Crawler Crane
The crawler crane is a specific type of mobile crane that is available with either a lattice boom or a telescopic boom that moves upon crawler tracks. As this unit is a self-propelled crane, it is capable of moving around a jobsite and accomplishing tasks without a lot of set-up. Because of their enormous size and weight, crawler cranes are fairly pricey and even hard to transport from one place to another. The crawler's tracks provide stability to the equipment and enable the crane to function without utilizing outriggers, however, there are several units which do utilize outriggers. In addition, the tracks provide the machine's movement.
Early Mobile Cranes
Initially, the very first mobile cranes were mounted to train cars and move along specially designed short rail lines. When the 20th century arrived, the crawler tractor evolved and this brought the introduction of crawler tracks to the agricultural industry and the construction industry. Not long after, excavators adopted the crawler tracks and this further showcased the versatility of the machinery. It was not long after before crane companies decided that the crawler track market was a safe bet.
The First Crawler Crane
Northwest Engineering, a crane manufacturer in the United States, was the very 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 middle part of the 1920s, crawler tracks had become the chosen 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, steam-powered, wheel-mounted crane. During 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 so as to manufacture it and go into business.