Swedish owner Broström is breaking ground with the first tanker newbuild with environmental class notation

Broström’s new tankers will set new standards in the intermediate product and chemical-carrying sector.

Developed in response to shipowners’ increasing requirements for environmentally-friendly operation, DNV’s ‘Clean’ class notation has been adopted by a wide range of vessel types, with the exception of tankers. That situation that is about to change, with Broström Tankers’ D-class, the company’s new class of very flexible, environmentally-friendly tanker, the first of which is due to be delivered early next year.

The specification for the 14,000dwt/ 18,700m3 D-class product and chemical tanker, the first of which was launched at Jinling shipyard in China in June, dates back to 2002, when well-known Swedish owner Broström undertook a comprehensive analysis of its customers’ requirements, analysing their distribution networks, refinery capacities and cargo sizes in depth.

Together with a survey of ports and terminals that the new vessels would trade into and out of, the studies resulted in a new class of four high-capacity ships based on Skipskonsulent’s SK4228AP design. Steel for the first and as yet unnamed vessel was cut in September 2004. It is currently due to be delivered in January-February and to enter service in North West Europe in the second quarter of 2006.

Broström believes that the keys to success in the shortsea shipping sector are flexibility, reliability and efficient use of time in port, and that to meet increasingly complex market demands, shipping companies have to become ‘service providers’ rather than purely owners and operators of tankers.

With this in mind, Broström has placed a high level of priority on becoming just such a service-provider in the intermediate tanker sector in Europe, and believes that when the new class begins to enter service, it will reinforce the owner’s position as a strategic business partner. The vessels are purpose-built for the North West European market and designed for intensive trading, at up to 70 voyages per year.

As Broström Tankers’ MD Tore Angervall explained, the new vessels will replace existing tonnage as part of a continuing fleet renewal programme. The most important emphasis in the design of the D-class has been on ‘green’ operation, typified by the ‘Clean’ class notation, and on flexibility – particularly cargo flexibility – along with a high level of manoeuvrability.

Ensuring that the vessels will have a quick turn-around is also highly important to Broström, and the requirement is reflected in the capacity of the ship’s cargo pumps (3,360m3/hr), and in the selection of the main propulsors and bow thruster. As Angervall told Solutions, the new, very manoeuvrable vessels would be capable of manoeuvring into and out of the ports and harbours they will serve without tug assistance (although international rules and regulations mean that tugs are required anyway).

An emphasis on safety and on manoeuvring is evident in the adoption of wholly redundant propulsion trains. Each D-class vessel will have redundant propulsion systems including separate 7-cylinder MAN B&W L27/38 engines rated at 2,380kW, fuel systems, shafts, propellers and steering units, fulfilling Broström’s requirement for ‘RP’ class notation.
Adoption of 360° fully azimuthing ‘Azipull’ pulling thrusters, combined with a 1,000kW bow thruster, provide the D-class with a level of manoeuvrability that Angervall believes is equivalent to that of a dynamically positioned (DP) ship, and a speed of 13kt.

The Azipulls were selected after what Angervall said was an exhaustive selection process – with at least five different iterations of the best propulsion machinery – and they confer on the new tankers excellent turning and stopping performance with big safety margins. “Selecting Azipulls has also saved us some space in the enginerooms,” Angervall explained. The move has resulted in increased cargo carrying capacity. “Of course, revenue earning potential is what it’s all about,” he told Solutions.

MAN B&W engines were also chosen as the auxiliaries and each of the ships is fitted with four 6L 16/24 gensets. All six diesel engines in the engineroom will be fitted with Munters catalytic reduction technology to reduce NOx emissions by injecting urea into the diesel exhaust lines. This will allow almost complete elimination of NOx emissions (a 98% cut), and combined with use of low-sulphur fuel oils, will make the new tankers one of the ‘cleanest’ designs in the world.

Interestingly, Broström has also paid a lot of attention to reducing noise levels on board, bearing in mind that the ships will spend about half of their time in ports and at terminals in urban areas. Proximity to urban areas while in port is a recurring theme in the design and specification of the D-class, Angervall explained, driving issues such as the ships’ environmental features and the selection of low noise pumps.

A ‘D class’ officer will be on duty in what Angervall calls a “tailor-made workplace,” the bridge being designed and built according to DNV Naut-Aw notation. The superior level of safety afforded by this design is underscored by the 360° panoramic view from the bridge, while all the officers on board will benefit from a class-specific training programme – including simulator sessions – to enhance skill and safety levels.

Security on board is also an important issue, and the D-class vessels will be equipped with CCTV camera systems on deck and in the engineroom, with lock and gate systems strategically positioned around to complement alarm systems.

In keeping with the emphasis on environmentally-friendly operation, all onboard cargo handling and tank cleaning systems are closed-loop systems, reducing the risk of spill or contact with products or residuals.

To reduce the risk of injury to the ship’s crew, the mooring drums are housed in a purpose-built arrangement that also reduces the risk of damage to the equipment, enhances efficiency and reduces time in port.

The outstanding cargo capacity for a vessel of this size means that the D-class will be particularly well suited to transporting light products. It features 14 tanks of different sizes in an optimised configuration that allows for up to nine segregations with an efficiency maximum of 1-5. The excellent ratio between draught and capacity (the ship’s draught being just 8m) also enables the D-class to gain access to ports with restricted water depths, increasing their operational utility.

Broström’s new tankers will, undoubtedly, set new standards in the intermediate product and chemical-carrying sector, but one operational matter remains to be ironed out before the ships enter service. This is the logistics of obtaining urea for the SCRs on board the ships.

“In the aftermath of 9/11 new rules and regulations have made it difficult in some ports to bring provisions onboard,” Broström’s MD explained. “It’s an operational problem, really. It will probably not be possible to source urea for the SCRs at every port where the ships make a call, but we are working on that, and are confident that by the time the first D-class enters service the logistics will be in place.”

Broström D-class product & chemical tanker

This article was originally published in Fairplay Solutions, and is protected by copyright.

Date: 2005-11-22