Dreager larv: The spec ops combat diver’s secret weapon

[Peter1469]

It isn't civilian scuba gear.


DREAGER LARV: THE SPEC OPS COMBAT DIVER’S SECRET WEAPON

Editor’s note: The following piece on the Dreager LarV was written by retired Delta Force Master Sergeant George E Hand IV. While this piece discusses special operations equipment, it does not reveal any classified information.

Recreational SCUBA diving with standard compressed air can give a diver about an hour of bottom time. That of course is largely dependent on the depth the diver spends his time at; the deeper one goes the less time he has at depth. A rule of thumb is 60 feet for 60 minutes and then you should come out of the water. The longer you stay at depth also governs how long you must wait on dry land before you can go back to SCUBA diving.

Imagine now being able to stay underwater for more than four hours without ever even exhaling a single bubble. The military has a system that “breathes” pure oxygen (O2) and is based on a closed gas system. SCUBA features an open gas system; that is where each exhaled breath is released out into the water and rises to the surface where it stirs up the water and creates an unmistakable profile that there is a person diving down below.


Draeger LarV: The Third Lung of Combat Divers

The LarV’s third lung bag is filled with O2 at the beginning of the dive. There are two breathing hoses on the rig; one is for inhalation and the other is for exhalation.


1. A breath of O2 is drawn from the breathing bag through the breathing hose


2. The breath is exhaled into the exhalation hose that leads to the scrubber canister where the CO2 is scrubbed from breath; the scrubber is a caustic soda-lime solution that has a great affinity to absorb C02 from a gas; it looks for all the world like cat litter (see image below of soda-lime product in a canister).

3. the exhaled breath leaves the scrubber canister and returns to the breathing bag with the residual O2 where it is re-breathed by the diver.
4. As the O2 is in your breath, that is, the volume of breathable gas in the third lung bag becomes depleted, the regulator detects the drop in pressure and refills the third lung. There is also a large override button on the top front of the LarV case that allows the swimmer to refill the bag at will. Sometimes the diver just doesn’t agree with how much O2 the LarV thinks he needs and feels the urge to override the regulator.

Staying Underwater

Read the rest of the article at the link.

[Peter1469]

Not every new naval vessel needs to be an air craft carrier or a ship-of-the-line. These smaller frigates will serve an important role.

US Navy to equip Constellation-class frigates with 57mm Mk 110 guns

The US Navy has decided to equip its new Constellation-class frigates with fully automatic 57mm Mk 110 naval guns.


The Naval Sea Systems Command Integrated Warfare Systems 3C (NAVSEA IWS) has placed a $26m contract with BAE Systems to equip the vessels with the Mk 110 systems.

As part of the contract, BAE Systems will deliver two Mk 110s for the USS Constellation (FFG 62) and USS Congress (FFG 63), the first and second ship of the Constellation-class of vessels.




The contract also includes engineering support for the naval guns.

Internationally known as the Bofors 57 Mk 3, the Mk 110 gun system is a multi-mission, medium-calibre shipboard weapon piece capable of firing up to 220 rounds per minute at air, surface or ground threats.


The gun has an effective range of more than nine nautical miles using BAE Systems’ six-mode programmable, pre-fragmented, and proximity-fused (3P) ammunition.