Search found 1276 matches

by marcelo_malara
Thu Dec 03, 2020 12:33 am
Forum: Hypothetical Naval Scenarios
Topic: US and IJN heavy cruisers
Replies: 3
Views: 73

Re: US and IJN heavy cruisers

The Baltimore class is quiet unique in being the only (AFAIK) cruiser class that has adequate protection against its own caliber, making it a kind of a scaled down battleship. Friedman´s British Cruisers mentions that the RN commissioned a study to know how big would be a cruisers with this kind of ...
by marcelo_malara
Tue Nov 03, 2020 3:07 am
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Re: Torpedo angle of attack

Sorry for the delay. I am thinking from another point of view now. My theory of the thrust cancelling buoyancy can be said to belong to the field of the statics. What happens in the field of dynamics? We can accept the vertical (to the bottom) movement inevitably caused by the negative buoyancy, but...
by marcelo_malara
Sun Nov 01, 2020 11:39 pm
Forum: Naval History (1922-1945)
Topic: Operations MO MI AL
Replies: 5
Views: 639

Re: Operations MO MI AL

Thanks Dave, this is something I doubted too, not only the real names of the operations but if the places name´s were the same in Japanese and in English.
by marcelo_malara
Sun Nov 01, 2020 11:36 pm
Forum: World War II
Topic: A Tallboy instead of a bouncing bomb
Replies: 11
Views: 580

Re: A Tallboy instead of a bouncing bomb

CEP factor here. The whole point of the bouncing bomb was that it would roll down the upstream side of the dam and end up right at the base. Anybody know the minimum CEP to be expected by a Tall Boy? I don´t know, but seeing what it took the the US to impact the Thanh Hoa bridge in Vietnam you can ...
by marcelo_malara
Thu Oct 22, 2020 3:01 am
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Re: Torpedo angle of attack

The 178/9 ish degree angle of the axis of the body of the torpedo to the thrust direction of the diverted prop wash gives the few hundred pounds of positive buoyancy necessary to balance the intrinsic negative buoyancy built into the design. High speed in an off-axis direction of travel in a dense ...
by marcelo_malara
Thu Oct 22, 2020 2:39 am
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Re: Torpedo angle of attack

Look at this graphs:

Image

Image
by marcelo_malara
Thu Oct 22, 2020 2:37 am
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

°

They are rudders and thus crudely divert water flow creating side thrust disrupting the hull's smooth passage through the water. They are just like a ship's rudder that pushes the stern to port to make the ship turn to starboard. They are not aerofoils/hydrofoils creating lift through differential ...
by marcelo_malara
Tue Oct 20, 2020 7:01 pm
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Re: Torpedo angle of attack

Hi Wadinga Because the negative buoyancy is small, water is dense and the torpedo speed is high Small or not, the negative buoyancy is present, and must be cancelled, if not the torpedo would accelerate vertically to the bottom, albeit almost in a horizontal position. the horizontal rudders do not h...
by marcelo_malara
Tue Oct 20, 2020 2:38 pm
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Re: Torpedo angle of attack

Yes guys, the control would ultimately fall to the depth rudders, but how? The rudders would push the tail down, so the nose will be pushed up, but that attitude would be maintained for all the travel, as the torpedo would constantly accelerate to the bottom because of its heaviness. The question is...
by marcelo_malara
Tue Oct 20, 2020 3:15 am
Forum: Naval Weapons
Topic: Torpedo angle of attack
Replies: 19
Views: 727

Torpedo angle of attack

Hi guys. WWII torpedoes had negative buoyancy, even with the fuel, water and air consumed. As they don´t have forward fins like a sub, they can not maintain depth generating lift from the fins, lift from the after fins alone would create a nose down momentum. I think that a nose up (positive angle o...
by marcelo_malara
Thu Aug 20, 2020 6:41 pm
Forum: The Dreadnought Era (1906-1921)
Topic: Blucher in Dogger Bank
Replies: 8
Views: 524

Re: Blucher in Dogger Bank

Robert! Good to see you, so much time! I was reviewing the case of Juneu, quiet different, it was more a case of wrecked sailors abandoned instead of a fighting ship. In the case of Bismarck, are you Robert referring to the possibility of PE standing by her? In Dogger Bank numbers were quiet even, 5...
by marcelo_malara
Wed Aug 12, 2020 4:31 pm
Forum: The Dreadnought Era (1906-1921)
Topic: Blucher in Dogger Bank
Replies: 8
Views: 524

Blucher in Dogger Bank

Hi guys. In this battle Blucher was abandoned by the rest of the German ships, that could (orders notwithstanding) have stood by her. Was there any other case of a fellow ship left alone like this (in any war in the steam era)?

Regards
by marcelo_malara
Mon Jul 27, 2020 8:19 pm
Forum: Hypothetical Naval Scenarios
Topic: RN USN and IJN ships
Replies: 8
Views: 958

Re: RN USN and IJN ships

I don´t know if BB and cruiser machinery can be easily compared. Power (hp) is the product of torque and rotational speed (in radians per second). BBs had big and slow turning propellers, while cruisers had smaller and faster turning ones, I am not sure that a cruiser turbine geared to a BB propelle...
by marcelo_malara
Mon Jul 27, 2020 7:30 pm
Forum: Hypothetical Naval Scenarios
Topic: RN USN and IJN ships
Replies: 8
Views: 958

Re: RN USN and IJN ships

No US BB developed more than 40.000 hp before the North Carolina class, most not even 30.000 hp, that´s why they were so slow.

Regards
by marcelo_malara
Sun Jul 26, 2020 5:43 pm
Forum: Naval Propulsion
Topic: Ships boilers
Replies: 6
Views: 1839

Re: Ships boilers

Thanks Bill. I strongly recomend the book Titanic Ships Titanic Disaster (coauthored by W Garzke): https://www.amazon.com/Titantic-Ships-Titanic-Disasters-Superliners/dp/093977335X Apart that it is an excellent book, almost unknown, they do an analysis about the question of exploding boilers, coming...