"Danger is My Business"

[Couv]

Good news if you have Netflix. There are 3 episodes on one disc available, just search for "Danger is My Business." Even though it is touted as a 2007 documentary, the 3 episodes are from the Colonel John D. Craig's 1950ies series. Please keep that in mind as the first episode is about shark hunting in HI, ridding the area of the dangerous animals that compete with the tuna fishermen. Check out Pete Wilson and his partner wearing cool double hose regulators as they ride in a shark-cage sled. The next is about hard hat diver and treasure finder, Art McKee. The final episode is about a Marine Land's shark doctor Dave Brown.

I would bet that anyone who likes the Vintage Forum would enjoy watching this disc.

Cheers,

Couv

 

[John C. Ratliff]

John "D." Craig was our uncle I am his youngest nephew John A. Craig the "D." was taken from our Dads middle name David his was youngest brother born in 1914. Uncle John did not have a middle name but used it for artistic/stage name. He had 4 brothers oldest was Tom born in New York in 1901. Uncle"Jack" or John was born in 1903 he and I are named after his Dad our grandfather John Craig born in Dalry Scotland in 1868. My uncle and his 4 brothers grewup in Long Beach California and had a Tom Sawyer childhood of mischef. It was fun and made us laugh to listen to all 5 talk about their boyhood adventures. I tried even to find video on youtube but found nothing. Uncle "Jack or John D. Craig was born in 1903 died on labor day weekend same as Princess Diana in 1998 or 1997 age 93-95. He was Col. in Army Air Corp during WW2 took pictures of Ploesti Raid in 1944 and after the war the Bikini Atomic bomb test.

Joctogun,

I ran into another reference to your uncle, John D. Craig, in Fred Roberts book, Basic Scuba. He was referencing the work of Dr. Edgar End when he was discussing the beginnings of research in deep diving using helium-oxygen mixtures. Roberts states:

...Doctor End conducted extensive human experiments3 with helium-oxygen mixtures and reported hdis findings in the American Journal of Physiology (120:712, 1937) in an article entitled "Rapid Decompression Following the Use of Helium-Oxygen Mixtures Under Pressure." He followed up with proof of his work by asisting Max Gene Nohl in his dive to 420 feet in Lake Michigan on December 1, 1937. A self contained dress weighing 228 pounds that was designed by Nohl employed a helium-oxygen mixture perfected by Doctor End. The Bureau of Mines followed with a simulated dive, using helium-oxygen, of 500 feet in the same year...

Fred Roberts then had a footnote, which is the point of this post:

3End conducted experiments on himself and three well known personalities in the diving field--Max Gene Nohl, Jack Browne (better known for his Browne back entry suit) and Captain John D. Craig. The latter men were concerned with developing a technique to photograph the liner Lusitania.

There was no mention of them ever diving the Lusitania, so I did a Google search. I found this article on-line:

Lusitania & Capt John D Craig - Tom Whiteley's life in full. Survivor of the Titanic. Actor.on stage and film.

It appears that they did not ever make it to the Lusitania, but did advance diving medicine in their attempt.

SeaRat

 

[John C. Ratliff]

I have access to some of the scientific papers, and was able to find the one Fred Roberts discussed in his text. I feel that it is appropriate at this time to copy as much as possible, and present it here, as much is not known to the general diving public about the contributions of there three individuals, especially Dr. End and John D. Craig. These will come in the next posts.

SeaRat

 

[John C. Ratliff]

RAPID DECOMPRESSION FOLLOWING INHALATION OF
HELIUM-OXYGEN MIXTURES UNDER PRESSURE
EDGAR END

From the Department of Physiology, Marquette University School of Medicine,
Milwaukee, Wisconsin

Received for publication June 23, 1937

The problem of determining decompression tables for divers using
helium-oxygen mixtures in the newly-developed Craig-Nohl diving suit
has resulted in findings of the most encouraging nature. This is the
report of a rigorous test of the suitability of helium-oxygen mixtures for
use by men working under pressure. As far as I have been able to deter-
mine, this is the first paper dealing with such work on human subjects.
The invention of the diving dress, the caisson, and compressed-air
tunneling were followed by the observation that on decompressing after
exposure to increased pressures, men often suffered from untoward symp-
toms. Various names such as the bends, caisson disease, divers’ palsy,
and compressed-air illness were given to these symptoms. In 1878 Paul
Bert described bubbles in the vessels of animals rapidly decompressed
after exposure to increased pressure, and to these bubbles he attributed
the symptoms just mentioned. Bert found by analyzing the gas in these
bubbles that they consisted chiefly of nitrogen, the principal inert con-
stituent of air, which he believed had come out of solution in the blood and
tissues so rapidly as to form gas emboli.

Bert’s work was followed by little advancement in the prevention of
compressed-air illness until 1908 when Boycott, Damant and Haldane
published tables establishing the principles of stage decompression.
Recent work by Hawkins, Shilling and Hansen (1935) has suggested
changes in favor of shorter decompression. Otherwise, little has been
done to permit a diver to descend to great depths or to remain under
pressure for long periods of time without spending an exorbitant amount
of time in decompressing. It is largely this length of time spent in decom-
pressing which limits productive diving to relatively shallow water. For
example, according to the decompression tables used by the United
States Navy (1925), a diver who descends to a depth of two hundred and
fifty feet and remains there for twenty minutes must spend two hours
and twenty-six minutes in being drawn back to the surface.
Some years ago Dr. J. H. Hildebrand, of the University of California,
suggested that if inert nitrogen is the cause of compressed-air illness,

 

[John C. Ratliff]

substitution of a less soluble gas for nitrogen in the air breathed by men
under pressure would permit more rapid decompression. Helium, which
was at that time becoming available in substantial quantities, presented
the ideal characteristics of being inert, odorless, tasteless, colorless, less
soluble than nitrogen, and also more diffusible than nitrogen. Working
with Sayers and Yant (1925), Hildebrand found that when animals
inhaled helium-oxygen mixtures under increased pressures they could be
decompressed safely in one-fourth to one-third of the time required for
safe decompression when nitrogen-oxygen mixtures were breathed.
To use helium-oxygen mixtures for ventilating the standard type of
diving dress which receives its air supply from the surface is impractical.
Recently the Craig-Nohl diving dress, a self-contained unit designed to
utilize the findings of Sayers, Yant, and Hildebrand regarding helium-
oxygen mixtures, has been developed for salvage work on the Lusitania.
The physiological problems involved in developing this equipment have
been worked out in this laboratory. A helium-oxygen mixture is used to
inflate the Craig-Nohl suit as the diver descends, and when the working
level has been reached flow of this mixture is stopped and oxygen is intro-
duced at a carefully controlled rate to satisfy the diver’s metabolic re-
quirements. With this equipment the diver is independent of the surface
for his air supply, carrying his helium-oxygen mixture and additional
oxygen in cylinders on his back.

In order to obtain data for determining decompression tables for divers
breathing helium-oxygen mixtures, Captain John D. Craig and Mr. Max
E. Nohl, designer of the Craig-Nob1 diving dress, have served as voluntary
subjects for tests which appear to establish beyond question the superi-
ority of this artificial gas mixture over ordinary air for men working under
pressure. Mr. Nohl is twenty-six years of age, and Captain Craig is
thirty-three. Both of these men are experienced divers capable of making
critical comparisons between the new mixtures and compressed air. The
experiments reported in this paper were performed in a steel recom-
pression chamber in the Milwaukee County Emergency Hospital through
the courtesy of its designer, Mr. Joseph C. Fischer, Chief Engineer of the
Milwaukee County Institutions. This recompression chamber is eighteen
feet long and seven feet in diameter and is divided into an inner and an
outer compartment by pressure-tight doors. In it pressures up to forty-
four pounds per square inch are available.

For these experiments two sets of rebreathing apparatus were con-
structed, each consisting of a spirometer, a soda-lime chamber, valves, an
air-tight mouthpiece, and necessary tubing and connections. Helium-
oxygen or helium-nitrogen-oxygen mixtures prepared beforehand were
admitted to these systems from a cylinder under pressure, and oxygen
was added from another cylinder at will. The subjects breathed from

 

[John C. Ratliff]

these systems during the entire period of each experiment. The gas
mixture in the systems was frequently changed to insure accuracy, and
addition of oxygen to replace that consumed by the subject was care-
fully controlled.

The work of Sayers, Yant, and Hildebrand showing that small animals
could be decompressed three or four times as rapidly from helium-oxygen
mixtures as from nitrogen-oxygen mixtures formed the basis for these
experiments. In addition, consideration was paid to the fact that helium
is less soluble than nitrogen, is more rapidly diffusible, and dissolves in
drawn blood in direct proportion to the helium pressure according to
Henry’s law (Hawkins and Shilling, 1936). Hildebrand, moreover, (per-
sonal communication) believes that the ratio of the solubility of helium to
nitrogen is much less in lipoids than in water, which is an extremely
favorable factor inasmuch as the great lipoid solubility of nitrogen makes
every lipoid tissue in the body a dangerous storage depot for this gas
under pressure.

Two methods of experimentation presented themselves for determining
a decompression schedule for helium-oxygen mixtures. In one method,
a pure helium-oxygen mixture could be breathed for a fixed period of time
in a series of experiments in which the pressure increased with each suc-
ceeding experiment. In the other method, time and pressure could be
kept constant, and the partial pressure of helium could be increased with
each experiment. This latter method was chosen because of the conven-
ience with which it can be employed during actual diving operations. The
partial pressure of helium can be increased conveniently by using it to
dilute and finally replace the nitrogen in prepared mixtures. In these
experiments, by maintaining the concentration of oxygen at twenty-one
per cent, easy comparison with atmospheric air was possible.

For the purpose of these experiments a graph was made (fig. 1) with
pressure in equivalent feet of sea water as ordinates and time as abscissae.
Decompression schedules for divers working in ninety feet, sixty feet,
and thirty feet of water are shown. These represent, respectively, the
nitrogen decompression schedules for three-thirds, two-thirds, and one-
third of the maximum depth (ninety feet) or for gas mixtures in which
nitrogen makes up three-thirds, two-thirds, or one-third of the total inert
gas being breathed. An assumed helium decompression line for ninety
feet was drawn as an unbroken line indicating decompression from maxi-
mum pressure to atmospheric pressure at a uniform rate and in one-fourth
of the time necessary for nitrogen. The work of Sayers, Yant, and
Hildebrand showed that animals could be decompressed safely from
helium-oxygen mixtures in one-fourth of the time necessary when nitro-
gen-oxygen mixtures were breathed. Because of the lower solubility of
helium and its more rapid rate of diffusion, decompression from helium-

 

[John C. Ratliff]

oxygen mixtures at a fairly uniform rate appears to be preferable to
stage decompression.

In diving work the rate of compression (i.e., descent) is limited in
practice only by the ability of the diver’s ears to adjust themselves to
changes in pressure and ordinarily occurs at the rate of forty feet a minute.
As will be appreciated by referring to figures 2, 3, and 4, however, the
length of time necessary to build up pressures to a maximum in the re-
compression chamber used in these experiments is enough to alter calcula-
tions considerably. This factor had been disregarded in previous work
until a subject suffered from painful and disabling cramps in both arms
following a decompression which took into consideration only the time
spent at maximum pressure. Following this unfortunate experience,
two-thirds of the time spent in compressing from atmospheric pressure to
maximum pressure were added to the time spent at full pressure when
computing decompression schedules. The value two-thirds was arbi-
trarily selected in preference to the obvious one-half because of the de-
creasing rate of pressure rise as maximum pressure was approached (not
indicated in figs. 2, 3, and 4) due to air compressor characteristics.
According to the helium content of the mixtures breathed, this exper-
iment can be divided into three parts. The following mixtures were
calculated and mixed to provide, respectively, a helium content, equal
to one-third, two-thirds, and finally three-thirds of the inert gas in the
mixture.

02 N2 He
Experiment I ........... 21 per cent 52.5 per cent 26.5 per cent
Experiment II .......... 21 per cent 26.5 per cent 52.5 per cent
Experiment III ......... 21 per cent 0 per cent 79 per cent

Inasmuch as the writer alone breathed air throughout the experiments
while making observations and adjusting apparatus, it was necessary to
employ the innermost room of the decompression chamber for decom-
pressing him at a slower rate while he observed the decompression of the
helium-breathing subject,s through a small window.

By referring to figure 1 it will be seen that in the first experiment, in
which nitrogen made up two-thirds of the inert gas in the mixture being
breathed, the subjects were under the same conditions as a diver breathing
air at a depth of sixty feet, as far as the nitrogen content of their bodies
was concerned. Decompression according to standard tables after ex-
posure at sixty feet for one hour’s time requires twelve minutes. Actually
(fig. 2) only eight minutes were spent in decompressing the two subjects.
There were two reasons for this reduction in decompression time. The
first reason was that while the standard decompression tables incorporate
a substantial margin of safety, these experiments were an attempt to
reduce decompression time to a minimum. The second reason was that

 

[John C. Ratliff]

there was actually less nitrogen in the body than was calculated, due to
the fact that the subjects breathed a mixture relatively deficient in
nitrogen, and early during the period of compression there was actual loss
of nitrogen from the body to establish equilibrium with the gas in the
rebreathing apparatus, this lost nitrogen being disposed of each time that
the apparatus was purged and refilled with a fresh mixture. Decompres-
sion in eight minutes’ time in the first experiment was followed by no bad
effects. This result justified the reduction made and provided a basic
figure from which to work with helium. In the two succeeding experi-
ments the nitrogen content was too low to require consideration in the
computation of decompression schedules (fig. 1).

In the second experiment, with the subjects breathing a mixture in
which helium made up two-thirds of the inert gas, it was decided to halve
the decompression time of the preceding experiment in order to bring out
any deleterious effects that helium might be capable of producing. It
will be remembered that the partial pressure of nitrogen in this experiment
was too low to require consideration in computing a decompression sched-
ule. As is depicted in figure 3, uneventful decompression in four minutes’
time was made after approximately one hour’s exposure to a pressure
equivalent to ninety feet of sea water. Decompression at a uniform rate
rather than by steps or stages was employed.

In the final experiment of the series (fig. 4), a mixture of 79 per cent

 

[John C. Ratliff]

helium and 21 per cent oxygen was breathed by the two subjects under
a pressure equivalent to ninety feet of sea water for a period of ap-
proximately one hour. At the end of that time, by employing several
emergency valves in addition to the regular outlets on the recompression
chamber, the two subjects were decompressed in two minutes without any
apparent ill effects. The reduction in decompression time, as computed
against standard navy tables, is forty-five minutes. The ratio of helium-
decompression to nitrogen decompression in this instance is as 1 is to 23.5.
The temperature in the chamber fell from 72’F. to 45’F. during the
period of decompression.

Aside from raising the pitch and altering the quality of the voice,
inhalation of helium-oxygen mixtures under pressure appeared to have no
unusual effect . It is my belief that in addition to shortening the time
necessary for safe decompression, helium may also free divers from the
untoward psychological effects of air at high pressures. Since Behnke,
Thomson, and Motley (1935) called attention to the fact that the lipoid
coefficient of nitrogen is great enough to cause it to be suspected as the
cause of the “narcotic” effect of air at high pressures, experiments in this
laboratory on the effects of helium on the state of consciousness of men
working under pressure have been very encouraging. The relative in-
solubility of helium in lipoid tissue makes it an ideal gas for use in testing
the theory of Behnke, Thomson, and Motley.

In this paper no attempt has been made to discuss the cause of com-
pressed-air illness or the factors influencing susceptibility to it. Considera-
tion of these problems in the light of complicating phenomena observed in
this laboratory will be attempted in a later paper. In this connection,
however, it is interesting to notIe that shortening of the coagulation time
of the blood after decompression has been found consistently.
While the results reported in this paper serve fully to justify the writer’s
expectations for helium-oxygen mixtures, they are reported in the hope
that they will stimulate more work by others in this very promising field.
Only by careful investigation such as is being carried on in developing
decompression tables and other data for use with helium-oxygen mixtures
in the Craig-Nohl diving dress will helium-oxygen mixtures be made
universally available to those individuals who are subjected to the dangers
of compressed-air illness. Above all, the fact that two persons have
suffered no apparent ill effects following decompression in two minutes’
time after having breathed a helium-oxygen mixture at a pressure equiv-
alent to ninety feet of sea water for approximately one hour should not be
interpreted by anyone as an attempt to establish this as a safe rate of
decompression under the circumstances. Such figures are, however,
highly encouraging.

Grateful acknowledgment is made to Mr. James T. Howington, Vice
President of the Girdler Corporation, for the helium used in these experi-
ments.

SUMMARY

1. After breathing a helium-oxygen mixture under pressure, two sub-
jects have been uneventfully decompressed in less than
of the time required when compressed air is breathed.
one twenty-third
2. Attention is called to several possibilities of helium-oxygen mix-
tures as a substitute for compressed air for men working under increased
pressures.

REFERENCES

BEHNKE, A. R., R. M. THOMSON AND E. P. MOTLEY. This Journal 112: 554, 1935.
BERT, P. La Pression Barometrique. Paris, 1878.

BOYCOTT, A. E., G. C. C. DAMANT AND J. S. HALDANE. J. Hyg. 8: 342, 1908.

HAWKINS, J. A., C. W. SHILLING AND R. A. HANSEN. U. S. Nav. Med. Bull. 33:
327, 1935.

HAWKINS, J. A. AND C. W. SHILLING. J. Biol. Chem. 113: 649, 1935.

SAYERS, R. R., W. P. YANT AND J. H. HILDEBRAND. Report of Investigations-
Bureau of Mines. R. I. no. 2670, 1925.

United States Navy Department Diving Manual. Washington, 1925.

 

[AfterDark]

The raw nerve of these men is awe inspring! This was tech diving in the raw. Similar to going to the moon using slide rulers! These men must be in the diving museum in FL?