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Any Navy / Submariners here??

Flying Clay DiskFlying Clay Disk Member Posts: 34,823 ✭✭✭✭
edited September 6 in General Discussion
Was watching a program about submarine rescue this morning (i.e. rescue of personnel).  The Navy currently uses a system which is comprised of two elements (the old DSRV's are now all decommissioned).
The first system is essentially a diving bell, called an SRM (submarine rescue module) lowered from a ship which mates onto the escape trunk of the submarine and allows for the rescue of 6 sailors at a time.  The maximum working depth for this device is about 850' feet.  Additionally, it requires the sub hull to be intact and the inside pressure to be the same as the surface pressure (i.e. sub not partially flooded and at different internal pressure than the surface).  Okay, so this seems to work.  Now let's look at the other part of this system.
If the sub is partially flooded, or below 850' feet, a different system is required, and this system is called the PRM (pressurized rescue module).  Similar to the SRM, this is also lowered from a ship, but it is larger and can hold roughly 16 sailors at a time.  The PRM has a maximum working depth of 2,000 feet (this is deeper than most subs crush-depth, but is widely publicized to submariners).  The operation is the same in that it is lowered down, mates with the sub and people enter it through the escape trunk.  Seems plausible at face value, but let's look a little closer.
So let's assume a downed sub is at 1,000 feet (just for easy numbers) and it is partially flooded.  Forgetting water temperature for a moment, let's just look at pressures and this brings about my question...
If the internal pressure aboard the partially flooded submarine is below 200' feet, Nitrogen Narcosis is a certainty among all the personnel.  If the internal pressure aboard the sub is below 400', oxygen is toxic unless all the nitrogen is removed and replaced with helium.
So what is the point of the PRM, unless being used on a perfectly intact submarine below 850'?  Is this just a "feel good" measure published to make sailors less afraid?  And why even bother publishing the 2000' number??  (not to mention the certain billions of tax payer dollars funding the development of such a system).
At the end of the day, when you consider the time it takes to locate a downed sub, the time it takes to airlift the system to the nearest country, the time it takes to put it on a ship, the time it takes to sail to the location...is there any practical hope that anyone could survive in a downed submarine?
And as a final note - Think about the downed Russian sub Kursk; a number of sailors actually did survive that  incident (wrote letters even), but only for a few days, not the weeks it took to get the proper equipment to the scene.

Comments

  • WarbirdsWarbirds Member Posts: 15,435 ✭✭✭

    Bean counters can kiss my * when it comes to trading American lives because the problem is hard to solve.

  • Flying Clay DiskFlying Clay Disk Member Posts: 34,823 ✭✭✭✭
    edited September 6
    I understand your point, but physics and physiology aren't just "hard" they're uncrossable barriers.  No amount of science is going to change the laws of physics.  It might help understand them better, but not change them.
    The reality is, below 200' feet of depth, normal breathing air is toxic to the human body.
    Unless you put everyone inside the submarine into a saturation environment for their entire cruise.  Decompression would then require 10+/- days at the end of every cruise.  Water pressure is a cruel master.
    ETA - Yes, there are subs which go far deeper than this with the occupants breathing normal surface pressures, but these vessels are very, very, small.  You couldn't build an SSBN to these specs and still have it be able to perform the functions they do.  The sheer volume of different gasses required would render the sub inoperable.
  • varianvarian Member Posts: 1,262 ✭✭✭
    i have a good friend who is now a health physicist.  he was in the navy on a sub, engine room guy for want of a better term.  his duty station was lower "lower level, aft".  bottom of the boat and all the way back, those guys never stand much of a chance of getting out in an emergency,  kind of like a tail gunner in a bomber.
  • Locust ForkLocust Fork Member, Moderator Posts: 29,875 ******
    I was a machinist on Sub Base, Pearl Harbor.   I was not stationed on a sub...the machine shop was right by the water in the harbor and we had several subs we worked with.    It was one of the best times of my life and I made a lot of friends.   The subs have this smell that you will never forget.   Its almost like a chemical/mold type smell and it gets deep into everything.        They leave the hatch open when they are in port, so we were making a large plate with big holes in it to keep people, tools and such from falling in.    My dad called one day and asked what I was up to.....and I got to tell him I was making screen doors for the subs.    It still gives me a little chuckle when I think about that and other things that happened.      
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  • FrogdogFrogdog Member Posts: 2,106 ✭✭✭
    edited September 6

    Whether there is any "practical hope" or not, you still try. If you start using practicality as a basis for leaving people behind, it is a slippery slope. There is little "practical hope" of finding downed airmen at sea in many circumstances, yet we search well beyond the limits of scientific survivability (and sometimes succeed). We medevac shot/blown-up soldiers who are all but dead from remote battlefields....and sometimes they make it.

    Could we leave our service-members behind to save money/resources and enhance battlefield effectiveness and efficiency? Sure. But, that's not how we do it (or ever should do it) in America. We try....even when it seems hopeless.

  • SW0320SW0320 Member Posts: 1,245 ✭✭✭

    My watch station in the Navy was in the forward engine room. We were below the water line and only had a ladder leading to a small scuttle opening. If we got torpedoed there was little or no chance of escape.

    While in the Reserves we did some of our damage control training at a sub base and trained in some of their simulators for flooding. Nothing gets you attention quicker then when they close the hatches and start flooding the compartment from various pipes to simulate a burst pipe and you have to stop the flooding. Did a couple of sessions where the flooding got to our shoulders.

  • AlpineAlpine Member Posts: 14,463 ✭✭✭
    I believe the oxygen partial pressure that becomes poisonous is a little deeper than 200 feet.
    However the problem with rescue of personal that have been at depth is one of decompression time. Where do you put people that may have to take a week to decompress from depth on a ship that is not equipped for it?
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  • Flying Clay DiskFlying Clay Disk Member Posts: 34,823 ✭✭✭✭
    edited September 6
    Just to be perfectly clear, I am in no way suggesting, in any way, shape or form, that efforts to rescue sailors stranded on a submarine is not a worthy pursuit.  Period.
    What I am suggesting is, that some of the solutions currently being fielded aren't really practical solutions in real world circumstances.  In fact, one might even say I am suggesting it is the Navy who are the ones not "trying" hard enough, because candidly, the pressure issue is not being properly addressed.  And, with the current system, they have to decompress rescued sailors inside the rescue vehicle and this means all the other survivors have to wait before they can be rescued.  Decompression from saturation (which almost any pressurized victims would be at by the time help arrived) takes roughly 24 hours for every 100 feet of depth.  SCUBA divers can decompress faster because they're not saturated. 
    ETA - the only reason I mentioned funding was simply to illustrate this research is not cheap, so find the absolute best solution available; don't just throw away money on solutions which aren't practical.
  • Horse Plains DrifterHorse Plains Drifter Member Posts: 35,540 ✭✭✭
    Used to be a member here whose handle was "Submariner". He hasn't posted in eons.
  • mark christianmark christian Forums Admins, Member, Moderator Posts: 22,846 ******
    That's s the member that I was thinking about. It must be ten years since he posted.
  • Don McManusDon McManus Member Posts: 21,827 ✭✭✭✭

    The rescue ship will have a decompression chamber to decompress the survivors.


    Crew is raised 16 at a time under pressure, quick trip to the chamber and days inside. It is practical in the sense that if alive in the sub, most will survive.

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  • mohawk600mohawk600 Member Posts: 2,673 ✭✭✭
    I took the ASVAB with the NAVY in 1987..............the recruiter tried to get me to go into the nuclear sub program based on my scores. I ended up going with the ARMY as a Medical Laboratory Technician. Being on a sub just didn't sound good back then.
  • mogley98mogley98 Member Posts: 17,565 ✭✭✭✭
    edited September 8
    I served on board the USS Ortolan ASR-22 for four years. (Engineman 2nd class)
    We practiced trying to simulate rescue and once we even transferred some crew but the damn thing was always breaking down. Also the angle of the hatch played in somehow. We had some (at the time) high tech listening devices we would drag around trying to locate the down sub (TACO?) and then we set a four point moor over her with four huge buoys. We called the DSRV the big pickle :)
    We were a Catamaran with twin hulls, decompression chambers on each hull and a large bridge crane that was used to drop the diving bells and DSRV, etc. I knew every inch of the engineering spaces. Quite a few Navy Seals and Sat divers on board. While in the Decompression chamber I observed them once seemed like they were drunk?
    After I got off they were involved in the work of the Titanic. That would have been cool.

    Why don't we go to school and work on the weekends and take the week off!
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