County ‘Builds a Better Mousetrap’

Ringgold County Secondary Roads Department was recently awarded first place in a statewide Build a Better Mousetrap (BABM) competition hosted by the Iowa Local Technical Assistance Program (LTAP).
Each year, county engineering departments compete in the annual competition by submitting innovative solutions to everyday challenges that local transportation professionals encounter.

Engineer Jared Johnson and Assistant to the Engineer Justin Frost teamed up to create reusable forms that could be used for constructing new Continuous Concrete Slab Bridges (CCSB’s) to reduce wasted lumber and save money.

They expanded on their idea by including a gantry hoist to lower these large forms in a controlled way so they can be removed and loaded onto a semi flatbed trailer transported to and from job sites without damaging them.

“Plans were drawn for the decking forms and the gantry system in house and constructed in our shop by our maintenance guys, [and they] built forms as a winter shop project utilizing equipment and materials we already had with some minor expenses to move the large forms around in shop during construction,” the project entry stated.

The total material cost was under $7,000, as the project used lumber that was already budgeted for forms and relatively inexpensive hardware to build the pre-tensioned cable floor forms that were bolted together.

The gantry frame was built from a re-purposed steel stringer I-beam and newly purchased square tubing steel to create vertical A-frames. Purchased chain hoists were then attached for form placement.
The deck forms have cable loops installed at exposed ends that are used to drag the forms out from under the new bridge deck with the county’s Komatsu 290 excavator and have solid steel 1” bars built into them to attach rigging so they can be picked up with a crane and placed onto a semi flatbed and transport them to the next jobsite.

The steel bar access openings are covered with flush fitting removable panels during construction.
Their innovative solution reduced the risk of injury when removing wooden false work under the bridge, and increased the efficiency of the bridge crew.  The time and labor to place and remove false bridge formwork was drastically reduced.

“We are now able to complete 3 local 100 ft CCSB bridge projects with each construction season with our own bridge crew and reduced overall expense and increased safety for our employees,” stated the county’s entry.

The new gantry and hoist system and the cable tensioned bolted forms allows the county bridge crew to safely and efficiently construct a CCS bridge of up to 150’ in length, which results in significant savings for each county bridge constructed.

Ringgold County was initially recognized at the ICEA Mid-Year Conference in July and received a plaque at the Iowa Streets and Roads Conference in September.

The Ringgold County Secondary Roads department also received a celebratory lunch at the county shop.
As the state winner, Ringgold County’s entry will be submitted to the National Local Technical Assistance Program/Tribal Technical Assistance Program (LTAP/TTAP) Build a Better Mousetrap Competition. National winners will then be announced next July.

Additional details about this year’s and previous years’ innovations are available on the Iowa LTAP’s Iowa Innovations web page at https://iowaltap.iastate.edu/iowainnovations/.