In deep

Milwaukee is hundreds of miles from any ocean coast, but the city has played a critical role in the development of commercial diving equipment. And some of that equipment is still made here.

During the 1930s, Max Noll, a Milwaukee diver, and several partners began manufacturing diving equipment that would allow Noll to reach depths that were previously unreachable. Reaching those depths required Noll to breathe a mixture of oxygen and hydrogen, unlike the normal atmospheric mix of oxygen and nitrogen.

Noll’s fledgling company was named Diving Equipment and Supply Co., later shortened to DESCO Corp. In December 1937, Noll used the new style of diving gear and its exotic mixture of breathable gases to dive to 420 feet in Lake Michigan, breaking the previous world record.

During World War II, DESCO Corp., a manufacturer of commercial diving helmets, employed about 150 people and made a significant portion of the U.S. Navy’s diving equipment for the war effort. The company made dive suits, knives, boots, belts and the Mark V, the Navy’s dive helmet.

“Milwaukee was where the foundries and machine tool shops were,” said Ric Koellner, who has owned DESCO for about 10 years. “And to this day, more (commercial) diving is done within a 500-mile radius of Milwaukee than all of the coasts combined. Every sewage plant, water treatment and dam, they all have to be dived into.”

DESCO still builds Mark V helmets, which are primarily sold to collectors. It also makes several new versions of other classic dive helmets, dive knives, diving boots and related gear, as well as the DESCO Air Hat – the preferred diving helmet for diving into contaminated water such as nuclear power plants, sewage and water treatment plants.

The Air Hat was developed in 1967 by Thomas Fifield, an attorney with Gibbs, Roper and Fifield (now known as von Brisen & Roper, S.C.), who purchased DESCO in the early 1960s. Fifield designed the helmet after he heard about commercial divers in Louisiana using motorcycle helmets sealed with silicone, Koellner said.

“He (Fifield) did all of the drawings then went into his basement and built all of the wooden parts,” he said. “He took them to the foundry – then he machined the parts, soldered them together and sent them to be tested in the Gulf (of Mexico).”

The DESCO Air Hat uses constantly flowing over-pressurized air flow connected to a compressor on the surface, making it highly sealed against leaks. The over-pressurized seal has made the Air Hat the diving helmet of choice for divers at nuclear power plants, sewerage treatment facilities, dams, rivers and other inland or contaminated waters, Koellner said.

The Air Hat does not use exotic gases, so divers can only use it up to depths of 160 feet or less, Koellner said. However, most commercial dives, especially those in fresh water, are of depths less than 160 feet and don’t require exotic gases.

DESCO’s Air Hat has won favor among commercial divers who work in nuclear power plant cooling tanks because the helmets are lower cost than plastic and fiberglass models, Koellner said. Those helmets must be discarded after one use in nuclear facilities because they cannot be decontaminated, he said. In some cases, the DESCO models can be decontaminated if they are stripped of all parts, sandblasted and rebuilt.

DESCO makes 12 other models of diving helmets, other than the Air Hat. Most of those models are classic designs, which are reproductions of diving helmets used before scuba gear became prevalent.

Although all of the DESCO helmets are suitable for diving, many are bought by collectors, Koellner said.

The company was recently commissioned by Historical Diving Society USA to create 26 U.S. Navy Mark V helium helmets to commemorate the salvage of the USS Squalus, a submarine lost in 1939. Twenty-four Navy divers and two civilians lost their lives when the Squalus sank.

DESCO has also done a large amount of work refurbishing old diving helmets for collectors. Many of those helmets weren’t made by DESCO, Koellner said.

“Every country in the world had companies making diving helmets,” he said. “The problem lies within the little differences between each.”

Each time DESCO receives a model of helmet it hasn’t refurbished before, it has its foundry make models of the hardware from that helmet so it can make additional parts later.

“There are hundreds of classic hats to rebuild, refurbish and bring back to diveable condition,” Koellner said.

DESCO does not cast its own parts – it relies on a nearby foundry that it has a long-lasting relationship with to do that. Components, including helmet casings, are delivered as raw casings. All machining, cutting and tooling is done at DESCO’s facility.

DESCO has six employees. The company has had about 45 percent revenue growth since Hurricane Katrina struck in 2005, Koellner said, largely because of the increased demand for commercial diving gear.

“There was so much contaminated water that (divers) had to use our products,” he said.

Several oil companies have purchased DESCO Air Hats to repair oil production facilities, Koellner said.

One of DESCO’s competitors that makes composite helmets which use exotic gases is still experiencing a 16-month backlog for orders, Koellner said. Some of the company’s other customers have turned to DESCO for faster order turnaround.

The increase in sales should last at least another two years, Koellner said.

“We’re sitting on the crest of it now,” he said. “In the first year after it, we were all working nine hour days. Now we’re back to a regular schedule.”


Address: 240 N. Milwaukee St., Milwaukee
Products: Commercial diving helmets, helmet restoration and commercial diving accessories
Revenue growth: 45 percent since late 2005
Employees: 6
Web site:

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