Crawler Crane
The crawler crane is a specific type of mobile crane that is available with either a telescopic boom or a lattice boom which moves upon crawler tracks. As this unit is a self-propelled crane, it could move around a jobsite and completing tasks without a lot of set-up. Because of their enormous weight and size, crawler cranes are fairly pricey and even difficult to transport from one place to another. The crawler's tracks provide stability to the machinery and allow the crane to work without utilizing outriggers, however, there are several units which do use outriggers. As well, the tracks provide the movement of the equipment.
Early Mobile Cranes
Initially, the first mobile cranes were mounted to train cars and move along specially made short rail lines. When 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, excavators adopted the crawler tracks and this further featured the versatility of the machine. It was not long after before manufacturers of cranes decided that the crawler track market was a safe bet.
The Very First Crawler Crane
In the 1920s, Northwest Engineering, a crane manufacturer in the United States, mounted its first crane on crawler tracks. 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 operations.
The Speedcrane
Developed by Charles and Ray Moore of Chicago, Illinois; the Moore Speedcrane was amongst the first to attempt to replicate rail lines for cranes. Manufactured in Fort Wayne, Indiana, the Speedcrane was 15 ton, wheel-mounted, steam-powered 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 in order to produce it and go into business.