At next week’s UK Seawork 2012 commercial marine exhibition, Scania will be unveiling its new V8 marine engine. Based on the truck engine introduced last year with a 130 mm bore, it displaces 16.4 liters compared to the previous model of 16 liters with 127 mm bore.

Caption: The new Scania V8 engine of 16.4 liters is patrol boat rated up to 736 kW (1,000 metric hp) at 2,300 rpm.
Image Credit: Scania AB

Scania is aiming the engine at the commercial market of workboats, ferries, and patrolboats and incorporates many features for that purpose. The fuel system is Scania’s own PDE high pressure fuel injection system with electronically triggered unit injectors. This system was chosen in favour of Scania’s more sophisticated Common Rail XPI system to enhance reliability, durability and greater tolerance to marine fuel conditions that are “less than perfect”.

A centrifugal oil cleaner and twin replaceable fuel filters contribute to the 500 hours oil change interval specified for the engine.

The new engine meets the latest exhaust emission regulations of US Tier 2, EU Stage IIIA and IMO II and will have the ability to meet future regulations, with additional changes. Electronic control of the engine is by a Scania EMS system which with plug and play, fully integrates via a CANbus with navigation and propulsion control systems. Monitoring of engine parameters is automatic and alarm levels can be preset to give warning of any malfunctions: this data also be monitored ashore using a communication suite.

The engine is offered in a number of power outputs to suit workboat and patrol boat ratings ranging between 550 to 1,000 metric hp (405 to 736 kW) in a speed band of 1,800 to 2,300 rpm

Caption: Cutaway of the V8 truck engine on which the marine engine is based.
Image Credit: Scania AB

The Indian Coast Guard has ordered six Advanced Offshore Patrol Vessels from the Ministry of Defence owned Goa Shipyards Ltd. The vessels are designed by Goa Shipyard Ltd, which has considerable expertise in design and construction of patrol vessels of different sizes for the Indian defence forces. The contract for the six vessels was signed on 9 May and just six days later the steel cutting ceremony for the first vessel was being celebrated!

Caption: The smaller 102m OPV presently in service with the Indian Coast Guard Service.
Image credit: Goa Shipyards Ltd.

When completed the ships will be the most advanced patrol vessels in service with the Indian Coast Guard featuring an Integrated Bridge System, CCTV systems and additional equipment such as 21 ft (6.5 m) fast response RIB for interception and rescue duties.

The steel hulled vessels have a displacement of around 2,300 t, and LOA of 345 ft (105 m), beam of 42 ft(12.9 m) and draft of 14.7 ft (4.5 m). Twin SEMT Pielstick 20PA6B STC diesel engines with sequential turbocharging are each rated at 7,792 kW at 1,050 rpm and power per shaft, a CP propeller and a reduction gearbox. Maximum speed is 24 kn and a cruising speed of 12 kn provides a range of 6,600 nm.

The ships have accommodation for 18 officers and 108 sailors and have a primary duty of patrolling and policing coastal and offshore maritime zones. The vessels can also carry out search and rescue as well as surveillance operations. They are also equipped to assist in pollution control and fire fighting duties.

Caption: The SEMT Pielstick 20V PA6B STC engine delivers up to 8,910 kW at 1,084 rpm at its naval rating.
Image credit: MAN Diesel & Turbo SE.

Ocean-going ships, presently in an excess for the amount of cargo to be lifted, increasingly steam at slower speeds in order to save expensive fuel oil bunker costs; better that than to be laid up reckon shipowners.

Photo courtesy of Maersk Line

The problem is that large marine diesel  engines are not designed to operate below 85% power for long periods without harmful effects; effects best ameliorated by getting lubricating oil of the right specs. After a quick look at lubricating oil solutions, a handy little device to check cylinder performance is spotlighted.

Marine Diesel Engines & Slow Steaming

Experts at Castrol Marine drew on OEM reports and their own engine performance tests to analyse the effects of slow steaming on engine performance, finding that the oil-feed rate as well as a lower engine operating temperature had a bearing on the amount of corrosion caused on piston rings and cylinder liners.

At lower loads, the cylinder oil’s feed rate is reduced, making less available BN (Base Number) constituents to neutralise acids and reducing the protective oil film thickness. This can mean lubricants degrade, increasing the potential for acidic corrosion and increased wear rates. Lower engine operating temperatures that come with slow steaming also further increase the risk of cold corrosion.

The conclusion drawn by Paul Harrold, Castrol’s Technology Manager, Marine & Energy Lubricants: “Higher BN lubricants provide greater neutralisation and hence better corrosion protection across the fuel sulphur range during slow steaming.”

While 40 BN cylinder oil suits vessels predominantly operating in ECAs, cylinder oils of 70 BN and above are better suited to those vessels regularly slow steaming, to ensure piston ring packs and liners remain in good condition.

With slow steaming likely to cause damage to cylinder components it seems apposite to mention a portable, inexpensive gadget made in Sweden  – Prisma Teknik’s ‘Bohman DEC-Tester'  –  which provides a simple, yet useful tool for  assessing cylinder condition.

Bohman DEC-Tester

Prisma Teknik’s ‘Bohman DEC-Tester': Photo courtesy of Prisma Teknik

Air (at standard 6 − 8 bar) is injected into the cylinder via the DEC-Tester, which the manufacturers say is an improvement on similar methods as it controls the pressure as well as the flow of air.

The unit is connected to the indicator valve of a cylinder whose piston has been cranked near TDC and will immediately show a reading on a scale 1 – 10. For example, a recently overhauled cylinder might show a reading of 1.5, another unit with a reading of 7.4, would indicate the need for investigation, while a reading at the top end of the scale normally suggests serious valve problems exist.

The tester can be used on both auxiliary and main diesel engines with a bore diameter of from 160 mm to 460 mm for both continuous follow-up of cylinder condition as well as for troubleshooting.

Worth its 3 kg weight in gold for the solutions it provides, the DEC-Tester comes for just 862 Euros.

As more and more ship owners and builders are evaluating the feasibility of using hybrid electric propulsion systems for existing or new build ships, GE is offering hybrid systems for military and commercial applications based on its LM series gas turbines using electric motors and drives, to reduce noise and emissions through improved fuel economy.

Caption: A GE LM2500 module with power out put of 25 MW
Image credit: General Electric

GE has a wide experience of hybrid systems, acting as systems integrator, GE is able to team with other industry suppliers to provide all electric propulsion solutions. The common factor for the successful application of hybrid systems is that the usage cycle is carefully studied and an appropriate combination of engines selected to operate efficiently at the required outputs.

A particularly successful combination with gas turbines is the CODAG or CODOG arrangement where diesel engines are employed at low output with the gas turbine(s) only used to produce boost power.

As the cost of fuel increases, such solutions are not limited to newbuilds, repowering of existing vessels can also provide tangible financial benefits. For example the cruise ship Radiance of the Seas was originally built with twin GE LM2500 gas turbines for propulsion and generation plus a Paxman 18VP185 auxiliary generator however it was later decided to add an 11.2 MW Wärtsilä 16V38B generator so that the gas turbine(s) would not have to be used at low power outputs where their efficiency is not optimal.

Some of the more modern designs of frigates use have two shafts powered by electric motors powered by diesel gensets with a single gas turbine available for extra power, added using a mechanical drive via clutches and a splitting gearbox to each shaft.

In the future wider use of fuel cells can replace diesel engines to provide further reductions in exhaust, noise and vibration emissions.

Caption: The hybrid twin shaft electric propulsion configuration with mechanical
gas turbine boost as used on the current FREMM class frigates
Image credit: Renk AG

The Volvo Penta IPS steerable pod drive introduced in 2004, is well known in recreational applications. The subsequent introduction of larger drives up to the IPS1200 model and the availability of light commercial ratings for the drives has widened the appeal of this type of propulsion system to workboat applications.

Caption: Alu Marine’s new Lightning 1200 Pilot Boat, designed by Geronimo Naval Design
office powered by twin IPS 450s cruises at 30 kn and has a top speed of 35 kn.
Image Credit: Geronimo Naval Design

In its publicity material Volvo Penta is claiming performance improvements of an increase in top speed of up to 6 kn and an improvement in fuel consumption of up to 30 per cent at cruising speed! While these claims may well be under perfect circumstances even if the improvements are only half of claimed, the benefits are considerable. Taking this a step further the considerable benefits in a recreational application become major through life operational cost savings in a commercial environment. What is saving hundreds of dollars annually in pleasure use becomes many thousands of dollars per year when considering the high number of hours a vessel is used in commercial applications.

A number of workboats and patrol boats have started to use IPS and recently Alu Marine, France introduced a new Lightning 1200 Pilot Boat, designed by Geronimo Naval Design office powered by twin IPS 450s. The 39 ft (12 m) LOA hull has a beam of 13.6 ft (4.2 m) and draft of 1.8 ft (0.55 m), draft, including IPS propulsors is 3.2 ft (1 m). Twin Volvo Penta in-line six cylinder D6 engines of 5.5 litres are each rated at 330 mhp (243 kW) at 3,500 rpm and power the smallest IPS drive in the IPS programme (of three drive sizes). The cruising speed is 30 kn and the fuel consumption is given as being 11.3 US galls per hour (43 l/h) per engine. The fuel capacity is 350 USgalls (1320 liters), sufficient for 15 hours operation at cruising speed: the top speed is 35 kn.

Caption: The Volvo Penta IPS450 has a D6 engine rated at
330 mhp (243 kW) at 3,500 rpm
Image Credit: Volvo Penta

The case for solar energy as a viable power source for marine propulsion was well made when news came just a few days ago that the world’s largest vessel entirely powered by solar energy, PlanetSolar, had completed its trans-world odyssey, returning to Hercule Harbour, Monaco, where it had set out for the world circumnavigation attempt.

An entry in the ship’s log the day before final arrival recorded the highest day’s energy yield –  661 kW hours –  from the 537 square meters of photovoltaic solar panels , the vessel’s sole source of energy,  since the voyage began on 27, September 2010.

PlanetSolar in Hamburg: Photo credit Wiki CCL Dr. Karl-Heinz Hochhaus

Constructed of weight-saving carbon fibre, the 31 m (101.7 ft) long PlanetSolar  (Swiss registered as Tûranor PlanetSolar or ‘Power of the Sun’ in Tolkien’s fiction) was launched in Spring 2010 from the Knierim Yachtbau shipyard in Kiel, Germany. Construction was to a design by LOMOcean Design (formerly known as Craig Loomes Design Group) for delivery to owners PlanetSolar SA, whose inspirational idea was to send the ship around the world with a view to showing that renewable energy and technology can be applied right now to achieve sustainable transportation.

Key to the success of the venture was the array of photovoltaic panels that predominate the upper deck of the vessel, totally responsible for capturing the energy to drive the four electric motor propulsion system that give Solar Planet a cruising speed of 7.5 knots, or for shorter periods a maximum 14 knots.

DuPont Tedlar® polyvinyl fluoride (PVF) film was used as an essential component of the photovoltaic ‘backsheet’ that was key to protecting the PlanetSolar’s panels (also supplied by DuPont) in the harsh weather conditions encountered by ‘Planet Solar’ over the nineteen month long voyage.

 “Our planet deserves a better, brighter and cleaner future,” said Raphaël Domjan, initiator and leader of PlanetSolar's expedition who first conceived the idea for the boat in 2004.  "I hope our success will motivate engineers and scientists to continue to develop innovative technologies …”

In complete accord with Domjan’s motivational ideals we are reminded that the annual ‘Dong Energy Solar Challenge’ (formerly known as the ‘Frisian Solar Challenge’) kicks off in The Netherlands in July next. Far smaller solar-powered boats than the PlanetSolar compete for six days over a 220 km course through the Frisian waterways with the aim of promoting sustainable energy among young people and students in technical colleges; the organisers have an eye to the part these participants may play in the future commercial development of solar-powered marine propulsion systems.

Dong Energy Solar Challenge Entrant: Photo credit Dong Energy

The use of LNG as a fuel is growing in popularity for ships of different sizes and power to provide a solution to increasing fuel costs and reducing exhaust emissions. Using LNG requires storage not only under but also at low temperature. Cooling the gas into a liquid state at the low temperature of approximately -162 ̊C (-260 ̊F) allows it to be maintained at the low pressure of only 3.6 psi (0.25 bar). While cooling plant and well insulated tanks are feasible on a ship, on small vessels - boats, this is not practical. To access the benefits of natural gas operation, a more practical solution for boats is to use compressed natural gas (CNG). The drawback is that CNG is 2.4 times greater in volume than LNG.

In the Netherlands ten percent of automobiles run on LPG and a very small number of boats use is as a fuel, however its use in boats is regarded as being potentially dangerous as it is heavier than air and any escaping gas will accumulate in the bilges. Natural gas on the other hand is lighter than air and any escaping gas is lost to the atmosphere.

Caption: The CNG Water Police 18 ft RIB used to patrol the Netherlands inland waterways and canals.
Image Credit: K.Henderson

This year the Water Police that patrol the Netherlands inland waterways are experimenting with a dual fuel gasoline / CNG Honda outboard powered patrol boat. The boat is a 18 ft (5.6 m) Dolphin RIB powered by a Honda 90 VTEC outboard. In addition to the standard gasoline tank, there is a 24 US gall (90 liter) CNG tank with a capacity for 33 lbs (15 kg) of CNG, held under pressure of approx 3,000psi (~200 bar). The fuel system cold starts on gasoline and when operating temperature is reached switches over automatically to CNG and remains operating on gas under 2,000 rpm. Above that speed it switches over to gasoline to realise the full power of the engine.

In practical terms, the boat can patrol all day on one tank of CNG, when speed is required, it is always available and the performance of the boat is not impaired in any way due to the dual fuel capability. The fuel cost of CNG compared to gasoline in the Netherlands is about half, giving a substantial through life cost saving.

Caption: The 24 gall / 33 lbs CNG fuel tank mounted in the bilges.
(GROENGAS is Dutch for Green Gas!)
Image Credit: K.Henderson

Last week saw the launching of the Russian corvette Makhachkala at the JSC Almaz Shipbuilding, St Petersburg. She is the third of class to be built by Almaz and will be joining sister ships Astrakhan and Kaspiysk commissioned in 2006 and 2011 respectively in the Caspian Flotilla. Project 21630 Buyan class was designed by Zelenodolsk Design Bureau, Tatarstan, Russia for coastal defense and engagement with surface warships . A later missile version of this class, of which three are planned, called the Buyan-M, is under construction at the Zelenodolsk Shipyard.

Caption: First of class Astrakhan presently in service with the Caspian Flotilla
Image Credit: Wikipaedia

The 550 t displacement corvette has an LOA of 203 ft (62 m), beam of 31 ft (9.6 m) and 7 ft (2 m) draft. The propulsion system is a twin screw CODAD (combined operation diesel and diesel) arrangement. This comprises two Zvezda M520 radial 56 cylinder diesel engines. Each of the two diesel engines has a bore and stroke of 160 x 170 mm and output power of 3,970 kW (5,323 hp) at 2,000 rpm.

The remarkable and unique Zvezda radial engine is made up of seven banks of eight cylinders with just over 51 degrees between banks. Boost pressure is provided by a crankshaft driven supercharger with water cooled intercooler. It is very light through the considerable use of aluminum castings in its construction.

Caption: Photograph of the M520 engine with power output of 3,970 kW (5,323 hp).
Image Credit: Zvezda

Ramform vessel construction made news last week as marine geophysical survey specialists Petroleum Geo Services (PGS) announced they had kept, but extended, their option with Mitsubishi Heavy Industries (MHI) for two more of their 5-G Titan-class ‘Ramform’ seismic research vessels to add to the pair presently under construction by the Japanese shipbuilders for 2013 delivery.

Seismic Survey Vessel 'Titan-class' Ramform: Image credit: PGS

Once seen, never forgotten, eight instantly recognizable Ramform vessels are currently operating globally (seven of them owned and operated by PGS). Ships built with an unusually broad after-deck to handle the deep tow of multiple arrays of equipment used to detect and signal back 3D pictures of untapped reservoirs of hydrocarbon fuels. What’s going to be different about the new Titan-class Ramforms?

PGS’s Next-generation Ramform Ships

The unique hull shape of the Ramform Class vessels was originally drawn from Marjata, a special Norwegian vessel whose role was to collect underwater defence electronic intelligence data from submarines; a ship whose sinusoidal curved waterline provided the stable operating base essential for its purpose, together with plenty of space aft for machinery and equipment for towing the transponders.

The latest 5-G Titan-class Ramform vessels under construction by MHI for PGS will have wider hull forms than the existing series in order to deploy the spread of streamer tows (up to 24 steamer cables, each a thousand metres in length) called for by PGS’s upgraded GeoStreamer® platform; a technology that is said to provide subsurface geophysical images of unprecedented quality. These streamers and source arrays are handled from workstations on two separate deck levels at the stern.

Seismic Survey with GeoStreamer®: Photo courtesy of PGS

Ramform Titan Class Specifications:

The main propulsion system is to be diesel electric, with six 3,840 kW gensets powering electric motors and electrical systems (contracted to ABB) to drive three controllable pitch propellers with associated nozzles and propellor shafts.

LOA: 104.2 m (341.9 ft)
Breadth: 70 m (229.7)
Draft: 6.4 m (21 ft)
Classification:  DNV +1A1, including SPS, ICE C annotations, etc.
Fuel capacity: 6,000 cu.m
Endurance: 150 days
Transit speed: 16 knots
Accommodation: 60 single & 10 double cabins
Helideck: 26 m 15t Super Puma/EH-101
Workboats: 2 x 30 ft davit-slung in well-deck hull spaces each side

Titan class Ramforms with the upgraded GeoStreamer®, ghost-echo free, seismic package are intended to operate in the ‘High Density’ offshore exploration market segments where large spreads, long streamers and towing efficiency are key to success in geologically complex areas off the coasts of Brazil, West Africa, and in the Gulf of Mexico.

Wärtsilä today announced the addition of a new X92 model with 9,200 mm bore. It builds on the first models of the X-series, a X62 and a X72, that were introduced in May 2011, offering low speed electronically controlled common rail engines. The X-series features an extra long stroke with reduced engine revolutions allowing a higher efficiency larger diameter propeller to be used. It offers a high degree of flexibility to deliver lower fuel consumption, lower minimum running speeds and full control of exhaust emissions including smokeless operation throughout the full rpm range.

Caption: Cutaway of a 6X35 engine which is similar to the X40-series
image credit: Wärtsilä

The X92 series is aimed at the market for large and ultra-large container vessels with a size above 8,000 TEU up to to any size under construction and beyond. The number of cylinders has not yet been released but as an indication, the larger RT-flex 96C model extends up to 14 cylinder. The first 92 bore engine is planned for delivery in 2014.

The choice of 9,200 mm bore lies between the existing models of 8,400 mm and 9,600 mm bore
with cylinder outputs of 4200 kW and 5720 kW respectively. Power output figures have not yet been released but an estimation would give a value of around 5,200 kW per cylinder for the new engine.

In November 2011 the X-series was extended downwards with the addition of Wärtsilä X35 and Wärtsilä X40 models. These two cover the market for a wide variety of ship types, such as small bulk carriers and product tankers, general cargo vessels, reefers, feeder containerships, and small LPG carriers. The two mid-sized engines Wärtsilä X62 and Wärtsilä X72, are designed for vessels such as capesize bulk carriers, Panamax bulk carriers, Suezmax tankers and Panamax container vessels.

Caption: The first models of the X-series were the X62 and X72 series announced in 2011.
image credit: Wärtsilä