Crawler Crane
The crawler crane is a particular kind of mobile crane that is available with either a telescopic boom or a lattice boom that moves upon crawler tracks. Because this model is a self-propelled crane, it could move around a jobsite and accomplishing tasks without much set-up. Because of their enormous size and weight, crawler cranes are are difficult to transport from one place to another and are fairly expensive. The crawler's tracks provide stability to the machine and allow the crane to function without the use of outriggers, however, there are some models which do use outriggers. What's more, the tracks provide the movement of the machine.
Early Mobile Cranes
The first mobile cranes were originally mounted to train cars. They moved along short rail lines that were particularly made for the project. Once the 20th century arrived, the crawler tractor evolved and this brought the introduction of crawler tracks to the construction business and the agricultural business. Not long after, excavators adopted the crawler tracks and this further showcased the versatility of the machinery. It was not long after before manufacturers of cranes decided that the crawler track market was a safe bet.
The First Crawler Crane
Around the 1920s, Northwest Engineering, a crane company in the United States, mounted its first crane on crawler tracks. 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 preferred means of traction for heavy crane operations.
The Speedcrane
The Moore Speedcrane, developed by Charles and Ray Moore of Chicago, Illinois was amongst the first attempts to replicate the rails for cranes. Made in Fort Wayne, Indiana, the Speedcrane was a steam-powered, wheel-mounted, 15 ton crane. In 1925, a company known as Manitowoc Shipbuilding Co, from Manitowoc, Wisconsin recognized the potential and the marketability of the tracked crane. They decided to team up with the Moore brothers in order to manufacture it and go into business.