David Strike <[log in to unmask]> wrote:
>It's easy for me to be an armchair critic without being in possession of
>all of the facts, but it seems to me to be strange that the Russian's
>have, while developing their submarine technology, apparently done
>little to advance their rescue techniques. The capsule method was, for
>a while, adopted by several Navies following its successful deployment
>in the rescue of crew members of the USS Squalus, back in 1939.

Unfortunately rescues from crippled submarines are pretty rare so I guess
everyone has fallen in to that rut thinking it will never happen. You would
think with the advances in technology this essential area would have
received much more attention & refinement to be adaptable in all
conditions. Just imagine if this incident had not got the worldwide
attention it has. If things turn out for the worse the parents would
probably have been told that their sons had died for their country, chin
up, get on with your life, and the whole accident hushed up.

>The problems with this type of rescue, however, are that a diver first
>needs to go down and attach a cable to the hatch against which the bell
>will dock. The cable is kept in a 'straight-up-and-down' position by a
>surface vessel that needs to maintain a steady position above the
>submarine.  In rough weather it's: (1) 'difficult' to put down a diver
>- even at shallow depths, let alone deeper depths - with the necessary
>skills and tools to complete the job.  (2) There's a constant risk that
>the rise and fall of heavy seas will shift the vessel from its position
>and cause the cable to part!

I hear the Artic Circle weather is getting even worse so doubtful a diver
would be able to locate the wreck in the muddy waters as they say even with
searchlights there was only a few centimetres visibility.

>As I understand it, the DSRV concept pioneered by the Americans - while
>less susceptible to bad surface conditions - still relies on the hatch
>being within a few degrees of its normal position before a seal can be
>effected. (The Australian system developed for the new 'Collins' class
>submarine apparently employs a mating collar with joints the same as
>those developed by Phil Nuyten for the 'Nuytsuit' and can lock-on at
>even extreme angles.)
>
>Although this type of craft is capable of rescue from deeper waters, in
>dispensing with the need to send down a diver there's a possibility that
>debris from the 'crash' may surround the hatch and prevent the collar
>sealing.

Hopefully the 21 tonne LR5 rescue sub of the Brits employs a mating collar
with joints as described above. From what Ive seen in newspaper pics it
looks like all the damage on the Kursk is in the bow area so it looks like
they have 2 escape hatches that are accessible IF the rescue sub can dock.

>In addition - when outside assistance may not be forthcoming - there's
>the 'self-help' apparatus for effecting an escape.  The decision as to
>whether it's used is a difficult one to make.  (I wrote elsewhere, Do
>the survivors have access to an escape chamber?  Do they have access to
>escape apparatus? Are they trained in its use?  If they have access to
>an escape chamber, is it multi-use?  Without being able to communicate
>with the surface how will surface ships know where and when to position
>themselves? Without a direct sub-to-surface line what are the chances
>of an ascending diver being carried far away from the rescue scene by
>tides and currents? What are the surface weather conditions like? Do
>they lend themselves to search-and-recovery?  Are any of the surface
>ships equipped with recompression chambers?  How many?  Can they
>accommodate all of the escapees???, etc. etc.)  In bad weather it may
>even be a case of from the frying pan into the fire!

Yes, this is not a straight forward exit out, locate a buoy line that leads
to the surface, and then "blow & go" upwards in warm, gin clear & still
waters. If the rescue vessels above them are having problems imagine what a
human being would have to go through .. and that is with no air reserve.
Nature is truely against them - cold, muddy water for starters. Poor
visibility making it difficult to pick out the buoy line, if one could be
attached for them. Strong currents that would sweep them sideways &
probably miles away from help if they managed to surface alive. I doubt
they would have enough decompression chambers up top to accommodate
everyone. Its a horrible situation to be in. I thought it was bad enough
when that dive bell with OZ & Kiwi divers inside sank during a typhoon
years back. Everyone felt so helpless. The weather hampered the rescuers &
even though they were successful it was too late :-(

>The fact that the tapping from inside the sub has apparently ceased is no
>indicator of whether crew-members are alive or not.  It's hard work that
>burns up oxygen (and creates CO2), and once the crew realise that they've
>been located it's probably better that they remain as still as possible.

They have probably all been told to lie down on their bunks & try to relax
their breathing now they realise someone is trying to rescue them. I hope
so.

>Whatever the outcome, it will have far-reaching effects as far as submarine
>escape training and rescue is concerned.

It's terrible that it has to take a tragedy before the powers that be put
in place measures that should have been top priority in the first place.
Viv