JAY CASHMAN, INC. provided marine support and tie-in for a 30-inch diameter gas pipeline as part of the Spectra Energy–NY/NJ Gas Pipeline Expansion Project crossing the Hudson River via horizontal directional drilling (HDD). The first natural gas pipeline into Manhattan in 40 years will lower energy costs and keep air cleaner. Working with prime contractor Michels Directional Crossing, CASHMAN was responsible for dredging and disposal of material including contaminated material, cofferdam construction, drill platform work, and pipeline tie-ins, worth $40 million of the $900 million total project value. CASHMAN also provided sheet pile cofferdam design construction and removal to facilitate tie-in, along with marine support during HDD operations.


PROJECT HIGHLIGHTS 

• The HDD method, along with the associated drill platform design and pipeline tie-ins, were all innovatively designed through partnering with the prime contractor, owner, and subcontractor. 
• Provided pipeline pullback design and execution. Utilized a pullback/above-water tie-in method of 30-inch gas pipeline, facilitating a 100% welded pipeline tie-in. 
• Support of 30-inch diameter pipe HDD operations from the water, due to limited land access to the drill site in Hoboken, NJ. 
• Provided 1,800’ x 70’ PZ-13 sheeting and associated falseworks for construction of a cofferdam to facilitate sub-bottom pipeline tie-in and backfill. 
• Supported the design, fabrication, installation, and removal of a 350-ton marine drill platform supported by forty 2.5-foot x 120-foot piles. 
• Using an environmental clamshell bucket, dredged 10,000 yd³ at two pipeline tie-in locations, with backfill after pipeline placement. 
• Disposed of 7,500 yd³ of contaminated dredged material, and provided amending and upland disposal. 
• Worked closely with the local transit authority to assure no disruption to the local commuter traffic. On-shore/near-shore work areas were close to pedestrian access ways and commuter terminals. Additional safety precautions were taken to assure no interruption to the +30,000 people per day utilizing the commuter ferries and trains. 
• High marine traffic in the Hudson River required constant monitoring of traffic with Port Control.