INTRODUCING THE AMSAC
The Quartermaster Review
A NEW streamlined container for dropping supplies by parachute has just been perfected by the SOS quartermasters of the India-Burma Theatre. It’s called “Amsac”-American sack and the most rigid tests have already proved its superiority over all containers previously used. With the exception of the American-made metal rings used for attaching it to the parachute, Amsac is made in India by Indian labor, from Indian products, thus saving valuable shipping space on the Army’s longest supply line. In addition, Amsac carries a far greater load than any other container, is much stronger, and costs $3.50. The old baskets kicked from planes cost up to $54 each.
The Amsac was developed after IB personnel engaged in air supply activities pointed out that the container previously used was costly, elaborately built, capable of carrying relatively small loads, and difficult to obtain in large quantities.
A brief glance at the problems encountered by the Air Supply Service in securing enough containers to handle the volume of supplies required will give a better picture of the development of the Amsac. Shipping space, rail and sea, is at a premium. A limited number of standard containers of local origin were available to the Air Supply Service, but the total was not sufficient to meet all requirements.
To fill in the deficiency during 1944, personnel of the Air Supply Service worked out a container known as the “country basket.”. This consisted of a woven bamboo basket, enclosed in hessian cloth, and reinforced by rope sewn around the sides and bottom. The parachute was attached to the rope, which then served as a harness to carry the container and its contents.
The country basket had several advantages. It was made on the spot from bamboo available locally. The hessian cloth and rope occupied comparatively little shipping space, and were indigenous in origin. It was used mainly with a cotton parachute, of local manufacture, 18 feet in diameter, capable of carrying a maximum load of 200 pounds. However, when used with the standard 24-foot American cargo parachute, much of the capacity of the parachute was wasted.
As operations progressed and troops moved forward it became apparent that air supply activities would have to be carried on in areas where bamboo would not be available for manufacture of the country basket. With speed the determining factor, a new type of container became a necessity.
(See “The Bund1es-for-Burrna Boys,” in the November-December, 1944. issue of The Quartermaster Review)
Lt. Col. James E. Darby, Air Supply Officer, long stationed in India, suggested that a sack-like container could take the place of the country basket. He discussed this with Colonel Ralph Richards, Chief Quartermaster, India-Burma Theatre, who directed that immediate action be taken to design, develop, and test a container to meet the need. Lieutenant Riley G. Jones, Officer in Charge of the Specifications Branch, got the job and carried on from there.
After considerable research and study of various materials, Lieutenant Jones decided upon two types of jute canvas, one type of jute cloth, one type of jute webbing, and one type of cotton webbing, as the materials to be used in experimental samples. Jute was chosen since investigations revealed that cotton materials were not available in the quantities necessary.
Various plans of construction were drawn up and studied from a manufacturing point of view. Most practical was a sack-like container, 21″ square and 36″ deep, with a double bottom, all corners of double thickness, and reinforced with webbing sewn across the bottom and up each side, the webbing terminating in loops at one end and in a long section of free webbing at the other. The free ends of the webbing could cross the top end of the container and be tied through the loops to secure the contents. The webbing thus formed a harness-like reinforcement by which the parachute could be attached. A tentative plan was finally drawn up, together with specifications covering five types of containers. Although all five types were of the same shape and size, each type was to be made from different combinations of the materials chosen. These plans and specifications were tentatively approved by the Chief Quartermaster, who directed Lieutenant Jones to have experimental models manufactured. He further directed that Lieutenant Jones take the models up to the Air Supply Service and assist in tests and further study.
In a relatively short time the first experimental models were ready for tests. These were carried out under the supervision of Colonel Darby, with the assistance of Captain Robinson, Air Supply Operations Officer, and Lieutenant Jones.
All tests were conducted under conditions approximating as nearly as possible the conditions of actual supply by air. The standard 24-foot American cargo parachute and items normally supplied by parachute were used. The latter consisted of rations of various types, ammunition, mortar shells, drums of water, reels of wire, and mixed loads of these items. Containers were dropped from a plane traveling at speeds up to 130 m.p.h.
In the first test, weights of loads ranged from 245 pounds to 298 pounds, and one container carried a 42 gallon drum of water weighing 404 pounds. The latter was an unintentional overload, but provided a useful test. Three failures resulted from the first test, one of which was not attributable to the container. Two failures were traceable to the weakness of the webbing used in the container.
Further study of test results revealed some weaknesses in all containers dropped. The body showed a tendency to rip at the seams where the webbing was sewn to it. The webbing, by which the parachutes were actually attached to the container, and which bore the brunt of the shock of the blossoming parachute, showed weakness at the point of attachment of the ‘chute. It was therefore decided to modify the original container by adding a fourth web strap and reinforcing the midsection by sewing webbing around the container, horizontally.
A second test was then arranged. Several containers were loaded to weights ranging from 313 to 354 pounds, and D-rings were used to attach the parachute. These modified containers were dropped with generally successful results.
It was finally agreed that certain types of jute canvas and jute webbing were the most satisfactory, but that a D-ring or V-ring should be developed for use in attaching American parachutes. The D-ring was decided upon, and arrangements were made to make a few for tests.
In order to determine the maximum loads which the Amsac could carry, and the possibility of using the containers a second time, a third test was carried out. Four containers from the previous test were used, along with containers not previously dropped. Loads ranged from 404 pounds to 465 pounds. The four containers dropped previously were loaded to 465 pounds, and all four broke free of the parachute, due to the breaking of the webbing where the ‘chute was attached. The body of the container was not affected by this load. A V-ring on a fifth container, carrying 465 pounds, also broke, causing the entire load to fall on the other V-ring, which pulled through the webbing. The remaining containers met the test successfully.
Rigid tests thus established that the Amsac could carry the average load of the 24-foot American parachute successfully and still have an overload capacity. The two defects, weakness of the webbing at the point of attachment to the ‘chute, and the weak V-rings-could be readily overcome, as was later proved, if heavy loads were to be dropped.
A fourth test was arranged, with loads of 354 to 360 pounds, to determine the suitability of the D-rings made locally from American metal salvaged from a scrap pile. All drops were successful, but studies of the D-rings led to the conclusion that V-rings of the same size would prove more satisfactory for use with the Amsac. Later developments showed that these V-rings could not be procured locally in the quantities desired, and arrangements were made for importing them from the United States.
In no case of successful drops was there any damage to the contents. The body of the container, after modification, showed no visible damage, even when loaded to 465 pounds.
All tests proved conclusively that the Amsac could not only replace the country basket but, in many cases, the prefabricated container supplied through local sources and the containers supplied from the States.
Lieutenant Jones, the officer chiefly responsible for development of the new container, has been in the Regular Army, and in the QMC, since 1934, when he signed up at Fort Riley, Kansas. He was commissioned in 1942, and since March 1943 has been stationed in India, most of the time along the Stilwell Road.