Left Coast Lifter is a floating derrick barge or sheerleg which was built to assist in the eastern span replacement of the San Francisco-Oakland Bay Bridge. The barge carries a shear legs crane which is the largest barge crane ever used on the West Coast. The barge's name is taken from "Left Coast", a slang term for the West Coast of the United States (which appears on the left side of a typical map and also refers to the region's liberal, or "left leaning", political tradition).
Video Left Coast Lifter
Operational history
Left Coast Lifter was built for the American Bridge/Fluor joint venture (ABFJV), which was the lead contractor on the self-anchored suspension eastern span replacement. The barge was built in Portland, Oregon by U.S. Barge, LLC and ferried to Shanghai, where it was fitted with a shear-leg crane manufactured by Shanghai Zhenhua Port Machinery Co. Ltd (ZPMC). The completed sheerleg was ferried back to the United States on a semi-submersible heavy-lift ship, Zhen Hua 22 (IMO 8106446). The total cost was approximately US$50,000,000 (equivalent to $55,820,000 in 2016).
While transporting the sheerleg, the heel pin support may be moved towards the bow of the barge in order to lower the boom and the overall profile of the barge, facilitating transport.
Liftech Consultants assisted ABFJV with design review for the crane, including developing the technical specifications sent to ZPMC. The project received three Excellence in Structural Engineering awards:
- 2010 Award of Excellence for Special-Use Structures, from the Structural Engineers Association of Northern California
- 2010 Award of Merit for Special-Use Structures, from the Structural Engineers Association of California
- 2011 Outstanding Project, from the National Council of Structural Engineers Associations
Before Left Coast Lifter was fitted out with the crane for bridge construction, it was deemed to violate the Jones Act, specifically in that since the integral crane would be built and installed in China, it could not be used to transport goods by water between U.S. ports. Therefore its first job, prior to installation of the crane, was to haul dredged materials to Long Beach.
After Left Coast Lifter arrived at the Bay Area in March 2009, it was used to place pre-fabricated falsework truss sections and the 28 box girder deck sections. Before the heavy deck sections for the Bay Bridge were lifted, Left Coast Lifter raised a sunken tugboat in August 2009, USS Wenonah. The first deck section was lifted in February 2010, and the last deck section was lifted in October 2011.
American Bridge/Fluor solicited offers for Left Coast Lifter in 2012, after the conclusion of its work on the Bay Bridge. A consortium of companies, Tappan Zee Constructors (TZC, a joint venture of Fluor, American Bridge, Granite and Traylor Brothers), purchased the crane barge, which gave them a competitive edge in the bidding process for the construction of the Tappan Zee Bridge replacement across the Hudson River. Reportedly, according to the purchase agreement between TZC and ABFJV, Left Coast Lifter will be returned to ABFJV once the work on the Tappan Zee Bridge is completed.
Now nicknamed I Lift NY, the barge is still officially registered with the U.S. Coast Guard as Left Coast Lifter. The crane departed San Francisco Bay under tow in December 2013, transited the Panama Canal in January 2014, and arrived at Jersey City at the end of January. There it was refitted with an upgraded control system before arriving at the job site in October 2014. Left Coast Lifter made its first lift on the new Tappan Zee bridge in April 2015, a steel-reinforced concrete pile cap which will form part of the bridge's foundation.
The massive crane is being used for heavy lifts of large bridge sections. After building the new bridge, Lifter will also be used for heavy lifts during the dismantlement of the old structure at that location.
Capacity
The shear-leg crane on Left Coast Lifter has a 328-foot (100 m) long boom, weighing 992 short tons (900 t) with a 1,873-short-ton (1,699 t) lift capacity. It is the largest barge crane ever used on the U.S. West Coast.
Maps Left Coast Lifter
See also
References
External links
- "I Lift NY Super Crane" (PDF). The New NY Bridge. 2015. Retrieved 11 March 2016.
- Lee, Kenton; Dix, Anna (July 2012). "The Left Coast Lifter". Structure Magazine: 51. Retrieved 11 February 2015.
- Rokeach, Barrie; Hall, Bill (February-April 2010). "Historic Lift of Self-Anchored Suspension Span Sections for New Bay Bridge East Span". Metropolitan Transportation Commission. Retrieved 12 February 2015.
Source of article : Wikipedia
0 Comments