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Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Mon Oct 03, 2022 4:53 pm
by Iceman 29
My favorite place is always the stern. There are a lot of small details to draw, 1/200 is better to make the ship credible.
A lot of work at home right now before winter, so less time to draw.
I drew the fresh air ventilation ducts at the foot of the C turret, not easy to draw, they follow the curve of the barbette, as well as the 340 mm shell supply hatches on the port side and the powder chutes on the starboard side.
The watertight door on the starboard side that leads into the Admiral's study. No door on the port side. Note that the Bretagne has fewer portholes on these bulkheads compared to other ships of the class.
The booms of the small cargo masts are stored on the bulkhead of this room on the port and starboard side.
I still have 2 hawser reels to draw and two fire hoses, which are fixed on the bulkhead, one can be seen near the barbette on the last picture.
There are steel plates along this bulkhead as well in the photos, maybe plates to close more efficiently the exhaust air ducts near the aft windlass, in combat or in heavy seas.

Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Tue Oct 04, 2022 4:50 pm
by Iceman 29
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Wed Oct 05, 2022 5:13 pm
by Iceman 29
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Fri Oct 07, 2022 5:03 pm
by Iceman 29
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sat Oct 08, 2022 7:26 am
by Iceman 29
Indeed:
The maximum thickness is 250 mm for the reinforced belt, it decreases in the lower part.
There is wood between the hull and the belt. You can see the wooden battens when the ship was launched in Brest and on a picture of the Lorraine in the yard in St Nazaire.
Part of the armor was removed during the second refit in 1924-25 in order to lighten the ship, which had a shallower draft after this period.
Part of her forward armor was removed to lighten the bow and increase her forward freeboard, while a group of coal-fired boilers was replaced by oil-fired boilers and the plane catapult installed on the central main batterie was removed.
Weight summary.
Belt cuirass
2131, 951 tonnes
Total amount of protection
7066, 670 tonnes

Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sat Oct 08, 2022 11:21 am
by Fliger747
Pascal:
Most interesting information! I have just begun reading the AOS book on HMS Dreadnought, a very slightly earlier evolution of ship building, but most fascinating to look at the great transitions and advancements which took place over a short time in naval architecture and technology. Th wooden backing of the main armor belt is interesting and I have seen reference to such construction before. I presume that very long rivets or bolts were used to attach this to the underlying ships plating.
There are some rather unique shapes for you to draw with regards to the vents and especially the chocks near the stern, on the external deck of the secondary battery.
Best regards: Tom
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 09, 2022 4:42 pm
by Iceman 29
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 09, 2022 5:04 pm
by Fliger747
Nice pulling boat! What will be interesting to see is how this complex vessel gets divided up for printing.
Best regards: Tom
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Mon Oct 10, 2022 3:36 am
by wefalck
Wooden backing for the armour-plates was used for quite a long time. All navies conducted extensive experiments by firing armour-piercing and explosive shells at ship-wall/armour mock-ups in different configurations. It seems that the wooden backing, being elastic distributed the impact stresses over a larger area. This had two effects, it dissipated the energy of the impacting projectile over a larger area, therefore making it less likely to punch a hole into the plating and it protected in this way also the structural integrity of the hull by distributing the energy over several frames etc.
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Tue Oct 11, 2022 12:09 pm
by Iceman 29
Tks for the very interesting information.
Not too advanced... I have work to do at home.
I have finished the whaleboat, it is 10 meters long.
I will start the other service boats.

Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sat Oct 15, 2022 9:50 am
by MartinJQuinn
Fantastic work! Love all the details.
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sat Oct 15, 2022 5:50 pm
by Iceman 29
Thanks Martin.
Beginning of a sketch of the front superstructure (1915).
The plans are not always easy to read and do not always correspond to the photos of the time (1915). Especially at the level of the front ventilation duct of the boiler room... To see all that. �:)

Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 16, 2022 4:38 am
by wefalck
As I am myself in the process of building ship's boats: did you draw yours with the scale thickness of the planking or do you make already allowances for the eventual printing constraints?
When designing parts for laser-cutting I often find that one needs to increase their thickness and sometimes their proportions, as the effect of the laser path is somewhat unpredictable. With time one gets some experience how much one needs to add (for outside contours) or reduce (say for holes) in order to arrive at the scale dimensions of the parts. I gather something similar happens in additive manufacturing.
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 16, 2022 7:09 am
by Iceman 29
Yes, I always take into account the printing constraints. As a result, sometimes the design is not as close to the original.
There are compromises to be made, at 1/100 less, etc...
For your information, the scuttles with grills are the crew's toilets on this deck, it's a pretty big space.
The name given at the time is "Corneaux de l'�quipage", a name I did not know. I had to search a little.
http://saintgeorgesdedidonnehier.blogs. ... 609394.pdf
Corneaux ( There is a spelling mistake in the dictionary):
Crew's toilet consisting of sloping troughs that flow into the pipes leading to the sea.
I guess this is what is represented by many small rectangles, I was wondering what it was.

. Hence a very good ventilation of the "places of ease".

Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 16, 2022 12:34 pm
by JIM BAUMANN
WOW !!!
what an incredible amount of work, analysis and excellent photo interpretation
It is complete educational journey on features that I not ever really taken into
my even peripheral vision !!
and had not really worried too deeply about their functions....
-- the propeller shaft brackets....!....and the cable clamping devices
( even the manner in which these operate ! )
have the benefit of sooo many of your hours dedicated to every aspect
absolutely stunning to read and behold.
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Sun Oct 16, 2022 11:52 pm
by DrPR
Pascal,
I find the blueprints to be very distracting from the modelling process itself. I can spend hours looking at internal structures and reading the instructions telling how to make the parts. But it is fun to learn how they made these things!
Phil
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Mon Oct 17, 2022 4:20 pm
by Iceman 29
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Thu Oct 20, 2022 8:32 am
by BB62vet
Pascal,
Quite the project!!! Excellent work! Your design experience is really quite extraordinary.
Hank
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Thu Oct 20, 2022 12:51 pm
by Gregory Shoda
Just marvelous! The detail is unprecedented.
Re: ? Battleship Bretagne - France - Design & 3D printing 1:
Posted: Thu Oct 20, 2022 4:04 pm
by Iceman 29
Thanks Hank, I appreciate !
