U.S. Assault Boats M1 & M2

Summary of U.S. M1 and M2 assault boats from Stream Crossing Equipment, Information Bulletin No. 120, Office of the Chief of Engineers, July 1943.


7. PURPOSE.—Assault boats are light, easily transported craft used to carry leading assault elements in a forced stream crossing. M2 assault boats are also used as flotation for the infantry support raft and expedient assault-boat bridge.


a. Description.

(1) The assault boat, M2 (fig. 2), is a scow type plywood boat with square stern, flat bottom, and slightly tapered bow. It has the following specifications:

Maximum width     5 feet 9 inches
Over-all length13 feet 4 inches
Depth2 feet 1 inch
Weight410 pounds
Useful displacement (8 inches free-board)4,000 pounds

M2 Assault Boat - U.S. Army in WWII

Figure 2.—Interior view of assault boat M2.

(2) Each M2 boat is equipped with two hinge connections and one boat-connecting pin, so that two boats may be coupled together, stern-to-stern, to form an assault-boat ponton of the type used in the infantry support raft and in the expedient assault-boat bridge. Two spacers for plywood treadways are located in each gunwale of the boats. Nine paddles are provided with each boat.

U.S. Army Assault Boat M2 with Crew in WWII

Figure 3.—Assault boat M2, with 15-man load.

b. Capacity.

(1) A three-man engineer crew is needed to operate an assault boat M2. The boat safely carries the following loads of combat-equipped infantrymen and weapons in addition to the three-man engineer crew:

(a) Rifle squad (12 men) with individual weapons and combat equipment (fig. 3).

(b) Two light machine-gun squads (10 men) with 2 caliber .30 light machine guns and 20 boxes of ammunition.

(c) One heavy machine-gun squad (7 men) with caliber .30 heavy machine gun and 13 boxes of ammunition.

(d) One Browning machine-gun squad (7 men) with caliber .50 machine gun and 4 boxes of ammunition.

(e) Two 60-mm mortar squads (10 men) with two 60-mm mortars and 72 rounds of ammunition.

(f) One 81-mm mortar squad (7 men) with 81-mm mortar and 50 rounds of ammunition.

(g) Infantry communication platoon wire section (8 men) with complete equipment.

(2) Two assault boats lashed together can carry the 37-mm antitank gun, its squad of 5 men, at least 100 rounds of ammunition, and an engineer crew of 3 men.

c. Carrying.—Ten to twelve men carry the boat (fig. 4). It is carried inverted to within a few yards of the water’s edge; then it is turned over, carried upright to the water’s edge, and launched.

U.S. Army Assault Boat in Carrying Position

Figure 4.—Assault boat M2 in upright carrying position.

d. Paddling.—The engineer in charge of the boat kneels at the stern and steers. The other two engineer crew members kneel, one at each side of the bow, and paddle. Six passengers also paddle.

e. Transportation.—The boats are nested in groups of seven (maximum 10) for transportation. These may be carried on 2½-ton trucks or two-wheel trailers.

9. ASSAULT BOAT M1.—The assault boat M1 (fig. 5) has been superseded by the assault boat M2. Since a considerable number of these boats are still in use, the boat is described briefly.

a. The M1 boat is a skiff type, flat-bottomed plywood boat. It is 13 feet 6 inches long, weighs about 200 pounds, and has a useful displacement of 3,200 pounds. It can carry safely, in addition to a two-man engineer crew, any one of the following loads of combat-equipped infantrymen and weapons:

(1) Nine riflemen with individual equipment.

(2) Eight men, 1 caliber .30 light machine gun, and 20 boxes of ammunition; or 8 men, 1 caliber .30 heavy machine gun, and 13 boxes of ammunition.

(3) Eight men, 1 caliber .50 machine gun, and 4 boxes of ammunition.

(4) Seven men, an 81-mm mortar, and 50 rounds of ammunition; or 9 men, a 60-mm mortar, and 150 rounds of ammunition.

(5) Seven men and equipment of an infantry communication platoon wire section.

b. The M1 boat is not equipped with hinge connections for making assault-boat pontons.

U.S. Army WW2 Assault Boat M1

Figure 5.—Assault boat M1.


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