Crawler Crane
The mobile crawler crane is specific crane designed with either a telescopic boom or a lattice boom. These move upon the crawlers tracks. As this crane is self-propelled, it could move around particular work sites without the need for much set up. Because of their huge weight and size, crawler cranes are are difficult to transport from one site to another and are rather costly. The crawler's tracks provide stability to the equipment and allow the crane to function without utilizing outriggers, however, there are some models which do use outriggers. Moreover, the tracks provide the movement of the machine.
Early Mobile Cranes
Originally, the first mobile cranes were mounted to train cars and move along specifically designed short rail lines. Once the 20th century arrived, the crawler tractor evolved and this brought the introduction of crawler tracks to the construction business as well as the agricultural business. Not long after, excavators adopted the crawler tracks and this further featured the machine's versatility. It was not long after when manufacturers of cranes decided that the crawler track market was a safe bet.
The First Crawler Crane
Northwest Engineering, a crane company in the USA, was the first to mount its crane on crawler tracks in the 1920s. It described the new machinery as a "locomotive crane, independent of tracks and moveable under its own power." By the mid-1920s, crawler tracks had become the preferred means of traction for heavy crane uses.
The Speedcrane
Developed by Charles and Ray Moore of Chicago, Illinois; the Moore Speedcrane was amongst the first to attempt to replicate rail lines for cranes. Manufactured within Fort Wayne, Indiana, the Speedcrane was 15 ton, steam-powered, wheel-mounted crane. In 1925, a company called Manitowoc Shipbuilding Co, from Manitowoc, Wisconsin recognized the tracked crane's marketability and potential. They decided to team up with the Moore brothers to be able to manufacture it and go into business.