GIBA engineering committee discusses small squeaks, jack systems and island access
■ SUBMITTED BY GIBA
At the last meeting of the Gasparilla Island Bridge Authority Engineering Committee which was held on Monday, May 20, a small squeak in the works led the conversation.
Apparently a small squeak was detected on the south east corner end lift. The manufacturing company was required to make a site visit to determine the cause and remediation plan. The reducer on the south east corner end lift was the source of the existing squeak. The cause of the squeak cannot be determined until the unit is sent back to the manufacturer for evaluation.
The engineering Committee also discussed the multiple steps of the repair of the end lift.
There was a review of the various components of the end lift system that would have to be disassembled and sent to Cone Drive manufacturing in Traverse City, Michigan. The first step in the remediation process is to order a new double reduction unit from the manufacturer (lead time approximately 10 weeks).
The committee requested that staff contact the manufacturer to inquire about the type of material used to manufacture the shaft. Recommended material was a corrosion-resistant material that is as strong as steel.
The actual replacement work will require the use of the temporary jack system (which is not yet designed or manufactured). The jack system requires detailed planning and engineering. The engineering cost to design the temporary jack system is approximately $25K. GIBA requested that Hardesty and Hanover (original swing bridge designer) design this temporary jack system. Once the temporary jack system is designed, the plans will be turned over to a machine shop for manufacture.
At the GIBA board’s last quarterly meeting a review of all emergency procedures for island access in the case of causeway and/or bridge failure due to storms or mechanical disaster was discussed. GIBA Executive Director Kathy Banson-Verrico reported on the coordinated planning with Boca Grande Fire Department Chief C.W. Blosser and the EOC team to enable fast return of traffic after a storm.
Board Member and Engineering Committee Chairman Peter Strong led the engineering discussion about the vulnerability of a few components of the bridge and developing a plan in the event of a mechanical failure. An end lift failure would require traffic to be prohibited from crossing the bridge. A temporary jack system would be required to raise a corner of the bridge to the roadway level, thus the need for the jack system to be designed, constructed and kept on site in case of any problems with the proper functioning of any of the four end lifts.
After the new double reduction unit and temporary jack system are on site, GIBA will be ready to hire a company to remove and replace the existing southeast end lift. This work will take coordination with the Coast Guard for a multiple day channel closure to boats. This will also require a one-to-two hour road closure to vehicular traffic. GIBA plans plan to do the work in the evening and will have a communication plan to give plenty of advanced notice. All components must be in place before any closure is confirmed and is not expected for several months.
GIBA is four years in to the existing five-year warranty and is working in conjunction with the warranty division of the manufacturer.
After a full discussion of the maintenance requirement as well as the new replacement manufacture of the double reduction end lift unit from Cone Drive, staff was directed to move forward with both projects. The current Bridge Inspection and Operation Maintenance budget is sufficient to fund both recommended actions. The progress of this remediation and preparedness plan will be discussed at the August board meeting.