The crawler crane is a particular kind of mobile crane which is available with either a lattice boom or a telescopic boom that moves upon crawler tracks. Because this unit is a self-propelled crane, it is capable of moving around a jobsite and completing jobs without a lot of set-up. Because of their huge size and weight, crawler cranes are fairly expensive and even hard to transport from one place to another. The crawler's tracks provide stability to the machine and enable the crane to work without the use of outriggers, although, there are some units which do use outriggers. As well, the tracks provide the movement of the equipment.
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. When 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 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 United States, was the very first to mount its crane on crawler tracks during the 1920s. It described the new machinery 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 Moore Speedcrane, developed by Ray and Charles Moore of Chicago, Illinois was amongst the first attempts to copy the rails for cranes. Manufactured in Fort Wayne, Indiana, the Speedcrane was a wheel-mounted, steam-powered, 15 ton crane. In 1925, a company referred to as Manitowoc Shipbuilding Co, from Manitowoc, Wisconsin recognized the tracked crane's marketability and potential. They decided to team up with the Moore brothers so as to produce it and go into business.