Voyaging up the St Lawrence River with cargo for the first time this month, the 25,800dwt Nukumi is an innovative addition to the self-unloader fleet working the eastern Canada and Great Lakes trades.
A multi-engine, diesel-electric propulsion system and unique aft underwater hull form confer operational flexibility and heightened efficiency for the intended sphere of employment, achieving a new environmental standard.
New-generation self-unloader to sustain vital Canadian trade.
Constructed by CSSC Chengxi Shipyard for Montreal-headquartered Canada Steamship Lines (CSL), the 226m bulker has been conceived primarily for the regional transportation of salt. Nukumi has the distinction of being the first diesel-electric bulker dimensioned and fitted for Lakes-going navigation, and is also the first single-point loader to operate in Canada.
Following the delivery passage from China, the vessel put into Halifax, Nova Scotia, on 27 March. She then made for Charlottetown, on Prince Edward Island, where the ballast load of stone was discharged, before proceeding to the nearby Isles de la Madeleine (Magdalen Islands) to begin servicing a long-term salt transportation contract.
The newbuild scheme arose from Windsor Salt’s requirement for a new ship to effect deliveries od de-icing salt from its salt mine on the Magdalen Islands to stockpiles in Monteal and other destinations in the provinces of Quebec and Newfoundland. The rock salt is applied during the winter season to roadways across eastern Canada.
Construction began at Chengxi’s Jiangyin yard on the lower reaches of the Yangtze during August 2020 after several years of collaborative planning, which included an environmental impact analyses, ship and shore personnel safety reviews, an efficiency evaluation of cargo operations, and navigational optimisation. The design was developed in co-operation with Deltamarin.
As the regular shipping route encompasses the sensitive marine environment of the Magdalen Islands, a small archipelago in the Gulf of St Lawrence, CSL and Windsor Salt worked together to incorporate solutions that promised a more ‘sustainable’ transport operation. The project drew on the know-how of technical consultancies and system specialists and has come to feature a novel diesel-electric propulsion system and aft hull design.
The combination of measures incorporated in Nukumi is expected to result in approximately 25% less greenhouse gas emissions and 80% fewer harmful air pollutants compared to previous vessels used to carry salt over the same routes.
The power and propulsion installation is based on four Tier III-certified MaK medium-speed engine gensets of total 9.5MW output feeding two permanent-magnet electric propulsion motors housed in fins with feathering, controllable pitch propellers. The chosen concept, the Berg Propulsion Twin Fin direct electric drive system, offers benefits in manoeuvrability and plant efficiency, and is suited to navigation in ice-prone waters and the shallow Magdalen channel.
The integrated approach to hull and propulsion design addressed goals as to operating economy while securing the requisite manoeuvrability and durability. As well as cutting emissions and improving energy efficiency, the machinery and propulsion arrangements promise reduced radiated noise and consequent impact on the wellbeing of the area’s North Atlantic right whales and other marine mammals.
The newbuild has a fixed, single point of loading system and sole hopper, combined with a cargo handling system that obviates the need for the vessel to shift during the cargo loading process, thereby improving cargo working efficiency and safety. Self-discharge is continuous by way of a gravity-fed hold conveyor and swivelling conveyor boom on the weather deck.
During the inaugural outturn in Montreal, it was reported that the vessel’s shuttle boom arrangement plus the sensor technology installed on the boom and programmed to ‘auto-pile’ mode contributed to savings in time and crew effort.
MAIN PARTICULARS -Nukumi
Length overall
225.5m
Breadth, moulded
23.8m
Gross tonnage
22,715t
Deadweight
25,800t
Propulsion system
Diesel-electric direct drive
Main genset engines, total power
4= 9,500kW
Propulsion motors
2 x 3,000kW
Class
LR
