Three Cranes Team Up for Massive Covered Bridge Project

Enlarge Image It took three cranes to place four hefty sections of the nation’s largest covered bridge.

November 5, 2008 – The Smolen-Gulf Bridge put Ashtabula County, Ohio, on the map this summer as the home of the nation’s newest and largest covered bridge. Made entirely of wood, the 40-foot-wide structure spans 613 feet over the Ashtabula River. Its claim to fame is also the proof of the benefits of frugal construction and the economy of time, space and equipment.

Four 152-foot long sections, weighing in at 325,000 pounds each, make up the driving surface of the covered bridge. In order to save money and labor while bumping up the safety factor, general contractor Union Industrial Contractors (UIC) of Ashtabula decided to build the sections at the site and place them with cranes. “We also realized a savings in not having to construct false work staging for the construction,” said Rick Miller, UIC project manager.

 

The spans were built on the ground and then lifted into place by the cranes on the project. The middle two spans were lifted into place from the valley below the bridge. The first and fourth spans were rolled out onto special launch frames from atop each bank. UIC hired ALL Erection & Crane Rental of Cleveland, Ohio, to lift the weighty spans into place 80 feet above the river. “Perfect planning and an experienced crane company are key,” said Miller.

 

All Erection’s Compu-Crane lift simulation software was used to help visualize the engineer-designed lift plan and to facilitate the final layout and setup as well as the sizing of the launch frames. The company also provided a 300-ton Manitowoc 2250 lattice-boom crawler, a 300-ton Terex Demag AC250-1 telescopic all-terrain, and a 500-ton Liebherr LTM-1400-7 all-terrain for the lifts. Lifting Gear Hire, of Bridgeview, Ill., provided rigging hardware for the project.

 

The Manitowoc was equipped with 100 feet of main boom, 70 feet of luffing jib and 369,000 pounds of counterweight. It was partnered with the Demag and its 115,000 pounds of counterweight, to lift the first and fourth sections of the bridge. The Demag AT was positioned above the site while the crawler worked from the valley below. The crawler was then partnered with the Liebherr AT, sporting an 84-foot main boom, 46-foot luffer, and 220,500 pounds of counterweight, to place the bridge’s midsections.

 

The hefty sections, coupled with the weight of the crane rigging, were the tip of the iceberg where challenges were concerned in this critical lift. The crane mats had to be made perfectly level with plenty of fill to make sure the crawler crane wouldn’t walk with the weight of the load. All Erection’s Marty LaCava, sales representative, reported as the first and fourth sections were rolled out onto the launch frames, they gained weight with every inch off the frame without support.

 

The working area below the bridge was tight, and the massive pylons, already in place, presented further challenges for not only crane operations, but crane setup upon arrival, said LaCava. The rigging plan had to be perfect, as did the timing, the weather, and the myriad other small details that go into a critical lift. And, although the crew worked 10- and 12-hour days on the project, the result was worth every minute, according to Miller. In fact, he reported the job came out ahead of schedule. “A project like this usually comes along just once in a lifetime,” Miller said.

 

Because planners dedicated two years to this project, they were able to minimize crane rental costs by limiting the time the machines were on the job. The Manitowoc crawler spent just 16 working days at the site, while the Liebherr spent four days, and the Demag just one day.

 

LaCava said though it’s rare for a crane company to have that much iron available at once, having access to such a vast fleet made it possible. “We appreciated ALL’s assistance in sizing the cranes and their flexibility with their equipment to meet our goals and to keep our budget costs in line,” said Miller. “We could not have found any other crane company with ALL’s equipment and qualified operators to perform the task.”