Crawler Crane
The mobile crawler crane is specific crane designed with either a lattice boom or a telescopic boom. These move upon the crawlers tracks. Because this crane is self-propelled, it can move around certain work sites without the need for a lot of set up. Due to their huge weight and size, crawler cranes are are difficult to transport from one location to another and are rather expensive. The crawler's tracks provide stability to the machinery and enable the crane to work without using outriggers, however, there are several models which do use outriggers. Additionally, the tracks provide the machine's movement.
Early Mobile Cranes
The very first mobile cranes were initially mounted to train cars. They moved along short rail lines which were specially built for the project. 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 showcased the versatility of the machinery. It was not long after when manufacturers of cranes decided that the crawler track market was a safe bet.
The First Crawler Crane
Northwest Engineering, a crane manufacturer in the USA, 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 mid-1920s, crawler tracks had become the preferred means of traction for heavy crane operations.
The Speedcrane
Developed by Ray and Charles Moore of Chicago, Illinois; the Moore Speedcrane was among the first to attempt to copy rail lines for cranes. Made within Fort Wayne, Indiana, the Speedcrane was 15 ton, wheel-mounted, steam-powered crane. In 1925, a company referred to 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 to be able to manufacture it and go into business.