Harbor tugs make the difference offshore

(For nearly forty years, LNG tankers traveled the oceans of the world without many publicized incidents. Suddenly, the world ran short of energy and needed LNG. The perils of LNG and the dangers presented by LNG tankers became the subjects of many heated discussions so that the last thing the LNG industry needed was a major accident. Recently, one nearly happened and its events are worth recording. Vincent Tibbetts, Jr., president of Boston Towing & Transportation, provided the shore-side details and the tug crews co-authored this collaborative article about an off-shore tow that Farley Mowat might have written about.)

Early on a chilly Monday morning in February, 2008 in bad weather, boilers on the 932-foot Teekay LNG tanker Catalunya Spirit shut down and the ship lost all electrical power. On board were 138,000 cubic metres of LNG from Trinidad & Tobago for Boston. The wind was off-shore and the ship was drifting at 2.5 knots toward Cultivator Shoals 21 miles away and the tanker crew was concerned enough that the Abandon Ship plan was rousted out and placed on the chartroom table. The situation was threatening to become a major front-page marine casualty featuring an LNG tanker unless help arrived soon.

A call was made to the Coast Guard, which responded quickly and perhaps over-enthusiastically by ordering the medium-endurance cutter USCGC Escanaba, two tugs from Boston, another tug from Portland and a fourth tug from New Jersey to head for the scene, along with the oil-spill clean-up vessels Maine Responder, New Jersey Responder and Delaware Responder.

First off the mark were Liberty and Freedom, two tugs from Boston Towing & Transportation. Both were 4,400-hp ASDs specially designed and built by Washburn & Doughty for escorting LNG tankers like the Catalunya Spirit in their frequent visits to Boston. Both are harbor tugs and neither had been offshore in rough weather so there was some head-shed concern about their performance and, indeed, safety. Captain Chuck Delory headed the crew on Liberty. The company’s head docking pilot Captain George Lee accompanied Captain Dave Black on Freedom as salvage master. Freedom departed at 1330 on Feb. 11, with Liberty waiting 45 minutes for the arrival of a Coast Guard observer. Both tugs ran downwind about 100 miles at 14+ knots through 14-foot seas and 45-knot winds. The two tractors performed extremely well under those conditions. Freezing spray was forecast but, running with the wind, the decks remained ice-free.
 
On-scene, Escanaba was reporting 15- to 20-ft seas and, when the tugs arrived, the powerless Catalunya Spirit had drifted ESE to a point approximately 35 miles ESE of Provincetown. On the ship, the only illumination sources in the engine room were emergency lights – the ship had no power to bring a heavy towing cable up to its bow. But the ship did have an emergency towing socket on the after deck. This consisted of a heavy wire cable with a socket on the end. It was about 100 meters long and attached to a series of messengers. Captain Black backed the Freedom into the wind to within about 40 feet of the Catalunya Spirit’s stern counter, close enough to receive a heaving line from the ship, pull the cable aboard and attach the tug’s towing cable to the socket. The tug’s decks remained dry but swells rolling in under the ship’s counter threw heavy spray at crewmen working on deck.

About 1,700 feet of 2-inch-diameter wire were reeled out and, after 2-1/2 hours spent backing in, hooking up, and stretching out, towing started. George Lee and Dave Black did not want to part anything so they initially used just enough power to slow the ship and eventually stop its drifting. It took Freedom another two hours to stop the Catalunya Spirit’s leeway drift, a long slow haul into the wind, never over half-speed during the first night due to sea conditions. Liberty stayed nearby, ready to steer the tanker’s bow if needed. Later the next morning when the seas had abated, the Freedom increased power and the towing speed went up

The next day, the Iona McAlister arrived from Portland. In the early afternoon, the Iona hooked into the socket along with the Freedom but the Portland tug had mechanical problems after only a half hour or so. But as seas abated, the stern-first tow would continue for 18 hours at a speed of 4 knots.

Meanwhile, Coast Guard helicopters lowered CG officials, a Lloyd’s surveyor and at least three repair technicians (The Coast Guard Safety Inspector aboard the tanker reported heavy seas, no heat, no food, etc.). Maine Responder arrived later that evening and took station aft of the tow along with Escanaba. The oil-spill-response vessel had 2,640 feet of containment booms on board but what it would have done with the booms in rough seas on Cultivator Shoal beggars the imagination.

Surprising almost everyone, Donjon’s 6,480-hp Atlantic Salvor appeared over the horizon late on the 12th claiming that it had the owner’s permission to take the tanker in tow. The harbor tugs had been hired by the ship’s owners and needed an okay from the ship’s master and the owners before releasing the tow. Since the three tugs already on-scene were out of radio contact with the shore side (a matter since fixed by purchase of satellite phones!), there was some confusion. As the matter was being resolved, the Iona had trouble with her towing winch, which greatly helped with the decision-making.

By decision time, the seas had calmed and the ship had power to the forward winches so the ship’s crew was able to hoist aboard the towing cable from the Atlantic Salvor and hook it into their emergency towing gear forward. The big tug then took over the tow and the four-tug-plus-other-vessels armada set off for Massachusetts’ North Shore and Suez LNG North America’s as-yet-unused Neptune Offshore LNG terminal. There, the tanker put down an anchor but was told to haul it up; the Coast Guard wanted the Atlantic Salvor to keep on towing the ship while repairs were made. Unfortunately, the Coast Guard-assigned towing pattern was rectangular, which presented problems in getting the long, deep tanker to make the square corners. The other three tugs, the spill-response vessels Maine Responder and New Jersey Responder (which had just arrived), and the cutter Escanaba were told to stand by. In a few more hours, repairs were completed on the Catalunya Spirit. Since the berth at the Distrigas terminal in Everett was occupied by another LNG tanker, Catalunya Spirit sailed for sea trials, its Boston-bound cargo still on board, and the rescue fleet was released some three days after the incident’s start.

Cause of the loss of power on Catalunya Spirit was initially reported as two bad electrical relays or two defective scavenging pumps but the last Coast Guard press release stated that a boiler feed pump was the culprit. Others sources suggest that the incident was probably caused by a chain of events; perhaps a precautionary shutdown of the boiler due to a false alarm on the computer alarm system, possibly due to the feed-pump, and an auxiliary-generator start-up that did not energize the main bus due to a faulty relay. (It was learned that service representatives later manually closed the relay contacts to make connections to the main bus.)