Challenging Project Showcases Global’s Capabilities Video
Global provided diving services for Phase I and II of the Shaft 6 – Tunnel and Shaft Rehabilitation Project. The work took place at Shaft 6 in approximately 685 feet of water at the bottom of a 13 -foot diameter shaft, located inside of a building on the shore of the Hudson River. Work was accomplished using Saturation Diving Methods.
Prior to start of the work on site, all aspects of the project had to be performed using a full scale mock up to demonstrate the methodology and constructability of the tasks.
Phase I required detailed inspection and measurements of an existing 4-foot wide by 7-foot tall horseshoe shaped horizontal drift and bronze hemispherical submarine door, removal of existing bronze piping, and replacement of a 24 inch gate valve encased in concrete. Highly specialized tooling to access the shaft and perform the work was designed and fabricated by Global.
Phase II of the project involved the installation of a 23,000-pound stainless steel bulkhead into the horizontal drift. Divers activated a mechanical seal and installed reaction struts to resist the over 2 million pounds of force the new bulkhead would incur if the original bronze door failed. This was a secondary means of protection to workers for subsequent operations in the dewatered shaft.