Scott Hydropack

[luis]

Sept 17, 2011 17:52:25 GMT -8 drado said:

Luis, does the tank need to be mounted that high? How was trim with this config? I'm thinking of a way to revive my Kirby Morgan mask.

No, it should have been lower, but it didn't bother me much.
That full face mask was very interesting. I have used a number of other FF mask and some are not very comfortable... this one was very comfortable. The only concern with this mask would be CO2 build accumulation.

[SeaRat]

Luis,

I noticed on the Jerry Lewis movie that the demand diaphragm and the exhalation valve were on opposite sides of the mask. Did this cause any free-flow problems when the mask was not horizontal?

John

[luis]

I don't remember the exhaust being an issue, but I don't remember the details about it.

I did a lot of playing in different diving positions and even flooding and purging the mask underwater. It worked amazingly well and it breathed very well, but it felt so different to other FF mask I have tried that it was hard to compare.

[SeaRat]

Has anyone thought of what would have happened if the Scott HydroPak had really caught on, and diving evolved toward full face masks with communication in the 1960s? I'm curious why the Scott HydroPak did not catch on, and instead we went to single hose regulators with mouthpieces.

John

[drado]

Was it expensive? Might've been a factor...

[luis]

Yes, my understanding is that it was a lot more expensive than the Aqua Lung (the “aqua lung” at the time consisted of the regulator, tank, and harness).

I have wondered how diving would have evolved if the Hydro-Pak would have had more of an influence.

The FF mask could have definitely used more refinement, but I was able to talk and the other divers could hear me and somewhat understand what I was saying (without any communication gear).

The clearing of the mask and limited provision for buddy-breathing also needed improvements. I say limited provision because in theory the metal snorkel on the right had a double duty of allowing a second diver to open the cap and breathe out of it. We did not try it, but I am certain that it would have been at least cumbersome and probably totally impractical.

The snorkel was handy on the surface and it worked well.

The mask also has a lot of potential for CO2 build up.

I do like the tank valve on the bottom.

[SeaRat]

I am curious about the CO2 buildup possibilities. I watched Jerry Lewis doing some rather strenuous work (or a stand-in diver) using the Scott FFM. Wouldn't CO2 buildup be more of a problem at deeper depths than sport divers usually dive?

Rick and Barbara Carrier, in their book, dive, the complete book of skin diving[/B], Wilfred Funk, Inc., New York, 1957, on page 277 list the Scott 8300B Double cylinder Hydro-Pak at $325. The 8400B Single cylinder Hydro-Pak was $250.

The U.S. Divers Aqualung, as listed in the Carrier's book appendix was "AJ Standard (D1 + H1 + J1 + LA) 70 cu. ft. tank (ICC 2150 p.s.i.) and an air reserve device; diving time, one hour" sold for $160. The "B2 Professional two-tank unit (D1 + 2H1 + J2 + L2 + W2) 140 cu. Ft. with air reserve; diving time, two hours" was $260. The "B3 Navy triple-tank unit (D1 + 3H3 + J3 + L3 + W3) 132 cu. ft." was $295.

So yes, the Hydro-Pak was very expensive. My first set cost about $65 (Healthways SCUBA regulator and 38 cu. ft. tank, used), and I worked a whole summer to get that.

John

[cg43]

Hello

I found this old thread by looking for the Scott Hydro-Pack .

You can found the drawings on the CG 45 side .

For me the Scott people made an exelent job .
They found solutions for four problems with this kind off full face masks (mask wihout internal mask and valves).



vel .




1. Reducing CO2 level   
    Inhale air comes from the right side , exhale air goes to the left side . And the one way valve that
    separates the inhale diapragm room from the mask causes not inhale diapragm dead space .
    That's not perfekt but better then inhale and exhale on the same side , like the Dräger R 60
     and fullface masks from other companies . You always have to breath deep and slow with this masks .

2. No freeflow !!!
    The exhale valve is freeflow compensated . 
    It's a two stage valve . The first stage is an ordinary one way flapper valve .
    The second stage  is an diapragm that closes a big exust orivice if the diapragm is feed by the littel pipe
    that ends in the inhale diapragm room . This room is conected to the mask by the big inhale one way 
    flappervalve .
    Lets look for the funtion:
    The exust shall be above the inhale diapragm .
    The higher pressure from the inhale diapragm room closed the exhale oriviece , so no freeflow .
    If you exhale your exhale pressur can not go to the inhale diapragmroom because of the
    big one way valve . You create a highter pressur on the exhale orivice side  and therefor you can exhale .

    The inhale diapragm is above the exhale .
    Now the exust orivice ist not closed by the exhale diapragm and we need the first stage exust oneway valve .

3. Drying the mask
    Simply push the purge button .
    The exhale diapragm closes the big exhale orivice with the same pressur that goes to the mask , so the
    only way for the air is to lift the mask .

4. No problem with the Cousteau/Gagnan patent .

Isn't that a great design !!!  I love it .

Rainer




    

[SeaRat]

If you are a member of the Historical Diving Society, USA, you can read about the Scott Hydropack here:

www.hds.org/journals/111

There is a really funny sequence of Jerry Lewis using a Scott Hydropack on film somewhere, I've seen it, but I cannot now find it. Maybe someone else here has better luck.

John

[cg43]

Hello  John

Thanks for the link to HDS .
Up to now I have seen the Hydro-Pack on Alec Peirce  SO 4E12
and Flipper "A job for Sandy" .
 
Rainer

[SeaRat]

Okay, I think I've found it. Jerry Lewis in "Don't Give Up The Ship."




There's a little of the use of the Scott Hydropack in this clip.

They used the Scott Hydropack in the film, "Errand Boy" too.


www.ebay.com/itm/304634131507

John

[cg43]

Hello John

Very funny both films , I had much to laught .
The Scott Hydro-Pack seems to work very good .

Rainer