Counting The Costs of Prevention

Real cost savings will be the major driver of shipboard Condition Monitoring (CM) techniques for the cruise and ferry sector, as expensive perceptions of the embryonic sector are assuaged by actual examples of their effect.

Speaking at the recent Carpe Diem Ship Engine Monitoring Conference, leading figures from different fields of monitoring were unanimous that the cost benefits of using CM outweigh the disadvantages. “It is very hard to quantify the cost of prevention and this may be a barrier to development, but the value proposition of condition monitoring is undeniable and clear,” says Gopinath Chandroth, director of CM at SeaTec Ltd, a subsidiary of the V.Ships Group. “It helps to prevent breakdown, detention, condition of class, fire and delays.”

According to Chandroth, over 60% of vessel casualties caused by machinery failure are maintenance induced. “Mistakes Costa Fortuna has had a monitoring station installed to measure man-made air pollution are made and in most cases the maintenance is unnecessary. That’s where CM is so effective.”

Recent surveys by SeaTec using CM techniques have prevented the breakdown of a number of vessels, including ferries, with savings ranging between $100,000 and $250,000.

SeaTech’s CM solution for vessels involves three distinct areas of coverage: focus, live and design. The focus element is ideally a survey carried out annually or four to six months before drydock; the live element is continuous monitoring by ship’s engineers; and the design element is raising the awareness of CM at the drawing-board stage.

In recognition of the importance of the latter element, SeaTec recently went into partnership with engine manufacturer ABB to incorporate CM into engine design for newbuilds. “There is still not enough work being done on developing CM specifications on newbuildings; something has to change in this area,” says Chandroth. “But hopefully this will be rectified. CM will be driven by owners and managers – they simply want to know how their vessel is performing.”

POD PROPULSION SYSTEMS

Podded propulsion drives have proven their worth in the cruise industry, but recent high-profile failures have brought the technology under renewed scrutiny.

Royal Caribbean took legal action against Alstom and Rolls-Royce in 2005 after the failure of Mermaid pods on its Celebrity Cruises vessel Summit following earlier problems on its sister ship Infinity. Summit was forced into dry dock in June last year to replace a radial bearing unit that showed premature wear in its starboard propulsion system.

“Problems have occurred across all manufacturers, but the benefits of pods are too great to switch back to normal technology,” says Rolando Ingles, vice president of engineering for Swantech.

Pod data acquisition can be a challenge both physically and technically, but the easiest way to measure operational conditions is through stress wave analysis. According to Ingles, stress wave energy can be used to identify early-stage deterioration of pods when observed over time. “Healthy drives produce low stress wave energy, as compared with damaged machines where energy levels are elevated, making it easy to identify bearing damage or water leakage,” he says. “Real-time data collection can provide real-time benefits to vessels and the saving can be huge.”

Leading manufacturers of pod propulsion systems signed an agreement in 2005 to harmonise and improve their quality instructions. The Pod Quality Forum consists of three major pod manufacturers – ABB, Rolls-Royce and Siemans/Schottel – which together account for more than 150 pod systems in the last four years. The common quality instructions will apply to generic pod units and technical differences between the manufacturers’ systems will still remain.

CLASSIFICATION SUPPORT

Classification societies have also been working closely together with shipowners to develop solutions. “For the shipowner, CM brings increased reliability in an increasingly competitive market by avoidance of unexpected breakdown,” says Jorg Rebel, head of machinery conditioning for Germanischer Lloyd. “Unexpected breakdown of critical components means high consequential loss of income, particularly for cruiseship and ferry operators.”

According to Rebel, classification societies must support shipowners and operators to achieve this benefit. “There needs to be cooperation and the ability to provide analysis between owner and class,” he notes. “You need to build up knowledge about specific condition monitoring techniques in the frame of pilot projects.”

Germanischer Lloyd has worked with operator TT-Line on gaining specific experience with CM on its passenger vessel Nils Holgersson. “We worked closely with the company on this pilot project by monitoring a number of essential components,” adds Rebel. “Once CM tools have been designed and piloted the class society can provide type approval of both hardware and software used and then look to provide an initial implementation survey, final approval and then regulate annual surveys.”

The use of CM techniques has been brought to the attention of the International
Association of Classification Societies, which is currently working on a set of common rules that will be approved and tested. “IACS is working on a new revision of the rules with specific emphasis on planned maintenance and condition monitoring,” says Rebel.

CM techniques have also been developed for lubricant analysis and emission monitoring. “Oil-based CM, when applied efficiently not only helps to find failure, but also improves reliability and bottom line,” according to Danny Shorten, senior specialist at Lloyd’s Register. “However, it needs to be looked at from a managerial aspect rather than in terms of preventing failure.”

Lloyd’s Register has been investigating the monitoring of lubricants by sensor. “Sensor solutions and the ability to look at debris in real time is the next significant step,” adds Short. “But this is still very much a lab project and the investment is not available on vessels.”

SECA COMPLIANCE

Comparative statistical methods hope to be able to develop a knowledge-based approach to management of CM data. The use of CM techniques could also assist in regulatory compliance to the latest emissions regulation under Annex VI of the Marpol regulations.

Restrictions on sulphur emissions were introduced in 2005 with the first Sulphur Emission Control Areas (SECAs) in the Baltic Sea. According to Simon Brown from Martek Marine, the shipping industry will come under pressure from green lobbyists to exceed IMO timescales: “The introduction of Annex VI hasn’t reduced emissions; they have just been formalised. This will ultimately create more pressure on the shipowner.”

The changes involve a lowering of the sulphur content of bunker fuel for all vessels including cruiseships from 1.5% to 0.5% within emission control areas and the creation of new SECAs in other parts of the world. The new North Sea SECA will come into force on 21 November 2006 with full implementation 12 months later.

Under the new rules, the sulphur content of bunkers is capped at 1.5% for ships operating in a SECA with a global cap by mass of 4.5%. “Emissions monitoring has its place, and integration with online technology will allow data to be collected at pre-determined level,” says Brown. “This data can then provide proof of compliance with the new regulations.”