Mammoet lowers Harbor Bridge span to speed Corpus Christi channel reopening

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Mammoet helped remove the 2,300 tonne center span of the historic US 181 Harbor Bridge in Corpus Christi, Texas, using a lift and lower method designed to reduce work at height and limit disruption to marine traffic.

The operation formed part of the Harbor Bridge Replacement Project led by the Texas Department of Transportation, with Flatiron/Dragados LLC serving as project developer.

The 1959 steel truss bridge had served the Corpus Christi area for more than 60 years before being replaced by a new cable stayed bridge built to improve road safety, pedestrian access and navigation clearance for port related traffic.

Project teams assessed several removal options, including piece by piece dismantling and controlled explosive demolition. The selected approach lowered the full center span in one unit onto a barge.

For a bridge over an active ship channel, the method worked like removing a table top without disturbing the room around it. Fewer workers were needed at height, nearby sensitive sites including the Texas State Aquarium faced less exposure to dust and noise, and the navigation channel could be reopened in a controlled sequence.

Four 900 tonne strand jacks were positioned in pairs at each end of the span. They took the bridge load before crews cut the connection points.

The lowering was scheduled for daylight hours to improve visibility during the most critical phase.

“Before the initial lift, an eyebrow cut was made above the pin to allow a small opening that enabled us to lift the span until we saw daylight,” said Bobby Martija, Mammoet project manager.

“This gave us an opportunity to check the deflection of the bridge and ensure everything was stable. Once everyone was satisfied that all the clearances were correct, the cutting began.”

The span weight was based on historic records, so engineers added contingency into the lifting plan. That margin gave the strand jacks additional capacity in case the actual load differed from the estimate.

The night before the lowering, the receiving barge was prepared with winches, support grillages and Mammoet self propelled modular transporters. Once positioned under the bridge, crews began a tightly managed 36 hour window to lower the span and clear the channel.

The span was lowered nearly 50 metres using 54 strand wires. Mammoet initially considered an umbrella setup, where strand wires would rest on the bridge deck. The team later changed to pre coiled wires to reduce handling time and limit manual work.

“We had two ways of setting up the strand jacks,” Martija said. “Initially, it was a simple umbrella configuration, with the strand wires resting on the deck of the bridge.”

“We realized that this would be too time consuming, with people required to manage and arrange them, so we decided it would be better to pre coil the wires instead.”

Two coilers were assembled at Mammoet’s yard in Rosharon, Texas, and brought to site for the operation.

After the span landed safely on the barge, it was transported about 10 nautical miles to a nearby dock for offloading and decommissioning.

For the load out phase, Mammoet used two sets of 54 axle lines of SPMTs to lift and move the structure from the barge deck. Before that could happen, crews reinforced the underside of the span with steel.

Carrying out that welding before removal would have required additional work at height. Performing the reinforcement on the barge deck gave crews a safer working position and simplified access.

The span was then moved by SPMTs onto steel supports, where it was prepared for decommissioning.

The operation shows how civil engineering, marine transport and heavy lift planning increasingly overlap on port related infrastructure projects.

For Corpus Christi, the bridge removal was not only a demolition task. It was a logistics exercise over a working waterway, with marine access, public safety, nearby businesses and environmental controls all tied into one schedule.

The project also underlines a familiar lesson for breakbulk and project cargo operators. The safest lift is often the one that removes unnecessary handling, even when the object being moved is a 2,300 tonne bridge span.