Mailing List Archive

Mailing List: techdiver

Message Display

You wrote: 
>
>Why do IANTD inist that bottom mix cylinders should be manifolded for
>trimix dives ?
>
>What is wrong for example with a 120cf main bottom mix
>cylinder with an independant 60cf bailout of bottom mix. This system 
is
>intended for clear surface diving in conjuntion with a 80cf of EAN32 
and
>25cf of EAN50. The ascent is planned to begin when the main bottom mix 

>cylinder has the same amount of air in as the bailout cylinder ( ie 
half
>full) and the bailout capacity was calculated for an ascent from the
>maximum local depth 300fsw to the EAN32 MOD with a 50% reserve. 
(Assumed
>ascent rate 33fpm). 
>
>Also what equivalent air depth ( and therefore ppN2 ) do IANTD 
>recommend for trimix dives? 
>( I know that WWKP are recommendend 130ft EAD and 1.4at pp02).
>
>  
>Cheers,
>
>Andy.
>IANTD requires manifolded doubles in all trimix traing programs as 
most divers to get the bottom time requirements in need the bottom mix 
gas volume, it is not as confussing as gases of varing mixes on the 
back. Back mounting different gas mixtures may be life threatening as 
it is impossible to see the MOD and mixes from in front of the tanks. 
Two divers have already died this year due to improper or lack of 
labeling and breathing the wrong gas. If you study the history of dive 
accidents you will quickly understand where IANTD developed its 
training standards. It was done from accident analysis, risk analysis 
and the experiences of many of the more experienced tech divers in the 
world.
In fact on independents IANTD only looks at independents as safe in 
training programs when dived in side mount fashion. You will find this 
true of NACD and NSS/CDS as well.

On END's IANTD recommends 130 feet and accepts ramges from 80 to 160 
feet in training programs. Once outside a course you must make your own 
decisions.
Tom Mount
 o --
>Send mail for the `techdiver' mailing list to `techdiver@terra.net'.
>Send subscription/archive requests to `techdiver-request@terra.net'.
>

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]