How to plan deco CC dives with OC bailout/deco

[Rui Guerra]

Hi all,

Hi have the OSTC-2N to use with my Poseidon MKVI CCR for deco dives.
I want to make the deco dive plans in CC mode but with bailout and deco in OC (just in case of a malfunction CCR).

I've tried to plan with V-Planner, but although OSTC-2N and V-Planner both use the Buhlmann 16 tissues algorithm, due to the Low/High GF in the OSTC-2N (and the CF11 and CF12 - factor saturation/desaturation), until now I wasn't able to exactly match the deco stops with the V-Planner (that doesn't have GF but "Conservatis" from Nominal to +5).

Since I can't match the V-Planner deco with the OSTC-2N deco, I can't use the V-Planner bailout/deco OC calculations to make a table and use it underwater in case of a breakdown of the CCR and the OSTC-2N. Also, I need to calculate the among of nitrox that I need for those OC bailout/deco, so I need an exact calculation that I can do in the V-Planner.

So, those are my two main questions:

1 - Is it possible to make the OSTC-2N and the V-Planner software to match exactly the deco plans in CC mode? If so, what would be the settings in V-Planner and in the OSTC-2N?

2 - IS it possible to plan a deco dive in the OSTC-2N in CC mode but with a change to OC, at the end of the bottom time, so the bailout and deco will be done with two diferente nitrox mix?

Thanks!

Best Regards,
Rui Guerra

[scubatinoo]

Rui Guerra Wrote:
-------------------------------------------------------
> I've tried to plan with V-Planner, but although
> OSTC-2N and V-Planner both use the Buhlmann 16
> tissues algorithm

Ehm, V-Planner uses the VPM-B model, and NOT the ZH-L16...


>, due to the Low/High GF in the
> OSTC-2N (and the CF11 and CF12 - factor
> saturation/desaturation),


You are only using one of these combinations: Either GF low / heigh for the deco model ZH-L16 GF or you are using ZH-L16 (=Bühlmann) pure with CF11/CF12.


> 1 - Is it possible to make the OSTC-2N and the
> V-Planner software to match exactly the deco plans
> in CC mode?

Most-likely no!

You can use OSTC Planner Software and start playing arround with GF values until you find a match...

[DTR.Diver66]

Hello Rui,

it is possible to simulate a dive in real time with change to a bailout mix.


Ragards

[Rui Guerra]

Scubatinoo: Are you refering to some software in particular? If so,does it run in Mac?

Dgr-Diver66: Yes I know that I Van simulaste a real time dive, but that solução be a real pain to wait more then one hour to figure out what OC deco a must do!!!!

Thanks for the help

[Rui Guerra]

I have just found the webpage of OSTC Planner. No doubt that it seems to be the answer to my questions.

Thanks once again,

[Rui Guerra]

Hi all,

After downloading OSTC Planner, I've run several CCR simulations and bailout deco and gas volumes calculations.
For instance:

Bühlmann ZH-L16C-1a 2002 with GRADIENT FACTOR decompression:
* GF_low (CF32) = 30 %
* GF_high (CF33) = 85 %
* deco offset (CF16) = 1.0 m
* last stop (CF29) = 6 m
* dive started at Pamb = 1100 mbar
* Gas switch delay (CF55) = 0 min

CCR mode:
* Setpoint1: 1.3
* Diluant gas#1 = 21/0
* Bailout gas#2 = 21/0 at 66 m
* Bailout gas#3 = 36/0 at 30 m
* Bailout gas#4 = 43/0 at 24 m
* Bailout gas#5 = 58/0 at 18 m

0:00 66.0m DESCENT DONE ppO2=1.30
...
35:00 66.0m Deco: ppO2=1.30
33 m : 1 ' 39 ' SWITCH Gas#1 -> Gas#2 at 66m
30 m : 2 ' 42 ' SWITCH Gas#2 -> Gas#3
27 m : 2 ' 44 '
24 m : 3 ' 47 ' SWITCH Gas#3 -> Gas#4
21 m : 4 ' 51 '
18 m : 4 ' 56 ' SWITCH Gas#4 -> Gas#5
15 m : 6 ' 62 '
12 m : 8 ' 70 '
9 m : 10 ' 81 '
6 m : 39 ' 120 '
0 m : --- ' 121 '
TTS = 87 '
CNS = 68%
==== BAIL-OUT runtime ====
35:00 66.0m Deco: ppO2=1.30
66 m : SWITCH Gas#1 -> Gas#2
33 m : 2 ' 40 '
30 m : 2 ' 43 ' SWITCH Gas#2 -> Gas#3
27 m : 2 ' 45 '
24 m : 3 ' 48 ' SWITCH Gas#3 -> Gas#4
21 m : 3 ' 51 '
18 m : 4 ' 56 ' SWITCH Gas#4 -> Gas#5
15 m : 5 ' 61 '
12 m : 8 ' 69 '
9 m : 10 ' 80 '
6 m : 50 ' 130 '
0 m : --- ' 131 '
TTS = 97 '
CNS = 58%
Depth = 66 m
Bottom time = 35 min
Bottom gas consumption (CF56) = 15 l/min
Ascent gas consumption (CF57) = 15 l/min
Gas#2 ( 21/00) = 2649
Gas#3 ( 36/00) = 2196


Where area the Gas 3 and Gas 4 volume calculations? Is this a bug in the software?

The above data was obtained with gas1 (diluant) unchecked (but with a check in "first gas") and all the others checked.
If I also put a check mark in the gas 1, the gas swith depth will be incorrect as follows:

Bühlmann ZH-L16C-1a 2002 with GRADIENT FACTOR decompression:
* GF_low (CF32) = 30 %
* GF_high (CF33) = 85 %
* deco offset (CF16) = 1.0 m
* last stop (CF29) = 6 m
* dive started at Pamb = 1100 mbar
* Gas switch delay (CF55) = 0 min

CCR mode:
* Setpoint1: 1.3
* Diluant gas#1 = 21/0
* Bailout gas#2 = 21/0 at 66 m
* Bailout gas#3 = 36/0 at 30 m
* Bailout gas#4 = 43/0 at 24 m
* Bailout gas#5 = 58/0 at 18 m

0:00 66.0m DESCENT DONE ppO2=1.30
...
35:00 66.0m Deco: ppO2=1.30
33 m : 1 ' 39 '
30 m : 2 ' 42 ' SWITCH Gas#1 -> Gas#3
27 m : 2 ' 44 '
24 m : 3 ' 47 ' SWITCH Gas#3 -> Gas#4
21 m : 4 ' 51 '
18 m : 4 ' 56 ' SWITCH Gas#4 -> Gas#5
15 m : 6 ' 62 '
12 m : 8 ' 70 '
9 m : 10 ' 81 '
6 m : 39 ' 120 '
0 m : --- ' 121 '
TTS = 87 '
CNS = 68%
==== BAIL-OUT runtime ====
35:00 66.0m Deco: ppO2=1.30
33 m : 2 ' 40 '
30 m : 2 ' 43 ' SWITCH Gas#1 -> Gas#3
27 m : 2 ' 45 '
24 m : 3 ' 48 ' SWITCH Gas#3 -> Gas#4
21 m : 3 ' 51 '
18 m : 4 ' 56 ' SWITCH Gas#4 -> Gas#5
15 m : 5 ' 61 '
12 m : 8 ' 69 '
9 m : 10 ' 80 '
6 m : 50 ' 130 '
0 m : --- ' 131 '
TTS = 97 '
CNS = 52%
Depth = 66 m
Bottom time = 35 min
Bottom gas consumption (CF56) = 15 l/min
Ascent gas consumption (CF57) = 15 l/min
Gas#1 ( 21/00) = 2649
Gas#2 ( 21/00) = 2631



As one can see, the change depth from gas 1 to gas 2 disappeared and was substituted for a gas 1 to gas 3 switch 30 m. Another bug????? Also, still ther is no calculation for volumes of gas 3 and gas 4!


Anyone is using this software? Maybe there is something I'm doing wrong but right now I don't feel like I will use this software for real dive planning, if in fact there is some bugs in it.

Any input will be welcome.

Cheers,

[DTR.Diver66]

Hello Rui,

i simulated a few dives with the OSTC Planner. It struck me, that's a change from Diluent Gas to one Bailoutgas everything is OK. During a change of more than one Bailoutgas, the gases are interchanged. It seems that there is a bug in the OSTC Planner.


Regards