The crawler crane is a particular kind of mobile crane which 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 could move around a jobsite and accomplishing jobs without a lot of set-up. Due to their enormous size and weight, crawler cranes are rather pricey and even hard to transport from one site to another. The crawler's tracks provide the equipment stability and allow the crane to function without the use of outriggers, however, there are several units that do utilize outriggers. Also, the tracks provide the movement of the machine.
Early Mobile Cranes
The very first mobile cranes were originally mounted to train cars. They moved along short rail lines that 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 agricultural industry and the construction business. Not long after, the crawler tracks were adopted by excavators and this further showcased the machine's versatility. It was not long after before manufacturers of cranes decided that the crawler track market was a safe bet.
The First Crawler Crane
Northwest Engineering, a crane manufacturer in the USA, was the first to mount its crane on crawler tracks during the 1920s. It described the new equipment as a "locomotive crane, independent of tracks and moveable under its own power." By the mid-1920s, crawler tracks had become the chosen means of traction for heavy crane operations.
Developed by Ray and Charles Moore of Chicago, Illinois; the Moore Speedcrane was amongst the first to attempt to replicate rail lines for cranes. Made within Fort Wayne, Indiana, the Speedcrane was 15 ton, steam-powered, wheel-mounted crane. During 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 so as to produce it and go into business.