Brass plated Hulls

[derekwarner_decoy]

Hi PD's ....& 'knor3' asks

Does anybody know of a website where I could see a brass hull being made?
I guess that would work only for a larger boat, because of the weight issue.

Well .... ..we have a few comments about strength & rigidity....but  about these

1) a 1000 mm hull of 0.05 thick brass shell is only a little stronger than 3 sheets of paper + glue
2) a 1000 mm hull of 0.05 thick brass shell without frames or perfect symmetry will collapse under the weight of the vessel or the water presssure on the hull
3) a 1000 mm hull of 0.05 thick brass shell soft soldered to ten frames is a LOT more secure than ZERO frames
4) the 'shell plate' or hull expansion plates look totally different than when assembled

a lot more research required ......regards Derek..................

[Bierjunge]

I really hope that Andy will enlighten us more on his construction methods.

Derek, why do you philosophize about 0.05 (mm?) thick brass sheet? Where does that value come from?

Andy tells in http://www.paddleducks.co.uk/smf/index.php?topic=3429.0 about a 2 m long hull out of 0.3 mm thick brass sheet, having only two bulkheads for torsional stiffness.
Btw, 0.3 mm brass has the same weight as 1.2 mm fiberglass. So it should be pretty light indeed.

Your comment on the hull collapsing under its own weight or the water pressure:
No, if you would build a hull as exact small scale version of the prototypes (including scale sheet thickness etc.), it would be much more stable than the prototype. But I don't want to bore you with similarity laws again...
Only an enlarged scale version of a spider, ape or boat hull would collapse under its own weight.

So we are in the lucky position that we can build our models even with scale material thickness (usually much thicker than scale) and nevertheless being simplified (less stringers, frames, etc., or none of them at all).

Regards, Moritz

[derekwarner_decoy]

Hi PD's....& Moritz asks ...

why do you philosophize about 0.05 (mm?) thick brass sheet? 

Somtimes Moritz...when the PD WEB is very quiet I throw  a RED HERRING.....to get people posting...it usually works & I have done this for years or hadn't you noticed? 

[scotfriend]

Hi PD's,

two or three year's a go on a modelshow ( Sinsheim or Friedrichshafen ) i saw a man from the Netherlands who has build hull's from brass in a large size, 1.5 - 2.0m long with all the frames. This hull's are really a nice piece of art. But i don't know how thick the material is, i think he soldered the pieces together. Unfortunately i can't find the photos, i will ask a Friend of mine maybe he has some.

Kind regards Hans.

[Bierjunge]

two or three year's a go on a modelshow ( Sinsheim or Friedrichshafen ) i saw a man from the Netherlands who has build hull's from brass in a large size, 1.5 - 2.0m long with all the frames. This hull's are really a nice piece of art. But i don't know how thick the material is, i think he soldered the pieces together. Unfortunately i can't find the photos, i will ask a Friend of mine maybe he has some.

In the original thread, http://www.paddleducks.co.uk/smf/index.php?topic=3401, Engineman has linked the very comprehensive article http://www.modelboats.co.uk/news/article/mps/uan/44 containing two pictures of what you are presumably talking about. Absolutely stunning masterpieces!

[derekwarner_decoy]

Hi PD's ....& well my ploy is working as people post......

If we consider a typical [modern] 5000 tonne naval frigate be it British, American or European.....or even OZ built  .....the hull material would be 10 mm thick high tensile steel plate

a) At a scale of 1:144 this plate comes down to 0.07 mm thick which is close to my nominated 0.05 mm thick brass shim as I have a 10 metre roll of this shim material when I considered a brass plated hull 25 years ago

b) At the same scale of 1:144....if one used 0.3 mm thick brass plate would represent a real plate thickness of 43.2 mm

c) If we look [in dry dock] at the underwater hull sections of this typical 5000 tonne frigate....all we see is a series of depressed plates approx 900 x900 mm supported only by the hull frames & stringers to which the hull shell is welded

After 1504 days at HMA Garden Island Naval Dockyard, my memory of these views are vivid

From this I must return to

1) a 1000 mm hull of 0.05 thick brass shell is only a little stronger than 3 sheets of paper + glue
2) a 1000 mm hull of 0.05 thick brass shell without frames or perfect symmetry will collapse under the weight of the vessel or the water presssure on the hull
3) a 1000 mm hull of 0.05 thick brass shell soft soldered to ten frames is a LOT more secure than ZERO frames

Clearly, from the snaps by Engineman.......extensive framing is used in these two brass plated hull models


regards Derek 

[scotfriend]

Hi PD's,,

here are the photos from my friend, he took they at the Friedrichshafen model exhibition in 2003, i hope you enjoy the photos.

[derekwarner_decoy]

Hi PD's...here is a snap of the hull of HMAS Adelaide [4200 tonne guided missile frigate] & she has a 10 mm thick high tensile steel welded hull & supported only by the hull frames & stringers to which the hull shell is welded.....as 10 mm plate is a thin skin 

Even in the above water areas you can clearly see the hull depressions centered from the frame & stringer locations

regards Derek

[derekwarner_decoy]

Hi PD's ...from the recent snap  by Hans.....of MS Sternenfries...provides a good question or and understanding of the brass hull construction method....& from this 

1) the brass keel plate section is laid [horizontal member]
2) all of the brass pre formed frames are soldered into the keel plate
3) the complete keel plate & frame assembly is then inverted
4) this then allows the commencement of hull plating

But .... we still have not opened the subject of LOFTING or hull expansion drawings of the hull plates or  ...... ...Derek

[andy]

http://picasaweb.google.de/a.heene/ModellDampferSCHONDORF02
http://picasaweb.google.de/a.heene/ModellRaddampferDIESSEN

Hi,
here some pics of models, made of brass sheets from my collection. Before these 2 models I made 2 others, in more simple construction. First was the PS ZAEHRINGEN, made with brass bulkheadds every 10 cm and o,2mm brass in the floor sheets, and 0,3mm lateral sheets. The 0,2 was not good, because it became "frogs" when soldering. But the hull, made with frames, was too heavy, so I developed a method with a positive moulding of the Hull, I modelled on a wooden plate. Deck stringers and spine of the hull integrated in the gipsen material. See pics of the SCHONDORF. Then I fitted the long sheets with nails (big heads) onto the moulding, front and rear I before had to do some works with a hammer to bring the sheet to its form. I always used the 0.3mm brass, in the quality "soft", because it can be formed very good. THese construction will bring a hull construction of a skin without skeleton- similar to a fiberglass hull.

I would not think to get a problem with a 2,5m hull, or maybe up to 3m, because the doubling of the brass on the connected, soldered zone between the sheets (about 4mm stripes) is doubled to 0,6mm, whitch gives a structure like long stringers.
In the hull of the SCHONDORF, about 90cm, stiffnes only is got by the deck, in the paddlewheeler DIESSEN, I think, it was good to give it 2 bulkheads. For a 3m model, I suppose, it will need 3 bulkheads. But these only give a good stiffness in combination with the deck always!
I never calculated statics for these things, but my experiments had shown , that it works very good.
As I told, I think, a 0.2mm sheet would work as well, but there only was the disadvantage of working with it.

What I was thinking about, was the same job with a soldered aluminium hull, maybe here the sheets had to be about 0,4mm, but soldering was a problem and too expensive.

kind regards

Andreas