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 model is a self-propelled crane, it could move around a jobsite and completing jobs without much set-up. Due to their enormous weight and size, crawler cranes are fairly expensive and even difficult to transport from one location to another. The crawler's tracks provide stability to the machine and enable the crane to work without the use of outriggers, however, there are some models which do utilize outriggers. Also, the tracks provide the machine's movement.
Early Mobile Cranes
Originally, 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 business. Not long after, the crawler tracks were adopted by excavators and this further featured 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 within 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 middle part of the 1920s, crawler tracks had become the chosen 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 copy rail lines for cranes. Manufactured in 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 potential and marketability. They decided to team up with the Moore brothers so as to manufacture it and go into business.