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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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18 hours ago, Escadrille Ecosse said:

@John DFlogging spanners. You can't measure torque so really they should be restricted for 'undoing' or in certain circumstances for initial pulling down when using bolt tensioners.

When I worked for BP I banned their use on my site except under special circumstances with my express permission as they were (and still are) used in a rather cavalier fashion across the industry in my opinion.

No reflection on you there Phil, looks like those floggers are for use in confined spaces and with tensioners

The nuts on those conrods are intended for bolt tensioning.

Flogging spanner very common all thru the oil (rig) industry. Just hit with the biggest hammer and largest rig hand. Most of the ones on a rig were in a terrible state all worn and bent. 
If you did need to do something up to a specific torque (usually all the well control equipment at the well head) then a hydraulic spanner was used, easy to calculate the torque from the piston size and pressure. This was usually after using the flogging hammer!

BTW really interesting to see such big engines, great..

mike

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  • 1 month later...

Well, it occurs to me that I haven't had an opportunity to update this thread overly much.

However, that's not to say there isn't material. I'll do a proper update soon (I promise) however I'll tease you with knowledge it involves a fairly serious fuel contamination, and today a bust cylinder head on one of my small diesel generators.

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And yes, one of these cylinder heads is probably about 2/3's the size of a Herald/Spitfire engine, to put it in terms you can all relate to. Anyway, I'll post more later, I'm just a la'al bit knackered today.

Phil

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Time to update!

So, firstly, my toys.

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The two "small" generators are low voltage beasts, 1.2MW each @440 volts.

The big generator (LHS, which on fact is the STBD side as we are looking aft here) is a High Voltage beast, producing 2.5MW @6.6kV (yes, I am qualified to operate and maintain equipment at any voltage worldwide!!).

Mostly, the HVDG has very limited running hours, and causes very few headaches. The LV's however require far more attention. The HVDG has not yet reached 10000 hours of operation in 7 years, whereas I am currently beginning to plan the 32000 hour overhaul for LV#1 which is due next year (but is being brought forward, more later). #2 LV is not far behind.

Plenty routine maintenance is carried out regularly, from tappet clearance checks:

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to fuel injector testing, centrifugal filter cleaning and regular performance checks. I'll maybe do individual posts about these, if I remember to take the photos!

Phil

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Now, first middling failure. This was originally caused by an attempt to use a new coolant additive, which worked fine for 5 years. However we have found in the last couple of years that actually it eats cast iron, so we have moved away from it. However, it's legacy is still living on.

This was a cooling water pump (engine driven) seal failure.

Pumps are hidden behind a rather heavy casing. The guy shown is actually our engine cadet, who in his past life was a fitter for Wartsila and gets dragooned into every DG job :biggrin:

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Inside the casing. You can't see much, bit this is where the thermostatic valves are installed, 2 on the LT (Low Temp) side and two on the HT (High Temp) side.

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And the two pumps. LHS is the HT pump, RHS is LT pump.

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This is where these engines differ from our car engines. They have two cooling systems, where the LT side comes from main ship cooling system and cools the air cooler (charge, or scavenge air after the turbo) and the Lube Oil cooler (plate cooler below the pumps). The thermostatic valves here maintain a 38 degree temp by allowing water to/from the main system vs recirc.

The HT system is fed from the LT, however this cools the cylinder jackets and heads, aiming for 86 degrees.

And the offending seal:

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Phil

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When the small is measured in megawatts..... you are playing with big toys.

I guess that’s the seal stationary seat? Does the rotating part use a bellows Or a ring and O-ring?

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3 hours ago, Nick Jones said:

I guess that’s the seal stationary seat? Does the rotating part use a bellows Or a ring and O-ring?

You guess correctly! And the answer for the rotating part is I am not sure. I presume it may be what you refer to as bellows type, it has rubber inside the spring which seals to the shaft? Couple of photos, not brilliant though as it was surprisingly difficult to capture!

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To be fair, it was the seal faces that suffered on the original item (the additive was not kind to them).

Phil

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Next failure. This one was potentially more serious, however we managed to keep it under control.

Simply, our MDO (basically dirty diesel) was contaminated. This happened shore side, we don't know how and likely will never find out either. However, the result on our equipment was quite, errrrrm, startling!

The first indication was a sudden large jump in flue gas temps on the boilers. We had to stop running the small Composite Boiler entirely, and struggled with the two big boilers. Furnace inspections showed a tremendous quantity of white powder coating everything like a massive flour (or cocaine as the guys here claimed) explosion.

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Phil

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Second indication came during the routine main engine piston inspection after the piston pull I posted about a while back.

This is what we found:

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Not what we expected, certainly! This triggered a much bigger response from the office, and we started collecting samples from every possible location we could think off.

More concerning was the measurements taken on the new rings that were just installed. They have a rough (coarse sandpaper) texture which essentially hones the liners to ensure that the rings/liners seal properly. This usually lasts for quite a while, however we found that we had the same level of wear after a week's sailing that you normally see after several months of sailing.

We started to get an inkling that this was going to be a somewhat larger problem than first envisioned............

Phil

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Fascinating!   Your stories and photos, Phil, remind me of reading forensic reports, of awful crimes!   The calm phrases and horrible photos!    Please, keep me engrossed!

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46 minutes ago, JohnD said:

 

Marine navigation, by mobile phone app!

savvy navvy The Boating App

At least the app will be reasonably accurate. When I was doing my master mariners ticket in the late 80’s it wasn’t unknown for coastal skippers/captains to use road atlases to navigate around Britain and Europe coastlines if it wasn’t one of their normal runs.

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1 hour ago, JohnD said:

interesting that they show the entrance to Poole harbour one of the most challenging entrances to navigate with a difficult Bar to cross too.

 

H

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A road atlas????? There was a guy a few years ago, set out to sail to South Africa (???).   The lifeboats kept on having to rescue him as he got into trouble in various ways.  Eventually, they asked him how he was navigating around the British Isles, and he had a tiny pocket compass and a road atlas.  The Lifeboats I think persuaded him not to go any further.

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Our entire international fleet (of all 20-sonething ships lol) no longer have paper charts onboard. It is all done by ECDIS. 

And no, I can't remember what that stands for!

A boon for 2/O's on short trip/coastal vessels as passage planning and chart corrections take far less time, but a complete nuisance for those on long voyages who used to eke out the corrections to while away the long bridge watches with nothing within several hundred miles or so!

Phil

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Fuel contamination. The third indication (well, more confirmation by this point) came when the bridge called and announced that we were making a substantial amount of black smoke.

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Sure enough, my generators had finally succumbed and injectors started to fail one after the other. This was all well and good, except I was lacking new spares. I had a set of 6 injectors without any history, all obviously used. Fortunately we have a sister ship here who did have 6 spare nozzles, which I quickly snaffled. Be we received these we did at one point end up juggling between generators trying to pull out injectors, and either overhaul or cobble together a replacement from not so badly damaged spares!

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So that's the working end. Except for the carbon build by the nut, doesn't look too bad.

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Then you open up, and find this! That top surface is supposed to be flat, this one was not so bad with only around 1mm indent!

These injectors are fairly simple in design. They are clamped in place between the rocker arms, see previous post for tappets and you can see the clamp there.

Nozzle on the end of the injector has a needle inside, which presses against the device above. Above that is a spring and setting screw for pressure. On the first pic you can see the hole in the side, the fuel delivery pipe screws in here, and fuel is pumped down a passage inside the body to the nozzle. When the pump pushes, the fuel pressure acts on the needle and once it over comes the spring pressure it lifts the needle and injects fuel. So the only setting I have is pressure, which I set at 440-460 Bar.

Ignoring the HV title (we basically didn't run this DG to preserve at least one working generator!) this was my final working records.

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Five complete failures, which left me with only 1 usable spare, until the pilfered spare nozzles arrived from the enemy (sorry, sister) ship!

Phil

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The final culmination of all of this was an emergency bunkering of MGO (marine gas oil), which is the expensive good quality shit! Basically red diesel.

This occured at the same time we received the nozzles, so I immediately swapped out one LVDG injectors and installed complete new nozzles. Then at the next port I received another set of nozzles that were on order, and we settled back to almost normality. Boilers behaving, generators happy, just the main engine showing signs of discomfort. So last week I pulled the injectors from one cylinder from that (the main engine has three injectors per cylinder), choosing the cylinder that seemed to be worst.

Turned out that two out of three injectors had failed! One was leaking, and the other had too low an opening pressure.

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The sheet of paper is "letter" size (US size!!), the Injector is about 1.5 feet long and over 10kg weight!

Causes. As I said earlier, chances are we will never actually find out the true story, it would cause too many red faces. However, as this is a test engine for one of the R&D companies in the corporation, they have a fair amount of "political" clout. They took samples and ran their own tests. The suspicion is that the fuel was contaminated with an additive normally used to stop aviation jet fuel from freezing! 

The eventual culmination was last week we pumped nearly 1500 metric tonnes of bad fuel back to the supplier. This was primarily due to the R&D company who put their weight behind this option, for all of us onboard this was the first time this has been done! Very rare that you cannot treat a fuel in some manner to make it at least acceptable! So now we have another week or two running the MGO, and then we go back to running MDO again.

Nick, the aluminium/silicates you mentioned first are cat fines. As you say, not something you really want, however they are common and fairly easy to deal with. Any decent separator will remove these with no difficulty. This contamination was not being touched by our separators.

Phil

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2 hours ago, thebrookster said:

It is all done by ECDIS. 

 

A boon for 2/O's on short trip/coastal vessels as passage planning and chart corrections take far less time, but a complete nuisance for those on long voyages who used to eke out the corrections to while away the long bridge watches with nothing within several hundred miles or so!

Phil

Electronic Chart Display and Information System.

Your absolutely on the nail Phil, great for coastal work and when on short hops but leaves nothing or not much to do on the longer legs. Didn’t take the company long to find us other stuff to fill the void!

john

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