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Bruce
>Decoplan uses
>Haldane with GFs reducing permissible M-values at depth and then subtracts
>33% of 10 ft stop time from Haldane.
Your statement that Decoplan subtracts 33% of the 10' stop is incorrect. In
my personal reply to you, I stated:
>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):
<table snipped>
In my public email I merely observed:
>Here is a comparison of the RGBM 20 minute ABT compared to Decoplan
>(GFLo=20%, GFHi=100%). Notice how close the profiles are when the last stop
>of Decoplan is when shaved by a third.
>
>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
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: Friday, January 14, 2000 8:55 AM
To: deco@de*.or*; techdiver@aquanaut.com
Cc: chris@ab*.co*
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
--
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