Only ten years ago, the motto of Dutch-built cargo ships was multi-purpose. A ship had to be versatile to adapt to the market and be suitable for bulk goods, tramp cargo, containers and project cargo. This way, the vessel could always be employed in the most profitable trade. Things have changed quite a lot since then.
Freight rates have plummeted and with them much of the profitability of shipping. Nowadays, the ships still making money are those that are most suitable for their particular trade, at the lowest costs.
Wagenborg Shipping has a young fleet of about 180 ships and has always been forward-looking. While a fairly large number of 2,500 ton – 12,000 ton cargo ships have come on the second-hand market from the insolvency of ship owners such as ABIS, Feederlines and Flinter, Wagenborg Shipping knows that these vessels can only be a temporary solution.
The ships were not specifically developed for their needs – hence less performant in operational costs – and also they do not have a remaining 25 to 30 years lifetime in them. To remain at the forefront in their trade in the long run, Wagenborg knew it was necessary to develop the next generation of ships with a focus on efficiency and sustainability. The Egbert Wagenborg is the first ship of this new generation.
What is the specific trade this ship is designed for? The trade is, in particular, the worldwide carriage of bulk goods, breakbulk and project cargo.
The dimensions of the vessel are designed to maximise the operational window of the EasyMax in the designated trading area of the vessel. This includes the Suez Canal, Panama Canal, Baltic Sea and St. Lawrence Seaway.
The ship should be large enough to cross the North-Atlantic in any weather condition, but small enough to navigate the Saint-Lawrence channel towards the Great Lakes and the local ports in the Baltic. By avoiding transshipment and using a vessel with a limited crew and a low fuel consumption, these relatively small bulk carriers are the most cost-effective size for this trade.
Jointly with its wholly owned shipyard Royal Niestern Sander, and later with Conoship and Maritime Technology for detailed design, naval architecture and engineering, Royal Wagenborg started the concept design in 2015.
Jan Doorduin, Managing Director of Royal Niestern Sander, said: “The main criteria were a maximum payload, with volume preferred over weight, a length-over-all below 150 metres, to avoid the requirement for tugs and to keep port fees low, an extremely low fuel consumption and low maintenance and operational costs. The vessel had to be fully seagoing and finally had to be able to be constructed at Royal Niestern Sander, which resulted in a maximum beam of 16 metres.”
The Egbert Wagenborg is the largest ship to be built at Royal Niestern Sander and leaving the build location involved an extremely tight turn which was a matter of centimetres. Careful planning with the help of Google Earth, some drones and four tugboats did the job.
Throughout the design process, the shipyard and owner strived for simplicity: “When in doubt, don’t do it” was the leitmotif. Nevertheless, the end result is a rather radical departure from conventional designs in this type of ships.
Most bulk cargo vessels have the accommodation at the stern. It’s mainly for reasons of trim control and weight saving that the accommodation is on the bow on the Easy Max series.
The forecastle is usually a vastly underused space on ships (in this case 50 tons), with no other purpose than to provide adequate freeboard and reserve buoyancy when heading into the waves. Locating the superstructure in the forecastle saves 30 tons of steel weight, high up.
Having the deckhouse on the foredeck also solves the problem of sight lines, allowing to build a lower accommodation tower, with again less weight aloft which would otherwise have to be compensated by ballast. Finally, the deckhouse is now located above a part of the hull which is designed for efficiency, and therefore incompatible with a box-shaped hold.
Due to its intended high-volume low-weight cargo, the ship has a high freeboard. The poopdeck is at the same level as the cargo hatch covers. In total, 100 tons of weight have been saved above the vertical centre of gravity, which results in a higher cargo capacity and less need for ballast water. Due to this layout, with lightship weight spread evenly over the length, the trim of the vessel is less dependent on the loading condition, and less ballast water is needed for trim correction.
People often wonder whether having a forward accommodation is not a punishment for the crew, especially for a ship navigating the North-Atlantic during winter time.
Jack Kuin, Project Manager of Royal Niestern Sander, commented: “Being part of the Wagenborg Group gives us a wealth of operational experience just a phone call away. Captains sailing on such vessels have no objections against a forward-positioned superstructure. There may be some more motions in heavy weather, but that is offset by a much quieter accommodation under all circumstances, as the engine room is very far away”.
To minimise those vertical accelerations and bow slamming and maximise waterline length, the designers have opted for a vertical bow with minimal bow flair and a high freeboard. The ship has such a range of different cargoes and therefore draught variations, that a bulbous bow was not deemed efficient for the entire operational profile.
Having the superstructure on the bow did actually provide one opportunity which the ship owner could not resist – in spite of the “keep it simple” approach: an open-top notation for the cargo hold. This will allow the vessel to ship project cargoes without the hatch covers on the hold, albeit with a restriction in cargo weight capacity.
For this reason, the ship has two Plimsoll marks and two stability booklets. The hull shape of Egbert Wagenborg is a combination of the foreship of the Kroonborg with a new aft ship. The Kroonborg is a walkto-work vessel which won the Ship of the Year award in 2015, for which an extensive model testing program was done, particularly to minimize ship motions while maintaining a high efficiency.
The aft ship was designed by Conoship and is conceived to ensure a good inflow of water towards the upper halve of the propeller disk, with as much of a homogenous wakefield as possible. For this reason, a sort of ‘cheeks’ are created in the pram form aftship, which can be compared to a very rounded version of the propeller tunnel used on inland waterway vessels. An integrated propeller nozzle is used to further increase the propeller efficiency.
Niestern Sander contracted the hydrodynamicists of Van Oossanen Fluid Dynamics to optimize together with Conoship the aftbody and the appendages using Computational Fluid Dynamics. This led to a further resistance reduction of 13 per cent. All the hard work certainly paid off: when fully loaded and sailing at a speed of eleven knots, the ship only consumes nine tons/day. The installed power was kept at 2,999 kW, just below the 3,000 kW threshold which requires higher manning levels.
Ice Class 1A
Maneuverability is ensured with a 750 kW Veth bow thruster and a single large free-hanging Benes spade rudder behind the propeller. This rudder is equipped with an ice knife as the vessel is built under the Finnish/ Swedish Ice Class 1A, which is also one of the reasons for the choice for a controllable pitch propeller.
Without a CPP, more engine power would have been required. The tunnel in the aft ship towards the propeller and the nozzle also contribute to a reduction in required power, as CPP, nozzle and tunnel are very effective at producing thrust at low speeds. Without ice class, a further efficiency gain could have been obtained from a larger propeller and a larger reduction ratio in the gearbox, but ice class requires the prop to be fully submerged under all circumstances.
A combination of economy of scale, hull shape, a lower design speed and a smaller amount of crew for a larger deadweight has reduced the operational costs substantially. Compared to the ship’s predecessor, the M-series of which the first one was launched in 1997, the fuel related costs to ship 1.000 tons over one mile has come down from EUR 1.52 to EUR 0.66: a reduction of 57 per cent. Compared to Royal Niestern Sanders’ latest newbuild Exeborg, which was launched in 2013, the cost per 1,000 tons per mile transported is reduced by 31 per cent.
A significant part of the operational efficiency is actually because of options which were on the table but where omitted. Two notable examples are in the cargo hold. The ship has no tweendecks as the tweendeck foundations themselves and the strengthening in the sidetanks would cost 100 to 200 tons in payload.
There are also no container fittings in the bottom of the cargo hold. Containers are rarely shipped on the multi-purpose vessels, as it’s a trade where overcapacity already exists, and the container fittings require a lot of cleaning work after each shipment of grain or other bulk cargo. To facilitate cleaning of the cargo hold, a hold cleaning system was installed with a fixed high-pressure water cleaner connected to many outlets around the hold for a hand-held pressure washer.
While the general arrangement and hull shape are extremely innovative for this type of ship, the propulsion installation is rather conventional: a single 6M32C MaK diesel engine of 2,999 kW – running on HFO – drives a 4.2 metres controllable pitch propeller from Cat Propulsion. A shaft generator is connected to the gearbox, providing power for both the hotel load and the bow thruster.
LNG propulsion was considered, but its investment cost and impact on the cargo capacity tipped the scale in favour of fuel oil. The ship has no scrubber installed – again to reduce the investment cost and to minimize the operational and maintenance costs – but the space is reserved for a fairly painless retrofit, should the differential in fuel oil prices warrant this when the global sulphur cap at 0.5 per cent comes into force (2020).
The same applies for the ballast water: no ballast water treatment system is required at the moment and has been installed, but the space has been reserved for it in the bowthruster room, as well as the needed piping for it, including a vent line through the accommodation.
The midship section is U-shaped, and there are two cargo holds. The width of the cargo holds is normally 13.2 metres on a ship with a beam of 16 metres. Because 13.5 metres would allow extra timber packets to be carried over the entire length and height of the cargo hold (an increase of capacity of 9 per cent) Wagenborg pushed the structural engineers to go the extra mile. The open top notation in combination with the 15 centimetres narrower wing tanks on each side required a very strong structure at the tips of U. Part of the load is also carried by the cargo hold coaming. Because the passageway on deck became prohibitively narrow, the bulwarks were placed on top of the rubrail, rather than on deck. To ensure passage from the accommodation to the lifeboat and the engine room aft, a corridor is provided under the deck from fore to aft. The fuel tanks are located in the double bottom. The ships frugal fuel consumption has kept the number of fuel tanks reasonable. All the piping onboard was installed by Wolfard & Wessels.
A lot of focus is placed nowadays on digital technology. The EasyMax is not behind on this evolution as it is equipped with a network on which most systems are connected. With an onboard info-system, these systems can be operated and monitored from several locations on board, such as the cabins, offices, mess room and gym. A fast satellite link not only provides onboard TV and internet for the crew, but also provides a shore connection for remote access. The technical department has access to most of the digital readouts on board and can assist the crew to operate safely and economically through the Remote Maintenance System of JRC.
Through this far-reaching implementation of automation, a next step towards autonomous shipping is made, resulting in a very low minimal safe manning required of 6. On the bridge, a state-of-the-art AlphaBridge console from Alphatron has four 46-inch screens giving access to ECDIS, radars, CCTV system and onboard information system. A lot of attention was paid to ergonomics and a 360-degree view outside with no line of sight restrictions. The Alphabridge console was built by Eekels Technology, who did the entire electrical installation of the vessel.
Whatever the fuel used after 2020, be it MGO, HFO or still-to-be developed LSFO, Wagenborg has made sure that the basics of its new ship series are right: a maximum cargo capacity at the lowest operational costs and lowest build cost possible. In this way, they have achieved a world-class low Energy Efficiency Design Index.
After an 18-month build period, the Egbert Wagenborg was named after the founder of the company, which shows how important this new series is for the company. The Easy Max series was presented to the industry at the Breakbulk tradeshow in Antwerp in April 2017.
While the Max in the name obviously stands for maximum payload and efficiency, the term Easy refers to many things: easy on the crew, easy to use, easy to maintain, easy to maneuver, easy to propel, but perhaps most of all, easy on the wallet.
This article was previously published in Maritime Holland edition #3 – 2017.