Zero angle of attack and they were lucky to be alive. Speed
is mentioned in the Albacore book form the Museum and/or Palomar’s
2nd volume on the history of US subs…I can neither confirm nor
deny the facts in those texts.
The standard design criteria for an airfoil-shaped rudder is to
have 30% in front of the rudder post for near balanced operation. I think
your logic is flawed in your concept for your rudders.
R/Jay
Respectfully,
Jay K. Jeffries
Andros Is., Bahamas
Talk sense to a fool and he calls you foolish.
- Euripides (484 BC - 406 BC)
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent
Hartwig
Sent: Thursday, August 28, 2008 5:21 PM
To: PSUBSorg
Subject: [PSUBS-MAILIST] U.S.S. Albacore Dive Brakes
Hello Ray,
Interesting information. Did they say at what angle of attack they were when
they deployed the braking flaps, or how fast they were going at the time? The
speed might of been left out because of it being classified. Did it say
any thing about whether of not all the flaps opened up at the same time
properly. If the flaps towards the bottom opened up first they would make the
sub point down very quickly.
I would think that what ever direction you were heading, the brakes if designed
and functioning properly, would simply slow you down without changing your
heading. To simplify the braking flaps on my sub designs I'm only thinking
about having one on each side towards the back of the hull, or the two flaps on
each wing, one opening up and one down, or a totally new system installed
instead of a basic single rudder, like I have on my K-250.
The new system would be used for steering and braking. It would basically
consist of two rudders about two feet apart or sandwiched together. Each rudder
can only rotate 90 degrees towards the side they are one, and are controlled
individually by a foot peddle that is just to control that one flap. This way
you can move one and steer or move both and brake and/or steer. This can be a
totally manual system, a partly manual system with a hydraulic assist like used
in a car, or fly by wire controlled hydraulic, electric, or pneumatic actuator
controlled. I'm designing a system like this to be installed on my K-250
For the purely manual configuration the steering/braking flaps need to have the
pivot point back from the leading edge a certain amount to help you in moving
the flaps with the assist of the water. My friend Doc, the inventor of the
Bionic Dolphin told me how much it should be, but at the moment I'm not able to
locate the data. I think it was about 30 percent surface area should be forward
of the pivot point. They do this sort of thing one the elevator of planes as
well. But they don't look to have as much as 30 percent.
Your resident possibility thinker. ;)'
Regards,
Brent
Hartwig
-----------------------------------------------------------------------------------------------------------------------
Hi Dean,
The U.S.S. Albacore had dive brakes around her circumference behind the sail.
The book "U.S.S Albacore" by Robert P. Largess says on pages 102 to
105 that they were a mistake. One time they were tried the sub lost control and
bottomed at 400 feet. Another time the brakes were to be flapped to create an
acoustical signal. A hydraulic seal failed and water pressure force hydraulic
fluid into the engine room.
The brakes were immediately removed and were never tried again on another US
sub.
Regards,
Ray