Advice - can this houseboat be made to sit level with extra buoyancy?

[fallguy]

Sywofp so what about the 500kg (approx) of glass in the front half and then the furniture and the galley/kitchen plus accommodation . A simple look at any Murray river house boat will tell you there is a lot missing, that needs to be taken into account before you break out the angle grinder!

If they already added weight and they DID; she is floating below design water line (DWL). You can't add more weight to make it float level because it may become unsafe!

It is not a simple matter of adding more flotation or weight. The boat, like this thread, will just become more and more convoluted from original design and that is rarely good.

 

[TANSL]

she is floating below design water line (DWL).

That is difficult to know but you are right as to what something should be done but prudently and what is prudent or what is not can only be ascertained with some calculations. Apparently the OP already know and has proceeded accordingly.

 

[fallguy]

That is difficult to know but you are right as to what something should be done but prudently and what is prudent or what is not can only be ascertained with some calculations. Apparently the OP already know and has proceeded accordingly.

Yes, partly. But it would be irresponsible, potentially dangerous for everytime someones vessel is trimmed wrong to start using weights to correct, so despite the OP taking a solid course; a public forum such as this can become a landing place for acceptance of ill advised ideas.

And despite the OP doing it right; the next guy might not if poor ideas are not questioned.

I am far from an expert and never profess to be one.

The OP said the boat was almost certainly already overweight; not me.

 

[TANSL]

@fallguy, I do not want to polemicize and I would not like you to bother with me but the design waterplane, for some reason, may be above the real waterplane at full load. It is not easy to know which design waterplane was adopted by the designer or why he adopted it.

 

[BlueBell]

The OP may be wasting their money if they start mixing forum advice with paid advice...
I suppose it was a fun adventure to explore ideas and get input from forum members while waiting for the hired professional to arrive but it's really just idle speculation from those who have nothing to lose.

Anyway, just a heads-up to the OP, not intending to insult anyone here... including myself, as I am just another forum member.

Will your NA allow you to post some of his/her proposals/ideas?

 

[bhnautika]

Question what is the point of trying to trim a half built boat when you don’t know where and what weight the other half is ? What is the designed freeboard, at what designed waterline?

 

[fallguy]

Question what is the point of trying to trim a half built boat when you don’t know where and what weight the other half is ? What is the designed freeboard, at what designed waterline?

Did you read the thread?

 

[bhnautika]

Yes . statement in the original post “I will be adding furniture etc, and have a separate tally of that weight, which could be used to help the balance. Windows will also add weight forward, but I want to start with understanding how to make the empty boat float level. “

 

[fallguy]

Obviously you have not read the subsequent discussion.

Where the OP realizes the boat has been probably overbuilt and modifying hulls is probably a little silly and he asked for the help of an NA to determine a plan?

 

[bhnautika]

So his statement that “ It was built as a river cruiser that could also be used to operate pedal boats from, and was designed for commercial use with 48 passengers. It’s (mostly) made from 5083 aluminium, and appears to be very well put together.” is now redundant, based on?

 

[BlueBell]

"Designed", by who, a sixth grader?
Just because it was designed doesn't mean it's seaworthy.

Aluminum welds are challenging to get right.
Just because it "appears" to be "well put together" means little.

Sywofp: Have you bought it yet or still "kicking the tires"?

 

[fallguy]

A designer can make an original design and the next owner can just slaughter the boat or build upper decks, etc.

I was on John Wayne's old boat a couple weeks ago and it isn't allowed to leave the harbor anymore as a charter-too top heavy I'm told by a former captain.

 

[bhnautika]

Bluebell this “Designed”, by who, a sixth grader? Is this based on your knowledge of Australian river boats? The look and construction, plus passenger vessels have to be built to a standard. Having not seen the boat up close I couldn’t offer an opinion (on welds) so I can only except on face value the advice of someone who has.

Fallguy you seem to dislike the upper deck on this boat but if you do some research on the this type of boat in Australia they nearly all have them because this is one of the main entertaining areas with accommodation below

 

[fallguy]

I had a problem with the OP trying to get more buoyancy from the hulls on a clearly boogered up design.

If the upper deck was designed to support a dynamic load of 48 or 25 people dancing and the OP wants to convert an overweight boat to a houseboat for a family; there is a rather obvious place to look. He might need a deck to support 8-10 people; not 48. Further in the thread, he said it looked like they added xtra supports at some point even iirc.

Personally, I find it to be a little big and it looks goofy with the massive enclosed stairs which also can't be very light.

But the OP left awhile ago to get some input from an NA, so this is all pot stirring afaic.

 

[TANSL]

Decks are designed, in general, to support a certain weight per square meter. Therefore, whatever the number of passengers, the maximum weight / m2 will be the same. In the case of people is 4 passengers (about 300 kg) per square meter, there is no room for more. And the dynamic loads generated by people moving when dancing, I do not think they are much greater than their own weight.