Crawler Crane
The crawler crane is a particular kind of mobile crane that is available with either a lattice boom or a telescopic boom that moves upon crawler tracks. Since this model is a self-propelled crane, it is capable of moving around a jobsite and completing jobs without much set-up. Because of their huge size and weight, crawler cranes are rather costly and even difficult to transport from one place to another. The crawler's tracks provide stability to the machine and enable the crane to function without the use of outriggers, although, there are some models that do use outriggers. Furthermore, the tracks provide the movement of the equipment.
Early Mobile Cranes
The very first mobile cranes were originally mounted to train cars. They moved along short rail lines that were specially made for the project. When 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 industry. Not long after, the crawler tracks were adopted by excavators and this further showcased the machine's versatility. It was not long after before crane companies decided that the crawler track market was a safe bet.
The Very First Crawler Crane
Northwest Engineering, a crane manufacturer within 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 operations.
The Speedcrane
Developed by Ray and Charles Moore of Chicago, Illinois; the Moore Speedcrane was one of the first to attempt to replicate rail lines for cranes. Made in Fort Wayne, Indiana, the Speedcrane was a wheel-mounted, steam-powered, 15 ton crane. In 1925, a company known as 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 in order to produce it and go into business.