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Tango - Douche Boat Conversion

TANGO (“Douche” Boat Conversion)

Displacement: 66 tons 
Length: 56.5 feet 
Beam: 17.5 feet 
Draft: 3.5 feet 
Propulsion: 2 Gray Marine 64HN9 225 hp, 2 shafts; 1 Detroit Diesel 12V71 driving 3,000 psi centrifugal pump feeding 2 water cannons Speed: 8.5 kts 
Crew: 7 
Weapons: 3 20mm Mk 16 or 2 20mm Mk 16 and 1 40mm Mk 19 grenade launcher

Photo: Matt Zimmer

Note: A Tango boat conversion that would literally wash away sun-baked mud bunkers along river banks that would stand up to 105mm howitzer fire. This “Douche” boat (above) was photographed at the Nha Be docks.

Another LCM-6 conversion was the “Douche” boat that had a pick-up, pump, and fire hose nozzle. The “Douche” boat was used to wash-away mud bunkers along the river banks with a high-pressure water stream.

HISTORY: Link to: for a complete description of this craft.  (Linked with permission)

09-10-07  Ray F. Longaker Jr., BMCM (SW) (CMC) USN/Ret.

In an attempt to support your on-line photo-history of Vietnam era boats, please find below photographs of the Armored Troop Carrier [Water Cannon Conversion] of which I was Boat Captain of Tango-14 Assigned to River Squadron 13, River Division 131 from October 1969 to June 1970.  Tango-14 was then turned over to the RVN Navy and I was transferred to River Squadron 15, River Division 153 as Boat Captain of Tango-32, the other Water Cannon Conversion. 

The well deck of each boat was fully loaded with machinery for the water cannons.  The prime mover was a Grey Marine 12V71 with a Power-Take-off-Transmission connected to an 18" Fairbanks-Morse centrifugal pump.  The suction line was 14" pipe running down the port side the stern where there was a swivel strainer which was lowered when the water cannons were to be employed.  Also in the well deck there was a diesel fuel tank for the 12V71, a vacuum pump connected to the 12V71, an vacuum expansion tank and the associated valves and piping to the Stang Intelligiant Water Cannons.

The water cannons put out 2,700 gallons of 'river' water a minute at 250 pounds of pressure at the nozzles.  Doesn't mean much, just words, however in other words if you stood to the side of the water cannon discharge and tried to drive a baseball bat through the stream of water, the water would tear the bat out of your hand and the resulting momentum would quite possibly fling you over the side! 

My assigned mission was to search out and destroy NVA/VC bunkers, spider holes, trenches, booby traps and cashes.  My crew and I did just that. 

If you so choose, I will be more than happy to provide you with what ever information you may need in this regard.  I've seen what people have said about my boat and it doesn't come close to doing the unique boat(s) justice. 

Anyway, submitted for your review are some photographs and drawings of "Irma-La-Douche."

 Most Sincerely, Ray

Rays Irma La Douche PowerPoint presentation can be seen HERE or review the individual slides below: