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Igor:
It is a little expensive to buy the NAUI Trimix Instructor's
book ($300) or the Abyss software (I think $216), just to
initially see how an RGBM profile compares -- particularly
when you are just interested in getting the RGBM info. I
found a prior post by Bruce Wienke on techdiver that might
be helpful:
Date: Fri, 14 Jan 2000 01:54:35 -0700
From: "Bruce R. Wienke" <brw@la*.go*>
Subject: Fwd: GF Decoplan And RGBM Comparisons/Schedules/FYI
approve 000112.813
All,
On the subject of tech deco diving, deep stops, RGBM
tables, etc., maybe
the following is of some interest, along with some discourse
with George and
David Shimell (UK). Some Decoplan and RGBM schedules are
also given
for a 220/20 trimix dive. We are releasing some RGBM ranged
trimix tables
down to 240 fsw at DEMA. These are not "Haldane modified"
tables -- they are
model schedules without any deep or shallow stop fudging.
The dives are 220/20 on TMX16/50 with switch to 50/50
heliox or
nitrox at 70 fws, and pure oxygen at 20 fsw.
David Shimell sent a Decoplan schedule against RGBM
schedule, and I asked
how he pulled up his GFs (gradient factors). RGBM does a
full iteration
on mixtuire profile using phase limits across whole deco.
Decoplan uses
Haldane with GFs reducing permissible M-values at depth and
then subtracts
33% of 10 ft stop time from Haldane. GF ranges .20 down to
1 for stops
(as best as I can estimate).
George and WKPP folks have been using non-Haldane
approaches for some
time (the long shallow stops are one of their concerns) --
as most
of you in the tech community know well from your own
experiences.
BW
David,
Thanks for your rapid response and your candor.
Certainly trial
and error works painfully sometimes, and chamber
tests would be
alternatives (thus data to correlate GFs in
Decoplan). Someday,
hope to be able to use RGBM data to help you (time
is problem
now). We have been using RGBM here at LANL and
NAUI TEC Operations.
Thanks again.
BW
David Shimell wrote:
Bruce
This is going to be hard for me to answer as I'm a
pragmatist
rather than a
theorist, and there are others with greater interest
in the
mechanics and
greater time using Decoplan (or GAP which is a similar
implementation) than
myself.
? Are GFs and 33% off last stop trial and error (hope
not),
? or is there a bio-physical basis. In other words,
what guides
your
choices?
> > >>I guess trial and error, but using other people's
trials and
>errors!
> > >>
> > >>>From a personal perspective, I started to realise
that I was
>doing too much
> > >>deco and started to hear of other ways - the WKPP and
Richard
>Pyle's deep
> > >>stops. I started to experiment and add deep stops to
my
>profiles, including
> > >>them in the deco calculations initially and latterly,
cutting
>the tables but
> > >>not telling the software of the deep stops added to
the dive.
>At that time I
> > >>did not shave the last stop. Then I started to use a
Beta
>version of deco
> > >>plan.
> > >>
> > >>The first question is at what depth to start the deep
stops.
>On some of the
> > >>deeper stuff, e.g. 360' dives, I'd apply a mixture of
Pyle deep
>stops and
> > >>what I understand the WKPP have found successful. So,
on the
>360' dives, I
> > >>was doing stops around 230'. I then talked with the
Beta
>testers of Decoplan
> > >>and they were using the GFLo of 20% or 30%, I tried
this out
>and it delivered
> > >>the deep stops where I would expect them for a range
of depths
>I dived,
> > >>albeit staying slightly longer at them than I had
previously
>done. The logic
> > >>for doing all of this was partially imitation of what
had
>worked for more
> > >>extreme dives than I do, and secondly, the belief that
it is a
>"good thing" -
> > >>that over pressurising tissues is bad, especially if
by doing
>deep stops that
> > >>I can reduce the shallower stops, and save on the
overall deco
>time.
> > >>
> > >>The second question then comes to why 100% and shave
33% from
>the last stop?
> > >>The honest answer here is blind faith and some risk
taking. I
>have to say
> > >>that I have not done enough dives personally to say
this works
>for me, but I
> > >>intend to do them. The Beta testers of Decoplan were
using
>GFHi 100% and
> > >>shaving with no problems for a year of diving. On a
4-day dive
>trip, I
> > >>watched them get out of the water much quicker than
myself on
>what I had
> > >>previously considered to be "quick" tables. So, I
though I
>have to try it
> > >>and did the next dives on Decoplan. No problems, so
far, on a
>small number
> > >>of dives.
? How do you "change" for different mixes, depths,
exposure times,
etc. in
? some systematic fashion?
> > >>There is nothing I would call a systematic
approach.
> > >>
> > >>Some people use GFLo of 30% for Nitrox and 20% for
Trimix.
>Personally, I
> > >>would not bother changing it and stick with 20%. The
question
>as to whether
> > >>I would do my 360' dive using a GFHi of 100% and
shaving is
>relevant. I
> > >>would not, since other dive partners have had minor
bends, so
>would want to
> > >>do a series of dives to monitor myself (unlikely now,
as these
>dives were in
> > >>South Africa).
> > >>
> > >>Another factor I would consider is the water
temperature.
>Finally, I've been
> > >>doing an ascent from 20' taking 2-3 minutes. What
people are
>suggesting is
> > >>that this should be more like 5-6 minutes, which
pretty much
>puts back in the
> > >>time removed by shaving.
? How do you generate GFs? We have done this
? for some meter implementations of the "modified"
RGBM across Haldane
? software using maximum likelihood to fit RGBM
f-factors to data
(similar
? to GFs). So what do you do to generate your GFs?
> > >>Simon Tranmer, the author of Decoplan, would be in a
better
>position to
> > >>respond on this. The limit of my knowledge is that
the GFLo
>determines the
> > >>first stop, after that there is a notional "straight
line is
>drawn" to the
> > >>equivalent last stop i.e. the GFHi-adjusted M-Value,
one line
>for each
> > >>compartment. This is the implementation of Erik
Baker's stuff.
> > >>
> > >>David Shimell
> > >>Email: shimell@se*.co*
<mailto:shimell@se*.co*>
> > >>Project Manager, IBM NUMA-Q, Sequent Computer Systems
Limited,
> > >>Weybridge Business Park, Addlestone Road, Weybridge,
Surrey,
>KT15 2UF, UK
> > >>registered in England and Wales under company number:
1999363,
>registered
> > >>office as above
> > >>
> > >>-----Original Message-----
> > >>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>Sent: Wednesday, January 12, 2000 4:10 PM
> > >>To: Shimell, David (shimell)
> > >>Cc: Nauitec@ao*.co*; chris@ab*.co*
> > >>Subject: RE: Re: Fwd: WKPP 220/20 RGBM TMX Schedule
with He
>or Ni
> > >>Switches
> > >>
> > >>OK -- rephrase. Are GFs and 33% off last stop trial
and error
>(hope not),
> > >>or is there a bio-physical basis. In other words,
what guides
>your choices?
> > >>How do you "change" for different mixes, depths,
exposure
>times, etc. in
> > >>some systematic fashion? How do you generate GFs? We
have
>done this
> > >>for some meter implementations of the "modified" RGBM
across
>Haldane
> > >>software using maximum likelihood to fit RGBM
f-factors to data
>(similar
> > >>to GFs). So what do you do to generate your GFs?
> > >>
> > >>Thanks.
> > >>
> > >>BW
> > >>
> > >>
> > >>>Bruce
> > >>>
> > >>>I'm not sure if I understand your question. If you
are asking
>where did the
> > >>>33% factor come from, then the answer is that others
have been
>doing it on
> > >>>this side of the pond without problems.
> > >>>
> > >>>David Shimell
> > >>>Email: shimell@se*.co*
<mailto:shimell@se*.co*>
> > >>>Project Manager, IBM NUMA-Q, Sequent Computer Systems
Limited,
> > >>>Weybridge Business Park, Addlestone Road, Weybridge,
Surrey,
>KT15 2UF, UK
> > >>>registered in England and Wales under company number:
1999363,
>registered
> > >>>office as above
> > >>>
> > >>>-----Original Message-----
> > >>>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>>Sent: Wednesday, January 12, 2000 3:16 PM
> > >>>To: Shimell, David (shimell)
> > >>>Subject: RE: Re: Fwd: WKPP 220/20 RGBM TMX Schedule
with He
>or Ni
> > >>>Switches
> > >>>
> > >>>David -- thanks. So then question is why shave 33%
the way
>you did?
> > >>>
> > >>>BW
> > >>>
> > >>>
> > >>>
> > >>>>Bruce
> > >>>>
> > >>>>>Have question on Decoplan -- will reply your
earlier email
>if I can dig it
> > >>>>up.
> > >>>>>Otherwise question is -- Decoplan schedule for
220/20 on tmx
>(etc)
> > >>>>>looks like Haldane (multiply the shallow stops by
1.33 since
> > >>>>>you you divided the Decoplan shallow stops by 1.33
to "track"
> > >>>>>our RGBM calcs) with deep stops inserted. How did
you
>insert deep stops
> > >>>>> (by reducing Haldane gradient at deeper depths and
not shallow
> > >>>ones).
> > >>>>>Then, if so, what is the "basis" for your "gradient
reduction"?
> > >>>>>How do you justify it within Haldane (data, model,
fiddling)?
> > >>>>
> > >>>>Correct on the Haldanean bit, however, the shallow
stops are
>straight out
> > >>of
> > >>>>Decoplan.
> > >>>>
> > >>>>Decoplan implements a straight ZHL-16B (or
optionally C) and
>implements
> > >>>>Baker's gradient factors. So, the table I sent out
in
>comparison to your
> > >>>>RGBM used GFLo 20% to generate the deep stops, and
GFHi 100%
>and had *no*
> > >>>>adjustment. This was what I sent out (straight
Decoplan):
> > >>>>
> > >>>>>Stop RGBM Decoplan
> > >>>>>140' 42m 1
> > >>>>>130' 39m 1 1
> > >>>>>120' 36m 1 1
> > >>>>>110' 33m 1 1
> > >>>>>10' 30m 1 1
> > >>>>>90' 27m 2 2
> > >>>>>80' 24m 3 2
> > >>>>>70' 21m 1 1
> > >>>>>60' 18m 2 2
> > >>>>>50' 15m 2 3
> > >>>>>40' 12m 3 3
> > >>>>>30' 9m 4 6
> > >>>>>20' 6m 5 7
> > >>>>>10' 3m 9 12
> > >>>>>Total 36 42
> > >>>>
> > >>>>What we actually dive over here are the Decoplan
tables but
>shave 33% from
> > >>>>the last stop (10') and do it at 20' together with
the
>existing 20' stop.
> > >>>In
> > >>>>this case, we would take the last stop, 12, and
reduce this
>by 33% to 8,
> > >>>>doing 7+8=15 at 20'. The whole profile then
compares
>favourably with your
> > >>>>RGBM, last stops at 20' of 9+5=14 vs. an adjusted
7+8=15.
>Total deco 36
> > >>vs.
> > >>>>an adjusted 38. BTW, we execute a slow ascent from
20' to
>the surface and
> > >>>>are introducing some other small tweaks.
> > >>>>
> > >>>>David Shimell
> > >>>>Email: shimell@se*.co*
<mailto:shimell@se*.co*>
> > >>>>Project Manager, IBM NUMA-Q, Sequent Computer
Systems Limited,
> > >>>>Weybridge Business Park, Addlestone Road, Weybridge,
Surrey,
>KT15 2UF, UK
> > >>>>registered in England and Wales under company
number:
>1999363, registered
> > >>>>office as above
> > >>>>
> > >>>>-----Original Message-----
> > >>>>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>>>Sent: Tuesday, January 11, 2000 6:45 PM
> > >>>>To: shimell@se*.co*
> > >>>>Cc: Nauitec@ao*.co*
> > >>>>Subject: Fwd: Re: Fwd: WKPP 220/20 RGBM TMX Schedule
with He
>or Ni
> > >>>>Switches
> > >>>>
> > >>>>Have question on Decoplan -- will reply your earlier
email if
>I can dig it
> > >>>>up.
> > >>>>Otherwise question is -- Decoplan schedule for
220/20 on tmx
>(etc)
> > >>>>looks like Haldane (when you multiply the shallow
stops by 3
>since
> > >>>>you suggested that you divided the Decoplan shallow
stops by
>3 to "track"
> > >>>>our RGBM calcs) with deep stops inserted. How did
you insert
>deep stops
> > >>>>(assume by reducing Haldane gradient at deeper
depths and not
>shallow
> > >>ones).
> > >>>>Then, if so, what is the "basis" for your "gradient
>reduction" and do
> > >>>>you justify it within Haldane (data, model,
fiddling)?
> > >>>>
> > >>>>Thanks
> > >>>>
> > >>>>BW
> > >>>>
> > >>>>
> > >>>>>From: kirvine@sa*.ne*
> > >>>>>Date: Mon, 10 Jan 2000 17:18:49 -0500
> > >>>>>Reply-To: kirvine@sa*.ne*
> > >>>>>MIME-Version: 1.0
> > >>>>>To: "Bruce R. Wienke" <brw@la*.go*>
> > >>>>>CC: nauitec@ao*.co*, tech@la*.go*,
techdiver@aquanaut.com
> > >>>>>Subject: Re: Fwd: WKPP 220/20 RGBM TMX Schedule
with He or
>Ni Switches
> > >>>>>
> > >>>>>The phase is everythiung. Let's do the tests
wherever you
>guys want .
> > >>>>>Let's try a 300 for 60 and see how fast we can get
me out .
>Then maybe a
> > >>>>>200 minute time and so forth.
> > >>>>>
> > >>>>>I remember the fist time I read your stuff - that
was the
>end of long
> > >>>>>decos for me ( at least the end of worrying about
not doing
>them ).
Bruce R. Wienke wrote:
George,
Thanks for your email. Let me know if you need any
"quick" calcs/schedules for pet projects. One
thing that
(always) bothers me these days is the insertion of
deep stops
into Haldane models, without proper accounting of
the bio-mechanisms.
Reducing gradient factors (GF) in Haldane models
can buy some safety,
but approach still suffers from Haldane
aberrations -- especially at
the shallow stops where "you can't reduce the GF
correctly".
Phase models iterate over the full profile for
consistency with gas
dynamics. Enough said -- you have heard it before.
Stuff at LANL is "closed door" -- we do some
chamber stuff as
you might expect (know) with NavWar/Spec/War/Ops.
As Tim suggested,
how about some commercial facility like OC
Stay in touch -- bueno.
BW
George wrote:
> > >>>>>> >Tim, I know. Bruce's stuff is excellent, and
compares
>closely to what
> > >>>>>> >Jarrod and I actually do for our own account but
can not
>recommend to
> > >>>>>> >others who do not have the same extreme
physiology that
>the two of us
> > >>>>>> >have. The only place we differ from Dr. Weinke
is in
>stops that
> > >>approach
> > >>>>>> >a gas switch - I blow them off almost completely
( like
>the 40 foot
> > >>stop
> > >>>>>> >on a very long dive), while Bruce extends them
quite a
>bit. The only
> > >>>>>> >differnce is that I accept the offgassing in
bubble form
>at that point
> > >>>>>> >in the deco as a vlaid method, while Bruce is
avoiding
>that and Bruce's
> > >>>>>> >way is a lot smarter unless you are bullet proof
in the
>precondition
> > >>>>>> >department, which I am as are most of the WKPP
gas divers
>- that is by
> > >>>>>> >process of eliminiation - you can't do what we
do and
>have any
> > >>preco's.
> > >>>>>> >
> > >>>>>> > Yesterday we had an impromptu deco contest . I
thought
>Werner had
> > >>>>>> >gotten ahead of me ( we were totally blacked out
from 120
>feet to the
> > >>>>>> >surface) and I abreviated about 40 minutes to
beat him ,
>but it was not
> > >>>>>> >Werner, it was Nanci LeVake who has about 80
minutes less
>bottom time
> > >>on
> > >>>>>> >her dive than I had on mine, but it make no
difference.
> > >>>>>> >
> > >>>>>> > If you have no preconditions, Weinke's stuff
is solid
>gold and is far
> > >>>>>> >more correct than any of the previous models in
my
>opinion, and can be
> > >>>>>> >fudged in the low ppo2 range for the good
offgassers.
> > >>>>>> >
> > >>>>>> > I like what you guys are doing out there with
this -
>how about let me
> > >>>>>> >come out and let's see what the human body can
take in a
>chamber test.
> > >>>>>> >
> > >>>>>> >
> > >>>>>> >Nauitec@ao*.co* wrote:
> > >>>>>> >>
> > >>>>>> >> George,
> > >>>>>> >> This was supposed to go to you and JJ for
comparison.
>50-50 Heliox
> > >>>>>>and 50-50
> > >>>>>> >> Nitrox begin at 70 fsw. This a true phase
model with
>compartment
> > >>>>>> >>integration.
> > >>>>>> >> Compartments are 1 through 720. However with
your
>applications (depth
> > >>>>and
> > >>>>>> >> duration), phase within the algorythm is
predominant.
> > >>>>>> >>
> > >>>>>> >> Tim O'Leary
> > >>>>>> >>
> > >>>>>> >>
>-----------------------------------------------------------
----
> > >>>>>> >>
> > >>>>>> >> Subject: WKPP 220/20 RGBM TMX Schedule with He
or Ni
>Switches
> > >>>>>> >> Date: Fri, 7 Jan 2000 17:07:17 -0700
> > >>>>>> >> From: "Bruce R. Wienke" <brw@la*.go*>
> > >>>>>> >> To: techdiver@aquanaut.com
> > >>>>>> >> Gentlemen;
> > >>>>>> >> >> >>> >
> > >>>>>> >> >> >>> > Tim O'Leary passed your "deco
help"
>message and
> > >>>>>>specifically a
> > >>>>>> >> >> >>> > request for a RGBM trimix schedule
>calculation for
> > >>tmx16/50
> > >>>>at
> > >>>>>> >> >> >>> > 220 fsw for 20 minutes, with a
switch to
>either 50/50
> > >>>>>>nitrox or
> > >>>>>> >> >> >>> > heliox at 70 fws, and pure oxygen
at 20 fsw.
>For
> > >>>>simplicity,
> > >>>>>> >> >> >>> > ascent and descent rates are 30
fsw/min.
>Notice deeper
> > >>>>stops
> > >>>>>> >> >> >>> > within phase RGBM, and total times
less than
>haldane of
> > >>>>>> >>comparable
> > >>>>>> >> >> >>> > conservatism -- moderate
conservatism in
>this case.
> > >>>>>> >> >> >>>
> > >>>>>> >> >> >>> We are in the process of
publishing some
>trimx and
> > >>>>helitrox
> > >>>>>> >> >>Tables
> > >>>>>> >> >> >>> for ranged mixtures. We have been
diving
>RGBM schedules
> > >>>for
> > >>>>>> >>awhile,
> > >>>>>> >> >> >>> here at LANL and NAUI Tec. We can
do other
>schedules
> > >>>>(within
> > >>>>>> >> reason, of course).
> Bruce Wienke
dive number = 1 altitude = 0.00 ft
RGBM Trimix Version
B.R. Wienke/Los Alamos National Laboratory
--dive profile--
surface breathed nitrogen = 0.79
level 1 depth = 220.00 fsw time = 3.67 min
level 2 depth = 220.00 fsw time = 220.00 min
trimix = 0.50 helium 0.34 nitrogen switches = 2
switch 1 depth = 70.00 fsw helium = 0.00 nitrogen
= 0.50
switch 2 depth = 20.00 fsw helium = 0.00 nitrogen
= 0.00
- excursion to depth = 220.00 fsw
- time at inital depth = 20.00 min
--------------------------------------------
- stop - depth - wait -
- 1 - 160.00 - 0.00 -
- 2 - 150.00 - 0.00 -
- 3 - 140.00 - 1.00 -
- 4 - 130.00 - 1.00 -
- 5 - 120.00 - 1.00 -
- 6 - 110.00 - 1.00 -
- 7 - 100.00 - 1.00 -
- 8 - 90.00 - 2.00 -
- 9 - 80.00 - 3.00 -
- 10 - 70.00 - 1.00 -
- 11 - 60.00 - 2.00 -
- 12 - 50.00 - 2.00 -
- 13 - 40.00 - 3.00 -
- 14 - 30.00 - 4.00 -
- 15 - 20.00 - 5.00 -
- 16 - 10.00 - 9.00 -
---------------------------------------------
- total time surface = 39.67 min
dive number = 1 altitude = 0.00 ft
RGBM Trimix Version
B.R. Wienke/Los Alamos National Laboratory
--dive profile--
surface breathed nitrogen = 0.79
level 1 depth = 220.00 fsw time = 3.67 min
level 2 depth = 220.00 fsw time 220.00 min
trimix = 0.50 helium 0.34 nitrogen switches = 2
switch 1 depth = 70.00 fsw helium = 0.50 nitrogen =
0,00
switch 2 depth = 20.00 fsw helium = 0.00 nitrogen =
0.00
- excursion to depth = 220.00 fsw
- time at inital depth = 20.00 min
--------------------------------------------
- stop - depth - wait -
- 1 - 160.00 - 0.00 -
- 2 - 150.00 - 0.00 -
- 3 - 140.00 - 1.00 -
- 4 - 130.0 - 1.00
- 5 - 120.00 - 1.00 -
- 6 - 110.00 - 1.00 -
- 7 - 100.00 - 2.00 -
- 8 - 90.00 - 2.00 -
- 9 - 80.00 - 3.00 -
- 10 - 70.00 - 2.00 -
- 11 - 60.00 - 3.00 -
- 12 - 50.00 - 4.00 -
- 13 - 40.00 - 5.00 -
- 14 - 30.00 - 6.00 - -
- 15 - 20.00 - 7.00 - -
- 16 - 10.00 - 8.00 -
--------------------------------------------
- total time surface = 49.67 min
total dives processed = 2
--
> > >>>>>> >> Send mail for the `techdiver' mailing list to
> > >>>`techdiver@aquanaut.com'.
> > >>>>>> >> Send subscribe/unsubscribe requests to
> > >>>>`techdiver-request@aquanaut.com'.
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<DIV><FONT face=3DVerdana size=3D2><SPAN=20
class=3D690254520-22022002>Igor:</SPAN></FONT></DIV>
<DIV><FONT face=3DVerdana size=3D2><SPAN=20
class=3D690254520-22022002></SPAN></FONT> </DIV>
<DIV><FONT face=3DVerdana size=3D2><SPAN class=3D690254520-22022002>It
=
is a little=20
expensive to buy the NAUI Trimix Instructor's book ($300) or the Abyss =
software=20
(I think $216), just to initially see how an RGBM profile compares --=20
particularly when you are just interested in getting the RGBM =
info. I=20
found a prior post by Bruce Wienke on techdiver that might be=20
helpful:</SPAN></FONT></DIV>
<DIV><FONT face=3DVerdana size=3D2><SPAN=20
class=3D690254520-22022002></SPAN></FONT> </DIV>
<DIV><FONT face=3DVerdana><FONT face=3D"Times New Roman"><FONT=20
size=3D2><STRONG>Date:</STRONG> Fri, 14 Jan 2000 01:54:35 =
-0700<BR><B>From:</B>=20
"Bruce R. Wienke" </FONT></FONT><A
href=3D"mailto:brw@la*.go*"><FONT=20
face=3D"Times New Roman" =
size=3D2><brw@la*.go*>=08</FONT></A><BR><FONT=20
face=3D"Times New Roman"><FONT size=3D2><B>Subject:</B> Fwd: GF
Decoplan =
And RGBM=20
Comparisons/Schedules/FYI<BR></FONT></FONT><PRE><FONT size=3D2>
approve =
000112.813
All,
On the subject of tech deco diving, deep stops, RGBM tables, etc., =
maybe
the following is of some interest, along with some discourse with George =
and
David Shimell (UK). Some Decoplan and RGBM schedules are also given
for a 220/20 trimix dive. We are releasing some RGBM ranged trimix =
tables
down to 240 fsw at DEMA. These are not "Haldane modified" tables -- =
they are
model schedules without any deep or shallow stop fudging.
The dives are 220/20 on TMX16/50 with switch to 50/50 heliox or
nitrox at 70 fws, and pure oxygen at 20 fsw.
David Shimell sent a Decoplan schedule against RGBM schedule, and I =
asked
how he pulled up his GFs (gradient factors). RGBM does a full iteration
on mixtuire profile using phase limits across whole deco. Decoplan =
uses
Haldane with GFs reducing permissible M-values at depth and then =
subtracts
33% of 10 ft stop time from Haldane. GF ranges .20 down to 1 for stops
(as best as I can estimate).
George and WKPP folks have been using non-Haldane approaches for some
time (the long shallow stops are one of their concerns) -- as most
of you in the tech community know well from your own experiences.
BW
David,
Thanks for your rapid response and your candor. Certainly =
trial
and error works painfully sometimes, and chamber tests would =
be
alternatives (thus data to correlate GFs in Decoplan). =
Someday,
hope to be able to use RGBM data to help you (time is problem
now). We have been using RGBM here at LANL and NAUI TEC =
Operations.
Thanks again.
BW
David Shimell wrote:
Bruce
This is going to be hard for me to answer as I'm a pragmatist
rather than a
theorist, and there are others with greater interest in the
mechanics and
greater time using Decoplan (or GAP which is a similar
implementation) than
myself.
? Are GFs and 33% off last stop trial and error (hope not),
? or is there a bio-physical basis. In other words, what guides
your
choices?
> > >>I guess trial and error, but using other people's =
trials and
>errors!
> > >>
> > >>>From a personal perspective, I started to realise =
that I was
>doing too much
> > >>deco and started to hear of other ways - the WKPP and =
Richard
>Pyle's deep
> > >>stops. I started to experiment and add deep stops to =
my
>profiles, including
> > >>them in the deco calculations initially and latterly, =
cutting
>the tables but
> > >>not telling the software of the deep stops added to =
the dive.
>At that time I
> > >>did not shave the last stop. Then I started to use a =
Beta
>version of deco
> > >>plan.
> > >>
> > >>The first question is at what depth to start the deep =
stops.
>On some of the
> > >>deeper stuff, e.g. 360' dives, I'd apply a mixture of =
Pyle deep
>stops and
> > >>what I understand the WKPP have found successful. So, =
on the
>360' dives, I
> > >>was doing stops around 230'. I then talked with the =
Beta
>testers of Decoplan
> > >>and they were using the GFLo of 20% or 30%, I tried =
this out
>and it delivered
> > >>the deep stops where I would expect them for a range =
of depths
>I dived,
> > >>albeit staying slightly longer at them than I had =
previously
>done. The logic
> > >>for doing all of this was partially imitation of what =
had
>worked for more
> > >>extreme dives than I do, and secondly, the belief that =
it is a
>"good thing" -
> > >>that over pressurising tissues is bad, especially if =
by doing
>deep stops that
> > >>I can reduce the shallower stops, and save on the =
overall deco
>time.
> > >>
> > >>The second question then comes to why 100% and shave =
33% from
>the last stop?
> > >>The honest answer here is blind faith and some risk =
taking. I
>have to say
> > >>that I have not done enough dives personally to say =
this works
>for me, but I
> > >>intend to do them. The Beta testers of Decoplan were =
using
>GFHi 100% and
> > >>shaving with no problems for a year of diving. On a =
4-day dive
>trip, I
> > >>watched them get out of the water much quicker than =
myself on
>what I had
> > >>previously considered to be "quick" tables. So, I =
though I
>have to try it
> > >>and did the next dives on Decoplan. No problems, so =
far, on a
>small number
> > >>of dives.
? How do you "change" for different mixes, depths, exposure times,
etc. in
? some systematic fashion?
> > >>There is nothing I would call a systematic =
approach.
> > >>
> > >>Some people use GFLo of 30% for Nitrox and 20% for =
Trimix.
>Personally, I
> > >>would not bother changing it and stick with 20%. The =
question
>as to whether
> > >>I would do my 360' dive using a GFHi of 100% and =
shaving is
>relevant. I
> > >>would not, since other dive partners have had minor =
bends, so
>would want to
> > >>do a series of dives to monitor myself (unlikely now, =
as these
>dives were in
> > >>South Africa).
> > >>
> > >>Another factor I would consider is the water =
temperature.
>Finally, I've been
> > >>doing an ascent from 20' taking 2-3 minutes. What =
people are
>suggesting is
> > >>that this should be more like 5-6 minutes, which =
pretty much
>puts back in the
> > >>time removed by shaving.
? How do you generate GFs? We have done this
? for some meter implementations of the "modified" RGBM across =
Haldane
? software using maximum likelihood to fit RGBM f-factors to data
(similar
? to GFs). So what do you do to generate your GFs?
> > >>Simon Tranmer, the author of Decoplan, would be in a =
better
>position to
> > >>respond on this. The limit of my knowledge is that =
the GFLo
>determines the
> > >>first stop, after that there is a notional "straight =
line is
>drawn" to the
> > >>equivalent last stop i.e. the GFHi-adjusted M-Value, =
one line
>for each
> > >>compartment. This is the implementation of Erik =
Baker's stuff.
> > >>
> > >>David Shimell
> > >>Email: shimell@se*.co* =
<mailto:shimell@se*.co*>
> > >>Project Manager, IBM NUMA-Q, Sequent Computer Systems =
Limited,
> > >>Weybridge Business Park, Addlestone Road, Weybridge, =
Surrey,
>KT15 2UF, UK
> > >>registered in England and Wales under company number: =
1999363,
>registered
> > >>office as above
> > >>
> > >>-----Original Message-----
> > >>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>Sent: Wednesday, January 12, 2000 4:10 PM
> > >>To: Shimell, David (shimell)
> > >>Cc: Nauitec@ao*.co*; chris@ab*.co*
> > >>Subject: RE: Re: Fwd: WKPP 220/20 RGBM TMX Schedule =
with He
>or Ni
> > >>Switches
> > >>
> > >>OK -- rephrase. Are GFs and 33% off last stop trial =
and error
>(hope not),
> > >>or is there a bio-physical basis. In other words, =
what guides
>your choices?
> > >>How do you "change" for different mixes, depths, =
exposure
>times, etc. in
> > >>some systematic fashion? How do you generate GFs? We =
have
>done this
> > >>for some meter implementations of the "modified" RGBM =
across
>Haldane
> > >>software using maximum likelihood to fit RGBM =
f-factors to data
>(similar
> > >>to GFs). So what do you do to generate your GFs?
> > >>
> > >>Thanks.
> > >>
> > >>BW
> > >>
> > >>
> > >>>Bruce
> > >>>
> > >>>I'm not sure if I understand your question. If =
you are asking
>where did the
> > >>>33% factor come from, then the answer is that =
others have been
>doing it on
> > >>>this side of the pond without problems.
> > >>>
> > >>>David Shimell
> > >>>Email: shimell@se*.co* =
<mailto:shimell@se*.co*>
> > >>>Project Manager, IBM NUMA-Q, Sequent Computer =
Systems Limited,
> > >>>Weybridge Business Park, Addlestone Road, =
Weybridge, Surrey,
>KT15 2UF, UK
> > >>>registered in England and Wales under company =
number: 1999363,
>registered
> > >>>office as above
> > >>>
> > >>>-----Original Message-----
> > >>>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>>Sent: Wednesday, January 12, 2000 3:16 PM
> > >>>To: Shimell, David (shimell)
> > >>>Subject: RE: Re: Fwd: WKPP 220/20 RGBM TMX =
Schedule with He
>or Ni
> > >>>Switches
> > >>>
> > >>>David -- thanks. So then question is why shave =
33% the way
>you did?
> > >>>
> > >>>BW
> > >>>
> > >>>
> > >>>
> > >>>>Bruce
> > >>>>
> > >>>>>Have question on Decoplan -- will reply =
your earlier email
>if I can dig it
> > >>>>up.
> > >>>>>Otherwise question is -- Decoplan schedule =
for 220/20 on tmx
>(etc)
> > >>>>>looks like Haldane (multiply the shallow =
stops by 1.33 since
> > >>>>>you you divided the Decoplan shallow stops =
by 1.33 to "track"
> > >>>>>our RGBM calcs) with deep stops inserted. =
How did you
>insert deep stops
> > >>>>> (by reducing Haldane gradient at deeper =
depths and not shallow
> > >>>ones).
> > >>>>>Then, if so, what is the "basis" for your =
"gradient reduction"?
> > >>>>>How do you justify it within Haldane =
(data, model, fiddling)?
> > >>>>
> > >>>>Correct on the Haldanean bit, however, the =
shallow stops are
>straight out
> > >>of
> > >>>>Decoplan.
> > >>>>
> > >>>>Decoplan implements a straight ZHL-16B (or =
optionally C) and
>implements
> > >>>>Baker's gradient factors. So, the table I =
sent out in
>comparison to your
> > >>>>RGBM used GFLo 20% to generate the deep stops, =
and GFHi 100%
>and had *no*
> > >>>>adjustment. This was what I sent out =
(straight Decoplan):
> > >>>>
> > >>>>>Stop RGBM Decoplan
> > >>>>>140' 42m 1
> > >>>>>130' 39m 1 1
> > >>>>>120' 36m 1 1
> > >>>>>110' 33m 1 1
> > >>>>>10' 30m 1 1
> > >>>>>90' 27m 2 2
> > >>>>>80' 24m 3 2
> > >>>>>70' 21m 1 1
> > >>>>>60' 18m 2 2
> > >>>>>50' 15m 2 3
> > >>>>>40' 12m 3 3
> > >>>>>30' 9m 4 6
> > >>>>>20' 6m 5 7
> > >>>>>10' 3m 9 12
> > >>>>>Total 36 42
> > >>>>
> > >>>>What we actually dive over here are the =
Decoplan tables but
>shave 33% from
> > >>>>the last stop (10') and do it at 20' together =
with the
>existing 20' stop.
> > >>>In
> > >>>>this case, we would take the last stop, 12, =
and reduce this
>by 33% to 8,
> > >>>>doing 7+8=3D15 at 20'. The whole profile then =
compares
>favourably with your
> > >>>>RGBM, last stops at 20' of 9+5=3D14 vs. an =
adjusted 7+8=3D15.
>Total deco 36
> > >>vs.
> > >>>>an adjusted 38. BTW, we execute a slow ascent =
from 20' to
>the surface and
> > >>>>are introducing some other small tweaks.
> > >>>>
> > >>>>David Shimell
> > >>>>Email: shimell@se*.co* =
<mailto:shimell@se*.co*>
> > >>>>Project Manager, IBM NUMA-Q, Sequent Computer =
Systems Limited,
> > >>>>Weybridge Business Park, Addlestone Road, =
Weybridge, Surrey,
>KT15 2UF, UK
> > >>>>registered in England and Wales under company =
number:
>1999363, registered
> > >>>>office as above
> > >>>>
> > >>>>-----Original Message-----
> > >>>>From: Bruce R. Wienke [SMTP:brw@la*.go*]
> > >>>>Sent: Tuesday, January 11, 2000 6:45 PM
> > >>>>To: shimell@se*.co*
> > >>>>Cc: Nauitec@ao*.co*
> > >>>>Subject: Fwd: Re: Fwd: WKPP 220/20 RGBM TMX =
Schedule with He
>or Ni
> > >>>>Switches
> > >>>>
> > >>>>Have question on Decoplan -- will reply your =
earlier email if
>I can dig it
> > >>>>up.
> > >>>>Otherwise question is -- Decoplan schedule for =
220/20 on tmx
>(etc)
> > >>>>looks like Haldane (when you multiply the =
shallow stops by 3
>since
> > >>>>you suggested that you divided the Decoplan =
shallow stops by
>3 to "track"
> > >>>>our RGBM calcs) with deep stops inserted. How =
did you insert
>deep stops
> > >>>>(assume by reducing Haldane gradient at deeper =
depths and not
>shallow
> > >>ones).
> > >>>>Then, if so, what is the "basis" for your =
"gradient
>reduction" and do
> > >>>>you justify it within Haldane (data, model, =
fiddling)?
> > >>>>
> > >>>>Thanks
> > >>>>
> > >>>>BW
> > >>>>
> > >>>>
> > >>>>>From: kirvine@sa*.ne*
> > >>>>>Date: Mon, 10 Jan 2000 17:18:49 -0500
> > >>>>>Reply-To: kirvine@sa*.ne*
> > >>>>>MIME-Version: 1.0
> > >>>>>To: "Bruce R. Wienke" <brw@la*.go*>
> > >>>>>CC: nauitec@ao*.co*, tech@la*.go*, =
techdiver@aquanaut.com
> > >>>>>Subject: Re: Fwd: WKPP 220/20 RGBM TMX =
Schedule with He or
>Ni Switches
> > >>>>>
> > >>>>>The phase is everythiung. Let's do the =
tests wherever you
>guys want .
> > >>>>>Let's try a 300 for 60 and see how fast we =
can get me out .
>Then maybe a
> > >>>>>200 minute time and so forth.
> > >>>>>
> > >>>>>I remember the fist time I read your stuff =
- that was the
>end of long
> > >>>>>decos for me ( at least the end of =
worrying about not doing
>them ).
Bruce R. Wienke wrote:
George,
Thanks for your email. Let me know if you need any
"quick" calcs/schedules for pet projects. One thing that
(always) bothers me these days is the insertion of deep stops
into Haldane models, without proper accounting of the =
bio-mechanisms.
Reducing gradient factors (GF) in Haldane models can buy some =
safety,
but approach still suffers from Haldane aberrations -- =
especially at
the shallow stops where "you can't reduce the GF correctly".
Phase models iterate over the full profile for consistency with =
gas
dynamics. Enough said -- you have heard it before.
Stuff at LANL is "closed door" -- we do some chamber stuff as
you might expect (know) with NavWar/Spec/War/Ops. As Tim =
suggested,
how about some commercial facility like OC
Stay in touch -- bueno.
BW
George wrote:
> > >>>>>> >Tim, I know. Bruce's stuff is =
excellent, and compares
>closely to what
> > >>>>>> >Jarrod and I actually do for our =
own account but can not
>recommend to
> > >>>>>> >others who do not have the same =
extreme physiology that
>the two of us
> > >>>>>> >have. The only place we differ =
from Dr. Weinke is in
>stops that
> > >>approach
> > >>>>>> >a gas switch - I blow them off =
almost completely ( like
>the 40 foot
> > >>stop
> > >>>>>> >on a very long dive), while Bruce =
extends them quite a
>bit. The only
> > >>>>>> >differnce is that I accept the =
offgassing in bubble form
>at that point
> > >>>>>> >in the deco as a vlaid method, =
while Bruce is avoiding
>that and Bruce's
> > >>>>>> >way is a lot smarter unless you =
are bullet proof in the
>precondition
> > >>>>>> >department, which I am as are =
most of the WKPP gas divers
>- that is by
> > >>>>>> >process of eliminiation - you =
can't do what we do and
>have any
> > >>preco's.
> > >>>>>> >
> > >>>>>> > Yesterday we had an impromptu =
deco contest . I thought
>Werner had
> > >>>>>> >gotten ahead of me ( we were =
totally blacked out from 120
>feet to the
> > >>>>>> >surface) and I abreviated about =
40 minutes to beat him ,
>but it was not
> > >>>>>> >Werner, it was Nanci LeVake who =
has about 80 minutes less
>bottom time
> > >>on
> > >>>>>> >her dive than I had on mine, but =
it make no difference.
> > >>>>>> >
> > >>>>>> > If you have no preconditions, =
Weinke's stuff is solid
>gold and is far
> > >>>>>> >more correct than any of the =
previous models in my
>opinion, and can be
> > >>>>>> >fudged in the low ppo2 range for =
the good offgassers.
> > >>>>>> >
> > >>>>>> > I like what you guys are doing =
out there with this -
>how about let me
> > >>>>>> >come out and let's see what the =
human body can take in a
>chamber test.
> > >>>>>> >
> > >>>>>> >
> > >>>>>> >Nauitec@ao*.co* wrote:
> > >>>>>> >>
> > >>>>>> >> George,
> > >>>>>> >> This was supposed to go to =
you and JJ for comparison.
>50-50 Heliox
> > >>>>>>and 50-50
> > >>>>>> >> Nitrox begin at 70 fsw. This =
a true phase model with
>compartment
> > >>>>>> >>integration.
> > >>>>>> >> Compartments are 1 through =
720. However with your
>applications (depth
> > >>>>and
> > >>>>>> >> duration), phase within the =
algorythm is predominant.
> > >>>>>> >>
> > >>>>>> >> Tim O'Leary
> > >>>>>> >>
> > >>>>>> >>
>---------------------------------------------------------------
> > >>>>>> >>
> > >>>>>> >> Subject: WKPP 220/20 RGBM =
TMX Schedule with He or Ni
>Switches
> > >>>>>> >> Date: Fri, 7 Jan 2000 =
17:07:17 -0700
> > >>>>>> >> From: "Bruce R. Wienke" =
<brw@la*.go*>
> > >>>>>> >> To: techdiver@aquanaut.com
> > >>>>>> >> Gentlemen;
> > >>>>>> >> >> >>> >
> > >>>>>> >> >> >>> > =
Tim O'Leary passed your "deco help"
>message and
> > >>>>>>specifically a
> > >>>>>> >> >> >>> > =
request for a RGBM trimix schedule
>calculation for
> > >>tmx16/50
> > >>>>at
> > >>>>>> >> >> >>> > =
220 fsw for 20 minutes, with a switch to
>either 50/50
> > >>>>>>nitrox or
> > >>>>>> >> >> >>> > =
heliox at 70 fws, and pure oxygen at 20 fsw.
>For
> > >>>>simplicity,
> > >>>>>> >> >> >>> > =
ascent and descent rates are 30 fsw/min.
>Notice deeper
> > >>>>stops
> > >>>>>> >> >> >>> > =
within phase RGBM, and total times less than
>haldane of
> > >>>>>> >>comparable
> > >>>>>> >> >> >>> > =
conservatism -- moderate conservatism in
>this case.
> > >>>>>> >> >> >>>
> > >>>>>> >> >> >>> =
We are in the process of publishing some
>trimx and
> > >>>>helitrox
> > >>>>>> >> >>Tables
> > >>>>>> >> >> >>> =
for ranged mixtures. We have been diving
>RGBM schedules
> > >>>for
> > >>>>>> >>awhile,
> > >>>>>> >> >> >>> =
here at LANL and NAUI Tec. We can do other
>schedules
> > >>>>(within
> > >>>>>> >> reason, of =
course).
> Bruce Wienke
dive number =3D 1 altitude =3D 0.00 ft
RGBM Trimix Version
B.R. Wienke/Los Alamos National Laboratory
--dive profile--
surface breathed nitrogen =3D 0.79
level 1 depth =3D 220.00 fsw time =3D 3.67 min
level 2 depth =3D 220.00 fsw time =3D 220.00 min
trimix =3D 0.50 helium 0.34 nitrogen switches =3D 2
switch 1 depth =3D 70.00 fsw helium =3D 0.00 nitrogen =3D 0.50
switch 2 depth =3D 20.00 fsw helium =3D 0.00 nitrogen =3D 0.00
- excursion to depth =3D 220.00 fsw
- time at inital depth =3D 20.00 min
--------------------------------------------
- stop - depth - wait -
- 1 - 160.00 - 0.00 -
- 2 - 150.00 - 0.00 -
- 3 - 140.00 - 1.00 -
- 4 - 130.00 - 1.00 -
- 5 - 120.00 - 1.00 -
- 6 - 110.00 - 1.00 -
- 7 - 100.00 - 1.00 -
- 8 - 90.00 - 2.00 -
- 9 - 80.00 - 3.00 -
- 10 - 70.00 - 1.00 -
- 11 - 60.00 - 2.00 -
- 12 - 50.00 - 2.00 -
- 13 - 40.00 - 3.00 -
- 14 - 30.00 - 4.00 -
- 15 - 20.00 - 5.00 -
- 16 - 10.00 - 9.00 -
---------------------------------------------
- total time surface =3D 39.67 min
dive number =3D 1 altitude =3D 0.00 ft
RGBM Trimix Version
B.R. Wienke/Los Alamos National Laboratory
--dive profile--
surface breathed nitrogen =3D 0.79
level 1 depth =3D 220.00 fsw time =3D 3.67 min
level 2 depth =3D 220.00 fsw time 220.00 min
trimix =3D 0.50 helium 0.34 nitrogen switches =3D 2
switch 1 depth =3D 70.00 fsw helium =3D 0.50 nitrogen =3D 0,00
switch 2 depth =3D 20.00 fsw helium =3D 0.00 nitrogen =3D 0.00
- excursion to depth =3D 220.00 fsw
- time at inital depth =3D 20.00 min
--------------------------------------------
- stop - depth - wait -
- 1 - 160.00 - 0.00 -
- 2 - 150.00 - 0.00 -
- 3 - 140.00 - 1.00 -
- 4 - 130.0 - 1.00
- 5 - 120.00 - 1.00 -
- 6 - 110.00 - 1.00 -
- 7 - 100.00 - 2.00 -
- 8 - 90.00 - 2.00 -
- 9 - 80.00 - 3.00 -
- 10 - 70.00 - 2.00 -
- 11 - 60.00 - 3.00 -
- 12 - 50.00 - 4.00 -
- 13 - 40.00 - 5.00 -
- 14 - 30.00 - 6.00 - -
- 15 - 20.00 - 7.00 - -
- 16 - 10.00 - 8.00 -
--------------------------------------------
- total time surface =3D 49.67 min
total dives processed =3D 2
--
> > >>>>>> >> Send mail for the =
`techdiver' mailing list to
> > >>>`techdiver@aquanaut.com'.
> > >>>>>> >> Send subscribe/unsubscribe =
requests to
> > >>>>`techdiver-request@aquanaut.com'.
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