Tag Archives: marine

question-mark

I often hear people discussing CM and CBM in terms of the difficulties that they face when trying to facilitate a change or approach to the management of maintenance or asset health, often citing manufacturers warrantee or PM handbooks as a blocker.

To them I say warrantee is normally 12 or at best 24 months so after that you are on your own. You can and often will get support from major asset manufacturers to maintain via a CM or CBM strategy and where you do not you can get class support via operation of related and class approved PMS, CM and CBM activities.

The next response may be that underwriters/insurers will not support claims where handbook activities have not been followed. This again is a weak argument as many detectable failures are not sufficiently significant to breach the deductibles threshold where a claim may be relevant. In the case where claims are appropriate, the loss adjuster will look to see that you have made sufficient efforts to prevent failures. Where you operate and comply with a class approved PMS plus CM or CBM approach then you will not only have demonstrated a degree or planning and procedure to protect the asset but will also have added an additional layer of assurance via the support achieved via class.

It is when companies make a claim for clearly preventable machinery failures that insurers and underwriters look to minimise their losses. It follows that insurers look to underwrite reliable assets that offer low risks  and where the company behaves as a prudent uninsured. This is why in the future it is likely that those who DO NOT add additional assurances via protective devices like CM and CBM may find that they cannot attract the most favourable rates.

What do you think?

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Not all scavenge drain oil analyses are the same

I can report that not all scavenge drain oil analyses are the same. There are many approaches and the end user needs to be specify the right approach.

Scavenge Drain or Used Cylinder Oil analysis cannot be viewed as a conventional lube oil sample. There are a great many variables that have to be accounted for and normalised before any diagnosis can be made.

Firstly there is no sump so there is a need to understand the relevance of the results to the engine condition at the time of sampling. Therefore feed rate and engine conditions need to be known RPM, %MCR, coolant and scavenge air temperatures, relative humidity and air intake temperatures. These factors at a minimum will indicate the likely conditions that the CLO will experience in terms of dwell time on the liner wall and exposure to water laden air. Both are factors in determination of the potential for corrosive conditions being present.

To get this information you require accurate power information as the feed rate will be normally calculated using grams per kWh, also power loss due to weather, hull condition rudder angle will impact upon the power to rpm relationship. Knowledge of the fuel quality during sampling allows you to understand what abrasive materials may be present and to what degree the presence of unburned or partially pyrolised fuel has on the lubricating qualilty and the determination of BN and viscosity values.

Clearly this information is not required by all analysis providers – FOBAS Engine provided by Lloyd’s Register, a service which I lead, is one service which considers the holistic view in this way – noting that FOBAS Engine has a wider remit for engine performance optimisation and training and is not simply provided to check feed rates etc, though this is performed and opportunities for CLO cost reduction are usually the first to be targeted.

What is clear however, is that there are significant differences between onboard analysis and lab analysis as well as differences between oil analysis suites.

As corrosive ear generates smaller wear particles which are not within the visibility of onboard magnetic PQ devices, these devices should only be used to warn of unexpected scuffing – therefore permanently installed in the drain line. Using the same technique onboard but offline for periodic sampling is often cited as being used to demonstrate that feed rate has not be “over optimised” to the extent that the oil film is being routinely disrupted and producing adhesive/scuffing wear debris. My view is that in reality this level of feed rate optimisation leaves no room for error and is in all probability a false economic approach in this application.

For lab analysis – there are the issues of immediacy for obvious reason but if your laboratory uses a sensible approach to dilution correction to normalise the effects of contamination by system oil, fuel, water and feed rate variability. Then it is perfectly reasonable to use such a test suite to help optimise feed rate in accordance with variations in Sulphur content and differences in CLO BN performance.

I would recommend to check that your lab based CDO analyses are subject to at least a system oil correction and I would also strongly recommend that a scavenge space cleaning regime is built into the schedule to ensure that each sample represents oil arriving via the liner and not simply that which has accumulated over the previous few days which will have no useful relevance to the operation at the time of sampling and thus weaken any diagnosis.

I would suggest that samples be drawn during steady state operation at a point approaching port which will allow the samples to be passed to the courier in the shortest time possible in order that your laboratory can get the results back to the ship in the shortest time thus increasing operational relevance to the task.

Quote 

“It cannot be stated how much care must be taken when assessing scavenge drain oil …..
Unless some extensive form of dilution correction is undertaken based upon knowledge of the fuel oil, new and used system oil, feed rates and operational data collected from the engine at the time of sampling, use as a routine condition monitoring tool is limited to the measurement of significant changes issues such as high iron, water or BN change.”

CIMAC Used Engine Oil – User Interpretation Guide
Guidance Number 30 issued 2011

Its all about the people not the products!

Lubes Panel Discussion at Riviera Propulsion Conference London – 7th and 8th March 2013

On the podium Castrol Marine/ExxonMobil/Gulf Marine/Shell Global/Total Lubmarine – Panel Chair Lloyd’s Register

DCS 002

Not so long ago the choice of cylinder lube oil was a relatively straight forward one based upon Sulphur content. Then we got the S/ECA’s meaning that we had to change between 70 and 40BN products when we were operating for more than a week or so on low Sulphur fuels.

WhichWay

At around this time universal products covering 0.5 to 3.5% Sulphur were being developed, which would have been fine if we had not also decided to throw a spanner into the works by slowing down our engines to conserve fuel.

As lubricant supply to the ring liner interface is proportional to the speed of the engine the the result is that the residence time of the lubricant upon the liner is increased as we slow down the speed – thus – as we slow down the speed, we also slow down the relative velocity between the ring and the liner. What this means is that there is more time for the acidic materials to form. In addition as this has the effect of reducing the temperature of the liner then the potential for acidic material formation H20 + S2 = H2SO4 is also increased.

Acidic Corrosion – Why?

As  it is not clear what the exacting conditions are for acidic corrosion we cannot yet manage this directly, instead we manage the potential effects of acidic corrosion by increasing/reducing the CLO feed rate and relying upon the additive performance to control the rate and degree of chemical corrosion.. However, often more neutralisation is required than can be accommodated without over lubrication, i.e. more per ml of lubricant, meaning that new higher,  80BN+ oils (Castrol Marine) have been made available and supported by engine makers.

On the other hand  there seems now to be a new thread of technology which relates to the neutralizing performance not in terms of the quantity present (BN#), but in terms of the quality of neutralization itself (Total Lubmarine and Shell Marine Products). Put in simple terms not all oils are the same. Unfortunately there is not yet an industry test to differentiate products in this way. BN may well be out as the metric used to select the right oil!

What is very clear is that CLO’s are NOT a fit and forget material  – they have to be managed in service to get the most out of them and to ensure that their use is optimized. ExxonMobil Marine place field support high on the list of important features choosing to differentiate themselves in this way and by avoiding the “universal” solution argument – although they too have a mid range universal product on their books.  Supporting the vessel engineers in the day to day activities has to be a priority as they are often criticized indirectly by means of the “reduced crew competence” argument which is often cited but rarely explored in any real way.

My own experience with FOBAS Engine has shown that ships engineers don’t seem to follow a specific path when setting lubricators to control feed rate. There is the tendency for everyone to over lubricate as they do not feel empowered to keep trimming – (Some use PQ style magnetic quantifiers to check that metal wear is not increasing – which is a bit late really!) but even so we often find engines with all units in the normal operational phase  with different settings. Meaning that CLO feed is simply not being managed – period!

Service not Commodity

Gulf Marine restated their position that the chosen lubricant supply partner needs to be considered across the whole range of products and services. Lubricants have been commoditized yet solution borne materials such as CLO’s for differing operational profiles, increased demand for biodegradable and environmentally responsible products plus the increasing need for service support and the role of educator and adviser should not be ignored as these differentiators may be critical when selecting your preferred supplier

The world has changed and we have not prepared for that change. Crew competency has not reduced but it is not aligned with what we ask of it. The industry itself is responsible for defining the need and so we should fix it and not simply deflect criticism onto others.

Ignore the human element at your peril!

A discussion about how we attract and retain high quality engineering staff into an industry that appears to neither provide the necessary human environment nor provide the sort of business structures which consider the person important in the operational structure, will not be possible here, but what we can do is remind ourselves that the shift of power away from the Chief Engineer to the Superintendent or further to the OEM, will not provide the degree of continuity and confidence to operate in the modern shipping world.

Companies like lube suppliers are keen to differentiate their capabilities, we should embrace this but not see it as a way to reduce our own. It will be by empowerment of the CE by reducing in paperwork, removal of unnecessary regulation and supporting the other core activities surrounding leadership and motivation that will lead to improvements.

My main point  – Let your Chief Engineers do their job and shield them from everything else that gets in the way!

No need to open main bearings on Man Diesel Engines

Click to view SL2012-522 Main Bearing Inspection

Man Diesel now state clearly that bearing removal is not recommended as normal practice and therefore not recommended unless evidence based reason dictates.

This is a clear indication that best practice has shifted from a direct inspection methodology to a condition based approach.

This represents a shift in emphasis where the OEM clearly states that opening bearings without cause is likely to increase the risk of issue, either directly by the introduction of new sources of failure such as dirt or re-build issues, or by implication by reducing the support in terms of warrantee, where non recommended strip down may in the future invalidate terms.

Herein a video of the process for bearing removal courtesy of Marine Insight (Apologies for corrupted quality at the end! DS)

Article in LNG World – Maintenance

LNGWSJan12LR

This is a short article that was created for LNG World and describes an overview of the soon to be available Machinery Condition Based Maintenance descriptive note which can be applied for companies who wish to operate their maintenance management on a risk based approach.

In essence this means that all nominated machines are maintained purely on the basis of condition as dictated by the condition monitoring analysis performed. In reality this means that NO item need be removed from service and required to be opened out for the purpose of credit for survey unless the CM data and associated records are unsupportive. Due dates will be removed and in all cases where condition continues to be acceptable items will not need to be withdrawn for inspection.

This is a high standard to achieve as it requires the cultural capability to manage risk based maintenance systems. It shall be viewed as an aspirational standard which rewards those who seek to exceed the minimal compliance requirements of the regulations but is also robust as the condition status has to be demonstrated as known on a continual basis.

We expect that there will be a number of companies who can move into this regime quite quickly but that what will happen is the vacuum that is created by this will be filled by companies who wish to perform at a higher level but who have some minor issues such as resourcing or implementation concerns. We will also be providing resource to assist these organisation to optimise their operations and move forward to a ensure that all operational and reliability related risks are As Low As Reasonably Practical – ALARP – a concept that must ultimately become accepted in the marine industry.

Can Classification Societies really align with Condition Monitoring?

Classification and Condition Monitoring

One of the things that seems unusual is that whilst approximately 10% of classed vessels have their planned maintenance systems recognised by their classification society. This allows the Chief Engineer to credit a number of items for survey at some convenient time, only about 10% of these use approved condition monitoring process which the Chief can use to avoid opening these assets purely for the purposes of satisfying the regulatory requirement.

What that means is that only 1% of ships use condition monitoring for the purposes of classification. It is suspected that a significant number of vessels successfully employ some form of condition monitoring on a regular basis and may even use condition as a foundation for their maintenance strategy but do not take up the opportunity to align these processes with their classification society and therefore must be performing unnecessary invasive surveys and in doing so increasing the risk to reliability.

Why is this?