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Aside from the pump, we took some bunkers whilst waiting between loadings. And the analysis of these came back atrocious (technically within spec!!). Basically full of cat fines, which do nasty things

Well, decided to take you advice gentlemen, and am remaining onboard  Or in reality, I should have signed off tomorrow, however news this morning is that Singapore Authorities didn't grant permiss

Well, another few interesting days (well, actually a few days back, but internet has been as reliable as usual). Back at the end of April I had the Fresh Water Generator open for cleaning, and al

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14th April, 0600 to 1800

ER Temp & Humidity: 40°C & 20%

Well, a reasonably calm day today. Started off with another regular task, that of disposing of the garbage. In these days of environmental concern, nothing can go overboard except ground food stuff, so current practice is to incinerate it. Not the most ideal solution, but very few ships have storage for several weeks worth of rubbish (bear in mind we have average 25 crew onboard, so that is a lot of rubbish) so needs must. To lighten the damage, plastics must be burned above 850°C which apparently ensures that nothing too harmful hits the atmosphere. Anyway, here is the instrument of torture in question:

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Aside from that, played with one of my favourite toys, the laser alignment kit. And got top marks, two smiley faces.

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And finally, to finish off the day, writing the oil record book. This details what happens to all oil/sludge/bilge water and a few other liquids onboard, and is the legal document by which we may be held to account. I take care of the bulk of it daily, which is actually not too onerous. 3 or 4 entries per day. (Apologies for the handwriting btw.)

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Except, not quite the final item. As requested by John, a picture of the engines. This ship is only Aframax size, so relatively small compared to what I have been on before.

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Phil

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Thank you,Phil!!

no one in the pic, but the stairs (stairs, on a ship? Ladders?) give the scale.   Six cylinders?   Bit more poke than a GT6 though I expect!

Edited by JohnD
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I can understand why such BIG engines don't rev fast, but the history of the study of torsional vibration, my pet subject, started with marine engines, that broke their propellor shafts.    Mind you, the shafts were probably a hundre times longer than even a straight sixes crank shaft!

And taking the specs of a ship's engine at random (a Wärtsilä-Sulzer RTA96-C) it has a bore of 960mm and a stroke of 2500mm (!! that's taller than most people!).   At 100rpm the pistons will travel that far twice per revolution, so will take 60/200 = 0.3seconds to travel that far.   At a mean velocity of 2.5/0.3 = 8.3 metres/second.    Hmm.    If 20m/s as a limit applies to such enormous rigs, it could stand 240rpm!

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I'll try and get some more pics later that give a better perspective, but here a few other factoids for you.

Main Engine - only the one! Very few ships have 2 engines (of slow speed category anyway), I have sailed on one in a previous company, but one is the norm. You want more oompf? Add extra cylinders and/or increase the size.

Engine is a DOOSAN (MAN) 6S60MC, which breaks down as follows: 6 - no of cups, S - super long stroke, 60 - piston diameter in cm, MC - camshaft.

Stroke: 2400mm

Power: 18420 BHP

Max RPM: 105 revs (this is otherwise known as MCR, maximum continuous rating, the maximum power you can run the engine at). Reasonably high on this engine, previous vessels max rpm is more 65revs!

We normally operate at less though, currently we have 97 revs dialed in.

If it helps with height estimation, the three Diesel Generator alternators at the back of the pic are about 7 foot tall.

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5 minutes ago, Nick Jones said:

You mention camshaft - presumably just operating the exhaust valve (and maybe injectors) as I'm pretty sure this will be two stroke?

 

Yup, exhaust valve and fuel pump. And most definitely two stroke, I don't think anyone has ever made a four stroke this size??

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Excellent. I love big machinery. I worked in the oil industry and I worked on a research drilling simulator in Cambridge. 11kV 2M Watt supply to 4 SCR DC drives to power 4 DC motor, each pair of motors  coupled to an oilfield pump, each pump capable of 2400 litre a minute  at a discharge pressure up to10,000 psi. It couldn't pump at max flow and max pressure simultaneously due to not having enough input power from the motors. 

Re your ship engine is it a direct drive from the engine to prop or is there a gearbox or 'clutch' between them? 

Mike

BTW have been tracking your progress... thanks!

Edited by mpbarrett
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15th April, 0600 to 1900, 2100 to 2200

ER Temp & Humidity: 39°C & 23%

1Hr Advance: 1500 to 1600

Getting cooler, but by heck you notice the relative increase in humidity, several boiler suits required today!

Mostly a quiet day, tidying up odds and ends so to speak. Tested the compressor, working fine except for the newly developed leak on the Cooling Water outlet hose! For which we have no spare, so looks like it gets a nice rest for a while.

Aside from that, I covered the 3rd of the "routine" duties of a 3/E, that of looking after the shit tank! Fortunately this system is fairly simple, and if looked after rarely goes wrong. Basically it is a vacuum system, it uses an ejector (Venturi) to create a vacuum in the piping, pressing a button on the throne opens a rubber diaphragm and contents of throne fly to tank. Whilst you may not have realised it, you have all come across this system, this is installed on airplanes and modern trains.

Today's job was simple enough, pump out to sea. Position taken start and finish, log in logbook.

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And just to finish off, some more pictures of the Main Engine, including some with myself as reference (I'm no the most photogenic bugger around, you'll just have to deal with it!!).

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Cylinder Heads.

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Maneuvering Platform (the bit at the far end is the emergency control station, this is the last resort for operating the engine)

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Crankcase

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Flywheel (behind the casing) and propellor shaft. You'll forgive me for not trying to stand on it for perspective!

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Turbocharger.

And to top it off, we have started hearing rumours of our next cargo. Nothing in any way confirmed, I shall be able to say more at a later date if it becomes a reality. Still got to reach Korea and discharge this cargo first after all.

Phil

Edited by thebrookster
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4 hours ago, JohnD said:

That the turbo charger whose intake pipe is behind your head in the first pic?    

Gosh, that ain't no Garrett GTX is it?

Outlet pipe that one John. In the first pic you see the manifold (horizontal, silver).

The turbo is on the opposite side from there, you can just see it top left on the turbo pic.

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16th April, 0700 to 1730

ER Temp & Humidity: 38°C & 22%

Well, nothing major going on these days, current plan is arrival at Korea 19th evening, so the next couple of days are mostly carrying out minor jobs and starting to test all equipment required for discharge.

My main aim today was to clear a small backlog of "bread and butter" jobs, pump and machinery performance tests etc. At least, it was, until I went to check my sludge tank that was evaporating water, realised it was empty so de-pressurised it. Then, with a wee bitty time to kill, I decided to clear the ash from the incinerator. 

Well, one thing lead to another, and 20 mins later I had every single access hatch wide open lol. Plenty slag inside, now all cleared out.

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However, on the downside I have discovered that an internal retaining wall is slowly disappearing. Not good, but in current shape not doing any harm. And to fix it would require removing the entire refractory, absolutely not a quick (or particularly easy) job. So it stays as it is for the time being.

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Other than that, some time was spent collecting some more vibration data. JohnD might be interested, this is the device we use for collecting the data.

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Phil

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22 hours ago, JohnD said:

Thanks, Phil!

Below rawdata, above an analysis?     Fourier transform?  How many  harmonics deep do you consider significant?

John, I have absolutely no idea! We generally don't analyse the data, simply take it and send it to a company based near Liverpool and they do that bit.

From memory, initial stages of bearing breakdown show in the higher frequencies, 25000 to 30000 Hz. As it gets worse, it comes down the frequency until it finally registers as a feature of rpm.

Higher velocities generally mean mechanical looseness, and higher accelerations is bearings. 

More than that, I have little idea. Not something we get much training in, my company pay decent sums of money for this, so we take the data and let them tell us what they think is wrong.

And "think" is often the operative term, I shall explain in today's post (I have to keep something to post about after all).

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2 hours ago, 2.5piman said:

Hello Phil,

 

thank you for all the pictures, very entertaining

That you incinerate your waste is interesting but do you have any practical use for the heat produced?

Alec

 

If only!

To be honest, I probably spend maybe one hour a day burning garbage (if I had it I would incinerate sludge waste as well, but what I have is mostly water), so probably not that much heat.

Phil

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17th April, 0600 to 1730.

ER Temp & Humidity: 38°C & 17%

Another quiet day, mostly clearing through the weekly routines. These are the basic maintenance tasks that are done once a week, rather similar to checking the levels etc on our cars. Some are legal requirements, others practical. For instance, I exercise all overboard valves every week, ensuring that they a) turn, and b) turn easily. After all, you never know when you might need to shut one in an emergency!

Also, yesterday I took vibration readings on the Main Engine Turbocharger. And the report suggested that there was a flow restriction on the air intake. Dirty filter kind of thing.

Except the filter is clean, and experts in vibration aside us mere engineers can normally be relied upon to notice if an engine is running short on air! This told me that something else was at fault, so I duly toddled off and investigated. Turns out the wee metal plaque that indicates where to take a reading (they are labelled) had been glued to the heat shielding instead of the turbo casing!

Simply, to take a decent vibration reading you want a direct and preferably solid path to whatever you are measuring. In most cases, a bearing and whatever that bearing is carrying. In this case (not yet confirmed to be fair) I strongly suspect that the heat shielding was inducing its own vibrations on top of those that were supposed to be measured.

Another set of readings later, and our onboard software certainly shows a distinct improvement, so these have now been submitted for detailed analysis. I think I have probably found the problem, but it does beg the question as to why it is there in the first place, or rather why has no-one else sorted it in the last umpteen years? Probably laziness, but I guess we will never actually find out.

That aside, a quick photo of what us officers get to relax in. This is the lounge for 10 people, fortunately not all at the same time.

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Phil

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"Custom & Practice", I fear, Phil!

It happens in medicine too.    Lots of "treatments" have no, zilch, basis in research evidence, from tonsillectomy for recurrent sore throat, via arthroscopy for sore knees to Electroconvulsive therapy for depression, but they still get used, sometimes, because nothing else has worked.     But if no one asks, "Does this really work, properly?", then it'll go on being used.

John

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That's the Placebo Effect.     Yes, it does work, and will augment effective treatment too.     

But surgery has risks, so does anaesthesia.     Those will usually be more than any benefit from placebo.

And there is a Nocebo Effect too!   People given sugar pills and told about potential "side effects and reactions" are more likely to suffer from those fictional ills.

My point was that these ineffective, risky procedures have been used for many years, because no one questioned their efficacy or their risks.    Until some did and showed how hollow they were.   Phil has been properly questioning something that others have accepted.

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The "we've always done it like this" effect applies to all walks of life.  Sometimes there are good reasons for it.  Others, not.  Then there are layers of systems/procedures/rituals evolved over time and changing technologies.  These are rarely efficient - often downright obstructive. 

My employers company IT structures are a case in point.  They have at least three separate systems (that I know of) developed at different times, by different people with different briefs, with some overlap in functionality, with different parts used to different degrees by different parts of the (geographic) organisation.  When being trained on a new development to one of the systems (and strongly advised to use it), we observed to the trainer (sent by head office) that it did much the same job as another system we use, and using it instead adds work and looses integrated reporting, it emerged that he was unaware of this other system and does not even know the people (his own colleagues, based in the same building!) who work with it.  WTF?!!  This isn't even a big organisation......

So yes, worth questioning - but carefully.  All too easy to get labelled as a trouble-making heretic!

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18th April, 0600 to 1700, 2100 to 2200

ER Temp & Humidity: 30°C & 20%

Delayed post, due to lack of interwebs.

Again, day spent on routines, today cleaning the strainers on the Boiler Fuel system.

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A horrible dirty job!

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Fortunately I only pull them out and put them back, the oilers do the cleaning. For all the major strainers we have a spare.

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Phil

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