Crawler Crane
The crawler crane is a specific type of mobile crane that is available with either a telescopic boom or a lattice boom that moves upon crawler tracks. Since this model is a self-propelled crane, it is capable of moving around a jobsite and accomplishing jobs without much set-up. Due to their enormous size and weight, crawler cranes are are hard to transport from one location to another and are fairly expensive. The crawler's tracks provide stability to the machine and enable the crane to function without the use of outriggers, although, there are some units that do utilize outriggers. Furthermore, the tracks provide the movement of the machine.
Early Mobile Cranes
The first mobile cranes were initially mounted to train cars. They moved along short rail lines which were specifically built for the project. Once the 20th century arrived, the crawler tractor changed and this brought the introduction of crawler tracks to the construction business as well as the agricultural business. Not long after, the crawler tracks were adopted by excavators and this further showcased the machine's versatility. It was not long after when manufacturers of cranes decided that the crawler track market was a safe bet.
The Very First Crawler Crane
Around the 1920s, Northwest Engineering, a crane manufacturer in the USA, mounted its first crane on crawler tracks. It described the new equipment 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
The Moore Speedcrane, developed by Ray and Charles Moore of Chicago, Illinois was one of the first attempts to copy the rails for cranes. Made in 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 in order to manufacture it and go into business.