Origin of Rebreathers & Underwater Warriors


by Mark Phillips:

LCOC unit approaching beach

photo credit: www.history.com


War is one of mankind’s greatest failings and perhaps one of the greatest instigators of invention.

In war men fight. Ships sink. When men learned how to extend their time underwater to salvage sunken vessels it was their nature to consider the concept of an underwater warrior. Those soldiers would have to be comfortable in most any condition of water. They would have to be able to swim great distances and still have the strength and stamina to carry out their mission and still escape unharmed.

They would need specialized breathing equipment that would allow them to breathe underwater. In order for the apparatus to allow for long range penetration of enemy held areas, it had to reuse the exhaled breath of the diver while preventing exhaust bubbles from escaping and giving away the position of the diver. It had to offer extended time underwater, be light weight, versatile and dependable. It had to be a rebreather.

On the morning of June 6, 1944, Operation Overlord commenced. It was an event like none other and was divided into many parts, each of which had to work with the others to be successful. It was also the beginning of Operation Neptune and began the invasion of France at Normandy. It was D-Day. It was the largest amphibious invasion in world history.

Those landing from water were to land on one of five beaches code named Utah, Omaha, Gold, Juno and Sword. The hard thing about such an invasion is that it is hard to hide. When those occupying the land do not wish to be invaded, they resist.

Fortifications, hedgehogs, steel and concrete spikes, some steel tetrahedral, mines and other hazards had been placed on the beaches and in the water. Guns were placed on heavily fortified bunkers perched on the hillsides. Fortified machine gun nests had overlapping fields of fire. And the guns of Pointe Du Hoc could rain down hell on both Utah and Omaha beaches and sink vessels at sea 15 miles out.

Before the landing craft could land the fortifications blocking their way had to be destroyed. Naval demolition teams were responsible for those obstacles underwater and the Army engineers above water. But plans never quite work out the way they are supposed to.

The weather changed. Conditions worsened but once started Operation Overlord could not stop. The degrading weather cost them time and high tide was missed. Because the tide was out when the demolition teams made it to their objectives, most of the obstacles were out of the water. The naval group took those seaward while the army teams placed explosives on those closer to land. On D-Day, they were not all referred to as frogmen. Those from the Royal Navy were Landing Craft Obstruction Clearance Units. More commonly called Lockyews.

LCOC

photo credit: www.wikipedia.org

Landing Craft Obstruction Clearance Units
The ‘LCOCUs’ were a vital part of the D-Day invasion forces in Normandy.

Four Royal Navy and six Royal Marines units comprising 120 divers wore newly developed neoprene suits with ‘blast proof’ kapok jackets underneath, helmets, breathing apparatus and fins.

They laid the foundations for the Very Shallow Water (VSW) and beach clearance techniques in use today.

Those remaining after the war were eventually incorporated into the Clearance Diving Branch.

A RN demolitions team was working Gold beach. When they arrived, they found that the obstacles they were to clear were underwater. Each of the hedgehogs they were to clear had to have 36 small charges placed at strategic positions so that the steel would blow into pieces with none more than 18 inches above the bottom. Each of these obstacles was covered with pressure sensitive explosives designed to punch holes in water craft.

Lt. Hargreaves described the experience:

“We must have been about four hundred yards from the beach when the firing first started, and they didn’t forget to inform us that they knew we were coming. When we finally got on the beach we discovered that we were being systematically sniped, not only with rifles but also by odd bursts of machine-gun fire – a most unpleasant experience”.

On another beach one of the men described his experience like this:

“We were spotted from a tower ashore and were subjected to pretty heavy mortar fire during which a petty officer was killed and two men were wounded. Later the R.A.F. blotted out the tower and things were more comfortable although shells still kept coming over. One shell destroyed our breathing apparatus, which we had not been using as the tide was low. When the water came up later, Leading Seaman A. Robertson and myself tried staying underwater by holding our breath. We blew about fifteen obstacles in this way, but we couldn’t keep it up. We carried on the next morning, after sleeping in a R.A.F. crater, where incidentally we were subjected to fire from an 88mm gun.”

Dennis Shryock was 21 years old when he landed on Utah Beach. Dennis had been trained as an explosives specialist and one of those elite men who were the forerunners of our modern day Navy Seals.

The machinegun fire was deadly. They did not have the protection of being underwater and had to wade to each of the obstructions to place explosives. He said the water “looked like pure blood.” But they did the job.

According to navy statistics, at Utah, the demolition teams lost six men and had eleven wounded. Omaha beach did not fare as well. They lost thirty-one and another sixty were wounded.

the cliffs at Pointe du HocPointe Du Hoc
The water was rough from the stormy wind and the unexpected rain soaked equipment that was intended to remain dry. It took the landing craft longer to reach the beaches than expected. The plan was to hit the beaches at high tide; for the troops to be able to take shelter in the bomb craters as they made their way up the beaches. But they missed high tide. Most of the obstacles placed to keep the landing craft away were on dry land. When they were able to land, the troops had to run through wet sand 300 to 500 yards just to get to the bomb craters. Landing craft that had been fortified with bullet proof plating caused the crafts to ride much lower in the water. Too many of them were swamped and sunk before they could reach shore. The majority of the soldiers on board, weighted by 70 pound of equipment, drowned. Those that survived had to face a wall of bullets and artillery shells.

The guns at Pointe Du Hoc had to be taken. The 2nd Ranger Battalion had trained hard in preparation for this day. They had practiced climbing cliffs and had brought along firefighting ladders and rocket propelled grappling hooks to help make the 100 foot climb. But it had rained.

The ropes were wet and the propellant used was calculated with dry rope. The ladders were hard to foot and difficult to climb. German machinegun fire was held to a minimum by sharpshooters on the ground but they could not stop them from dropping hand grenades in an effort to keep them from climbing.

The 2nd Ranger Battalion clawed their way to the top using footholds in the mud and rocks and bayonets driven into the cliff side when necessary. It took them twenty minutes to make the climb and take the Pointe. They held it for two more days before reinforcements reached them. Of the 200 men that started, only 90 were left in fighting condition.

What exactly was the breathing apparatus used by the USN frogmen and the Royal Navy Landing Craft Obstruction Clearance Units? It was able to supply an extended amount of breathing gas underwater by reusing the exhaled breathe of the diver. It did not allow exhaust bubbles to escape and was stealthy. It was lightweight and maneuverable. It was a rebreather.

While only remotely similar to rebreather units today, the ones used in 1944 were many generations of development old. In fact, the Italians started the concept of underwater assault teams using specialized equipment. And they recognized the need as early as World War 1.

In 1918 two members of the Regia Marina (Royal Navy) literally rode a torpedo into a harbor and sank an enemy ship. At the time, they had no breathing equipment and had to guide the torpedo at the surface in order to breath. They sank the ship but were captured when they tried to swim away. These human torpedoes became more like mini submarines and were human guided. Obviously the ability to be under the water, able to breath and stay stealthy was an advantage.

By 1941 the Italian navy had both a surface unit that operated fast, explosive motor boats and a subsurface unit that used manned torpedoes. Within this group they also had assault swimmers. It did not take long before other countries developed their own versions.

The idea of an underwater warrior is older than modern history. The functional ability to use such a warrior has always been limited by the inability to breath underwater. Throughout history, man has found ways to extend his time underwater and by the turn of the 20th century, some of the first closed circuit rebreather systems had been experimented with and used. The rebreather units used on D-Day were rudimentary compared to the modern versions we see today. But at the time, they did the job and those who used them had to be beyond courageous.

On June 6, 1944 those underwater warriors had a mission to do and short of being killed or captured, that is what they did.


Mark PhillipsMark Phillips is a retired 33 year career firefighter and Public Safety Diver; A Master Scuba Instructor an ERDI trainer, and Publisher of PSDiver Monthly, an Internet magazine dedicated to advancing the safety and knowledge of the Underwater Investigator.



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