The Ability-Adaptation Squeeze Model

[wjohnson100]

"First, let me say that I am not trying to postulate a universal theory of everything. I am merely trying to get us to a model which is valid to the extent that it is useful and suggests productive avenues of improvement in our thought processes, training, and tactics. I will be making some generalizations, as that is the nature of models, but rest assured, I am aware that no model can possibly account for all the variables that present themselves on even one dive. Still, I feel that this model will be useful, because I think it brings a bit of a useful focus to the recent events that have traumatized all of us."

The rest of the article is at The Ability-Adaptation Squeeze Model, or if your browser will not support embedded .pdf viewing, you can go to The Ability-Adaptation Squeeze Model. Hi-def 1920x1080 illustrations related to the article are available at Illustrations.

 

[wjohnson100]

Illustrations (1920 x 1080) available for download​

 

[cdavis]

Graphs on FRC and 1/2 lung are good illustrators of the squeeze dangers of that approach. I agree completely with the principals illustrated.

Just a quibble. I don't think that being able to equalize 1/2 lung to 30 meters is quite equivalent to equalizing at 70 meters full lung, don't care what the math shows, there is something else involved.

The rest of the article is a very good and thoughtful read.


Connor

 

[wjohnson100]

Thanks, I am glad you found it all interesting.

Difficulty of equalization is a whole 'nother animal. To model eq, I would also have to account for, among other things, air density variation with depth, and how that affects airflow resistance through the eustachian tubes. I am in no way trying to say that eq is the same at 70/full-lung as 30/half-lung, just that the volume of air in the lungs ends up the same.

By the way, feel free to "quibble." No harm, no foul.

 

[wjohnson100]

Did a bit of research, and it appears that flow resistance increases linearly with density. All other things being equal, it should be harder to push air into the ears at 70 meters than at 30, or just take longer with the same force applied.

 

[pingshui]

Your graphs are good for teaching. They illustrate very well the squeezing-dangers at depth.

 

[wjohnson100]

Your graphs are good for teaching. They illustrate very well the squeezing-dangers at depth.

Thanks, I made them especially for educational purposes.