Re: [PSUBS-MAILIST] Stopping Flaps etc. etc.

["Andrew Goldstein" <ag@desertstar.com>]

I dont think any of the highly maneuverable subs (deep flight, those dolphin ones, that spaceship looking one in Florida,etc.)
have additional breaking mechanisms.  It may be that a k boat with vectorable side thrusters has more breaking ability than most subs.

It is most advisable to follow the KISS principle when designing anything, but certainly adding well engineered features/redundant systems (i.e adding complexity) can be  a good idea.  Fuses, circuit breakers, GFI, spare air, drop weights, etc, all add complexity but can be considered a good idea / critical.   If you follow KISS ad absurdium everyone should be building bathyspheres. 

Another consideration against more complex stopping mechanisms (flaps, sea anchors, retro-rockets, grappling hook, giant boxing glove on a spring...) is the natural world.  Evolution has gone through many more design cycles than we have time for.  Most benthic  animals do not move at high speeds, esp. those with great mass (poor manatee).   Those sea creatures that are capable of great speeds tend to be large pelagics that move fast when away from the bottom.   I cant really think of any massive one that is cable of stopping on a dime.  Maybe a squid or something can (vectorable thrust).  An exception might be a pinniped (like a seal) that moves with pretty startling velocity near obstructions and is pretty massive.  But they seem to favor hydrobatics, swooping and diving and rolling, rather than  breaking ability.

So maybe maneuverability is a better design target than stopping ability.   Things like vectorable thrusters, or additional thrusters (vertical, laterial, etc.)  while adding complexity may be beneficial.

-a


ps.  I think all of the objections to the scuba bottle retro-rocket idea can be alleviated by using a propellant denser than air and maybe denser than seawater.  How about super compressed cheeze-whiz?  I think you could get quite a bit thrust from cheese at 3000 psi, plus by "en-cheesing" the water you may get some added buoyancy as well....JUST KIDDING!!!! 



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