Algoma Central Corporation has not built a new Canadian Laker since 1983, writes Al Vanagas, Senior VP Technical at Algoma Central Corporation. The current Algoma dry bulk laker fleet is composed of a combination of 29 gearless and self unloading ships. These ships move bulk commodities on the Great Lakes and St. Lawrence River and Gulf over an increasingly long operating season.
Many of these commodities, such as salt, potash and cement, are aggressive to the ship’s structures and ballasting with sea water in the lower St. Lawrence into uncoated ballast tanks have combined to cause escalating requirements for steel renewals on our lakers as they aged. The winter layup periods traditionally allowed us to maintain the ships to a safe standard but shorter lay periods, and increased cost of steel repair have become burdensome. It has long been recognized that fleet renewal was overdue but building costs and production capacity/capability made a domestic building solution elusive.
Up until 2007 foreign shipyards were overbooked with standard ocean type vessels and had little interest in our peculiar, self-unloading, Seaway-sized lakers. Also, at that time, a 25% Canadian import duty and an unfavourable currency exchange provided more disincentives.
In spite of the problems,Algoma formed a project team and started to design the next generation of Seaway-sized gearless and self-unloading lake vessels. The team was tasked to find the best compromise of cargo deadweight, speed and energy and environmental efficiency. The result is Algoma’s Equinox-class vessel.
After the global economic meltdown in 2008 shipowners around the world were reluctant to place new orders and many were unable to execute on existing orders and cancelled or delayed contracts. Shipyards found themselves looking at order books that did not fill their capacity beyond 2011. As a result our peculiar, self-unloading, Seaway-sized lakers became much more interesting and yards were now competing to build our design. After an involved review process we settled on a yard we had done business with before, Nantong Mingde Shipyard. We now found ourselves with Canadian currency on par with US and as Chinese shipbuilding contracts are executed in US dollars, one more obstruction fell. Finally, in October 2010, the Canadian government repealed the long-standing 25% import tariff on foreign-built ships. This all cleared the way for Algoma to enter into contracts with Nantong Mingde for a series of new gearless and self-unloading Great Lakes vessels, the first of which is expected to arrive in Canada in early 2013.
A cursory look at the Equinox design does not reveal anything extraordinary. There is only so much that can be done with a box that must fit a Seaway lock. But when all the small improvements that have been made to benefit propulsion efficiencies, environmental concerns, crew habitability are tallied it becomes obvious that this design is like no other previous Lakes vessel.
 
HULL
The hull form is arguably the most important part of any ship design. Laker hull dimensions have been defined by the Seaway system and the locks they transit. Those parameter limitations have driven large cubic, boxy and slow hulls. In days of low fuel prices this was acceptable but today’s environment is different. Deltamarin, a ship designer in Raisio, Finland was contracted to design a better ‘box’ for our ships. The result is a vessel which will provide the most efficient transportation through the
St. Lawrence Seaway system, in terms of fuel economy, deadweight and speed.
Laker proportions, having a length to beam ratio of 9.5, a block coefficient greater than 0.9 and a required speed in excess of 13 knots presented designers a considerable resistance and propulsion challenge. Since the last series of model tests on such forms was completed over 30 years ago, at a now-defunct model towing tank, Deltamarin started with little reference data. It conducted preliminary analysis in the virtual realm, utilizing computational techniques (CFD) to solve Reynolds-Averaged Navier-Stokes equations (RANSE). Equinox is the first fully RANSE CFD optimized hull form by Deltamarin including wave pattern.
Particular attention was paid to the entrance waterlines so that the bow and shoulder waves were moderated, without unnecessary loss of displacement as well as to the aft body to ensure negligible surface disturbance aft and exemplary flow into the large, slow turning propeller; apparently no mean feat for a full form which includes very full U-shaped sections fore and aft. Much of this work was an extension of analysis done by Deltamarin on its B37, B64 and Panamax designs although changes in detail were required due to the unusual proportions of a laker. The final approach to resistance reduction was the specification of very smooth hard coatings below the waterline. Each of the five
iterations generated by the CFD analysis was run at model scale in the HSVA ship-model basin in Hamburg for performance confirmation. These tests included resistance, self-propulsion, wake survey, cavitation testing, propeller-induced pressure pulse measurements which all confirmed that designers had satisfied the design criteria. A comparatively large rudder with an integral rudder bulb fairing aft of the hub having a maximum angle of attack of 70° will provide improved course stability at service speed and increased turning moments while manoeuvring.
Efficiency could be further improved by designing as large a diameter and as slow turning as possible propeller. This has resulted in a propeller specifically designed to give the best performance over the speed range and power demand of the hull. The propeller was designed by Wartsila and is a moderately skewed design which has exceptionally low cavitation at all power demands over the full engine speed range. Towing test tank data predicts the hull will achieve just over fourteen knots turning a 6m propeller at 99rpm and 5,400kW of power. This will be at a draught of 8.15m and a sea margin of 10%.
These very impressive results are complemented in the very small wake produced by the vessel even at full sea speed which will reduce river bank erosion concerns during transits in areas of concern.
 
PROPULSION AND POWER
Once the hull form had been fully tested and optimized the team began working with engine and propeller manufacturer’s to determine the very best possible fit considering fuel efficiency, environmental impact, life cycle costs, service and support and, of course, space. The team also incorporated a philosophy of using a common manufacturer to the greatest extent possible. In this case the main engine selected is the two-stroke,Wartsila 5RT Flex 50. This newest generation of engine gives us the very best possible fuel efficiency throughout the full power range giving consideration to the amount of time spent in the Seaway and rivers. The fully electronic engine meets Tier II NOx emissions requirements and is smokeless at all engine loads and speeds. All main engine functions are electronically controlled without a camshaft. Fuel injection is by a common fuel rail system which provides constant injection pressure at all engine speeds. Injection timing, exhaust valve timing, cylinder lubrication timing is all variable according to engine load demands and speeds. Control electronics have redundant systems and common components to ensure reliability and safety.
An electronic propulsion control system interprets the power demand input from the bridge control stations into an output command to the propeller and engine to respond in the most efficient combination of engine speed and propeller pitch possible. This propulsion control system will also distribute information to the vessel performance monitoring system which monitors shaft power, electric load, and fuel consumption which, along with inputs from the navigational equipment allows the vessels crew to monitor and adjust the operation of the vessel.
The electric power generation and distribution system also takes full
advantage of electronic control and monitoring, from the same platform as the propulsion control system. The main
generators are Wartsila 6L20 Auxpac units which each produce over 1,000kW of power, these units were selected on the basis of fuel consumption as well as maintenance and life cycle cost evaluations. They also have a slightly smaller footprint which eases the demands in the machinery spaces thereby improving ergonomics for maintenance activities, when they are eventually required. The Power Management System (PMS) monitors the power demand and ensures that sufficient generating capacity is available at all times. It starts and stops generators automatically based on the power demand as well as having various operating modes to accommodate specific operating conditions such as unloading and transiting the locks. The system also handles blackouts, should they happen, with a fully automated response requiring a minimum of action by the watch keepers.
 
ENVIRONMENT
In order to minimize risk of pollution, reduce operating cost, maintain regulatory compliance and promote sustainability the design has been developed with consideration to waste stream management, focusing on all applicable elements of the VGP. For instance pumps with mechanical seals instead of packing glands were specified to reduce bilge water. There are no drains that lead to the bilge areas. All possible sources of leakage are segregated and directed to an appropriate tank for storage and eventual treatment or disposal to a shore facility. The oily water separator is a high efficiency unit which is type approved to the Lakes standard of 5ppm and typically achieves oil contents lower than 1ppm in bilge discharge. A major operating headache comes from leaking stern tubes in oil-lubricated propeller shafts or packing glands in water lubricated arrangements. The Equinox class of ships will be fitted with water lubricated stern tube bearings and use a mechanical seal inboard to prevent leakage into the machinery spaces.
The sewage treatment unit is the latest available technology and uses a membrane filter to remove virtually all bacteria and produce an effluent that is significantly below the latest IMO standard without the use of chlorine or UV sterilization. Both grey and black water are fully treated prior to discharge overboard. The effluent can be diverted to a large tank for storage, retreatment or discharge to shore for disposal as required.
The largest impact on the environment by a motor cargoship is the exhaust gas emissions from fuel burning equipment. The new ECA regulations will allow ship owners to either burn expensive, low sulphur fuel, or use heavy fuel and scrub the sulphur from the exhaust. As things are today both the economics and environmental factors support the use lower cost, heavy fuel and treating the exhaust through an Exhaust Gas Scrubber (EGS). The Equinox vessels have been designed to accept an EGS. All engines and the thermal oil boiler will be routed through the scrubber ensuring that the Equinox ship will be capable of operating full time on HFO. The various providers of this technology have made submissions to Algoma and we fully expect that a provider will be selected in time for the Equinox ships to be fitted with an EGS before delivery from the shipyard.
Space has also been reserved for ballast water treatment. Due to the uncertainty of the regulatory environment the system has not yet been defined. Until such time as the authorities are able to provide a consistent and achievable regulatory scheme for the Great Lakes and manufacturers are able to produce equipment which can be type approved and accepted for the life of the vessel we are unable to do more than allow for future space and power requirements in the design. This is a very regrettable situation for all parties, as we certainly do not wish to face having to perform a major modification to the vessel after delivery but cannot add millions to the cost of the vessel in an uncertain regulatory environment.
 
OUTFITTING
The Equinox design incorporates the latest in navigational technology to enhance the navigational safety of the vessel in all weather conditions, including an integrated bridge system, a high visibility ergonomically designed bridge to give maximum advantage to the officers, a low light/infra-red camera system to improve night vision even in the worst of weather conditions. Attention has been paid to safety and security with access and egress easily controlled and directed through the ship’s office from where officers can monitor the bridge and foremast mounted security cameras.
The accommodation areas on the Equinox class vessels are well equipped and comfortable. The smallest of the crew cabins is 15m2 and all have private washroom modules. Cabin temperature is controlled through a dual string heating and cooling system, where one duct delivers cool air and another delivers hot air to the cabins and each cabin has a local air
regulator for temperature control. The electric re-heaters which were the standard in the past have been eliminated. Cabins are fitted out with sleep, work and sitting areas and each cabin is equipped with connections to broadband internet and satellite TV. Beds are all full size and attention has been paid to isolate accommodation areas from machinery spaces and therefore limit noise and vibration transfer to levels approaching cruise ship standards in most areas.
The design also looks at the ergonomics of all vessel operations to reduce risk of accidents, elimination of the poop deck means that materials loaded aft do not need to be moved down a flight of stairs to the main deck, stairs are inclined at angles of less than 45° wherever possible rather than the typical 50° angle used. Work flow has been considered in the arrangement of all work spaces on board to reduce lifting and carrying requirements for the crew, full lighting calculations and noise and vibration studies have been completed to ensure crew safety during work and also to allow for maximum comfort during rest periods.
The galley is spacious and designed for a workstation/ process flow as well as ease of maintaining a high standard of hygiene. High-quality equipment of European design has been specified. Dry and refrigerated storerooms are adjacent to the space, as are garbage compacting/disposal areas. Accommodation areas are equipped with well laid out dayrooms and a full gymnasium.
The bowthruster on the Equinox class vessel will be 1,200kW, some 50% larger than those traditionally installed in our fleet, allowing for more manoeuvrability for the master, when in tight quarters. These vessels will be equipped with 17 large hatch covers (6.8m x 15.54m), the vessel is designed for a variable- frequency drive gantry crane, which will include a hydraulic knuckle crane for service functions, using our deck to tunnel access trunk. The vessel also include two hydraulic knuckle cranes on the aft deck for provision and engine parts supply, these cranes can directly access the engine room through main deck access.
Cargo hold cleaning can be done manually, but, the vessels come equipped with automated cargo hold cleaning machines.
The cargo holds have been redesigned to allow for efficient use of these machines with the deck arches normally hanging into the cargo hold being eliminated and instead the strength requirement has been incorporated into the hatch coaming structure above the deck. This will reduce the water consumption required, although the self-unloader has two tanks each of 300m3 for used wash water storage. Impact- and abrasion-resistant glass flake epoxy coatings above the cargo hold linings offer longevity to this structure and present an excellent surface for assisting in cargo flow and water clean-up. Cargo and deck runoff is controlled with the inclusion of a vertical gutter bar extension to the shell. The deck scuppers can allow for overboard flow of water, or can direct the flow to the used water tanks for storage and later disposal.
Concerns over cargo hold drying and potential cargo contamination have been eliminated in the gearless bulker version of the design with the inclusion of additional ballast capacity in #4 cargo hold. This modification to the design gives better flexibility for draught and trim and assists with vessel stability at same time; this modification is incorporated into the design with a minimum loss of cubic capacity.
 
COATINGS
Underwater coatings on this design are the ‘hard coating’ type, the frictional coefficient of which is less than glass. The function of these coating is twofold: to supply a non-permeable, non-porous surface which will protect the hull steel surface and decrease purchase for marine growth. These types of coatings also reduces the drag effect on the vessel by reducing the frictional component of a vessel travelling through water, this makes for a more efficient use of engine created power — more speed, less fuel.
Ballast tanks are to meet the requirements of the PSPC standard, with all tanks treated with abrasion resistant full epoxy coatings, this is expected to not only extend the life of the structure in these areas, but also assist with reducing sedimentation (this accomplished through our tank structural design and our modifications to the ballast piping system).
 
STRUCTURE
Hull structure borrows heavily from successful existing designs, but is distinguished by the extent of higher tensile steel used in the longitudinally-framed hull. Five cargo divisions are defined by non-water tight screen bulkheads which are common by virtue of the self-unloading tunnels and served by twin tunnel belts.
Double skin is arranged between collision and engine room bulkheads. Double bottom, hopper and side tanks are combined but subdivided port to starboard at the ship’s centre line. All fuel and lube oil tankage is separated from the adjacent shell plating to provide an added measure of environmental protection. Maximum commonality between the self-unloading and gearless bulker variants has been ensured, which will allow the shipyard to enjoy the maximum benefits of series construction, regardless of an individual ship’s mission and will also facilitate post-delivery conversion of bulkers to self- unloaders.
 
SELF-UNLOADING
Cargotec of Enko¨ping, Sweden was designated as the sub- contractor for the critical self-unloading systems. Innovative features include a stressed-skin, fully enclosed, 80m long, self- unloading boom, state of the art feeder gates, which rely on variable speed tunnel and elevator belts to permit changes in discharge rate without the need to adjust cargo gate opening. The conveyor system will have the ability to handle coal at a discharge rate of 4,360tph (tonnes per hour) or 5,450m3/h, whichever first reached and aggregates at a rate of 5,400tph or
3,600m3/h, whichever first reached. A high degree of automation and remote control is included within all aspects of the self- unloading system. All equipment within the tunnel, loop and boom will be certified for carriage of coal in accordance with the latest Transport Canada requirements.
 
SUMMARY
The Equinox design has been developed over the last two years under a mandate to produce a modern Great Lakes carrier and incorporate new technologies that have been developed over the three decades since a new vessel was designed and built for service in this region. The primary focus of this effort was to recognize all elements of sustainable marine transportation recognizing the limitations imposed by the operating theatre of the vessel. At every step of the process the design team looked for ways to improve safety for the crew and the vessel, reduce the environmental footprint of the operation, and reduce the maintenance requirements on the basis of both material and labour.
Further, full consideration has been given to the need to meet or exceed all current regulatory requirements and to anticipate to the greatest extent possible future regulatory standards. All this had to be done while observing the commercial realities of the vessel in terms of cost and earning potential. The Equinox design represents the very best of sustainable marine transportation on the Great Lakes for our employees, our customers, and the communities around the Great Lakes who also use the waterways for business and pleasure. Algoma Central Corporation has been in business for 112 years and the Equinox design is a confident step towards the next century of marine transportation Algoma will provide to its customers.