Blue Angel (Canados 70s) Rebuild thread

[BartW]

In order to make the stringers really concurrent to the whole structure, it's necessary to build some "L" shaped steel plates, bolted through the stringers and supporting the pull of the external bolts, rather than having only the transom supporting the whole effort.
Below I added in blue the "L" plates on stbd side, with a couple of through stringer bolts in red (obviously there should be more), to better show what I mean.

all understood MapisM,
The stringers are GRP'ed on the transom with a 8mm thick x 100mm wide GRP flap,
see picture red arrows.

dont you think that a flat plate with slot holes for the nuts ,
and pushing that plate in the croner transom > stringer
would be sufficient ?

ofcourse L-shape is better, but difficult to make and fit.
the cross section of the stringer is not rectangular,
100mm (transom side) x 280mm x 75mm (visible side)
and the corner has a big radius

 

[MapisM]

Well, it's difficult to judge from the pics how strongly the stringers are attached to the transom.
My previous thoughts were based on the principle that any stringers (also those along the hull bottom) are meant to give structural strength to a surface, but the forces the're designed to cope with are from the outside towards the inside, "pushing" the hull towards the stringers, so to speak.
And even when there are forces working the other way round (e.g. engines attached to the stringers), these forces are still "pushing" the stringers towards the hull.
Here what you have is a force (the hi/low platform and its weight) which is trying to "pull apart" the transom from the stringers, unless the bolts are attached also to the stringers somehow.
Mind, I'm not expecting the transom to detach from the stringers so easily of course, but surely the stringers are not concurring so much to the overall transom structural strength if the external supports are only bolted to the transom.
Maybe you could explain this doubt to HK (and also to your men in Rome), and hear what they say.
After all, it's their drawing which made me thinking, because they aligned the supports with the stringers, and if they did because they're concerned about the transom strength (as I would), then they should be able to assess the need (or not) of some steel counterplates attached to the stringers.

 

[BartW]

Maybe you could explain this doubt to HK , and hear what they say.

I've send this question (and your drawing) to HB this afternoon,
will see what they come up with
thanks for the advice !

 

[vas]

just saw this last set of posts and photos and I have to fully agree with MM.
From an engineering pov, it's hideous to have the beams there and just go 50-60mm away and bolt on through to the grp, no matter how strong it is. You're introducing a set of substantial forces for no apparent reason, and bearing in mind all the drilling and cutting you've done on the transom, I simply don't think it's wise!

What's the weight again of the platform, what's the max weight expected, and what's the expected stress on the bolts?
This whole levering multiplies forces and shouldn't be taken lightly (no pun)

Definitely go for some L shaped plates, ok maybe not U as it's a pain to do in one go, the folding blades of the machine with intefere with each other and will end up doing a Z and an L and welding them together anyway...

cheers

V.

 

[BartW]

just saw this last set of posts and photos and I have to fully agree with MM.
From an engineering pov, it's hideous to have the beams there and just go 50-60mm away and bolt on through to the grp, no matter how strong it is. You're introducing a set of substantial forces for no apparent reason, and bearing in mind all the drilling and cutting you've done on the transom, I simply don't think it's wise!

What's the weight again of the platform, what's the max weight expected, and what's the expected stress on the bolts?
This whole levering multiplies forces and shouldn't be taken lightly (no pun)

Definitely go for some L shaped plates, ok maybe not U as it's a pain to do in one go, the folding blades of the machine with intefere with each other and will end up doing a Z and an L and welding them together anyway...

cheers

V.

after reading MapisM's posts, and explaining the forces that these stringers are designed for, I more or less agree with his and your concern, so will defo consider the L-brackets,

but when you are in the boat, and see and feel the actual strength / size of the parts, I believe that it will be OK.
also remember, besides the vertical stringers, we have the horizontal fixed platform in opposite direction on the outside which make it all really stiff

If the new platform wiggles, when moving on it, I could even consider a 45° diagonal bar, connecting the the L-bracket, with a bottom strimger...which would add a lot more stiffness. (there is room to do that)

lets hear what HB comes up with, they did quite a few installations, and some hulls must be "lighter build" then mine.

 

[vas]

after reading MapisM's posts, and explaining the forces that these stringers are designed for, I more or less agree with his and your concern, so will defo consider the L-brackets,

but when you are in the boat, and see and feel the actual strength / size of the parts, I believe that it will be OK.
also remember, besides the vertical stringers, we have the horizontal fixed platform in opposite direction on the outside which make it all really stiff

hm, I don't think that there is a serious case of this failing and transom dissintegrating and boat sinking.

HOWEVER, no matter how strong the layup, it's no doubt that structurally its WRONG to introduce these forces to the GRP when there is a structural member nearby to take the forces and redistribute them the way god intended...

So, I'd definitely put some sort of plate that will transfer the forces to the stringer and let the whole construction restabilise itself on the new forces.
The existing platform can only help distribute the forces left to right, but we're not really talking about that now, unless considering hitting the mooring at an angle at any force (which I hope's never going to happen!)

TBH, within the greater scheme and costs involved, a 200-300euro set of 4-6mm plates and matching bolts is negligeable.

cheers

V.

 

[BartW]

within the greater scheme and costs involved, a 200-300euro set of 4-6mm plates and matching bolts is negligeable.

absolutely !

 

[BartW]

Today I've confirmed the order for the HB system, including platform and teac.

I prefer their platform, as ao the weight is under controll, (175kg platform with teac) I expect the Italians to make it unnecessary heavy,
and I like the "compact" design from these Germans

about the L-brackets, they don't think it will be necessary, they will just supply the contra plates, I will probably add myself the L-plates, when everything is in place (correct in situ measurement)

QUESTION
looking at the position of the lift system, we will have to move the generator exhausts. (that 80mm hose just near the stringer)
I was thinking to move them to the sides of the hull, same height, There is space, inside aswell as outside.
Now that we will do the work of moving these exhausts, is there something else I should consider or change on them ?
Is the position on the sides OK ?

 

[jfm]

I see no problem putting the gen set exhausts on the hull sides

If they are working fine, do nothing else. If they are noisy, you could change the exhausts for water-silenced and discharge them below the waterline. but it may not be necessary to do any of that

Regarding the mounting of the platform, I must say I agree with MapisM and Vas. I don't like attaching them close to the stringer but not to the stringer. It "feels" to me like there will be stress concentrations. also, what matters here is not strength but stiffness, and a few mm less deflection is a good thing. I have some good in-build photos of how the same platform is attached to Sq78 which I will post when i have time. Mine is very stiff by the way - the platform doesn't seem to move when you walk on it

 

[MapisM]

Looking at your pic below, it looks like there are already some plates, each side of the stringer, bolted to the transom.
What are they made of, and are those bolts passing through the whole transom?
It looks like at Canados they already integrated in the original design some plates meant to better attach the stringers to the transom, making them concurrent to the overall structure.
Actually, I've never seen stringers built like that, but if that's what they did, the concern on how to attach the platform also to the stringers might be "automatically" solved...

Re. the genset exhaust, I would take the opportunity of fitting it just below the w/l to make it more silent, regardless of how noisy it is - while you are at it, why not?
Other than that, I also don't see a problem fitting it on the sides.
Maybe, with a flattish steel intake/cover oriented backwards, along the lines of better safe than sorry...

 

[BartW]

I have some good in-build photos of how the same platform is attached to Sq78 which I will post when i have time. Mine is very stiff by the way - the platform doesn't seem to move when you walk on it

yes would be interested to see some pictures from your in-build, thanks for that !

I agree about the stiffness, thats why I was sugesting a 45° SST rod or plate, connection to the bottom stringer, there is room for that.

as I sayed, will try to place the L-plates

 

[BartW]

Looking at your pic below, it looks like there are already some plates, each side of the stringer, bolted to the transom.
What are they made of, and are those bolts passing through the whole transom?


Re. the genset exhaust, I would take the opportunity of fitting it just below the w/l to make it more silent, regardless of how noisy it is - while you are at it, why not?

these nuts are from the fixed bathing platform,
when you carefully look at the pictures, you will see there are plenty of nuts, spread all over full beam width.
I think that the stringers are only GRP'ed on the hull.
You can look and inspect yourselves in a few weeks.

such a underwater exhaust, is this just an opening under water level, (with a backwards oriented cover) nothing more involved ?
doesn't this create water bubling noise ?

 

[ARE]

such a underwater exhaust, is this just an opening under water level, (with a backwards oriented cover) nothing more involved ?
doesn't this create water bubling noise ?[/QUOTE]

I think people are talking about a Exhaust gas water seperater. so that the water is seperaterated from the fumes and discharged below the waterline and the dry fumes are discharged above the waterline. This means you do not get the water noise at rest,

Halyard and Centek make them - http://www.halyard.eu.com/Products/separator_ms5000.html

Anthony

 

[BartW]

I think people are talking about a Exhaust gas water seperater

thanks for the info ! makes things clear now.

no experience myself with such systems,
but within a few weeks I wil have a mate on board who probably knows a lot more about this, and can help me to sort out the details of what we need.

 

[BartW]

Here some pictures from my last visit to the boat:

The copilot table is made smaller, and can now be transferred in to a double bed (1.60x1.80m)

We went to one of these small local company’s to order a extra matrass for the bed

Here is the saloon table with the newly build extra extension:

Which still can be stowed away when not needed

The workers started making the new caulking grooves.
They didn't like that work, (they preferred to put new teak) I had a discussion with them about it.
Luckily I was well informed about how this work could be done right,
thanks to a very comprehensive magazine article I got from Jfm. (Thanks J !)
Hopefully the work will be completed correctly.

This plank of marine plywood, is extra protected against moisture;

And then put in position and glued on the inside of the gunwale, temporarily fixed with these wooden slats:

Then our famous new cockpit bench, and gate doors;

Pay attention at the wooden piece, with that wedged groove - water drain:

Here the bench is finalized with rounded corners, and sanded, ready for painting.
the lower dark part is made from a solid wood beam.

This space below the new steps, is perfect for the dryer / washing machine. I have been able to turn the position of the electric motor from the vertical windle ass.
The workers will make a new shelf over the engine exhaust tube. actually the space is bigger then the picture shows.
If the new steps were not that solidly build, a separate dryer and washer could fit in, but I believe there is still hope we will be able to do that .(the second machine slightly "behind" the steps)

Here the new steps in preparation;

The new gate door

A small gap between the door and the upper step, yes I know this could have been avoided with special hinges, but I don’t really care.

The other 3 steps temporarily, not completely in correct position yet.
The risers will follow.

The caulking of the first step.
Steps are made from marine plywood with 10mil teak, border is solid teak.

Apology’s for the geekyness of the next picture, taken from the airplane, flying back home, departure from Rome Ciampino:

Ostia is the hometown of the Canados factory (near Rome).
Last year we discovered / purchased Blue Angel in that marina: Porte di Rome
Isola Sacra is the island between the two arms of the river Tiber, and the sea
Fiumicino is a fishermen village, daily fresh fish available.
Nearby is also that other bigger airport from Rome
the biggest white spot in that cue is Blue Angel (white plastic covering)

15 minutes later I got a glimps of the Costa Concordia on Giglio,
But it disappeared behind the clouds, so could not make a picture, sorry for that ;-)

 

[AndieMac]

Great picture on the wall behind the table!

Good progress with the job Bart, some fantastic joinery work being done there.

 

[jimmy_the_builder]

Bart, this is fantastic stuff, thanks for all the updates and photos. Hugely impressed by your confident approach to this very substantial customisation.

Ref your last photo, as you know we flew over that very same spot a couple of weeks ago - but I didn't know where to look!

Cheers
Jimmy

 

[vas]

Excellent workmanship Bart, looks like it's coming along nicely. Well Done!

Fumiccino otoh is not a place I had particularly fond memories, either stuck in traffic for hours, or having delays on transit, or worse missing a connection and spending a night (courtesy of Alitalia of course) in a hotel somewhere there...

When is the delivery #2 (trip back to Cassis) scheduled for then?

cheers

V.

 

[jfm]

Ostia is the hometown of the Canados factory

That's how the brand name was formed: Cantieri Naval di Ostia = Canados.

Fantastic stuff Bart. Your customisations are turning BA into a great yacht and I like your confidence in just chopping her apart and improving her. Loving this thread. Please keep posting pictures, and I hope to see her sometime this summer. Will the work be finished in time for Easter holidays?

 

[vas]

ah, before I forget, I'd be very interested on a report on primer/top coats used by the team for the plywood around the gunwale and aft deck areas.

I'll need to do a lot of painting there as well and I'm not sure on brands/types of paint yet.

cheers

V.