Bid for trouble-free availability
David Tinsley looks at current developments in machinery control and monitoring, starting with monitoring condition.
Although condition based monitoring has been formally recognised, through the classification community, as a proven and effective tool for managing shipboard machine condition, with the potential to contribute directly to reduced equipment failure rates and overall running costs, its adoption in commercial shipping remains limited.
In landside industry, maintenance philosophies are changing from a traditional model, with regular, scheduled overhauls and correction of problems as they occur, to an optimum strategy that anticipates, avoids and eliminates problems and scheduled maintenance. This strategy improves availability and efficiency, reduces maintenance costs, extends lifetime, and minimises the scope and duration of overhauls. Reliability-centred maintenance, predictive and proactive maintenance are central to such an approach.
Condition based maintenance represents an endeavour to supplant time-based maintenance practices and unscheduled, corrective equipment maintenance with a preventative and predictive strategy based on the evidence of need. Using the requisite tools and technologies, shipowners and operators can identify and respond to deteriorating equipment or machinery condition more effectively, rather than acting at the time of failure.
Techniques available to the shipping industry include engine performance monitoring, vibration analysis, thermography, lubricating oil analysis, and ultrasonic measurements.
Although still very much in the minority, the practitioners of condition based maintenance strategies are growing, and the intensification of market competition and rising operating costs gives added relevance to the approach in the context of factors of vessel availability, scheduling dependability, productivity and running costs.
SKF contends that the promise of condition monitoring as a means of reducing shipboard machinery maintenance costs has long been understood and accepted by shipowners worldwide, but resulting gains have often fallen short of expectations. For the optimum benefits to be gained, it attributes fundamental importance to ensuring that the solution is tailored to the operator’s precise requirements. An in-depth discussion of needs and objectives lays the groundwork for a recommended condition based monitoring and maintenance programme.
For instance, an owner sought advice from SKF on a suitable monitoring system for the main and auxiliary engine turbochargers on a series of LNG carrier newbuilds. This was required to take continuous measurements from each shipset of nine turbochargers, and to be connected to the vessel’s control system to provide immediate warning of unexpected deviations in machine condition. As a consequence, the vessels were fitted with SKF’s latest generation of Multilog IMx-S on-line surveillance system, enabling multi-channel measurements and a flexible configuration to support different operating conditions. The link to the ship’s control system enables operating parameters to be compared.
In addition to continuous read-outs from the Multilog IMx-S units, periodic data collection is made on close to 200 auxiliary machines, such as pumps, fans and blowers, purifiers, and lube oil circulators, using portable condition monitoring technology. Data is relayed via the ship’s communication system to an SKF marine remote diagnostic centre for further analysis.
Adapted from the remote monitoring architecture developed by Wärtsilä for engine monitoring, the Propulsion Condition Monitoring Service(PCMS) was launched last autumn as a tool to help owners and operators avoid problems and minimise unplanned downtime. PCMS determines the operational condition of a vessel’s propulsion equipment by comparing parameters from both measured and database sources, in real time, and is claimed to be the first of its kind in the marine propulsion market.
The system is available for controllable pitch propellers, steerable and transverse thrusters, electric thruster pods and waterjets, and can also be used to monitor equipment supplied by companies other than Wärtsilä.
Data from sensors that measure vibration, hydraulic pressures and temperatures are combined with operational parameters of the thrusters such as set point and feedback signals, and also the vessel’s pitch, speed, rate of turn and draught. One of the distinguishing features of PCMS is the fact that it takes nautical parameters into consideration, so that the measured values delivered by the sensors can be related to the physical condition of the thruster or other equipment.
Data acquired can thereby be linked to the way or conditions in which a vessel is being used as well as to the equipment’s physical performance.
PCMS installations can be completed in just a few days, without necessitating drydocking, and offer a means of preventing damage before it occurs, and obviating time-consuming and costly physical inspections.
In addition to the primary benefits for owners and operators, the uptake of PCMS will provide an accumulating store of information for Wärtsilä, as a designer and producer of propulsion equipment. Over time, data from a population of systems serving a wide range of installations will help with the analysis of the strengths and shortcomings of different propulsion solutions.
With advanced monitoring now available for both engines and propulsion equipment, Wärtsilä indicated that the next step could be risk-based maintenance systems for entire installations.
Remote engine monitoring and data analysis forms an integral part of the 10-year maintenance package provided by MTU on the recently-commissioned North Sea rescue tug Nordic (see The Motorship, April 2011). Leased to the German government in an emergency towing and rescue role, the 17,200kW Nordic is one of the most powerful vessels of her type and is owned by the ARGE Kuestenschutz, or Coastal Protection Consortium, comprising Germany’s three leading tug operators.
The bespoke maintenance contract is intended to ensure reliable engine servicing combined with guaranteed predictable costs, and extends not only to preventive servicing but also corrective maintenance such as component replacement. Through MTU Remote Services, the tug’s two MTU Series 8000 engines are monitored from the shore, with real-time transmission enabling key engine operating data to be called up and read out from any location.
Key benefits of the diagnostic tool are early fault identification, saving valuable service time, prevention of damage and associated downtime, rapid identification of spares requirements, decision support on operational issues, and ultimately increased engine efficiency.
The 2010-delivered, 173,600m3 capacity Spanish LNG carrier Castillo de Santisteban provided the opening reference for dual-fuel MAN medium-speed main engines at sea, and has also given new dimension to the engine company’s on-line diagnosis and troubleshooting service.
Over 200 sensors onboard Castillo de Santisteban collect readings of data every second from the vessel’s five 8L51/60DF engines, which can run on LNG cargo ‘boil-off’ gas as well as heavy fuel oil or marine diesel. The massive amount of information yielded by the sensors is compiled and compressed by the onboard systems and then sent to the MAN Online Service Centre at Augsburg through a secure and encrypted communication channel at a give time once per day.
While the experience and knowledge of the technicians ashore is vital to interpreting data and formulating response solutions, the pure volume of information from the continuous reporting from this and other ascribing vessels means heavy reliance on computer support. The system at the control centre analyses the incoming readings and checks them for anomalies.
The fact that recourse can be made at Augsburg, the fountainhead of MAN four-stroke engine technology, to the engine designers has a signal bearing on the quality of service afforded the client. Rapid troubleshooting and fault resolution, efficient maintenance and high availability are watchwords of the system.
There is a strong case for greater, functional integration of vessel control systems, against the backcloth of the increasing complexity of instruments and control devices for the various propulsion, navigation, machinery and communications systems, making for a growing array of screens, buttons, dials and alarms with which today’s watchstander has to contend. Investment in carefully designed, integrated control is in the ultimate interests of both safety and efficiency. In this respect, the shipping industry is once again being exhorted to take a leaf out of the aviation industry’s book.
After three years’ development work, Wärtsilä has introduced the 3C Communication and Control Centre, serving as a single control point for all of a ship’s functions. The 3C configurations will use proprietary propulsion and control systems, designed in-house, with compatible navigation systems supplied by Raytheon Anschütz.
It is claimed that optimised, integrated control systems could eventually realise considerable savings in operational costs, by as much as 30%, through improvements in power management, route and schedule planning, and reduced fuel consumption.
The 3C system can, for example, help the master choose the best draught and trim configuration, as well as machinery usage, and also show how much power and redundant power capacity is available overall at any one time. Many kinds of information can be incorporated, including weather forecasts and port arrival slots. The system automatically calculates the best options as regards vessel route and speed.
One of the benefits of standardised vessel control systems and consoles, as encapsulated by the 3C approach, is the increased scope offered for standard training in bridge resource management and emergency skills. It would allow more extensive training to be provided in land-based simulators contends Wärtsilä, which has a vested interest in the field through its Land and Sea Academy worldwide network of training facilities.
The various control devices and instruments, often from different manufacturers, that make up a typical bridge layout are regarded as more akin to industrial control panels than the kinds of coordinated control systems used today in aircraft. It is felt that bridge consoles in the years to come could begin to take on more of the look of airliner cockpits. Increasing levels of automation, reduced manning levels, and the requirement for crew members to carry out a wider range of tasks than in earlier years, would all seem to favour demand for comprehensive functional integration, as encapsulated by the pioneering 3C concept.
German electronic measurement technology has achieved a new reference in Japan, where Kawasaki Heavy Industries has adopted the IMES hand-held EPM-XP cylinder pressure indicator as standard for MAN two-stroke engines. IMES believes that Kawasaki is the first low-speed engine builder to specify the electronic device with new production.
The unit combines ease of use with high accuracy, and its nomination underscores the central importance of indicated cylinder pressure as a value from which much can be deduced about an engine’s operation and overall condition. In addition to the prospective benefits in fuel savings, the optimisation of engine settings on the basis of accurate cylinder pressure readings has assumed added importance as a way of ensuring that NOx(oxides of nitrogen) emissions are contained within the new IMO Tier II limits.
The IMES device has been designed for periodic monitoring of cylinder pressure on two-stroke engines running at speeds up to 300rpm, and on four-stroke medium- and high-speed diesels operating from 200rpm to 1,500rpm. After acquisition, data can be downloaded to a PC or laptop via USB cable, and IMES’ visualisation and data processing software then applied, and transmitted by telephone or the Internet for remote analysis.
Wärtsilä has introduced Intelligent Combustion Monitoring for mechanically-controlled, two-stroke diesel engines. The system provides information that enables operators to optimise engine performance, and to be aware of the condition of components in the combustion chamber. Potential benefits are fuel cost savings of up to 2% and improved maintenance management.
The Intelligent Combustion Monitoring system affords a means of measuring the pressures in each cylinder during the entire combustion process on a continuous basis, in parallel and under all load conditions. The system monitors the exact position of the crankshaft, and combines the information with mathematical modelling of the engine to provide highly accurate, real-time data for diagnostic analysis. This has been developed as a more precise, accurate alternative to conventional cylinder pressure measurement systems.
Wärtsilä plans to extend the technology in early 2011 to the company’s range of electronically-controlled RT-flex two-stroke engines.
As one of the leading lights in vessel control and monitoring technology, Kongsberg Maritime has developed a new generation of its well-proven K-Chief marine automation system, with the accent on greater functionality, flexibility and efficiency. Commercial uptake of the K-Chief 600 and its integrated vessel performance system (IPS) has been rapid, and the spread of applications across the crude carrier, containership, ro-pax ferry, dry cargo vessel and other categories is testament to its adaptability to differing marine automation requirements.
K-Chief 600’s enhancements over the previous offering include touch screen and split screen capabilities, trend analysis facilities, and a proprietary, new human machine interface(HMI) compatible across all Kongsberg Maritime systems.
The system is based on the company’s unified automation concept, whereby each vessel configuration is built up using standard modules communicating on controlled area (CAN) and local area(LAN) networks. The modular design enables solutions to be tailored to precise user requirements, be it a low complexity alarm system, to a highly integrated alarm and monitoring system with advanced process control and power management. Due to the flexible architecture encapsulated by K-Chief 600, additional input/output (I/O) modules can be connected in the network at any time, allowing functionality to be extended or new process areas to be brought within its remit.
The engine performance and optimisation application is an extension of Kongsberg’s AutoChief propulsion control and integrates the AVL engine performance and optimisation system(AVL EPOS) and other performance monitoring sensors, serving as a practical tool of engine monitoring and tuning.
K-Chief 600 also integrates Marorka’s Maren energy management application, including energy system monitoring, simulation-based decision support and energy analysis. This delivers real-time information, comparing fuel consumption and energy output, and providing recommendations as regards settings, such as engine rev/min, vessel speed and trim, in the interests of lower overall consumption. The vessel performance system assists in determining optimal vessel speed, draught and trim, engine modes and sailing route.
While a solution in its own right, K-Chief 600 can share sensors and information across proprietary system borders, facilitating combination with other products such as the K-Gauge cargo monitoring and control system, AutoChief C20 propulsion control, main engine monitoring systems, K-Log electronic logbooks, FleetMaster vessel primary data and VDR voyage data recorder system.
South Korea’s unerring bid for greater technological self-reliance in the maritime sector has found new expression with Hyundai Heavy Industries’ recent presentation of an IT-based ‘smart’ system for ship monitoring and control.
Developed in association with the state-run Electronics & Telecommunications Research Institute and the Korean Ministry of Knowledge Economy, the system has its first application on a 4,500 TEU containership delivered to A.P.Mø ller-Maersk towards the end of March 2011. A further 21 vessels ordered by the Danish group will be similarly equipped, and the system has also been specified for a pair of boxships ordered from HHI by Consolidated Marine Management(CMM).
At the heart of the smart system is the ship monitoring and control system known as SAN (ship area network), which integrates ACONIS-DS (advanced control and integration), VDR (voyage data recorder), and the BMS (bridge manoeuvring system). SAN enables operators to remotely control engines and controllers and manage other key onboard systems, and to obtain real-time feedback on vessel status via satellite link.
Data collected, processed and analysed via SAN can help enhance operational efficiency and reduce ship management costs.
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