AMO Currents - AMO-manned Reliance Class ships installing Hibernia Express Cable System

AMO Currents - Posted: August 12, 2015

AMO-manned Reliance Class ships installing Hibernia Express Cable System

By Captain Carl Winter
Master, C.S. Responder

Transoceanic Cable Ship Company, LLC, the ship operation and management arm of TE Subcom has entered a period of full utilization of its fleet of seven AMO-manned cable ships.

The cable ships Durable and Global Sentinel are both working on cable maintenance projects in the Pacific region.

The Reliance Class cable ships Reliance, Responder, Resolute, Dependable and Decisive have been working this spring and summer on a new fiber optic cable system running from Halifax, Nova Scotia to Ireland and the United Kingdom. The Hibernia Express Cable System follows a great circle across the Grand Banks of Newfoundland and the North Atlantic into the Irish Sea and Bristol Channel.

The five Reliance Class ships that have participated in the project have had their fair share of challenges thus far: storms, icebergs and fog have been a few of the elements that have made life interesting thus far.

The Decisive and the Responder both had to shuffle their work routines to avoid the high concentrations of icebergs and floes on the Grand Banks this spring and summer.

The Dependable was faced with extremely hostile bottom terrain, which caused severe damage to the sea plow. The ship's crew rallied and salvaged the damaged plow off the seabed, and with the aid of a support vessel, was able to get the plow back aboard, repaired, and back working in short order.

The marine program of the Hibernia Express installation began with route clearance. This is where one of the cable ships runs the installation route dragging a specialized set of grapnels behind her. This ensures that any out of service cable systems, abandoned fishing gear, abandoned rigging, etc. are removed from the sections of the route where the cable system will be buried in the seabed.

The Hibernia Express Cable System has three landing points: Halifax, Nova Scotia; Cork Ireland; and Brean, United Kingdom. The landings in Halifax and Cork are direct landings. This is where the cable ship maneuvers into shallow water, close the beach, and floats the end of the cable ashore on inflatable floats. The landing in Brean was a pre-laid shore end. This is where a smaller vessel or barge installs a section of cable from the beach out to a point where the cable ship can recover the cable end and splice it into the cable they have aboard.

Once the connections are made to the beach, the cable ship begins moving offshore. The owners of the Hibernia Express Cable System desired maximum protection of their investment, so the cable was buried in the seabed in areas of high fishing activity. This is done using a sea plow. This is a large device towed behind the cable ship with the fiber optic cable threaded through it. As the ship tows it, the plow cuts a furrow in the seabed, burying the cable 1.5 meters below grade. Maximum speed for the ship and plow is 1 knot, but due to the hard bottom conditions on this project there were many days spent going at .3 knots.

Once clear of the shallower waters where fishermen work the bottom, the sea plow is recovered and now the cable is simply deployed over the stern of the cable ship to lay on the seabed below. Speeds during this portion of the installation can reach 6 knots.

Once the installation is complete, the ships are tasked with performing post-lay inspection and burial operations. This is where the vessel will deploy its remotely operated vehicle (ROV) to descend to the seabed and inspect the cable for proper installation and burial to the required specifications. The ROVs use a combination of cameras and magnetic and electronic sensors to ensure the cable is buried to specification. Additionally, any areas required to be buried where the sea plow could not be used or had to be recovered to deck for maintenance can be buried by the ROV using a high powered water jet system.

The Hibernia Express Cable System should be ready to carry communications traffic across the Atlantic this fall.

The Reliance Class ships are manned by AMO officers in all licensed positions. In addition to the traditional roles for mates and engineers, the operation of the plow handling equipment, cable installation machinery, specialized rigging, and DP operations are accomplished by the AMO officers. The ships have also hosted cadets from the various maritime academies and the AMO TECH Program.