The tugboat Ap Chau handles a line from the stern quarter of a containership.
As much as he takes pride in his British roots, he enthuses equally about the boat-handling skills of Coxswain Lo Kwok Kuen, with whom he was docking ships in Hong Kong this past March. They worked onboard the recently delivered z-drive tug Ap Chau. Putting a line up on the stern quarter of a 900-foot containership that he was about to assist into the pier, Lo adhered to the unstated order concerning vessels under the guidance of Hong Kong pilots: “Do not touch the ship!”
The well-fendered bow of the tug rode a few feet from the ship as a deck hand received the heaving line and made it fast to the larger messenger line. The ship’s crew hauled the messenger aboard and set the eye of the 33-foot, 1.5-inch wire pendant over a bollard. Lo paid out another 130 feet or more of the 360 feet of polyprop line that Ap Chau carries on her bow winch.
The super-fiber lines popular in America are not favored on Hong Kong tugs. Pointing out the winch control handle mounted on the port side of the operator’s console, Macleod explained that it is there, rather than in a central location, as on some tugs, so that the deck hand can sit to one side and operate the winch, should an emergency require the operator to use both hands on the propulsion controls.
Details such as the winch control highlight the attention to detail in the design of the Hong Kong Salvage and Towage tugs. The third of four in the Chau, or Island, class, the 4,000-bhp boat is remarkably different from similarly powered boats that dock the same ships on the American side of the Pacific. Delivered from her Japanese builders, Kegoya Dock Co., in early 2003, Ap Chau is a sister to Cheung Chau and Sha Chau, delivered in 2002. With a length overall of 95 feet and a 31-foot beam with a 15.4-foot molded depth, she is similar in size to many North American ship-handling tugs. But she is powered by a medium-speed diesel that turns at a maximum of only 750 rpm, compared with the 1,600 to 1800 rpm more commonly found on American boats.
The main engines are a pair of 6N 260-EN Yanmars. Each of the 2,000-hp engines drives into an azimuthing Kawasaki Rexpellers KST-180F/A z-drive. Each unit has a fixed-pitch Kaplan skewed propeller in a nozzle. An insulated compartment between the two main shafts contains the boat’s twin 80-kw generator sets.
The lack of rpm range is made up for with a slipping-clutch provision on the marine gear. In docking the 900-foot containership, the engine and propeller tachometers on the control panel showed the variable ratios. Pushing the stern of the ship into the dock, the gauges showed 600 engine rpm for 240 propeller rpm. When the pilot asked for “half ahead,” Lo moved the controls until the ratio shifted to 550:220. Then, as the pilot said in Cantonese, “Push slow,” the gauges shifted first to 400 rpm on the engine and 100 rpm on the propeller gauges. Then, with the engine remaining at the 400-rpm idle speed, the props were slowed still further to 75 rpm.
The slipping clutch together with the throttle controls gives great flexibility in thrust control. The consensus of the operators is that the control system takes a little more to get accustomed to than the twin rotating combined nozzle and throttle controls common in North America. But they feel that once an operator gets the feel of controlling the nozzle directions with the big, integrated single joystick with his right hand and the individual throttle controls with his left hand, the range of operational variables is equal or greater. There is a provision that allows the two nozzles to be delinked and operated with separate controls. But this is seldom used, as the programmed system under the single joystick provides the appropriate combination of nozzle directions for most situations. The fact that the Hong Kong tugs are built with rounded chines and bilges, rather than the double-chine construction that is the practice on a good many North American tugs, may contribute to these handling differences.
Most Hong Kong berthing tugs, like their North American counterparts, maintain a three- or four-person crew, but Ap Chau has a crew of seven. This is so she can maintain a seagoing readiness for both ocean tows and salvage work. For towing, she is equipped with a single drum deck winch loaded with 2,460 feet of 1.75-inch towing wire. A towing staple and bollard combination is mounted several feet aft of the winch. Capt. Macleod’s presence on the tug is also a condition of her seagoing readiness, as the coxswain, with his finely tuned boat-handling skills, is only licensed for Hong Kong waters. Most of the other crewmembers have extensive deep-sea experience.
Whatever differences and similarities there are in the tugs, there is no question that Hong Kong Harbor offers some unique traffic challenges that are unparalleled anywhere in North America. In 2001, about 14,000 local boats were licensed in Hong Kong — including passenger vessels, tugs, cargo, and fishing and pleasure vessels. With land in short supply, many ships take positions at one of the 56 mooring buoys for oceangoing vessels in the port, and their containers are lightered ashore or to ports in mainland China by barge or small container vessels.
Over 37,000 oceangoing vessels entered Hong Kong in 2001. On an average day, there are about 100 deep-sea ships working in the port, about 1,200 oceangoing and river-trade craft enter or leave the port, and about 10,000 local craft move within the port. High-speed ferries calling at two terminals move 17.7 million passengers annually between Hong Kong and mainland China or Macau. The wakes of these thousands of craft create an unending turbulence in the port waters.
An extensive vessel traffic control system monitors the movements of deep-sea ships. Ka-mo Lee, assistant director of port control for Hong Kong, said in a recent port publication, “Our VTS system is constantly monitoring Hong Kong waters. We give direction and advice for all oceangoing vessels. Like other ports, we find our oceangoing vessels are law abiding and manageable. Our headaches tend to be created by the river cargo vessels. We are handling more than 300 of these vessels a day, in and out of our port, and we don’t have the capability at the moment to communicate and give advice or direction to all of these vessels.”
An additional challenge for the port of Hong Kong is the annual typhoon season. Hong Kong Salvage and Towage gives out large calendars that feature a map where one might ordinarily expect to see a picture. This map is in the form of an erasable white board that serves as a typhoon plotter for the region, including the Philippines, Taiwan and Okinawa, with Hong Kong in the center. This is to encourage customers and ships to plot the direction and distance of approaching typhoons. Fleet Operations Manager Jerry Lo explained, “Once the number-three signal goes up, all ships have to leave the piers and go to anchorage. In the typhoon season, from April to November, we often have as many as seven of these alerts, although last year, 2002, there were only about three.”
A number-three signal indicates that “strong winds are expected or blowing in Victoria Harbour, with a sustained speed of 41 to 62 kilometers per hour. Gusts may exceed 110 km/h,” Lo said. “Winds are normally expected to become generally stronger in the harbor areas within 12 hours after the issuing of this signal.”
The challenges for tug companies at such times are huge. Not only must they be ready to assist ships that get into trouble should the typhoon actually hit the port, they must also arrange to get all the ships away from the piers on very short notice. “Since 1996, we have had a 10 percent decline in business. Now we compete for our share of the remaining work with two other companies. The work peaks around a typhoon warning,” Lo explained. “Our highest number of ship moves was in 1997; just after a typhoon, we handled 143 ships in a 24-hour period.”
The location of Hong Kong, near the mouth of the Pearl River, is such that deep-draft vessels leaving the newly developed Chinese mainland container port of Shekou must transit Hong Kong waters on their way to the open sea. Shekou is located on the east bank of the Pearl River about 20 miles from Hong Kong. Its only deepwater access passes around Ma Wan Island in Hong Kong waters, where currents can reach 5 knots. As they come up to the turn around the island, the pilots like to maintain speed for steerage. Regulations require a tug escort for vessels over a certain size.
On a recent transit by the containership MSC Louisiana, the Hong Kong tug Tai Koo was assigned escort duty. It is a relatively straightforward task, with the tug standing by at the entrance to Ma Wan Passage and tracking the ship through the pass and around a hard turn to starboard. The challenge comes in passing the work order from the tug to the ship to be signed and returned. This is accomplished with a small net basket on the end of a pole. With a limited top speed, it will often be all Tai Koo can manage to maintain adequate speed to make the pass.
Tai Koo is considerably over-equipped for this escort job. Like Ap Chau, she is maintained with a large crew for ocean operations. She is also fully equipped for salvage work. At 114 by 34 feet and with three decks, she is significantly larger than Ap Chau. In the space between the main drive shafts that is occupied by an isolated generator room on Ap Chau, Tai Koo has a compartment for storage of salvage equipment and gear for the four divers that she carries. Her engineer does, however, enjoy a sound-insulated control room. She is classed Bureau Veritas 1 3/3E Maltese cross tug/firefighting ship1/water spray/deep sea. A pair of remote- or locally controlled fire monitors projecting 5,200 gallons per minute are supplied by pumps off the front of the two Yanmar 2,000-hp main engines. This is a lot of boat with a list of equipment that includes a pair of 3,000-watt searchlights.
The multinational crew of 11 people includes Philippine as well as Chinese sailors and officers under the command of Chinese-born San Francisco resident Capt. N.Y. Li. Coxswain Lam Ah Kee works ships with the same easy confidence of others in the fleet. Born on a fishing boat based in the Hong Kong Island port of Aberdeen, Lam has traveled extensively because Hong Kong Salvage and Towage uses him to train local coxswains in foreign ports where the company keeps tugs.
Built at Imamura Shipbuilding in Kure, Japan, in 1993, Tai Koo has controls similar to those on Ap Chau; but rather than the slipping clutch to give precise control on the slow-speed diesels, she has variable-pitch propellers.
Docking a ship, Lam gains the precise thrust by setting his controls at 500 rpm and 21 percent pitch for the pilot’s request of “half ahead.” For “quarter ahead,” he goes to 400 rpm and 21 percent, with 25 percent being the maximum pitch. When the pilot asks for “stop,” Lam maintains the minimum 400 rpm but keeps 5 percent on the prop to hold the tug gently against the ship. All of these are delivered with the z-drives set on 0Â° or straight ahead. The astern pitch is not used, as it is more effective to rotate the drives.
Even the above is an oversimplification of the coxswain’s boat handling. It is a much more fluid set of hand and control movements, more akin to a fisherman handling an unseen net with a powerful boat, than any image of a captain sending simple telegraph commands, although in Hong Kong, as in North American ports, most pilots continue to use language that derives from the days of the brass engine room telegraph. The challenge is for the tug operator to adapt those requests to the modern propulsion systems.
Ship-handling tugs have evolved to meet the needs of ever-larger containerships demanding ever-faster turnaround times. Form and function have determined some large commonalities in tugs designed and built in nations around the world. At the same time, the Japanese-built tugs of Hong Kong offer some interesting variations on the theme.
The Chau class of tugs is meeting with satisfied approval from their operators. In March of this year, a pair of the company’s 15-year-old 2,600-hp tugs was sold to an English buyer. As they were being prepared for load-out on a heavy-lift ship, Hong Kong Salvage and Towage General Manager and Salvage Master Alan Loynd explained, “Our boats put on a lot of working hours in Hong Kong, and we expect a 20-year life from them. By selling these boats at this point to a less busy port, we can feel comfortable that they will give at least another decade of good service to their new owners.”
Although business in Hong Kong has leveled off in recent years, the company is experiencing demand for its boats and ship-handling expertise in places as far flung as Mexico, Trinidad, Dubai, Australia and Indonesia. To keep up with the demand, the company has an aggressive newbuild program. In mid-March, Macleod flew from Hong Kong to Japan to pick up one more vessel in the Chau class. Also on order for 2003 delivery are several 3,200-hp dedicated ship-berthing tugs.
The boats of the Hong Kong Salvage and Towage fleet are impressive in their technological sophistication, but that is surpassed by the pride and boat-handling knowledge of those who work them. Signs on all exterior doors inform that work boots are not to be worn in the shining companionways. From the deck crews and Philippine salvage divers, to Chinese, Scottish and English officers, including those who have come ashore to office jobs, there is a seamless understanding and expectation that Hong Kong, one of the world’s premier ports, deserves appropriate levels of professional seamanship.