Development of the M1966 Jungle Hammock began in July 1966 when USARV requested a lightweight compact hammock for use in Vietnam. The standard model was too heavy (3lb 14oz.) and too bulky to be carried on combat operations and as a result soldiers frequently slept on the jungle floor.
Natick Labs fabricated a prototype 1lb. 6oz. hammock made from a single layer of nylon fabric that was based on a captured North Vietnamese design. They also procured a 1lb. 8oz. rectangular nylon fishnet type hammock from commercial sources. One hundred hammocks of each design were sent to Vietnam for evaluation in September 1966 and in April 1967 ACTIV recommended that the NVA style model be procured for issue to U.S. forces.1
The production M1966 hammock was made from a single layer of 100” by 34”nylon cloth with a draw cord tunnel at each end through which 14ft of braided rope was passed. An elastic cord with a toggle was attached to each rope, which allowed a poncho to be quickly suspended above the hammock for rain protection.2 Spreader sticks could be inserted into the corner grommets of the poncho to ensure a rain shedding gable-ended canopy.
Unfortunately, though the nylon fabric used in the production M1966 hammock was sufficiently tightly woven to stop mosquitoes biting through it, it also made the bed virtually waterproof and prevented sweaty skin from drying.3
1. Support To United States Army In Vietnam - Clothing & Equipment (United States Army Material Command Feb 1967)
2. Support To United States Army In Vietnam - Clothing & Organic Materials Vol II (United States Army Material Command Aug 1968)
3. Jungle Snafus...and Remedies by Cresson H. Kearny (Oregon Institute Of Science And Medicine 1996)