Beginners Guide To Boating Stuff!

Thanks for your kind words folks i mean its really special that you would ask about some one whom you have never met just to check on him ... thanks ...

Things have been very very tough in Egypt and its been well one of the worst periods we have seen so far. I will update in details in the Trumoil thread as to keep this as its intended ....

 

I'm thinking of moving from a sailing cat to a motor trawler. In my research for a sound passagemaker, many major trawler makers offer single engine as their standard design. However, arguments abound regarding single vs twin engines e.g. Great Harbor Yachts argues strongly that twin engine is the way to go. http://greatharbourtrawlers.com/truths.html. Anyone cares to share their views on this subject?

 

Any news on the boat building project?

 

Unfortunately suspended i have not taken any real steps because of many factors.
I am however going to move to a new house in 1-2 years time there will be plenty of space there for me to start the project and till then i could start saving some cash.

 

- just catching up with the thread after a long absence - a note about soldered connections:

They are regarded with suspicion by the electrical industry due to the tendency of solder to wick up the strands of electrical flex, creating a potentially brittle length of conductor that is vulnerable in a vibration environment. Such flex should be supported for a couple of inches both sides of the joint, my own preference being heat-shrink sleeving - the type with the hot-glue inside for a water-tight seal to prevent corrosion.

 

I like the hot melt glue idea for inside the shrink wrap. I had not seen that before.

 

Heat shrink crimp on connections are expensive, but very durable. Use them whenever the joint may be exposed to weather.

Soldering is troublesome. It requires professional craftsmanship and is best done on a workbench. Poorly soldered joints are worse than crimp joints.

I see very ,very, very few soldered joints on commercial marine electrical systems

 

I think much simpler than that. Would be to have your primary circuit on a fuse.

Have the secondary circuit on a heavy switch. Then if you 'must' turn on the bilge, you can flip the switch. But, if you need circuit protection, you have it.

 

Well since seeing a few number of boats sink (3 recently!!!) i put together an excel to calculate bilge output after reading marine investigator book.

Hopefully needs some ironing but i thought to share it !
P.S feel free to let me know if i have anything wrong !!!!

 

Hi Vulkyn. Did those boats sink in Egypt? Perhpas they are having maintenance issues or problems getting parts . . .

 

My friends boat was put in the water with out the drainage plug. By the time he noticed the sluggish movement he was able to turn around and save his boat. The bilge was not able to keep up. His quick action saved him.

The 2nd boat lost the rubber seal between the engine and the transmission in an in/out speed boat. The bilge couldn't keep up and the boat capsized (thankfully every one aboard was saved). The rubber was not replaced regularly and was almost 3 years overdue, the owner was not given any instructions from the boat seller.

The 3rd was out in the water when the weather turned suddenly it sank very close to shore. (open deck speed boat and that is not suitable for high water but lakes and the bilge was very inadequate as well.

The 4th boat was brand new, caught fire and sank. Thankfully every one escaped.

The calculator i made was for the boat i am building i wanted to have a reasonable safety margin and to better understand how much output you need.
I know with small boats you have very little for safety, but its ridiculous when your bilge can't even keep up with a drainage hole size.
My friend fitted another higher capacity bilge on the other side of the boat as well as an extra battery after his incident (operated separately on a buzzer and a floating switch.)

 

If you use a calculator and figure out how much bilge pump you need (GPM/LPM), you quickly find that almost all boats haven't enough bilge pump installed. This is because these aren't designed to save your boat in the event of a bellows rupture on an I/O or other mishap. The average arrangements are easily overwhelmed in a sudden thunderstorm down burst in most cases.

In most production boats, they're only to satisfy an arbitrary requirement, established by committee, likely motivated by political pressure. Requirements decided like this are rarely effective. In fact, most pumps are just window decoration.

The reasons are simple: the regulators don't want to send you out with nothing, if only to cover their butts, but more importantly and unfortunately, you can never tell how much you need, until you have a hole size to measure. Lacking a crystal ball to predict this particular aspect of the problem, even the biggest, most powerful bilge pump may not be enough. Simply put, in order to calculate how much pump you need, you have to know how much is coming aboard, which requires a hole size. If you knew what this portion of the equation was, you'd probably not need the pump.

 

Very well said PAR, for my case in the area i am going to put my boat in the kind of problems i have mentioned is where i will base my calculations.

Its just a safety margin and nothing more, in the mean time i do not accept a setup where a small drainage pipe hole sinks a boat ! I mean thats just ridiculous.

Fitting another pump like my friend did would not prevent his boat from sinking in a thunderstorm but should give him extra precious time to react, specially if one of them breakdown.
Small boats have such a small margin of time to react, anything additional will help.

 

A 1" (25 mm) hole in a 20' (6.09 m) long boat will sink it in less than 5 minutes. So, you design a pump arrangement to keep up with a 1" hole, right? What happens if you have a 2" (51 mm) hole? Okay, so you design a pump setup to handle down flooding, for a hole of this size. What happens if the outdrive bellows tears off from dry rot? Okay, so you design a system that can handle a 6" (152 mm) hole and now the whole interior of the boat has pump pickups everywhere and you have no place to store and anchor.

My point is you can't design for the worst case situation. The best you can do is make it as safe as practical, drive safely and keep up with the maintenance. The majority of sinking can be traced back to negligence. Thru hulls that haven't seen new bedding since the boat was built, outdrive bellows that are hard as stone, poorly located pumps, lack of weep holes, plugged scuppers, etc. These are the usual things that sink boats, unless you run across a log at 40 knots, at which point the best thing you can do is find the nearest sand bar or shore line and get her up on it quick.

 

Pumps come with two descriptions. Bilge pump and dewatering pump.

A bilge pump is for dealing with drips...a dewatering pump is for dealing with plumbing failures or hull breaches.

No such thing as a small craft dewatering pump.

Best to use logic when choosing and installing a bilge pump on a small craft.