Lesson Learned – Avoided Catastrophic Failure

Sharing an experience.....

2005, Mainship 430 Aft Cabin Trawler, 2,000 hours; We recently had the impellers replaced and barnacle buster used to clean the cooling system. On our first voyage with new impellers, after about 15 minutes above idle speed I heard an unusual alarm under the upper helm dashboard. I have never heard this alarm before. I looked at all of the gauges and all were reading normal. I immediately handed off the helm to my wife and I went into the engine room where I saw sea water all over the engine strainers and deck. I quickly realized the starboard engine cooling hose that goes from the impeller assembly to the heat exchanger experienced a slight burst and sea water was streaming into the engine room at 2600 RPMs.

I ran to the helm, put the engines into idle speed and told my wife we need to return to the marina – at idle speed. I returned to the engine room and used Rescue Tape to wrap where the burst was, which sufficed until we got back to the marina.

I usually do one-hour engine room checks, and this reinforces the need to check the ER often. I’m not sure if the alarm I heard could have been a low-pressure alarm on the cooling water? All I heard was a steady tone.

What I do know is that if I hadn’t caught the leak while it was small and my RPMs were relatively low, when I would increase the RPMs I probably would have seriously burst the hose and salt water would have gone all over both engines, the batteries, alternators etc… and could have created a catastrophic situation.

When I got back to the marina, we ordered all of the hoses for the engines and they will be replaced this week.

JimL

My rule of thumb is have bilge pumping capability of at least the amount that can come in from your largest thru hull.

Even if one pump fails, you should still have long enough until you start loosing systems.

psneeld said:

My rule of thumb is have bilge pumping capability of at least the amount that can come in from your largest thru hull.

Even if one pump fails, you should still have long enough until you start loosing systems.

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I follow that philosophy as well. And with twin engines, a failed intake hose shouldn't be a scramble, it should just be a matter of shut one down, confirm water has stopped, get boat to engine-out cruise speed and then deal with the problem when it's safe or practical to do so.

I’m concerned about the alarm you heard. Why didn’t you hear it at the FB station? You need to resolve that.

Good idea to have rescue tape handy. I’d also recommend having a small damage control kit with some plugs, wedges, Okum, Marlin, and a hammer available. I’d keep the rescue tape in the kit too. But if you ever have a thru hull or a hole in the hull it could save the boat. Just my 2 cents.

Jmk2000 said:

Good idea to have rescue tape handy. I’d also recommend having a small damage control kit with some plugs, wedges, Okum, Marlin, and a hammer available. I’d keep the rescue tape in the kit too. But if you ever have a thru hull or a hole in the hull it could save the boat. Just my 2 cents.

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The wax toilet rings are good to fill holes, too.

I agree that the alarm may be not quite what is needed.
Both stations should have one.
A warbler peizo electric alarm is more effective than a single tone.

A louder one also but from my own experience a warbler is FAR more effective at getting attention. The single tone ones unless they are really loud tend to just blend into the background noise.

C Lectric, love the cat avatar. Is he yours?

I had the same issue with a BADLY burst hose right after the raw water pump at 3400 RPM on my 315-HP Yanmar, but my alarm arrangement I had was vastly different leading to different responses. I was quite unhappy with the single piezo alarm hidden behind the helm console with no visual indicators as to the nature of the possible six alarms from the engine. Mainship cheaped out in not using the Yanmar alarm panel with all the idiot lights. I connected a six-light aftermarket display to the engine and mounted it alongside the wheel. I was thinking of adding a Borel exhaust heat alarm to the engine, but had not done so when the hose burst - wished I had. Anyway, when the hose burst spewing 35 gallons of seawater a minute into the bilge, the engine rapidly overheated setting off the piezo, and the overheat light and the bilge pump light on the other side of the wheel came on. Those two lights told me that the engine was overheating without having to check the gauge and that the bilge was flooding because there was a break in the seawater cooling system AND that running the engine another second was an unacceptable option. I yanked the throttle to neutral and killed the engine before the boat even dropped off plane (BAD thing to do, but at that RPM things were already VERY serious), and the engine burped and gurgled for a long time. Rather than try a tape repair, I called for a tow the mile back to pier where I went through a lot of preparation including all new hoses, impeller, a new Borel alarm, and an oil and coolant change, and a Barnacle Buster flush before I was ready to chance it. All seems well these days two years later.

Along with tapered wooden plugs, I carry this stuff for emergencies:

' http://www.stayafloatmarine.com/
Fortunately, I haven't had to use it yet!

Archie, I did hear the alarm from the fly bridge station. It was a constant tone and was faint. It was on for probably 2-3 minutes before I confirmed that I was hearing the tone. This is the first I ever heard any alarm other then low oil pressure when you first start the engines - and they are loud.

Thanks for the feedback.

Jim

A Bell alarm takes more juice to operate , but there hard to ignore.

jimL said:

I usually do one-hour engine room checks, and this reinforces the need to check the ER often. I’m not sure if the alarm I heard could have been a low-pressure alarm on the cooling water? All I heard was a steady tone.

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High water alarm? I was once aboard a friend's pilothouse sailboat with engine under PH floorboards, not unlike a trawler. High water alarm triggers and we popped-up the floorboards to see a remarkable amount of water flowing in from his PSS. It was breathtaking! Fix was relatively simple - the shaft-collar had not been properly installed and had backed-off. Simple hose clamp around the shaft held it in place easily.

Peter

jimL said:

Archie, I did hear the alarm from the fly bridge station. It was a constant tone and was faint. It was on for probably 2-3 minutes before I confirmed that I was hearing the tone. This is the first I ever heard any alarm other then low oil pressure when you first start the engines - and they are loud.

Thanks for the feedback.

Jim

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Ok you heard it eventually. Why the difference? My Perkins oil pressure and coolant temperature (as well as transmission temperature )
trigger the same buzzer at the keyswitch. Do they use different horns for different causes on your boat? Was it a bilge high level alarm on a separate panel? My point is two minutes of recognition time of ANY alarm is horrible and must be improved.

This thread is a great reminder for us all to review our alarm systems for proper operation and upgrade to make the alert response immediate. This Mainship joins another MS recent post where the bilge pumps and high water alarm needed attention and upgrade. I'd urge any Mainship owners especially to look for deficiencies soon.