Copyright 2011 by Brandon Cope
ALVT (Assault Landing Vehicle, Tracked)
Inspired by Atlantean designs (but using only 1942 Earth
technology), the ALVT was intended to provide significant fire
support to the first troops to come ashore during an amphibious
operation. Rather unusually, it was designed specifically for the
USMC, who normally got rejects or left-overs from the Army and Navy.
The armor was superior to that of the LVT(A) (p.W:DF89) and
M-3 halftracks (p.W.109), but poor compared to even light tanks. It
did have impressive firepower: a 105mm howitzer to deal with dug-in
troops and fortifications, a 20mm cannon to handle vehicles (later
replaced with a flamethrower) and three machineguns. Initially it was
planned to only carry a nine-man squad but the Marines objected and
the vehicle was enlarged to carry a full thirteen-man unit (the
larger size actually improved sea-keeping, which is still poor).
The ALVT was never intended to replace the cheaper LVT, only
to augment it. Each Marine division was equipped with an ALVT
battalion of 46 vehicles (with 14 per company and 4 per platoon).
When used, they were in the first wave of any major Marine amphibious
operations. A total of 329 were operated by the six Marine divisions
from January 1943 through the end of the war (including replacements
to cover losses and those retired for training).
The vehicle
also carries four M-1 carbines, eight fragmentation grenades and four
smoke grenades for the crew. Additionally, the bow MG can easily be
removed and placed on a tripod if required.
The ALVT-1 has a
crew of four. The commander sits in the turret and mans the
open-mount A/A machine gun. The gunner and loader/radio operator are
split between the turret and body; the gunner fires the howitzer,
autocannon and coaxial machinegun. The driver is in the hull, to the
left (with the engine and fuel tank to his right) and fires the bow
MG (which is in a fixed mount). Thirteen troops are carried and exit
either via two roof hatches or a rear drop ramp. The gunner and
loader manually traverse the turret at 4.5 degrees per second. The
ALVT-1 uses 8.3 gallons per hour at routine usage.
Subassemblies: Waterproofed Immense Tank chassis with mild
slope +4, full-rotation Medium AFV turret with mild slope [Body:T]
+3, full-rotation Mini Weapon open mount [Tur:T] +0, amphibious
tracks +3.
Powertrain: 186-kW diesel engine w/ 186-kW
tracked drive train and 54 gallons fuel in self-sealing fuel tank
[body]; 8,000-kWs batteries.
Occupancy: 1 CS Body, 2 CS
Body/Turret, 1 CS Turret, 13 PS Body Cargo: 2.5 Body.
Armor
Body/Turret: F 5/45, 4/30 other
Tracks: 4/28
Weaponry
105mm Short Howitzer/M-2A1 [Turret:F] (48).
20mm Long Ground AC/M-2 [Turret:F] (450).
Ground LMG/M-1919A4
[Tur:F] (3,000).
Ground LMG/M-1919A4 [Body:F] (2,500).
Very
Long Ground HMG/M-2HB [Mini:F] (400).
Equipment
Body: Fire extinguisher, medium radio
receiver and transmitter. Turret: 6 smoke dischargers.
Statistics
Size: 25'x11'x8' |
Payload: 3.16 tons |
Lwt: 17.8 tons |
Volume: 178 |
Maint.: 55 hours |
Price: $13,400 |
HT: 11
HP: 1300
[Body], 112 [Turret], 450 [Each Track], 30 [Open Mount]
gSpeed: 27 |
gAccel: 4 |
gDecel: 20 |
gMR: 0.25 |
gSR: 6 |
GP: Very Low (4/5) |
wSpeed: 7.5 |
wAccel: 0.2 |
wDecel: 10 |
wMR: 0.1 |
wSR: 2 |
Draft: 2.2' |
Floatation: 18.8 tons
Design Notes
The cost, weight and HPs of the chassis and
turret were divided by two. Track DR was also divided by two.
The 105mm was normally provided with 40 HE and 8 WP shhells. The 20mm autocannon normally used API ammo.
Variants
The Army, in anticipation of the coming
invasion of Fortress Europe, ordered 500. The first 100 were the same
as the Marine version, to speed delivery. By late 1943 these had been
removed from front-line use and were transferred to training
units.
The Army was unhappy with several aspects of the
design, however, and changes were made to create the ALVT-2 (1944).
The next 400 differed in having the diesel engine replaced with two
linked 95-kW gasoline engines (as used in the M-3 halftrack).
Additionally, the tracks were replaced with a more standard design,
giving a speed of 48 mph on land and 4 mph on water (as these
vehicles were primarily used on land and for river crossings, this
was not a large decrease in capabilities). Finally, and most
drastically, the armament was reduced as the Army considered it
excessive;.the 105mm howitzer was replaced with a 75mm howitzer (75mm
Short TG) with 96 rounds and the 20mm AC was simply removed.
Hydraulic traverse (1-kW) was added, good for 13.5 degrees per
second. Cargo is 7.5 VSP. Cost was $11,700 and weight 17.6
tons.
Most of the Marine vehicles replaced the 20mm cannon
with a more useful flamethrower (Medium Vehicle FT with 15 shots) as
the war went along; this was much rarer in those operated by the
Army. These were designated ALVT(F)-1 or -2.
There were also
some field tests of ALVT-1's replacing the 20mm cannon with a 37mm
anti-tank gun. Only a few vehicles were modified and it was not found
to be very useful (in particular, it cut into the limited ammo for
the howitzer)..
The British received 16 ALVT-1's and 49
ALVT-2's through Lend-Lease. They replaced the 105mm howitzer with a
25 pounder (56 shells) and kept the 20mm cannon. The ALVT-1's were
operated in Greece and the ALVT-2's in Burma.