With effect from March 1, Australia’s leading transport company Toll Group has introduced two new ro-ro freight vessels to the Bass Strait service linking the mainland and the island of Tasmania. The Chinese-built, 12,000dwt sisters Tasmanian Achiever II and Victorian Reliance II bring a 40% advance in capacity and an increased speed relative to their predecessors, plus a different internal configuration to expedite loading and discharge times, writes David Tinsley.
Constructed by Jinling Shipyard, the 210-metre newbuilds cost around AU$86m (US$61m) each, accounting for AU$172m (US$122m) of Toll’s AU$311m (US$220m) investment programme for the Bass Strait trade link. Deploying larger ships required terminal upgrades at the Webb Dock in Melbourne and at McGaw Wharf, Burnie, where AU$35m (US$25m) is being spent on a new ramp and other facilities.
Based on a design developed by the NAOS Group of Trieste, each vessel has a payload intake corresponding to some 3,100 lane-metres of ro-ro cargo on lower, main and weather decks, plus a car deck. A total of around 700TEU containers can be carried using mafi-type rolltrailers, compared to the 500TEU of the previous mainstays of the Burnie/Melbourne route, the 20 year-old, 184-metre Tasmanian Achiever and Victorian Reliance.
All ro-ro cargo access and egress is via a stern ramp whose 25m width is only slighty less than the ship’s 28m beam and which feeds to and from the system of internal, fixed ramps serving the four cargo levels. Simultaneous working of the decks by way of fixed rather than movable ramps means that trailers can be loaded right up to the time of sailing. The dedicated tweendeck for cars allows separation from trailers and containers.
Each of the new ships has 260 reefer plugs, to accommodate current and anticipated growth in flows of temperature-controlled goods. The ro-ro connection provides a lifeline for Tasmania’s population and vibrant economy, which has seen a steep increase in exports over recent years. The Bass Strait traffic as a whole is extremely varied, and reflects the island’s main industries of mining, agriculture, aquaculture, fisheries and forestry, as well as consignments of retail goods.
Toll’s injection of new, higher capacity tonnage will enhance access by Tasmania’s primary producers and manufacturers to mainland and international markets via Melbourne on a daily basis.
Each of the new ro-ros is powered by electronically-controlled, two-stroke MAN machinery, in the shape of twin nine-cylinder versions of the S40ME-C9.5 engine, driving controllable pitch propellers. The nine-cylinder model is a relatively recent addition to the 400mm-bore engine series, and offers a maximum continuous output of 10,215kW at 146rpm, providing a 20,430kW power concentration in each vessel, enabling crossings to be made at some 20-21 knots.
Transits of the 396km Bass Strait route are now scheduled in 13 hours, one hour less than with the previous ships. The time saved will be used in port for the simultaneous loading and unloading of the extra cargo that the new generation can accommodate.
The scope of supply from MAN Energy Solutions also embraces three nine-cylinder auxiliaries of the L21/31 type, individually specified at 1,980ekW. Electrical power delivery when under way is economically and flexibly realised by two 1,700ekW shaft generators of the permanent magnet (PM) type emanating from the Finnish company The Switch.
The on-line direct-drive shaft generators engender power up to 3,400ekW for the ship’s electrical network, including the bow thrusters, while enabling the main engines to be operated at variable speeds. As the propulsion machinery can be run at optimal duty points at all ship speeds, this solution promises significant fuel savings over the course of the vessel’s operating pattern, with corresponding decreases in emissions.
Furthermore, use of the diesel gensets can be reduced or obviated in harbour through the arrangements for drawing electricity from the shoreside grid.
Newbuild project management was assigned to Clydebank-based Tritec Marine, part of the Stena-owned UK company Northern Marine Group. The range of services delivered by Tritec for the project, starting in 2016, included initial contract specification, plan approval, shipyard selection, machinery tests, and on-site newbuild construction supervision.
Tritec’s scope and technical knowledge base benefits from its strategic partnership with Shanghai Bluesoul Environmental Technology, maker of the BlueSulf range of exhaust gas cleaning systems. Toll’s decision to incorporate scrubbers in its latest ships ensures compliance with IMO’s 2020 global sulphur cap while burning heavy fuel oil (HFO), and affords protection from possible future shortages and price volatility of more costly, ultra low-sulphur diesel.
The array of Lloyd’s Register class descriptions attributed to the design by NAOS includes the society’s descriptive notation GR (A), indicating a certain level of gas-fuelled readiness. This will help facilitate any future decision to adapt the main machinery so as to render an LNG dual-fuel capability.
Effective roll reduction in the often rigorous conditions of the Bass Strait is exercised through the Flume passive stabilisation system provided by the Hamburg firm Hoppe Marine. In a seaway, the liquid flow within the Flume tank spaces lags behind the resonant roll motion of the ship by up to 90 degrees, exerting a stabilising force directly opposing the forces created by the passing wave. Hoppe bought Rolls-Royce Marine’s Intering business in May 2017.
In parallel with the commissioning of tonnage yielding increased route capacity and higher productivity, Toll is phasing-in a new wharf management system and customer booking software. The landside initiatives are intended to improve terminal operating procedures and minimise traffic congestion, facilitate better freight tracking and monitoring of refrigerated cargo.
The superseded pair on the Melbourne/Burnie run, the 11,000dwt Tasmanian Achiever and Victorian Reliance, have now been withdrawn from service and are to be sold on the international secondhand market. The vessels were delivered by Samsung Heavy Industries in 1999 to the order of Brambles Shipping, which was purchased by Toll in 2002. Beyond its Australian interests, the Toll Group is a growing force in global logistics, and is foreign-owned, having been acquired several years ago by Japan Post.