Portland Harbor, Maine Maintenance Dredging / Rock Removal

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DETAILS

Client: US Army Corps of Engineers, New England District
Value: $9.2 million
Project Date: January 2014 - March 2014
Project Cut-sheet: Download

SUMMARY

CASHMAN  DREDGING performed the first maintenance dredging in Portland Harbor to occur in over 15 years. In 2014, CASHMAN was once again awarded the contract to perform the maintenance dredging. Our crews worked 24 hours a day, seven days a week to complete the project, which required removal of some 700,000 cubic yards of sediment from the harbor’s shipping channel. In addition to maintenance dredging, our team drilled and blasted approximately 1,500 cubic yards of rock. Each shift, the CASHMAN crew lifted the clamshell bucket 300 times – removing enough mud to fill more than five Olympic-sized swimming pools. The sediment was disposed at the Portland disposal site 10 miles away. Dredging was performed to achieve -37 feet mean lower low water (MLLW). The rock drilling and blasting portion of the project entailed the removal approximately five rock pinnacles protruding just above the 35 foot MLLW plane.  Portland Harbor is a busy commercial harbor, and CASHMAN ensured that no dredging activities interfered with ship traffic. Additionally, in preparation for the project a non-Federal sponsor relocated lobsters to protect the lobster fishery.


PROJECT HIGHLIGHTS

  • Crews worked 24 / 7 to complete the project, which removed ~700,000 cubic yards of sediment from Portland's shipping channel.
  • Dredging was performed to achieve -37 feet mean lower low water (MLLW).
  • The rock drilling and blasting portion of the project entailed the removal of five rock pinnacles protruding just above the -35 foot MLLW plane, totaling ~1,500 cubic yards.
  • CASHMAN used the Dale Pyatt, the F.J. Belesimo, and the Kraken to complete the work.
  • Lobster relocation was conducted prior to dredging, requiring close coordination with all parties.
  • Dredged material disposal was in open water at the Portland Disposal Site, ~10 nautical miles away.
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