Rebreather DIR?

[Essroc123]

...two dive Buddies- one has a REbreather - one OC-- Bad MIX! I know that for a fact!

I gather that is not a good combo?

Safe Dives,

Will Johnson

 

[BigJetDriver]

You are only doing a partial analysis, which is inconsistent with DIR positions. FFM's for use as a diving tool brings with it a host of problems, the least of which is donating a long hose. Particularly when you are discussing working at depth, the dead air space in the FFM allows for an unnecessary risk with respect to C02 accumulation..

Hope that helps.

The FFM is an acceptable and effective tool for diving situations which require comm or in Public Safety Diving situations.

It does require special training and is not for novice useage. The dead air space problem is overcome by utilizing one with a small oro-nasal cup volume. The long hose regulator will (Sorry for the heresy!) have to be the secondary, due to the nature of the beast!

BJD :anakinpod

 

[TechBlue]

The FFM is an acceptable and effective tool for diving situations which require comm or in Public Safety Diving situations.

It does require special training and is not for novice useage. The dead air space problem is overcome by utilizing one with a small oro-nasal cup volume. The long hose regulator will (Sorry for the heresy!) have to be the secondary, due to the nature of the beast!

BJD :anakinpod

Let's not forget the additional safety you get from using a FFM with a RB and as we know DIR does not accept any ECCRB's. With our teams we would hand off with a stage if it required OC bailout anyway.

 

[caveseeker7]

The FFM that Chickdiver desribed, the Kirby-Morgan M-48 Supermask, retains a bite piece inside the pod (that's the removable section that hooks up either to a second stage or a DSV which can also have an integrated 2nd stage for bailout). It a bellows that allows the diver either to keep the bite piece in his mouth, in which case CO2 is not an issue. For use with comms it can be removed.

The RB80 also has a DSV with an integrated 2nd stage for bailout or use at the surface. For the diver to switch from the loop to OC all he has to do is turn a lever on the DSV. The switchblock which is used to supply the RB with different offboard gas mixes also supplies the integrated DSV, so bailout gas is the same as loop gas. If equiped with a matching QD any tank can be plugged into the loop, including one you get from your partner or safety diver.

I don't know about the long hose reg, though, I would think the DSV-integrated replaces it. That is one reason why you don't just mix OC and RB divers - they have quite different protocols.

Don't know how WKPP does it, but EKPP uses large 20ltr tanks in the back on the RB's frame as bailout. The loop gas taken from stage tanks.

As for an RB80 during DIR-F, that won't happen anywhere. In order to take the first of the two available RB80 classes you are required to pass DIR-F and
Tech-1.

For those of you who don't quite understand the RB80's inner workings, Halcyon's website gives excellent info. For illustration follow this link,
it leads to a detailed teardown of an RB80 as well as graphics of the gas flow.
http://www.golemgear.com/scr/scrteardown.htm
Stefan

 

[BigJetDriver]

-----a DSV with an integrated 2nd stage for bailout or use at the surface. For the diver to switch from the loop to OC all he has to do is turn a lever on the DSV. The switchblock which is used to supply the RB with different offboard gas mixes also supplies the integrated DSV, so bailout gas is the same as loop gas. If equiped with a matching QD any tank can be plugged into the loop, including one you get from your partner or safety diver.

I don't know about the long hose reg, though, I would think the DSV-integrated replaces it. That is one reason why you don't just mix OC and RB divers - they have quite different protocols.

Stefan

Stefan, et al,

When I use an FFM on my Expedition Inspiration, for situations requiring comm for instance, I use the Widolf DR-600 with a DSV and attached Apeks TX-100 second stage built by Divematics USA. Even without that, however, I have a TX-100 available on a long hose at all times.

As pointed out by TechBlue, the side-slung cylinders are also available for "take-out", so to speak!

Cheers!

BJD :anakinpod