Sailing Visitors Blown Away By Help

[Seaslug Caravan]

Originally Posted by tuskie

No, two. But both in central bilge area of each hull. Explained in post#84

Thanks for the response.

Sorry to be pedantic but is that TWO in each hull, making FOUR total in boat , or is that ONE per hull , making TWO total. Post #84 is not clear on this point.

Thanking you for your patience.

[tuskie]

Originally Posted by Seaslug Caravan

Thanks for the response.

Sorry to be pedantic but is that TWO in each hull, making FOUR total in boat , or is that ONE per hull , making TWO total. Post #84 is not clear on this point.

Thanking you for your patience.

Two bilge pumps in each hull = 4 in total.

We, like most cruisers also carry a spare. In our case a portable 3500GPH with 10m x 50mm layflat hose and long heavy electrical cable fitted with heavy alligator clips. Will add 2 more in engine compartments.

From the photos of the breach in "Felix's" hull, I doubt that any sensible bilge pump configuration would cope with the ingress of water.

[PaulinOz]

My L450 has an automatic electric pump, a manually operated electric pump (separate to the first auto pump) then a hand operated manual pump. In each bilge. That is a total of 6 pumps on the boat.

If they are all operated at the same time they would not have a chance in hell of keeping up with the water ingress through what appears to be at least a 200mm square hole, that this unfortunate vessel suffered.

The water ingress through an 100mm dia round hole at 300mm below the water line is approx 1250 lt/min, so a 200mm hole will be upwards of 5 tons (5,000 lt) of water a minute.

The primary way to stop the boat from flooding when it has a large hole below the water line, is stop the water entering first.

Very few vessels if any have large enough pumps to cope with this high volume of water ingress.

I also carry 32,000 lt/hr (8,000 GPH) emergency pumps on board they have 70 mm dia hose and draw 30 amps each when operating. 2 of these running will not keep up with a 100mm dia hole 300 mm below the water line. So my oversized bilge pumps are useless, unless I can first stop the water coming in.

So Mr Seaslug Caravan if they had 1, 2, 3 or 6 of the normally installed on yachts (1000 to 2,500 GPH) bilge pumps, they would not have made any difference to the outcome.

"Sorry to be pedantic but" what exactly do you have installed in the bilge of your vessel.

[Seaslug Caravan]

Originally Posted by tuskie

Two bilge pumps in each hull = 4 in total.

We, like most cruisers also carry a spare. In our case a portable 3500GPH with 10m x 50mm layflat hose and long heavy electrical cable fitted with heavy alligator clips. Will add 2 more in engine compartments.

From the photos of the breach in "Felix's" hull, I doubt that any sensible bilge pump configuration would cope with the ingress of water.

Thanks Mr Tuskie.

I reakon most here (mmm maybe not) understand that a 12v standard bilge pump ain't going to keep up with a hull breach that size. However am I understanding this correctly that this vessel type has NO dedicated bilge pump in the engine room. The engine was flooded (rendering the engine unserviceable) via a couple of small gland/drain holes, that any off the shelf bilge pump could have handled if fitted, giving the skipper time to run the boat up the closest boat ramp/beach.

Please correct me if I am reading this wrong.

Hence my line of questioning in regards to pumps in each of the three main hull compartments.

[Bean Counter]

Regarding the engine compartment "back flooding" from the central / bilge area, would a simple flapper type check valve prevent this happening? I can see need for water to go from engine bay to central bilge sump, which would activate alarm and automatic pump, but not the other way. Of course a check valve can clog, so maybe an additional bilge pump and alarm in the engine bay would give added protection from say a raw water leak or sail drive diaphragm failure.

[StuM]

Originally Posted by PaulinOz

So Mr Seaslug Caravan if they had 1, 2, 3 or 6 of the normally installed on yachts (1000 to 2,500 GPH) bilge pumps, they would not have made any difference to the outcome.

"Sorry to be pedantic but" what exactly do you have installed in the bilge of your vessel.

[tuskie]

Originally Posted by Seaslug Caravan

Thanks Mr Tuskie.

I reakon most here (mmm maybe not) understand that a 12v standard bilge pump ain't going to keep up with a hull breach that size. However am I understanding this correctly that this vessel type has NO dedicated bilge pump in the engine room. The engine was flooded (rendering the engine unserviceable) via a couple of small gland/drain holes, that any off the shelf bilge pump could have handled if fitted, giving the skipper time to run the boat up the closest boat ramp/beach.

Please correct me if I am reading this wrong.

Hence my line of questioning in regards to pumps in each of the three main hull compartments.

A bilge pump in the engine compartment MAY have prevented it flooding, but so to correct operation of the valve already installed on the drain tube connecting the two compartments MAY have had the same effect.

[tomfl]

Originally Posted by donradcliffe

So there you have your answer from the catamaran community. Don't post anything bad about catamarans or we will personally attack you until you go away.

Myself, I like to hear about problems other people have had so I can avoid them. Mono's, cats, tri's, powerboats, bring them on.

Always a good idea to try an learn more.

What we have learned from Seaslug's last two threads is that if your boat is Tboned by a 65 foot trawler you most likely will get a hole in the hull and take on water and that if the boat docked ahead of you has it's head sail come lose in an ~ 65 knot wind and breaks it's mooring lines and crashes into your boat knocking your boat's hull into the dock and putting a hole in your boat you will take on water.

So don't get Tboned and don't dock close to a boat who's head sail will come lose in a storm.

Lessons learned.

Just as an aside if you don't know it already don't stuff beans up your nose.

[JPA Cate]

There was an old, old song, "My Momma Says Not To Put Beans in Your Ears"...for real! I still remember the tune.

Ann

[DumnMad]

Originally Posted by JPA Cate

There was an old, old song, "My Momma Says Not To Put Beans in Your Ears"...for real! I still remember the tune.

Ann

I remember that.

I'll bet that song was responsible for a lot of beans stuck in kids ears.

[JPA Cate]

Originally Posted by DumnMad

I remember that.

I'll bet that song was responsible for a lot of beans stuck in kids ears.

Ah, yes, the chicken vs. egg problem. Cheers, guys,

Ann

[PaulinOz]

https://www.youtube.com/watch?v=KZw7lWd1btQ

[senormechanico]

I'm still waiting to see at least ONE photo of Seaslug's vessel.

[Tetepare]

Originally Posted by JPA Cate

were the dock lines too light or were the attachment points for the cleats not strong enough? or of a size to accommodate large enough diameter line? Was this a" silver line" failure

Ann

Oddly, I haven't heard confirmation of microbursts, though I suspect that was the cause of the damage.

In 1998 the mid-southern shore of Lake Ontario experienced epic destruction following a thunderstorm. The weather service, after a few days, announced that indeed there had not been tornados which is what everyone surmised. Instead, they said the damage was due to microbursts, a term new to most of us in the area.

Following the storm, an old salt (who also happened to own a different marina) emerged from belowdecks on his 42' brick shithouse powerboat a bit confused because his view wasn't what he expected. His boat had spun 180 degrees from the linear docking position. The bow and spring lines (which I'm sure were 3/4" or more) had ripped out the cleats and he was hanging by one line.

Our boat- not 50m away- looked like nothing happened.

Three boats at anchor were dismasted. Two were Beneteaus. I say that not to disparage Beneteaus, but because Beneteaus had only recently become popular, ergo most Beneteaus were at least 1990 models- more likely 1995+. Thus, being in fresh water and with a standing rig that was only a few years old, one can only imagine what it would take to dismast those boats. At least one of the Beneteaus the mast was snapped in half.

If one has ever heard a mature tree snap in half, it sounds like a bomb. I recall hearing repeated explosions of trees during the storm. In some areas, acres of trees were destroyed, snapped in half. The undergrowth was completely gone- it looked like Tunguska. The trees weren't blown over, they were blown to pieces. Yet, less than a klick away the forests were fine.

Wind gusts were reported by NWS at 115 MPH- in an area that wasn't particularly harmed. Here is the Wikipedia summary https://en.wikipedia.org/wiki/New_Yo...r_Day_derechos

So it is quite possible that if this storm in AUS included microbursts the damage could be, effectively, blamed wholly on the weather event.

[gary789]

There was virtually no warning of it being a severe thunderstorm ( 10 minutes ) and yes it was the docklines that let go.