State of the art, 1969

[SEALAB Author Ben H.]

Anyone ever see this rig? Good to 600+ feet . . .

 

[steveharriss]

Theoretically only assuming he had an umbilical that long

Good to see these old pictures.

 

[SEALAB Author Ben H.]

Theoretically only assuming he had an umbilical that long

Good to see these old pictures.

Thanks! Glad to share. The umbilical didn't need to be that long because it would come from SEALAB III, which in early '69 was placed on the bottom at a depth of about 610 feet.

 

[Luis H]

Thanks for the pictures.
Do you have more information about it?

---------- Post added December 1st, 2012 at 06:03 PM ----------

I can't tell if it has any means to recycle the breathing gas, either as a conventional re-breather or like what Cousteau team used during Conshelf III. For Conshelf III they recycled the gas back to the habitat. The umbilical supplied and recovered the gas that the diver was breathing. Do you know if this was a similar system?

I don't see a lot of space for the counter-lungs and scrubber of a typical re-breather, but it is hard to tell.

Thanks

 

[DA Aquamaster]

IIRC the MK IX system used on Sealab III was a semi closed rebreather system. The diver exhaled through the scrubber with the gas then being augmented by a small amount of additonal gas provided through umbilical into the counter lung.

I suspect the doubles were for bailing out back to the habit or transfer bell.

 

[Luis H]

That unit looks very different to the pictures that I have seen of the MK-IX.

You can download a report on "The Mark IX Semi-Closed Circuit Mixed Gas Breathing Apparatus" from here:
The Mark IX Semi-Closed Circuit Mixed Gas Breathing Apparatus.

The unit looks very different.

 

[Rich Keller]

I do not know this rig but if you look at the end of the yellow part of the umbilical you will see two black hoses going to the diver. My guess is the black hose going up the left hand side of the diver is providing gas and the one coming out from the bottom of the doubles is recycling the gas.

 

[drbill]

It was the 60s and I was there (and diving) but I don't remember seeing this!

Seriously... pretty serious rig but I know on my teacher's salary that year I could never afford one.

 

[SEALAB Author Ben H.]

Good points all! This was in fact the Mark VIII, designed specifically for use from the Sealab III habitat. As Luis H points out, the Mark IX was a considerably more compact unit, designed for use from the four-man bell that took divers to and from Sealab. The Mark IX is described in some detail in SEALAB, my new book (as is a similar rebreather called the Mark VI that was used on Sealab I and II) because it figured into a tragic accident and the demise of the Navy's Sealab program.

Like the Mark IX, the Mark VIII pictured here was an umbilical-fed, semi-closed rebreather. It looks a lot bigger than the IX mainly because of those double 90s, which were indeed for bailout, as DA Aquamaster says – they had to be large to buy much time at 600+ feet. That hefty yellow umbilical is split between a gas line (on the left) and an electrical line that plugged into the back to power a heated suit, voice communication and a few other devices - so all in all a pretty different setup from the Conshelf III apparatus that Luis H mentions.

I don’t believe the Mark VIII was ever commercially available – very much a Navy prototype – but if it had been, I'm sure drbill is right that he would have had to supplement his teacher’s salary to buy one, not to mention covering the cost of the helium. . .and some bottom time in Sealab.