Who invented the bulldozer?
Germany began to use bulldozers extensively in the project. After 1945, in the reconstruction of Britain and Europe, as well as many construction projects in the United States, bulldozers were indispensable and important construction methods. At present, some countries are testing a kind of underwater bulldozer which is monitored by television and operated by robots. Tunnel excavators have long excavated tunnels in ancient Mesopotamia, but the tunnel has not been successfully excavated until nineteenth Century. Dig a tunnel in the soft soil to prevent mud and water from seeping through. In 1818, an engineer, British engineer, designed the excavator to dig the tunnel under the thames. He observed a soft bodied mollusk called a boat worm, and found that the worm used a round hard shell to support the material around the hole and continued to drill forward. He was inspired to create a box shell (called the shield), by Jack forward in the soft soil.
Bulldozer is a kind of road machine which is equipped with pushing and shoveling device in front of tractor. It is used to push soil and smooth construction site. In the mid 1870s, the United States had used rough horse drawn earth scraper to smooth the land. In 1906, caterpillar tractor inventor, Holt in the United States have developed a gasoline engine tractor first, Holt worked as a supporting device installed on the tractor shovel, and become the world's first bulldozer. In 1909, Germany began to build a large scale highway network, because of the first World War, the project was not completed until 1921.
Mining workers in the iron shell side mining, on one side of the inner wall of the tunnel lining brick. From 1825 to 1841, the world's first water use cloth design of shield Wei Lun Noel drove almost to the rother Hayes tunnel, about 1100 meters long. In 1865, the British bridge engineers invented a Barlow shield, and registered patents. This shield is cylindrical, the diameter is Buren Knoll design for small, no wall brick tunnel, and iron block. Barlow Greathead and engineers use this shield within a year under the river Thames chisel Tongtai second tunnels. Greathead also improved tunnel technology, the pressure of compressed air, offset outside London in 1890, with this technology built the world's first underground railway.
