The new Wärtsilä 46DF engine has been specifically developed for the high-output market and is fuel flexible as well as power flexible with 1045 kW or 1145 kW cylinder power options.
Compactness and reduced weight are the key attractions of the medium-speed engine, giving ship designers the option of increasing a new vessel’s revenue-earning capacity to get the most efficient propeller speed through mechanical (reduction gearing), or through diesel-electric transmissions.
With the cruise ship, ferry, LNG carrier and offshore vessel markets for this type of engine in mind, the 46F engine design is based on the well proven Wärtsilä 46F engine, popular since the early 2000s, but with the advantage of being able to use natural gas, heavy fuel oil (HFO), or marine diesel oil (MDO) bunker fuel.
The Wärtsilä 46DF extends Wärtsilä’s dual-fuel engine family by covering the power range from 6.2 MW to 18.3 MW at 600 rpm.
• Cylinder bore 460 mm
• Piston stroke 580 mm
• Cylinder output 1045/1145 kW/cyl
• Engine speed 600 rpm
• Mean effective pressure 21.7, 23.8 bar
Wärtsilä 46DF engine: Image courtesy of Wärtsilä
Fuel flexibility & automation
Wärtsilä’s proven dual-fuel technology enables a choice between gas and liquid fuels, with a switch between the two according to cost, availability, and local environmental regulations. Wärtsilä say that the switch between fuel types is made without loss of power or speed. The engine automation adapts automatically to the relevant fuel selection, both in normal and emergency modes.
In gas mode, the natural gas is fed to the engine at low pressure. This facilitates a simpler and space saving engine room configuration, while providing easier and faster maintenance activities.
The engine’s gas piping is double-walled as standard, and the advanced integrated automation system enables enhanced safety and local monitoring, which leads to safer and more reliable operations under all conditions.The complete built-in automation minimizes the need for external controls, thus saving engine control room space.
The Wärtsilä 46DF is designed for a broad range of marine applications and the engine can be optimized for constant speed diesel electric operation. It also meets the need for direct drive main engine propulsion, operating at either constant speed or along a combinator curve.
Fuel savings for LNG carriers
For LNG carrier applications, the engine builders say that the 46DF can offer fuel savings of as much as 20 tons/day compared to the first introduced DF engines. With up to 14 fewer cylinders installed, the overall lifecycle installation costs are significantly and positively impacted by roughly 1000 USD/day.
Exhaust gas emissions
When operating in gas mode, the Wärtsilä 46DF engine is already compliant with IMO Tier III regulations without any secondary exhaust gas purification systems. In liquid fuel oil mode, the Wärtsilä dual-fuel engines are fully compliant with the IMO Tier II exhaust emission regulations set out in Annex VI of the MARPOL 73/78 convention.
Drive coupling specialists Vulkan, based in Germany, is supplying both fixed and flexible drive couplings to Brazil’s home-built burgeoning offshore energy sector, and interestingly is also involved in a project to develop a nuclear-powered submarine propulsion system for the Brazil Navy.
The diesel engine beats to the sound of a pulsating drum in its cycle giving rise to shaft vibration. Secondly, slight misalignments, in connected drive shafts also need to be smoothed out, and to achieve this, flexible couplings incorporate rubber-like polymer subrstances in their design – elastomers.
Vulcan explains that compound research in its R&D facility with highly specialized vulcanization technology has led to the development of an elastomer with considerably higher power density – the 'Acotec' compound. This new compound distinguishes itself from other conventionally used materials not only through its enhanced tensile and tear strength and increased ultimate elongation, but also through a high thermal resistance and reduced ageing.
Vulkan’s latest project was to supply highly flexible couplings for Caterpillar gensets and electric motors, as well as torsionally rigid couplings for the waterjets of six drillships built for Petrobas in a Brazilian shipyard.
Image courtesy of Vulkan
Nuclear-powered submarine project
Brazil’s ambitious plan is to have six nuclear-powered submarines out of a total fleet of no less that twenty in the long term. The Brazil Navy is tasked to protect the nation’s vast subsea energy resources in fields located up to 350 kilometres off the coast and at a depth of over 3,000 meters. Preliminary estimates suggest that up to 100 billion barrels of oil are to be found there.
The planned nuclear submarine will displace 6,000 tonnes and be 96.6 meters in length, with construction planned to take eleven years. It will be driven by a nuclear reactor developed at the Marine Research Centre Aramar.
A land prototype for the entire drive of the nuclear submarine is currently under construction, of equal size to the drive to be built later. Once this test phase has concluded, the entire submarine will be completely assembled for testing purposes in a multiple-story building. For the drive test rig, Vulcan says it has delivered in co-operation with its Brazil and Italy subsidiaries a RATO S 731 coupling and the elastic mounts.
Heavy fuel oil will remain the main fuel for deep sea shipping in year 2030 indicates new research from Lloyd’s Register and University College London’s Energy Institute. In a complex study involving many inter-related factors, ‘Global Marine Fuel Trends 2030’ (GMFT 2030) limits itself to the container ship, bulk carrier/general cargo and tanker (crude & chemical/products) sectors which represent about 70% of the shipping industry’s fuel demand.
VLCC: File photo
Marine fuels considered:
Ranged from liquid fuels used today (HFO, MDO/MGO) to their bio-alternatives (bio-diesel, straight vegetable oil) and from LNG and biogas to methanol and hydrogen (derived both from methane or wood biomass) were included in the study.
Included were 2 or 4-stroke diesels, diesel-electric, gas engines and fuel cell technology. Since the uptake of certain fuels is influenced by them, a wide range of energy efficiency technologies and abatement solutions (including sulphur scrubbers and Selective Catalytic Reduction for NOx emissions abatement) compatible with the examined ship types were included in the modelling.
Three scenarios applied
Shipping is the enabler of world trade – if world trade grows then so will seaborne tonne miles of cargo. The Global Merchant Trends 2030 report issued last year indicates we can expect strong growth for shipping. With emissions regulations and rising energy costs, shipping decision makers will benefit from a clearer understanding of the potential scenarios for marine fuel demand. These were:
- Status Quo – The world will continue its current growth momentum with some booms and busts over the next twenty years.
- Global Commons – A shift to concern over resource limitation and environmental degradation will see a desire for a more sustainable world being developed and fairness in wealth distribution. Governments will find common ground and accelerated economic growth, within a framework of sustainable development, which will follow.
- Competing Nations – States act in their own national interest. There will be little effort to forge agreement amongst governments for sustainable development and international norms. This is a self-interest and zero-sum world with a likely rise in protectionism and slower economic growth.
Brief conclusions: Fuel mix in 2030
- Heavy fuel oil (HFO) will still be very much around in 2030, but in different proportions for each scenario: 47% in Status Quo, to a higher 66% in Competing Nations and a 58% share in Global Commons, the most optimistic of scenarios for society. A high share of HFO, of course, means a high uptake of emissions abatement technology when global emissions regulations enter into force.
- The declining share of HFO will be offset by low sulphur alternatives (MDO/MGO or LSHFO) and by LNG, and this will happen differently for each ship type and scenario. LNG will reach a maximum 11% share by 2030 in Status Quo.
- Interestingly, there is also the entry of Hydrogen as an emerging shipping fuel in the 2030 Global Commons scenario which favours the uptake of low carbon technologies stimulated by a significant carbon price.
To download a PDF of the report go to www.lr.org/gmft2030, hard copies can be ordered from the Lloyd’s Register Webstore at www.webstore.lr.org
Ships with Wärtsilä’s Airguard and Oceanguard propellor shaft seals have no need to change from mineral oil to a bio-degradable lubricant (formally ‘an Environmentally Acceptable Lubricant’) when they're in U.S. waters as these seals meet Vessel General Permit (VGP) requirements. How these particular propeller shaft seals comply, and more about these newish VGP amended regulations follows:
Seals,bearings and stern tube arrangement: Image courtesy of Wärtsilä
No oil-to-sea interface
Wärtsilä explain that Airguard is suited for merchant ship stern tube and thrusters, and Oceanguard for cruise, ferry and offshore stern tube, thruster and electric pod face type sealing.
The Airguard and Oceanguard sealing systems have been designed with no oil-to-sea interface (the essential point): an air chamber or separation space within the seal captures any water or oil leakage, which is then transferred to inboard tanks for monitoring and further treatment. This stops oil drips or leakage into the sea. In the case of system failure, both systems also prevent any oil leakage. The manufacturers say that these seals are also designed to withstand abrasive waters and are compliant with all anti-pollution requirements.
Shaft seals and US Vessel General Permit (VGP)
The revised VGP came into force on 19 December 2013 and applies to non-recreational vessels that are 79 feet (24.08 meters) and greater in length in US waters. For these vessels, the VGP requires environmentally acceptable lubricants (EALs) to be used in all applications that have the potential for an "oil-to-sea" interface (which, as mentioned above, Airguard and Oceanguard seals do not have). The VGP states that oil-to-sea interfaces include any mechanical or other equipment where seals or surfaces may release small quantities of oil into the sea.
The most relevant components are the stern tube, rudder bearings, CP propellers, thrusters and fin stabilisers. However, any ship components that can potentially cause the leakage of lubricants into the sea are in principle to be considered according to the VGP.
Although environmentally preferable, EALs may have some major disadvantages. The most important one, according to classification society DNV GL, is that many conventional rubber (seal) materials are not compatible with the new EALs. Such lubricants will also absorb more water than mineral oils, so water control (i.e. sticking to the recommendation of the EAL supplier) becomes important to maintain lubrication capacity and keep the risk of corrosion and bacteria growth under control. Understandably, technical superintendents will rejoice if they have in place one of the Wärtsilä propeller shaft seals mentioned here.
For detailed information on the revised VGP visit:http://1.usa.gov/1diKHeL
Tags: Wärtsilä, propeller shaft seals, lubirication, Oceanguard, Airguard, merchant ships, ferries, cruise liners, offhore vessels, US Vessel general permit, vgp
American shipbuilders rarely deliver a ship that’s built for heavy duty offshore rig supply work that also turns heads, but a recent delivery from Houma, Louisiana-based New Generation Shipbuilding is already doing just that with the new 171-ft ‘Mr. Ernie’.
OSV Mr. Ernie: Photo credit: Cummins Hotips/Alan Haig-Brown
This striking vessel was built for same-name owner Ernie Vicknair and his partner Joe Gregory for rig support work in the Gulf of Mexico. According to Cummins Hotips, credit for the distinctive super-structure design goes to Incat-Crowther, although the design and engineering support team also included Parfait Maritime; Mino Marine LLC; and Farrell & Norton Naval Architects. The outcome of their collective effort contradicts the old saw that if you want to kill any idea in the world set a committee to work on it.
A pair of Cummins K38M Tier 2 diesels deliver a total of 2000 HP through Twin Disc MGX-5321 gears to 72x65-inch Bird Johnson 4-blade propellers to give the vessel a respectable and economical 13-Knot service speed.
K38M Tier 2 diesel (installed elsewhere)
Photo credit: Cummins Hotips/Alan Haig-Brown
Cummins explain that this engine is an upgrade of their rugged KTA38-M0 turbo-charged and after-cooled engine to fill a much needed gap in the market for durable, reliable power designed for use in areas covered under U.S. EPA Tier 2 and EU Stage IIIA emissions regulations. The 38 liter, V-12 K38-M Tier 2 has the same footprint, mount, ratings and optional equipment similar as the previous engine and thus installation is simplified.
Emissions compliance is achieved by minor modifications in air handling and fueling, adjustments to timing and the addition of low temperature after-cooling. The engine also features the proven simple mechanical Cummins PT fuel system enhanced by CENTRY electronic governing, making it one of the few high horsepower Tier 2 certified engines with a mechanically controlled fuel system.
Cummins also supplied a 350 HP QSM11 engine to power the Bruvoil bow thruster (DP1 class vessel) and a pair of ABS-rated QSM11 powered 300 kW gensets meet electrical needs.
The raised focsle deck extends well forward and right to the side-shell allows for roomy accommodations with bunks and mess room for 32 people. This provides a variety of 6, 4 and 2-person cabins for the four crew-members and 28 other workers. At the same time, the aft deck provides an impressive 112 by 30 feet of clear cargo space with a 375 LT capacity.
Below deck there is extensive tankage including dual-purpose tanks for fuel or liquid mud.. In addition to a dedicated 13,460 US-gallon potable water tank, there is also a 92,328-gallon ballast or potable water tank. This will give the supply vessel great flexibility with a total deadweight of 707 LT.
More than half of all ship detentions involved ships of 20 years or more in age according to preliminary results from the recent Concentrated Inspection Campaign (CIC) on Propulsion and Auxiliary Machinery in the Paris MoU region. Problem areas included the propulsion of the main engine, cleanliness of the engine room and emergency source of power/emergency generator.
There is a saying that research confirms what you already knew, and the essential inspection finding that things are more often not as they ought to be in an older engine room than in a more modern one is no exception to that rule. Why that should be so is not pointed up in the CIC preliminary report, so we’ll circle around that question here.
Cleanliness is next to …
There’s no excuse for badly maintained and dirty machinery in dirty engine room compartments – no matter what the age of the ship – but far more time and effort is needed to keep them up to the mark. Sleeves have to be kept rolled up to avoid compromising the safety of the whole ship: according to classification society DNV GL casualty statistics, more than 60% of all engine room fires have been initiated by oil of one kind or another, fuel, lube or hydraulic fluid, coming into contact with a hot spot. The photo below taken aboard a Port State Control detained ship qualifies as a fair example of a marine accident waiting to happen.
Main engine detail bulk carrrier (keel laid 1980): Photo courtesy office of Paris MOU
Marine diesels are long-lived
There seems little excuse for owners unwilling to spend on maintenance and correct operation of engine plant, as marine engines have no ‘built-in obsolescence’, on the contrary the major manufacturers are fiercely competitive and work constantly to extend the durability of components, the periods between major overhauls, and to simplify operation and maintenance.
Such was evidenced in 2009 when the European Union approved the ‘Hercules-Beta Project’ which was a major international cooperative effort by major engine builders to maximise fuel efficiency, and to develop future generations of optimally efficient and clean marine diesel engines.
Propulsion and Auxiliary Machinery CIC Analysis
Richard Schiferli, Secretary-General Paris MoU on Port State Control informs that the detailed results of the September/November of 2013 campaign will be further analysed and findings will be presented to the 47th meeting of the Port State Control Committee in May 2014, after which the report will be submitted to the International Maritime Organization.
The CIC preliminary report can be accessed via: https://www.parismou.org/preliminary-results-cic-propulsion-and-auxiliary-machinery
Yacht charterers and workboat operators may be interested to hear that the satellite-based tracking, monitoring and notification system GPlink has just been upgraded so that fleet commercial users can download reports detailing fuel burn and engine hours for any chosen time frame.
The sensing system, GPlink, in conjunction with the Iridium Global Network, protects yachts and workboats by remotely monitoring engines and on-board critical systems and relaying data wirelessly to an internet enabled computer on shore. The manufacturers say that although this new feature has only been available for a few weeks, fleet managers have found it a useful tool for information sharing with vessel owners. Business managers are enthusiastic too, as it helps determine profit and loss on jobs; apparently one charter company even uses these reports to invoice at separate rates for running versus non-running hours.
On-board monitoring units: Photo courtesy of GPlink
GPLink monitors marine engines and critical systems in a wide range from bilge and battery levels to power interruption, fire alarms and engine diagnostics, all the while tracking the precise location of the boat.
Additional reports and archiving for commercial vessels include:
• Fuel usage by day/week/month/shift
• DM2 code history
• Alert history
• Geofence history
• Location/position history and log
Coverage & interface
On board sensors feed information to the communication system which provides reliable worldwide coverage, no matter where the boat goes. .
The manufacturers claim that the system (developed specifically for Caterpillar powered yachts & commercial vessels, but also available for other makes of engine) can interface with more DM and DM2 codes than any other remote monitoring solution. The on-shore receiving dashboard can be easily configured to track any of the resulting multitude of available diagnostics .
The system has a small, unobtrusive footprint, with no exterior or hard-top mountings required. The transponder unit and small wired antenna is usually mounted under the helm console or engine room.
Beyond showing near real-time data, GPlink also archives all data, which can be referenced at any time. On-demand reports can be compiled by date range, shift, alarms, DM codes, geofences, engine logs and position. Users also get monthly updates on any alarms received during the month, a complete engine diagnostic report and any other important updates.
Remote display using 'Follow Vessel': Image courtesy of GPlink
Floating assets can be monitored from any internet enabled computer, smart phone or mobile device. Owners, operators and engineers can track operating parameters and assess system efficiency in near real-time.
Users have only to tap the ‘Follow Vessel’ tab to bring up a view of a chart with the vessels current location plotted on it without the need to use custom search features; and this view will continue to update as long as the vessel is under power: a feature that will simplify things, especially for anyone who charters out a yacht.
More information: gplink.com
Up to 5% of additional power can be extracted from the main engine exhaust gases by the first marine application of a new generation of Waste Heat Recovery (WHR) units from MAN Diesel & Turbo.
The order for the TCS-PTG 20 (Turbo Compound System with Power Turbine and Generator) units is for a pair of 4,700 TEU container ships being built for Germany’s Reederei Horst Zeppenfeld in the Samjin Shipbuilding in Weihai, China. These WHR units, which have recently passed their factory acceptance tests at MAN Diesel & Turbo’s Augsburg’s facility, will run alongside the MAN B&W 6S80ME-C9.2 low-speed main engines (rated at 27,060 kW) and the engine builders say they will also supply four TCA88 turbochargers, two for each ship.
Through using the TCS-PTG units, Zeppenfeld look not only towards saving fuel but for a reduction in the operating costs of their gensets as these can be run on part-load or switched off when the TCS-PTG units are in operation.
Briefly this is how the WHR system works: the power turbine is inserted into the exhaust gas system parallel to the turbochargers where it drives an electrical generator via a reduction gearbox and receives up to 13% of the exhaust gas flow, diverted from the main engine exhaust gas receiver, as shown in the diagram below.
Marine Diesel Engine Waste Heat Recovery System:Diagram courtesy of MAN
Depending on the size of the MAN Diesel & Turbo engine involved, a maximum of 4,700 kW can be produced. The additional power output from the TCS-PTG system is in the form of 50 or 60 Hz electrical energy for the onboard power grid.
With this TCS-PTG 20 waste heat recovery ‘stand alone’ unit in operation, auxiliary engine fuel, emissions and maintenance costs can be saved and generator set maintenance more flexibly planned, since it can be carried out while while the ship is at sea.
• Exhaust gas driven power turbine and gearbox.
• Coupling PTG-generator
• Synchronous or asynchronous generator
• Control and safety equipment consisting of: control valves, emergency valves
• TCS-PTG-control cabinet including unit software
• Thermodynamic layout
Waste Heat Recovery System Components: Image courtesy of MAN
MAN Diesel & Turbo claim that used in combination with high efficiency turbochargers on the main engine, and depending on fuel oil prices, payback periods as short as 2 to 3 years can be expected.
Source: MAN Diesel & Turbo
DP3 is a new offshore vessel positioning technology standard set by IMO that will enable a couple of new Farstad offshore vessels on the stocks in Norway to work safely in the most demanding and potentially dangerous situations using systems equipment provided by Rolls Royce.
Basically, to maintain an accurate position determined mainly by satellite navigation system (anchoring is not in itself precise enough) an offshore vessel needs to be equipped with propulsors and thrusters controlled automatically by a dynamic positioning (DP) system in such a way as to oppose the resultant force of wind, waves, tides and currents.
Dynamic positioning, propulsion & thruster schematic: Courtesy of Rolls-Royce
Deep-water drilling for oil or gas (common now as shallower resources deplete) is an operation that often carries with it the need for jack-ups, construction and support vessels to operate in extremely demanding situations where any loss of position might result in fatal accidents, severe pollution or damage with major economic consequences. In such an environment Rolls-Royce’s most advanced DP3 system has been developed in order to help operators circumvent such catastrophes.
System redundancy is key
Icon DP3 is fully integrated with the Rolls-Royce propulsion and thruster (P&T) control system. System architecture features distinctive fault tolerance and positioning performance by combining two diverse and complimentary redundancy schemes. Maximum effect of a single failure in the control system is loss of one thrust device or one sensor group.
Icon DP 3 consists of two separate and diverse DP control systems, a triple redundant DP Main system and a single DP Alternate system, set up in an online / hot standby redundancy scheme.
The combined redundancy schemes of Icon DP 3 enhance system dependability as DP Alternate has no dependencies with DP Main, is ready to accept command and maintain position at any time and increases tolerance to systematic faults as shown below.
DP 3 redundancy: Schematic courtesy of Rolls-Royce
DP Main is the primary system for DP operation and features:
• Dual redundant network
• Triple redundant controllers working in parallel in triple work-by scheme
• Distributed 2-out-of-3 voting
• Graceful degradation and online repair
• Fire tolerance ensuring continuous DP operation in case of fire in one zone
Arnt-Ove Austnes, Rolls-Royce, Sales Manager – Automation and Control, said: "An increasing number of offshore operations are performed with rigs and vessels having to be kept in precise position without using anchoring systems. With an increased focus on risk limitation in the oil and gas sector, we expect a growing demand for DP3 classed vessels."
Source: Rolls Royce
One of the new tools that engine builders are using these days to reduce fuel consumption and greenhouse gas emissions is Valve Control Management (VCM), ABB’s variable valve train system, more so since duel-fuel engines become an increasingly popular choice by ship-owners.
Valve Control Management System (VCM): Image courtesy of ABB
Initially introduced in the shore-based gas plant sector, Christoph Rofka, Senior General Manager for New Business at ABB conjectured at that time and with an eye to the future: “A technology like this speaks to the increasing trend to explore dual-fuel options and create solutions for gas. These engines are also very similar to what you find on many ships, and we believe that VCM will very soon be highly relevant for and effective in the marine industry.”
Basically the technology helps a turbocharger to manage air actively, and is particularly effective for high-performance engines in which large operating ranges or rapid load responses are required such as tugboats, icebreakers, pump drives, compressor drives and power generators.
The manufacturers explain that generally, most valve train systems must be set for a particular engine load and they are matched to a particular operating condition, consequently they cannot switch flexibly from one load to another and so compromise on fully leveraging the engine’s full potential. Running an engine with this type of valve train system at a load other than what it was originally set to results in lower efficiency, smoke, and greater thermal load on the engine.
To ameliorate, VCM was specifically designed as an intelligent valve train system that responds adaptively to change the timing in an engine’s valves so that it always receives an ideal amount of air. This technology thus manages transient behaviour – i.e. changes in engine speed, load or both – so that engines can accelerate more rapidly from one load point to another. VCM optimizes the configuration of the engine for every load, allowing the engine to work as efficiently as possible. A turbocharging solution equipped with VCM can take an engine that is idling to full load in half the time that it normally takes – in some cases even more quickly.