Crawler Crane
The crawler crane is a particular type of mobile crane which is available with either a lattice boom or a telescopic boom which moves upon crawler tracks. Since this model is a self-propelled crane, it could move around a jobsite and accomplishing tasks without much set-up. Because of their huge size and weight, crawler cranes are are difficult to transport from one location to another and are fairly costly. The crawler's tracks provide stability to the machine and enable the crane to function without utilizing outriggers, however, there are some models which do utilize outriggers. Furthermore, the tracks provide the machine's movement.
Early Mobile Cranes
The first mobile cranes were originally mounted to train cars. They moved along short rail lines that were specifically constructed for the project. When the 20th century arrived, the crawler tractor evolved and this brought the introduction of crawler tracks to the agricultural industry as well as the construction business. Not long after, the crawler tracks were adopted by excavators and this further featured the versatility of the equipment. It was not long after before manufacturers of cranes decided that the crawler track market was a safe bet.
The First Crawler Crane
Around the 1920s, Northwest Engineering, a crane company within the USA, mounted its very first crane on crawler tracks. It described the new machine as a "locomotive crane, independent of tracks and moveable under its own power." By the middle part of the 1920s, crawler tracks had become the preferred means of traction for heavy crane uses.
The Speedcrane
Developed by Ray and Charles Moore of Chicago, Illinois; the Moore Speedcrane was one of the first to attempt to copy rail lines for cranes. Manufactured within Fort Wayne, Indiana, the Speedcrane was 15 ton, wheel-mounted, steam-powered crane. In 1925, a company called Manitowoc Shipbuilding Co, from Manitowoc, Wisconsin recognized the marketability and the potential of the tracked crane. They decided to team up with the Moore brothers to be able to produce it and go into business.