Is there an amphibious car?

The experience of World War I shows that amphibious landing under enemy fire is a very difficult combat operation, which can be seen from the fiasco of Commonwealth troops in gallipoli during the war. In the 192s and 193s after the war, the decision makers of the US Marine Corps began to try to find a better amphibious landing solution. However, under the background of the reduction of troops in various countries after World War I, the budget obtained by the US Navy is quite limited, so neither the amphibious landing craft nor the development of new amphibious tracked vehicles can get enough financial support.

Early development attempt of tracked vehicles

In fact, as early as the 192s, an imaginative American inventor, J. Walter Christie, had put forward a proposal to the US Marine Corps and Army to develop tracked amphibious combat vehicles; At the same time, he also provided the United States Marine Corps with the M1923 amphibious tank designed by himself. To be exact, this "amphibious tank" should be called a self-propelled gun, because a 75mm cannon is fixedly installed on its car body. The prototype of the M1923 amphibious tank participated in the landing exercise of the US Marine Corps in Puerto Rico in 1924. Although the officers of the Marine Corps thought it was a "very interesting" vehicle, in the exercise, its wave resistance, underwater maneuverability and speed disappointed the Marine Corps. The navy and marine corps immediately rejected this design after the exercise. Instead, the US Marine Corps decided to choose another 6-ton "special amphibious engineering vehicle" design. This kind of engineering vehicle is designed based on the famous FT-17 light tank of the French army in World War I.. Although both the US Navy and Marine Corps approved this design, at that time, the military did not have enough budget to support this plan, so the development of tracked amphibious vehicles once again ran aground.

Donald Roblin and his "alligator"

In 1935, an unprecedented hurricane hit Lake Okeechoby, Florida, which caused a lot of casualties. John Roblin Jr., a local engineer, suggested to his son Donald Roblin that if there was an amphibious vehicle that could be unimpeded in the swamp area, the casualties caused by this disaster could be greatly reduced. So Donald Roblin began to design a new amphibious rescue vehicle.

Note 1: The Roblin family is a famous American engineer family. Donna Roblin's grandfather, Washington Roblin, is the designer and builder of the famous cable bridge in Brooklyn, new york.

At the end of p>1935, Donald Roblin designed and built the first prototype car. Roblin nicknamed this new type of tracked amphibious vehicle "alligator". Its car body is made of aluminum alloy, and it uses crawler-type mobile device and suspension system. Its speed on land can reach 4 km/h, but its maximum speed in water is less than 4 km/h, and its handling performance in water is poor, which does not seem to meet the original intention of Roblin's design. In February, 1936, Roblin completed his second prototype. The total weight of the new car was reduced by about 1 ton, and the inclined track gear was installed on the track plate, thus improving its speed in water. Now the speed of alligator in water is increased to 1 km/h, but its speed on land is reduced to 27 km/h. Of course, the second prototype did not satisfy Roblin.

After repeated modification and verification, in 1937, Roblin redesigned and manufactured an almost brand-new amphibious rescue vehicle. The new amphibious vehicle weighs about 3.9 tons. Due to the further improvement of the crawler system, its speed on water has reached 13.5 km/h, while the speed on land has reached 32 km/h.: Moreover, due to the adoption of Ford's 85 horsepower gasoline engine, its power system is more reliable.

(Figure 1): The first alligator prototype car completed in Roblin in 1935. From the appearance, it has almost no similarity with the later LVT series amphibious vehicles. (Figure 2): The second prototype completed in 1936 already has some prototype of the LVT-1 amphibious vehicle.

(Figure 3) The prototype car completed in 1937, the new alligator improved the original suspension system, because it caused too much resistance in the water. At the same time, due to the reduction of car body size and weight, its speed and maneuverability in water have been improved. This should be the picture published in Life magazine.

In 1937, Life magazine in the United States published an article introducing the tracked amphibious rescue vehicle made in Roblin. This article attracted the attention of the high-level marine corps. They realized the potential military value of this vehicle, so they proposed a plan to use similar amphibious vehicles for landing combat tests to the Navy Department. However, it seems that the top management of the navy is not very interested in this. The request of the Marine Corps was rejected by the Admiralty on the pretext of insufficient funds, and the Marine Corps protested. In October 1939, Gen.Moses, the chairman of the Marine Corps Equipment Committee, persuaded Roblin to design a special amphibious vehicle for military applications. General Moses pointed out that the military amphibious vehicle should be more reliable, and its body structure should be able to withstand the impact of waves better.

Note 2:

At that time, the Marine Corps was a branch of the Navy. As the largest unit before the war, the position of the Marine Corps in the naval system can be imagined. At that time, the senior officers of the navy were basically naval lineages, so the Marine Corps not only lacked its own interests spokesmen at the top, but also lacked strategic think tanks and command positions at the theater and campaign levels. Generally speaking, they have no independent say in grand strategy and army building.

The outbreak of the European War greatly increased the budget of the US military. Under the pressure of the Marine Corps, the US Naval Ship Bureau finally decided that the military would come forward and sign a contract with Donald Roblin to build a prototype with a 12 horsepower Lincoln-Zeffer gasoline engine. In November 194, the prototype was manufactured and transported to the US Marine Corps base in Quantico, northwest Virginia. It participated in the joint exercise held by the Navy in January and February 1941, during which it left a deep impression on the observers of the Navy and the Marine Corps. However, naval personnel believe that this kind of vehicle needs further improvement: the aluminum alloy structure of alligator is somewhat fragile for military vehicles, and at least steel structure should be used; At the same time, the crawler and suspension system should also be redesigned to adapt to the impact of sand friction and seawater erosion on the crawler and bearings in future amphibious operations. At the request of the military, Donald Roblin revised his design again. Because he didn't have enough production capacity, he sought help from the famous Ford Motor Company, which had participated in the manufacture of alligators. In this way, the improved prototype is made by Ford Motor Company. It is worth mentioning that this is the first time that Ford has manufactured military tracked vehicles, but taking this opportunity, Ford has become the largest manufacturer of tracked armored vehicles in the United States in the future.

Figure 4: The prototype LVT-1 produced by Ford is being tested at the Marine Corps base in Kuangtico.

The military is very satisfied with this new amphibious vehicle, and it has also been given an official name: LVT-1. "LVT" is the abbreviation of Landing Vehiche Tracked, which means "Crawler Lander". At the same time, Ford Motor Company also won the contract to produce 2 LVT-1 amphibious vehicles for the military. The first LVT-1 was driven off the production line in July 1941. Usually, we also call the LVT-1 amphibious vehicle "alligator".

Note 3: In English, an amphibious vehicle is usually called "amtrac", which is the abbreviation of "amphibian-tractor".