of magnet will the judges use to test the steel’s magnetism? Varand Aghakhani, California State University, Long Beach

A. Any permanent magnet that is attracted to steel can be used to determine if the steel making up the bridge is strongly magnetic. The exact type of magnet used is dependent on the host school. [8.1, 12.1]


Q8.6. Are connections with internal threads allowed where the internal threads are not a result of a welded nut? Seth Caudle, University of Tennessee at Chattanooga

A. No. The bridge will be disqualified if any bolt or externally threaded part of a member is not secured with a loose or welded nut. Even if the connection is augmented with a loose nut, there will be a penalty of 25 pounds added to the weight of the bridge for each and every threaded hole or member with internal threads. Each individual nut must also be visible for inspection purposes. [Glossary, 8.2, 8.2.4.1, 8.2.4.2, 8.2.5, 9.4.1, 9.4.2, 9.4.4, 9.5]


Q8.7. Are the threads of a loose bolt or externally threaded part required to be in the shear plane of the connection? Kienan Dalesandro, Pennsylvania State Harrisburg

A. No. Loose bolts and externally threaded parts are not required to be threaded over their full length and there is no restriction in regards to whether the threads are excluded or not excluded from the shear plane. The threads of loose bolts and externally threaded parts do need to extend around its full circumference and the terminal threads need to extend beyond or be flush with the outer face of the nut. [Glossary, 8.2.3.1, 8.2.3.2, 9.4.2]


Q8.8. Are U-bolts considered bolts? Christopher Wongsavanh, California State University, Fullerton

A.  No. U-bolts are not considered bolts within the AISC Student Steel Bridge Competition because they do not have a head. Although not explicitly stated, the rules require bolts to have a head. The length of a loose bolt requires measurement from the bottom of the head to the end of the bolt, which is not possible with a U-bolt. The head of a loose bolt also needs to be in contact with the outer ply of the connection and must be visible. Since U-bolts do not have a head, these rules would be violated. If welded to a member, a U-bolt is considered an externally threaded part of the member. [8.2.2.1, 8.2.2.3, 8.2.3.1, 8.2.3.2, 9.4, 9.5]


Q8.9. May a member be able to fold or be collapsible? Jude Rene Vallon, New York City College of Technology

A.  No. A single member shall retain its shape, dimensions and rigidity during construction and shall not have moving or flexible parts. [8.2.2.1]


Q8.10. May a turnbuckle be used as part of the bridge? Jarad Roschi, Saint Martin’s University

A.  No. The bridge shall consist of only nuts, bolts and members. A turnbuckle is either a member by itself or if welded to a member then it is part of that member. Since a turnbuckle has threaded holes, it violates the rule that holes in members or in parts of a member shall not be threaded. There would be a penalty if a turnbuckle is used as a nut unless it is threaded for its full length and has the external shape of a single hexagonal prism over its full length. [8.2.1, 8.2.2.1, 8.2.4, 8.2.5]


Q8.11. Are bolts with button heads allowed to be used? Carthney Laukon, Saint Martin’s University

A.  Yes. The shape of bolt heads is not restricted, but modifications to bolts, including heads, are penalized. [8.2.3]

9. Structural Specifications

Q9.1. May the stringers be different lengths provided that they each are at least twenty-two feet long? Alexa Janikowski, University of Pittsburgh at Johnstown

A. The stringers must be straight and contiguous over the full length of the bridge, such that they can support the decking anywhere along the span. Since the two rabbets of the clearance template, held plumb and perpendicular to the span of the bridge, must be in contact with the tops of both stringers along the full length of the stringers during verification of the passageway clearance, the stringers must be equal length (at least 22 feet in length, but no more than 23 feet). Failure to meet this requirement may lead to the bridge being deemed unsafe to load test by the head judge. Measurements of L1, L2 and S are taken from the east end of the right side stringer as shown in the Lateral Load Test Plan and Vertical Load Test Plan and Elevation Drawings. [9.2.1, 9.3.6, 9.3.8, 9.3.9, 9.3.10]


Q9.2. Does there have to be at least one loose bolt or one loose nut for a connection between two members to satisfy the requirements of Section 9.4.1? Varand Aghakhani, California State University, Long Beach

A. No. A connection satisfying the requirements of Section 9.4.1 can consist of any combination of a loose bolt or an externally threaded part and a loose nut or a welded nut provided that the combination needs to be unscrewed in order to separate the two members being connected. A bolt welded to a member is considered an externally threaded part of that member. [Glossary, 8.2.2.1, 8.2.2.3, 8.2.3, 8.2.4, 9.4.1]


Q9.3. Are the stringers required to be two inches wide? Lukas Barr, University of Tennessee at Chattanooga

A. No. Stringers may be any width that fits within the two-inch wide rabbets in the clearance template while allowing the clearance template to pass unobstructed along the stringers length. [Glossary, 9.3.9, 9.3.10]


Q9.4.
May the stringer on the right side of the bridge terminate at the staggered leg leaving a corner of the bridge missing? Callum Langford, West Virginia Institute of Technology

A.   No. The decking unit must be able to be placed anywhere along the bridge span where the bridge span is determined based on the longest side of the bridge. Without a continuous stringer over the whole length of the bridge, the lateral load test will not be able to be conducted for load cases 3, 4 or 5 leading to disqualification of the bridge. See clarification Q9.1 for further information in regards to requirements for the stringers. [7.1, 9.2.1, 9.2.2, 9.3.6, 9.3.7, 9.3.9, 9.3.10, 11.4.1, 11.4.2]


Q9.5. Is there a violation if the head of a bolt rests on the top side of a stringer? Absalon Pineda, University of Arizona

A.  Yes. The tops of the stringers shall be free of discontinuities except those permitted by Specification 9.3.11. The clearance template must be able to be slid without obstruction along the full length of the stringers with the tops of the rabbets in contact at all times with the tops of the stringers. A bolt head resting on the top of a stringer will obstruct the passage of the clearance template and would be subject to the penalties specified in Specification 9.3. A bolt head resting on the top of a stringer also may violate the requirements of Specifications 9.2.1 and 9.2.3. [9.2.1, 9.2.3, 9.3, 9.3.9, 9.3.10, 9.3.11]


Q9.6. If two members are in contact with one another at multiple locations, how many connections are required that comply with Sections 9.4 and 9.5? Austin Doucet, University of Louisiana at Lafayette

A.  One. [9.4.1, 9.4.2, 9.4.3, 9.4.4, 9.5]

10. Construction Regulations

Q10.1. May a tool support a constructed portion of the bridge provided the tool does not touch the ground? Sébastien Lépine-Lacroix, Université de Sherbrooke

A. Yes, but the constructed portion shall be in contact with a footing at all times. [Glossary, 10.3.7, 10.3.10, 10.3.12, 10.4.2]


Q10.2. May a tool be attached to an article of clothing or a pouch? Sébastien Lépine-Lacroix, Université de Sherbrooke

A. By definition, a pouch is considered an article of clothing. A tool may be attached to an article of clothing, but construction cannot start if a tool is held by or attached to a builder or to a builder's clothing. A penalty will be applied if the tool is not returned to the ground in the appropriate staging area at the end of timed construction. There also will be a penalty if the tool touches the ground outside the staging area, even when attached to the clothing of a builder.  [Glossary, 10.1.4, 10.4.2, 10.6.1, 10.9.2]


Q10.3. May builders be in any location within the staging yard and in any position (sitting, kneeling, standing, etc.) at the start of timed construction? Sébastien Lépine-Lacroix, Université de Sherbrooke

A. Yes. There is no restriction on the location or position of builders within the staging yard at the start of timed construction provided they are not touching members, tools, nuts, or bolts.  [10.6.1]


Q10.4. Does a tool assembled after the start of timed construction need to weigh less than or equal to twenty pounds? Zack Coleman, Lafayette College

A. No, there is no weight restriction on a tool that is assembled after the start of timed construction. However, the requirements of Section 10.2.4 must be satisfied prior to the start of timed construction, and 10.9.2 must be satisfied at the end of timed construction. An unassembled part of a tool prior to timed construction refers to a tool that will be combined with another tool after the start of timed construction.  [Glossary, 10.2.4, 10.2.9]


Q10.5. May a tool be used to transport a single member outside of the staging yard? Moshe Carron, University of Illinois at Chicago

A. Yes, if it is done safely as determined by the judges. [10.1.4, 10.2.4, 10.3.1, 10.3.7, 10.3.14]


Q10.6. May a tool have foldable, collapsible or hinged components and if these components are detachable is the tool still considered a single tool? Moshe Carron, University of Illinois at Chicago

A. Yes, tools are not required to be rigid. The tool is considered a single tool if its components are attached to it prior to the start of timed construction, regardless of whether they are detachable, and must meet the requirements of Section 10.2.4. [Glossary, 10.2.4, 10.9.2]


Q10.7. May a tool touch the ground within a footing? Moshe Carron, University of Illinois at Chicago

A. No, Section 10.4.2 states that a tool cannot touch the river, ground outside the staging yard or floor outside the site boundary. Aside from builders, only a member or constructed portion of the bridge may touch the ground within a footing. [10.4.2]


Q10.8. Must a tool fit within a right rectangular prism with dimensions of 3’-6” x 6” x 4” only before and after timed construction as stated in Sections 10.2.4 and 10.9.2? Ryan Harrington, California Polytechnic State University

A. Yes, there are no dimensional restraints on tools during timed construction. [10.2.4, 10.9.2]

11. Load Test Instructions

There are no clarifications for Section 11 at this time.

12. Equipment Provided by Host

There are no clarifications for Section 12 at this time.

13. Interpretation of Rules

There are no clarifications for Section 13 at this time.

14. Judging

There are no clarifications for Section 14 at this time.

15. Appeals

There are no clarifications for Section 15 at this time.

APPENDIX

  • Construction Site
  • Bridge Diagrams
  • Lateral Loading Plans
  • Vertical Loading Plans