Crawler Crane
The crawler crane is a particular 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 completing tasks without a lot of set-up. Due to their huge size and weight, crawler cranes are fairly costly and even hard to transport from one place to another. The crawler's tracks provide stability to the machinery and enable the crane to work without using outriggers, however, there are some units which do use outriggers. Moreover, the tracks provide the equipment's movement.
Early Mobile Cranes
Initially, the first mobile cranes were mounted to train cars and move along specifically built short rail lines. Once the 20th century arrived, the crawler tractor evolved and this brought the introduction of crawler tracks to the construction industry and the agricultural industry. Not long after, excavators adopted the crawler tracks and this further featured the machine's versatility. It was not long after when crane companies decided that the crawler track market was a safe bet.
The First Crawler Crane
In the 1920s, Northwest Engineering, a crane company in the United States, mounted its first crane on crawler tracks. It described the new machine 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
Developed by Ray and Charles Moore of Chicago, Illinois; the Moore Speedcrane was amongst the first to attempt to copy rail lines for cranes. Manufactured within 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 potential and marketability. They decided to team up with the Moore brothers in order to manufacture it and go into business.