Preventing failure with software

‘‘Many ship owners wish their vessels could be more maintenance-free,” says Gerald Rolfe, manager for Asset Management Services at SKF Focused Industries Marine, ”but the marine sector also needs to comply with international maritime laws and a regulatory environment, which ensure the regular, invasive inspection of critical equipment, to ensure structural integrity and reduced risk to human life on board. Therefore, traditional maintenance and inspections are usually based on fixed calendar intervals or machine running hours, within a planned maintenance regime.” And that is where maintenance software can help.

Key software tools used to support effective ship operations include: Asset Performance Software which can help to create an ideal maintenance plan; Maintenance Management Software which is used to plan and execute maintenance tasks, including scheduled work, spare parts and resources; and Condition Monitoring Software which can provide early warning of developing faults and reliability issues in critical equipment, allowing planned intervention, before they become a significant risk to the ship operations. Maritime by Holland Magazine takes a look at these different kinds of software of two companies: MaxGrip and SKF.

Alignment and vibration issues

In addition, there are other advanced calculation and simulation tools, such as ShaftDesigner software developed by SKF, which can be used in specific applications, for example to correct the geometric alignment of propulsion trains. Geoffrey de Vlaam, marketing and sales manager at SKF Solution Factory – Marine Services in the Netherlands says: ”When a problem occurs on a shaft line or a shaft component, we come in. With our software we make a 3D model of the shafts on board based on the drawings and compare this to measurements done to the real shafts, so that faults can be easily spotted and corrected. The software can also be used during ship design and yard new building phases to make predictions of shaft deflections and vibrations, so we can prevent problems in service, by acting on a potential problem in the design phase. Supported by direct measurements using strain gauges, dynamic shaft alignment is also made possible, reflecting real ship operating conditions, rather than a simple static model. This means deflections and vibrations that occur in operation can be detected and taken into account for determining the optimal alignment. ShaftDesigner can be used throughout the whole life cycle of a vessel.”

Maintenance strategy optimisation

Then there is software that supports the optimum selection and planning of maintenance. ”Everyone wants to get the most out of their vessel. Asset Performance Management software makes sure this can happen, through the selection of the optimum maintenance concept, which can be made operational within the Maintenance Management Software systems used by the client. At MaxGrip we have developed Optimizer+ and strEAM+ software for this purpose, which are basically the same product, except that strEAM+ can also be integrated as an add-on into Enterprise Asset Management systems like IBM Maximo, Infor or SAP. In short, the software uses an assessment process support solution to create the concept – strategy – for the maintenance plans and calculate the effect that these selected maintenance plans will bring in terms of asset availability, risks, failures, costs and other production losses. First we determine our clients’ business objectives as a starting point, followed by the failure mode effect and criticality analyses of failures (FMECA and RCM). Then, risk and stock analyses can be made. With the help of our industry specific failure mode libraries with quality data we can speedup this process dramatically for our customers. In addition, we can simulate what the selected maintenance strategy will deliver in terms of business performance and bottom line results over the coming five, ten or even 20 years”, explains Wilco ten Have, business unit manager at MaxGrip.

Ten Have continues: ‘‘Without such software clients are under- or overspending on maintenance. We try to prevent this from happening by providing the tools to make the right decisions. In the optimum maintenance strategy, advice is given which maintenance tasks are necessary and justified, and which spares should be held in stock. We have designed the maintenance strategy for a fleet of dredgers belonging to a global market leader in dredging and mining vessels, in which we have calculated various scenarios on what would happen if certain equipment would fail in service: should they return to mainland, or can it be fixed on board? These scenarios are now integrated in the maintenance management software that has already been used by this company, so there was minimal impact on day-to-day business. Next to this, we have given them inventory advice, as there is limited space on board available for storage of spare parts, so choices need to be made based on the risk analysis made earlier. When failure occurs, they are more likely to have the required spare parts available, reducing down time and costs.” And cost reduction is where the profit lies.

From a distance

De Vlaam adds: ”Of course not all maintenance can be planned. A lot ofthe time we get a call when a failure has occurred and they need someone to fix it, known as reactive maintenance. We need to create awareness that SKF can help fleet operators to avoid such problems before they occur, and avoid significant costs, as a lot of money is involved for every hour a vessel is off hire. Condition-based maintenance seems to be the right solution, providing the early warning required to avoid these failures and their costs.”

Furthermore, condition monitoring technology can solve other important problems. Rolfe explains: ”The challenge for many critical marine applications is that the actual operating conditions can be extremely variable, causing different results from similar measurements, which are then extremely hard to compare. SKF Multilog allows online collection of selective data, taken under similar operating regimes, enabling the comparison of ‘apples with apples’.”

He continues: ”The online monitoring systems can be used in locations which are difficult to reach, or in unsafe areas, avoiding additional risks to human life on board. Condition monitoring data is measured at selected machinery positions, and automatically uploaded to the software database, using portable devices such as the SKF Microlog analysers, after which the data may be sent to an SKF remote monitoring centre for more detailed analysis. Within our CM support contract with BP Shipping, staff is trained to routinely collect vibration data from a selected number of machines during regular daily routes. This data is sent to our monitoring centre, where a detailed analysis is made and recommended actions given when problems seem to occur. This way, catastrophic failures can be prevented from happening, reducing machine down time and maintenance costs.”

In addition to the early warnings the condition monitoring system can provide, it can be used to make predictions based on historical evidence. Rolfe says: ”We have made approximately 10,000 maintenance recommendations for the BP fleet during the past seven years. This allows detailed data mining to identify, for instance, common equipment alignment issues, or how many times a specific machine type has failed, allowing a more proactive approach to improve equipment reliability in future.”

Anne Kregting