Salty Bob,
Man, that is an old set up! I remember pictures like that from the period
before those wiley divers hooked a new fangled gasoline engine to a
compressor!
The Navy used various models, without much change in design, of the Mk 5 hat
from the 1840s to the 1980s.
As I remember (got an old dive manual around here somewhere, hell if I know
where) the handle was like on the old manual rail cars, you know the ones 2
guys would stand on and pump the handle from the ends, up and down for
moving down a rail to perform maintanence?
Didn't John Wayne have a rig like that in "Wake of the Red Witch"?
As I remember a Mk 5 diver would be conscious for something like 6 minutes
if he lost his air supply, so if the supply flow replaced the air in the
suit every 2-3 minutes he'd be fine. Running a compressor like that directly
to a hat or mask, would only require a 2-3 cfrm and about 15 psi over bottom
pressure? Add depth and add cfm.
MMC
"Bob" wrote in message
oups.com...

MMC wrote:
Good post Robb.
The toxins are minute until the compressor pistons rings get worn (or do
not
fit right from the beginning) and allow oil to enter the cylinders.
Absolutely right about the oil free compressor!

Thanks for adding your ideas here. Finally some advice based on
training, experince, and still here to give it. Unlike the other past
posts that simply said, "Ive been doing it this way for years and never
had any porblems."

Here is my question for you MMC:

A few comments earlier in this discssion I described a hand pump that
supplied diver air to about 20'. Did you ever run into anything like
that in the service? They were a little (maybe 25 lbs.) two cylinder
thing with a five foot handle that a person push-pulled too operated
the pump. The guy who made the new prototype said he got the idea from
one he saw in an old USN Dive Manual.

Thanks,
Bob