Denzai Engineering Corporation in Japan needed to remove a 150-ton overpass bridge to allow work to begin on a planned runway extension at the Narita International Airport. Using the Enerpac JS-250 Jack-Up system, they were able to remove the bridge overnight, minimizing traffic disruption on the busy Higashi-Kanto Expressway.
The extension of Runway B at the airport required the creation of a new grade-separated intersection between the expressway and the extended section of the runway. Removing the bridge allowed a temporary rerouting of the expressway during the intersection construction.
The Enerpac JS-250 Jack-Up in position to lift the bridge deck.
Due to the tight space of the work area, Denzai wasn't able to bring in a crane to remove the bridge, so they used the JS-250 jack for its lifting capacity, stability, and compact size. Two JS-250 towers were each mounted on a self-propelled modular transporter (SPMT) with a steel support platform placed on top. The platform was used to support the 69 x 16 ft (21 x 5 m) bridge deck as it was lifted and transported to a rigging location near the expressway.
Enerpac's JS-Series jack-up system is a multipoint lifting system that combines 4 jack-up towers, one positioned under each corner of a load. The lifting frame of each tower contains 4 hydraulic cylinders, which lift and stack steel barrels. The load is lifted in increments as barrels are inserted by an automated system and stacked, forming the lifting towers.
Able to be managed by a single operator, each tower's lifting and lowering operations occur simultaneously while the systems synchronous technology maintains the balance of the load.
Capacity/tower:280 tons
Maximum Sideload:3% @ 33 ft (10 m)
Maximum Lifting Speed:10 ft/h (3 m/h)
Electric Power Pack:20 hp
Weight per Jack-up Unit: 16,535 lb. (7,500 kg)
Weight End Barrel 3D Swivel: 5,291 lb. (2,400 kg)
For more information on the Enerpac JS-250 Jack-up system, visit www.enerpac.com.
For more information on Denzai Engineering Corporation visit www.denzai-j.com.
Enerpac is a leader in high-pressure hydraulic tools, controlled force products, portable machining, on-site services, and solutions for the precise positioning of heavy loads. With a 110-year legacy, Enerpac has helped move and maintain some of the largest structures on Earth. For more information, visit www.enerpac.com.
