as of 12/05/13
All current production DESCO helmets
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Light Duty Diving Outfit
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sold by DESCO
Composite Beat Engel Demand Helmet
as of 12/04/13
& Viking price lists.
Product warnings and
What gear it takes to dive.
What goes into making a diving helmet
Real or Replica?
Features of the various helmet models
General product history. Catalogs, significant orders, etc.
DESCO A, B, C Rebreathers Recirculating Helmets
SCUBA Lungs, Water Skis, and Miscellaneous Water Sports Products
How DESCO started
Those who built DESCO
Magazine or News
articles related to diving.
Links to online diving videos.
DESCO company photos
and photos from our archives
Commercial Diving Photos supplied by customers
Classic equipment &
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Photos of helmets from
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DESCO Historical Item Collection
Miscellaneous Photos, Old diver and/or equipment photos
On this page we bring you articles sent to us by the authors or editors and are reprinted by permission. We will also provide links to diving related video on the web.
Print Media Video Media
Article written for Military Vehicle Magazine by Vince Scarponi
Below is an article written by Richard Boyd and published in the Fall 2005 issue of Mari-Times, the newsletter of the Door County Maritime Museum. It is presented here courtesy of DCMM.
Thanks to Assistant Curator June Larson for providing the photos from the article.
Door County Maritime Museum & Lighthouse Preservation Society
Wisconsin Underwater Archeology Association
Door County Maritime Museum & Lighthouse Preservation Society
Mari-Times Fall 2005
VOLUME 13, ISSUE 4 FALL, 2005
A Commercial Diver's Story:
The Career of Pearl Purdy
by Dr. Richard Boyd
Wisconsin Underwater Archeology Association
Richard J. Boyd, Ph.D. in microbiology and oceanography, has been an active diver since 1954, specializing in shipwreck, TEK, and commercial diving, including underwater demolition. PADI national diving instructor for 35 years. Director of Wisconsin Underwater Archeology Association and instructor for underwater archeology courses. Presenter of national workshops on mixed gas technology, pressurized oxygen management, and scuba equipment maintenance. Currently Technical Director of Global Mfg. Corp., a major producer of SCUBA test apparatus and gas mixing equipment in Milwaukee.
The commercial diving and salvage industry on the Great Lakes has been an important, but generally unsung sector of maritime history. In the late 19th and early 20th centuries, nautical accidents and waterfront mishaps were daily occurrences at one place or another around the lakes. This resulted in a steady demand for underwater repair and recovery services which were performed by early commercial divers. Nicknamed "hard-hat divers," these men (and a few women) used a copper metal helmet mated to a counterweighted canvas suit to descend to their workplace. Compressed breathing air was delivered by crude rotary hand pumps which operated progressively harder as the diver went deeper, and usually kept several "pumpers" hopping to maintain the required gas supply.
These subaquatic workmen operated in a dangerous environment using primitive equipment with only fledgling knowledge of diving physics and medicine. As a result, some of these individuals met with an untimely watery demise or suffered crippling injuries which haunted them in later life. In that era, very little was known about the bone and tissue-crushing damage that could be inflicted by water pressure. Even less understood were the disabling effects of decompression sickness, commonly called the "bends," which struck divers who went too deep or stayed too long at depth. The toxic, incapacitating embrace of nitrogen narcosis during deep dives was largely a complete mystery, and was simply referred to as "Divers' Blackout."
Besides the danger factor, early divers worked for wages which today would seem pretty paltry, although they were considered good money in those days. For example, in 1901 at Detroit, a new Divers' Association was formed which established rates for work under the Great Lakes. Divers received $10.00 per day; tenders got $3.00; pumpers got $5.00, and general helpers, about $3.00.
As maritime casualties increased after the Civil War, professional wrecking and recovery businesses sprang up across the lakes, staffed by personnel specializing in vessel reclamation and rehabilitation. There was never a huge contingent of trained divers on the lakes at any given time, but nearly every major port was home base to a wrecking company and some underwater workmen. Surprisingly, even small ports such as Marquette, Cheboygan, St. Ignace, Grand Haven, and Manistee boasted a local resident diver. The "Divers' Advertising Section" of Beeson's Marine Directory for 1914 listed about 25 companies and individuals offering underwater services on the western lakes. The deeds of some of these men such as Tom Reid of Sarnia and the Falcons of Chicago became legendary.
The life and times of an early 20th century diver were exemplified by the career of Wisconsin's own Percy E. Purdy. Known far and wide by his nickname "Pearl," Purdy worked for various Great Lakes wrecking and salvage companies, while also operating his own commercial diving service. He sought (and found) steady work around the lakes as detailed in his yearly advertisement found in Beeson's Marine Directory (see reproduction above). A 20 year resident of Sturgeon Bay (WI), he was originally from the Detroit area where his three brothers and two sisters still resided. In 1907, he married May Donovan of Sturgeon Bay; they had two children.
Most of Purdy's jobs were typical of the sort of underwater engineering and maintenance duties performed by divers of that era. Many of these tasks were routine, if not mundane or unpleasant. They included the inspection and caulking of ship hulls, repair of vessel machinery, retrieval of lost items, harbor maintenance chores, and body recovery. Purdy was always busy during the shipping season as typified by the summer of 1913. In April of that year, Pearl recovered the rudder of the big steamer George F Baker which had been lost in the Manitowoc River. He extended his stay in Manitowoc into May to do some routine harbor maintenance at the shipyards. In early June, he raised the tug Duncan City which had sunk in a local waterway and also contracted to raise another small tug later that summer. This second vessel, the Minnie Warren, had sunk in a nearby shipyard. That period also found Pearl inspecting the hull of the tug John Hunsader at Sturgeon Bay. Come September, he returned to Manitowoc to plug a leak on the steamer Rend. When not busy in Wisconsin waters that season, Purdy's talents were in demand by various salvage and wrecking firms around the region, including that of such famous mariners as Captain John Roen of Sturgeon Bay.
Over the years Purdy inspected and repaired many prominent lake vessels, some of which became Wisconsin shipwrecks. In 1915, he caulked the leaky hull of the steamer City of Glasgow, which eventually was converted into a Wisconsin stone barge. The Glasgow, at 297 feet, was one of the giant wooden ships produced by the famous Davidson Shipyards in Michigan. Today it's a wreck resting in Lilly Bay near the Sturgeon Bay Ship Canal and was recently studied by underwater archeologists from East Carolina University. The wooden steamer Atlanta, which burned and sank in 1906, was also explored by Purdy who determined that its porcelain cargo had been ruined and was not worth salvaging. In modern times, this shipwreck near Port Washington has been a popular dive site.
Like most divers of that day, Purdy had some harrowing misadventures and close-calls. Perhaps his greatest escapade came during the salvage of the John M. Nicol, a wooden freighter which stranded and sank off Big Summer Island (MI) in December 1906. Its cargo included 2,500 tons of valuable coiled barbed wire which immediately became the target of salvors. The portion of the Nicol remaining above water was rapidly stripped by thieves from the Garden Peninsula. Among these robbers was the infamous Captain Dan Seavey, the only mariner on Lake Michigan ever to be arrested for piracy!
In late February 1907, as ice conditions on the lake abated, professional salvager Captain Coffey cruised to the wreck site to recover the barbed- wire. His men installed a ladder from the surface of the ice into the hold of the Nicol and Diver Purdy descended into the vessel. While wrestling with the coils of wire, Pearl accidentally fell underneath the engine and boiler. The fall apparently injured and disoriented him and, while trying to find his way back to the ladder, he actually staggered around it twice. This maneuver thoroughly entangled his lifeline and air hose and soon choked off the gas supply.
Purdy's tender, Frank Isabel, quickly realized that no signals were coming up the lifeline. Alarmed at this lack of response, the surface crew pulled Pearl feet-first to the surface, ladder and all. Isabel, at great personal risk, leaped into the icy water and cut the fouled lines so that Purdy could be hauled aboard the salvage tug. He was unconscious and bleeding profusely from his mouth, ears, and nose. Isabel was suffering from hypothermia. Both men were rushed by boat to Manistique (MI) for medical treatment. After a few days, they had recovered sufficiently to return to work. Two weeks later, Purdy and Captain Thomas Isabel, assisted by brother Frank, resumed the salvage work and recovered all the wire from the Nicol! This is quite amazing by modem standards ... today medical experts would probably disqualify a person from future diving after suffering a serious case of barotrauma (pressure damage) such as Purdy had obviously endured.
In many situations, divers of that era had to be a jack-of-all-trades, and Pearl was no exception. They routinely had to perform a variety of mechanical repairs, often involving underwater metal cutting, rigging, lifting, or dredging. Occasionally, they even had to employ specialized paraphernalia such as explosives. As previously suggested, the "fine points" of using such technical material often was not appreciated. In 1908, Purdy was working on the sunken tug Kate Williams in Jackson Harbor on Washington Island (WI) (see photo, page 1). Dynamite was being utilized to shear the shaft and propeller from the derelict. As reported in the Door County Advocate, Purdy lost the thumb and index finger of his left hand due to the premature detonation of a blasting cap. As is often the case with old newspaper accounts, sometimes only part of the story is presented, and so it was with this Purdy incident. Raymond MacDonald, Washington Island historian, recorded the "rest of the story" in 1985.
It is well known to underwater blasters that the concussion from an explosion instantly kills any nearby fish, which promptly float to the surface. Moreover, the force of the blast literally filets the fish, allowing all the bones to be quickly and easily removed. Although an illegal act, explosives have occasionally been employed to facilitate a quick fish-fry! It seems that Purdy, preparing a blasting cap for this very purpose, was carelessly picking at it with a pocket knife when it suddenly went off!
Having lost two digits on his hand, Pearl was taken to the MacDonald's residence; they, in turn, rushed him to the doctor's office, about seven miles away. It was very apparent that his finger stubs would have to be trimmed and stitched up, a most painful operation. Thus the crew stopped en route at Charlie Johnson's where some whiskey was procured to use as a surrogate anesthetic. By the time they arrived at the clinic, Purdy was "feeling no pain" and ready for surgery!
During the late fall and winter seasons when diving jobs were few, Pearl often worked on lake freighters as a cranesman. He had done this successively for about 16 years, and it was this part-time occupation that eventually cost him his life. In September 1924, he shipped out aboard the whaleback freighter Clifton which was transporting a load of, limestone from Sturgeon Bay to Detroit. At this same time, Purdy's wife and two children were moving to Detroit where the family was planning to establish a new home.
As the Clifton headed into Lake Huron, a nasty storm rolled in from the southwest. Sometime on September 21, the vessel disappeared with its entire crew. The freighter was last seen by the tug Favorite slogging along near 40-Mile Point, and it is assumed that she foundered about 25 miles off Thunder Bay. Some bodies were recovered on the Canadian shore of Lake Huron, but Purdy was never found. The Clifton itself still remains one of the true ghost ships of the Great Lakes. Thus the lakes inducted 42-year old diver Pearl Purdy as a permanent resident of that watery kingdom where he had made his living for so many years.
A few weeks ago HDS member, diving historian/writer, and our friend Kent "Rocky" Rockwell passed away after a long battle with cancer. Rocky had written articles for HDS USA Historical Diver/Journal of Diving History and HDS SEAP Classic Diver. Below is an article we collaborated on with him as it appeared in issue 59 Spring 2011 of Classic Diver Magazine. Our thanks to Jeff Maynard and HDS SEAP for allowing us to reprint here.
Historical Diving Society South-East Asia - Pacific
MAKING AN ICON
DESCO’s US Navy MK V, Mod 1, Diving Helmet
Known MK V diving equipment manufacturers Schrader and Morse were obvious choices for contracts (the MK V was developed in 1915 and first produced in 1916) but the little known Diving Equipment and Salvage Company (DESCO) had also received the drawings and by the end of the War they had produced more than 3000 MK V helmets…making DESCO the largest diving equipment manufacturer in the world.
By December of 1942, some eight months after the blue prints were finished; DESCO had produced upwards of 100 sets of MK V gear (the first helmet Ric has in DESCO’s historical record is #170 dated 12/20/42 and the last is #3088 dated 12/5/45. Ric thinks DESCO started numbering at 100). Thus, in a very short period of time a complete production facility was built to manufacture, not only the helmet and breastplate but the rest of the diving outfit as well. Fortunately for DESCO’s co-creators, the innovative Max Gene Nohl and his companion Jack Brown, Norman L. Kuehn stepped in as partner and vice president in the fledgling enterprise. Kuehn was already a successful rubber goods manufacturer and, initially, in 1938, housed DESCO in his Kuehn Rubber Co. building at 1053 N 4th Street in Milwaukee, Wisconsin. By 1940, Nohl had sought the more lucrative lecture circuit to tell the story of his historic 420 foot record helium/oxygen dive back on December 1, 1937, leaving Browne and Kuehn with the struggling company. By 1942 DESCO was in its’ own facility at 922 N 4th Street, also in Milwaukee (the city known as the “nations machine shop” before the war). Kuehn provided the capital, the managerial expertise and the contacts to develop the new company. The first step in building the MK V helmet required drawings of the individual parts. The USN drawings consisted of ten sheets. The General Arrangement drawing indexed the succeeding nine composite drawings. DESCO produced individual parts drawings from these ten sheets and then developed a production line flow chart. The drawings were sent to the new shops where the necessary machinery, tools and fixtures were organized on the production line process. The parts that were machined from raw stock had the materials shipped directly to the shops. Parts to be sand cast were created in wooden patterns first and then sent to the foundry where the rough castings were poured. These castings were then returned to DESCO for machining. Spinnings of the helmet shell were done in house and the resulting goal was to have all of these parts finished and in stock, ready for final assembly at the soldering stations. The MK V helmets were then tin plated and sent to final assembly. The MK V helium/oxygen helmet was the standard MK V hat modified with a venturi injection system and CO2 scrubber to conserve the rare helium. It used many of the same parts and was built right along with the MK Vs on the same assembly line.
There are four viewing ports soldered to the shell. Originally,
safety glass was sealed in place with a Red Lead compound. By the time Ric
Koellner started working for DESCO in 1980 they had switched to using the
current Litharge (PbO) and Glycerin. After WWII the Navy changed the lens
specification to acrylic plastic. The oval top and round side ports are sand
cast rings with polished cast brass guards. These rings are ground smooth,
machined for the acrylic lens and drilled and tapped for the guard’s 10-32
screws. The front port has a hinged faceplate and a guard of polished cast brass
as well. Both the faceplate and the door base are machined to mate with a groove
for the rubber sealing gasket and the faceplate is recessed for the lens. At its
hinged side…the faceplate and ring are milled for a perfect fit and drilled for
the pivot pin. The pivot pin has two holes drilled for cotter pins; the lower
hole is used when the welding shield is fitted. The faceplate is held closed
with a toggle bolt and a wing nut. The toggle bolt (called swing bolt in the USN
Diving Manual and screw bolt on the USN drawings) is machined from free
machining (FC for free cutting) Yellow Brass square stock on the Brown & Sharpe
Wire Feed Screw Machine. Once the ½-13 thread is cut, the square end is drilled
for its’ pivot pin and rounded to clear the inside of the hinged recess. The
threaded end is necked down to 5/16th inch for about a thread for a brass
retaining washer. The bolt will be pinned in place before tinning the helmet.
The polished cast brass wing nut is drilled and tapped for the ½-13 thread. It
has a tapered seat to lock into the faceplate’s countersunk recess and once
closed the faceplate seals against the flat gasket. The safety lock dumbbell
lever and its’ pivot body is machined and pinned together. It will be soldered
and tinned on the helmet as an assembly.
shell is placed over a heavy steel male mandrel, the collar ring is clamped down
over it. The edge of the copper sheet is trimmed and then peened over the ring,
ready for soldering. Four, heavy, straps, called brails (short for brass rails),
are drilled, ground smooth and polished to fit the studded flange and are
stamped “front” and sometimes “back”. These brails (also spelled brales) are
called “sectional collar straps” on the USN drawings. They will clamp the
dresses’ rubber neck gasket to the breastplate providing a water tight seal.
Eyelets are ground and polished from small castings and will be soldered to the
front of the breastplate. These are used to tie off the air hose and
communications/life lines to the front of the breastplate. The twelve studs are
cut on the B&S Screw Machine…threaded ½-12 from 5/8 inch round bar stock leaving
a 3/16 inch head. As noted the “bastard” stud, is slightly longer. And,
finally, the twelve wing nuts are drilled and tapped to ½ inch -12 thread to fit
the studs and polished. There are eight regular nuts and four with large flanges
to fit over the gaps at the ends of the brails.
THE SOLDERING STATION
The safety lock’s dumbbell (ball lever) pivot pin is retained by peening over its’ retaining washer and then the small assembly and the spit-cock’s body is clamped thru the shell with a threaded washers on the inside and then soldered in place. The transceiver’s cup is soldered in place over its’ cutout. On the back of the shell the two goose necks are riveted on with three copper rivets through large backing washers on the inside and then are soldered in place. While on the inside, the thin sheet air ducts, the transceiver mounting studs and small tabs for wires are soldered in place.
THE MK V FINAL ASSSEMBLY
Fastened to the right hand gooseneck is the non-return check valve. Straight
forward in design the valve requires great care in assembly. The reason for the
check valve is subtle but critical. Should the compressor or air line
fail…without the non-return valve the greater pressure in the dress would try to
escape up the hose to lower pressure. This will, in effect, try to force or
“squeeze” the diver into the rigid helmet and will result in serious injury or
death. The non-return feature prevents this from happening. As little as
one-fourth p.s.i. air line pressure will open the check valve and flow air into
the helmet but when the pressure drops the valve closes promptly. The non-return
valve design was changed by the US Navy in the late 50’s or early 60’s from a
multi part spring/stem and leather seat arrangement to a body utilizing a
standard check valve cartridge made by Kepner Products Company. DESCO’s current
non-return valves are of the later cartridge style. This valve should be tested
before every dive. It is easily assembled and disassembled for regular
inspections. The protective caps for the gooseneck fittings, sealed with leather
gaskets, are an added necessity.
Links to other online articles
SS Westmoreland Salvage attempt by Jack Browne & Max Nohl in 1936 Michigan Mysteries website
Max Nohl diving bell for Silver Springs Milwaukee Journal article January 21, 1940 found on google news
Life of Max Nohl Milwaukee Journal article February 6, 1960 found on google news
Videos posted on Youtube.com
U.S. Navy Training Videos:
U.S. Army Diving Video:
Miscellaneous Diving Videos:
Diving on TV