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Old 23-08-2008, 19:41   #16
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Some will argue this can't happen;

A pinhole leak in a high pressure diesel injection line, or perhaps a poorly maintained fitting, could spray vaporized diesel fuel mist into the engine room. Vaporized diesel fuel mist can be explosive.

Add one automobile grade alternator, which does not have the USCG-required spark protection that marine alternators would have, and you if the alternator is old and worn and makes sparks, KABOOM.

That's all you need--besides the exact bad luck to have the correct fuel/air mixture for an explosion. Neither diesel nor gasoline will cause an explosion, unless you get the mixture just right. Or wrong, as the case may be.

It would be easier to have some bozo using a home kuldged propane cooking system that flooded the bilge and engine spaces with propane, which the same automotive grade alternator could spark off.
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Old 23-08-2008, 19:53   #17
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Some will argue this can't happen;

A pinhole leak in a high pressure diesel injection line, or perhaps a poorly maintained fitting, could spray vaporized diesel fuel mist into the engine room. Vaporized diesel fuel mist can be explosive.

Add one automobile grade alternator, which does not have the USCG-required spark protection that marine alternators would have, and you if the alternator is old and worn and makes sparks, KABOOM.

That's all you need--besides the exact bad luck to have the correct fuel/air mixture for an explosion. Neither diesel nor gasoline will cause an explosion, unless you get the mixture just right. Or wrong, as the case may be.

It would be easier to have some bozo using a home kuldged propane cooking system that flooded the bilge and engine spaces with propane, which the same automotive grade alternator could spark off.
I could see the pin hole leak developing from a leaky sea water pump spraying on a belt and slinging salt water every where over a few years.
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Old 23-08-2008, 20:00   #18
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Thanks for all the advice so far. I did some research a while ago on the difference between gasoline and diesel engines, although there was almost as much disagreement over which kind was safer as there is disagreement over which school has the better football program, Georgia or Georgia Tech...but I digress.

In my book, the boat owner, who is a fisherman squeezed by lots of debt, is cutting all the corners he can. He's using a diesel-kerosene mix to save on fuel costs, and is using cheaper parts when he can. His son, who knows how to fix and maintain engines but doesn't know that his dad has used cheaper auto parts, helps his dad fix up the boat some. The scenario I had in mind was the fuel mist--I've read a diesel-kerosene mix can cause injectors to drip, especially if the injectors aren't clean enough to begin with or aren't appropriate for the boat. I wanted this to lead to a fire which then leads to a crankcase explosion.

So if I have a non-marine alternator, and bad injectors, is this plausible?

I want to avoid completely ridiculous mistakes like it sounds Patterson made in "Sail"--thanks for the warning!
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Old 23-08-2008, 20:07   #19
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I hope your book doesn't start like this.

It was a Dark and Stormy Night.....

or

While watching the sunset go down while at anchor at......

the best way to start is

You ain't gonna believe this $hit.......
God, no. I was thinking something like this:

"Tim, stretching his arms like a lion yawning before dinner, watched the sunset go down over the blue water of the Gulf of Mexico, and wondered whether the diesel-kerosene mix in his Yanmar marinized diesel--which he suspected had once been a tractor engine--would gum up the injectors. Nah, he thought, and he took another sip of his margarita.

Think I'll have me a cigar, he thought, and he reached for his lighter."

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Old 23-08-2008, 20:22   #20
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are we talking about a trawler, luxury slow retirement vessel?


or a trawler/shrimper working fishing boat?
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Old 23-08-2008, 20:45   #21
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are we talking about a trawler, luxury slow retirement vessel?


or a trawler/shrimper working fishing boat?
A trawler/shrimper off the Georgia coast. A working fishing boat.
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Old 23-08-2008, 20:48   #22
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30-40' would be small for that environment. Most are 50-70. This would put them in the 700hp range. Gonna be Caterpillar, Cummins or Detroit's in the old ones.
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Old 23-08-2008, 21:07   #23
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If it's boom that you want

try base explosion.....I was in the engine room of a tug when that happened.

It was a Fairbanks Morse 10 cylinder opposed piston engine.

I had me a Guardian Angel that day.....

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Thanks for all the advice so far. I did some research a while ago on the difference between gasoline and diesel engines, although there was almost as much disagreement over which kind was safer as there is disagreement over which school has the better football program, Georgia or Georgia Tech...but I digress.

In my book, the boat owner, who is a fisherman squeezed by lots of debt, is cutting all the corners he can. He's using a diesel-kerosene mix to save on fuel costs, and is using cheaper parts when he can. His son, who knows how to fix and maintain engines but doesn't know that his dad has used cheaper auto parts, helps his dad fix up the boat some. The scenario I had in mind was the fuel mist--I've read a diesel-kerosene mix can cause injectors to drip, especially if the injectors aren't clean enough to begin with or aren't appropriate for the boat. I wanted this to lead to a fire which then leads to a crankcase explosion.

So if I have a non-marine alternator, and bad injectors, is this plausible?

I want to avoid completely ridiculous mistakes like it sounds Patterson made in "Sail"--thanks for the warning!
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Old 23-08-2008, 21:15   #24
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30-40' would be small for that environment. Most are 50-70. This would put them in the 700hp range. Gonna be Caterpillar, Cummins or Detroit's in the old ones.
As soon as I wrote 30-40' in my previous post, I knew it was wrong--the boat I have in mind is at least over 40' in length. Don't want it too big, though--I need for the boat to be able to be manned by 2 people (short fishing runs) and not require a large crew.
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Old 24-08-2008, 01:17   #25
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Wow some people have wild imaginations. You can not make an engine "explode". You can not make fuel explode even. You can make fuel vapor explode if given the right percentage of oxygen and confined environment.
The only engine I know that can "explode" would be a coal fired boiler for a steam engine and even then it is the boiler, not the engine and only if the boiler is flooded with the right quantity of water.
What could explode on a boat would be Gasoline fuel vapor or Propane/Butane gas in the bilge.
As for parts on engines. Many engines are the same in both on land and on water environments. There are two major area's of difference however. The main one is the Injector pump governor. The way the speed of the Engine is governed is different. The other is the the cooling. Most boat engines have a water cooled exhaust manifold. the additional cooling parts are normally external to the engine. OK, there maybe three differences now I think of it. The raw water cooling pump can often be found driven directly off a PTO on places like the IP or similar. Apart from that, they are the same.
Now in a large engine, like a really big mother, you could have two area's that would cause some concern for safety. One would be a con rod of a big sucker driving out the side of the casing. The other would be a centrifugal oil cleaner not put back together properly. The disks can fly all over the place and can kill. Both those situations can be scary and dangerous, neither would cause an explosion.
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Old 24-08-2008, 01:23   #26
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try base explosion.....I was in the engine room of a tug when that happened.
Chief, are you refering to a sump explosion? I have had that happen as well. In a small 50Hp Diesel Tractor. It shot the dipstick a good 70ft into the air. But once again, not something that could be considered an "explosion". More like a damn good backfire.
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Old 24-08-2008, 02:21   #27
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Crankcase Explosions in Two-stroke Diesel Engines

Check it out:

http://www.manbw.com/files/news/file...le09-12-03.pdf
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Old 24-08-2008, 02:42   #28
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You ain't gonna believe this $hit.......
....., f*** lo**r installed 1984 Yugo Koral cooling tube
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Old 24-08-2008, 03:05   #29
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If you want to have something explode in a commercial boat how about a propane line to the galley? Or knocking the end off a cheap propane torch.
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Old 24-08-2008, 13:03   #30
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A fishing boat could be using anywhere from 60 to 450 hp diesels, either specifically built as marine engines, or marinized commercial engines. You can't walk into an autoparts store and buy cheap imitations; the market is too small and the users are too wise. That theory works somewhat for airplanes, but not for big heavy run-for-hours-at-WOT boat engines.
Marinized engines are usually painted all one color, over hoses, thin covers, and cast iron parts alike. Here is a possible scenario:\
Shady/sloppy mechanic can't get proper replacement part (supplier won't deal with him, bad credit, ??) so he fixes or patches up the worn/cracked/warped part and paints it the right color, claiming it to be a new replacement part, and de-tunes the engine to keep it from blowing the repair. Someone else, unaware of the kluge fix, restores the engine to normal operation. It lets go, nicking a fuel injector line, and breaks one of the lugs on the battery bank, which arcs continuously, eventually igniting the sprayed diesel. There won't be an explosion, but a fire could just possible be sustained. There would be more danger from the carbon monoxide in the smoke than from the fire itself at first.

You are far more likely to find the results you are looking for from a large gasoline engine in a fishing boat. A really raggedy-assed boat could have just that. In 1965 my Dad and a few friends bought a small shrimp boat with a Chrysler Hemi V-8 in it, that was so screwed up the boat ran faster when we installed a six from a chevy pickup. I would be amused to hear what an AMS surveyor would have had to say about it either before OR after the swap !

p.s. The trawl net was worth more than the boat, and we lost it to a sunken barge in the first month of fishing.
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