Equipment Specs
Content
Languages
This article is also available in French or Spanish.
1971 American 597C 35-ton Crawler Crane
A crawler crane is a type of mobile crane available with either a telescopic or lattice boom that moves upon crawler tracks. As a self-propelled crane, it is able to move around a site and perform jobs without much set-up. However, because of its great weight and size, it is quite difficult and expensive to transport the crawler crane from site to site.

Besides movement, the crawler tracks provide stability enabling the crane to operate without the use of outriggers, though some models do include them.

Contents

[edit] History

[edit] Early Mobile Cranes

Early mobile cranes were mounted to train cars and moved along short rail lines constructed for the project. With turn of the twentieth century came the crawler tractor, and the introduction of crawler tracks to the agricultural and construction industries. Eventually the crawler tracks were adopted by excavators, which further showcased their versatility. It was only a matter of time before crane manufacturers jumped on the crawler track market.

[edit] The First Crawler Crane

The U.S. crane manufacturer Northwest Engineering mounted its first crane on crawler tracks around the 1920s. It described the new machine as a “locomotive crane, moveable under its own power and independent of tracks.”[1] By the mid-1920s crawler tracks were “the preferred means of traction for heavy cranes.”[2]

The Worlds first All Hydraulic Crawler Crane was Designed and Manufactured by HYMAC LIMITED of Rhynmey Wales UK.

[edit] The Speedcrane

One of the first attempts to replicate the rails for cranes was the Moore Speedcrane developed by Ray and Charles Moore of Chicago, Illinois. The Speedcrane, manufactured in Fort Wayne, Indiana, was a steam-powered, wheel-mounted, 15-ton crane. A company named Manitowoc Shipbuilding Co., of Manitowoc, Wisconsin, recognized the marketability of a tracked crane and in 1925 it teamed with the Moores to manufacture it.

The first Speedcrane built by Manitowoc was a success, but further adjustments needed to be made. Roy Moore, who had been hired by Manitowoc as a crane designer, understood the industry was moving from steam power to internal combustion engines and his crane had to change with it. He redesigned the Speedcrane for a gasoline engine and strengthened its frame by using cast steel carbody, replacing its original riveted construction.

This new machine was extremely versatile. The Model 125 could be used as a crane, shovel, dragline or trench hoe. Manitowoc continued development in the crane industry, always adopting the latest advancement into its machines.

[edit] Other Companies' Developments

After witnessing the Speedcrane's versatility and success, other manufacturers began producing crawler cranes. In 1935, Ruston-Bucyrus introduced the 22-RB crawler crane, which remained popular for decades.

In 1941 Manitowoc designed the M3900 heavy crawler crane, capable of lifting 103.5 tons. It introduced the first integral torque converter.

With the end of the 1960s came the introduction of a new boom mounting system: the Ringer. The ring consisted of several sections, fitted together, encircling the crane. The boom was no longer fixed to the crawler’s frame, but was instead supported by the ring. It allowed for unrestricted slewing. The first crane instituting the Ringer was the Manitowoc M4000 Vicon. The new system reduced crane mobility, but increased lift capabilities.[3]

HYMAC UK 1966 designs and manufactured the first all hydraulic crawler crane, this was built at the Rhynmey works Wales,

the Hymac Jupiter high lift, a 35 ton crawler crane as seen on the oxford design awards register and cranes today history archive.

HY-MAC HIGH LIFT CRANE.jpg

In 1976, the British company Ransomes & Rapier introduced fully hydraulic systems for crawler cranes. The Olympus HC150 improved crawler crane operation immensely. Still, mechanical cranes continued to be manufactured to satisfy the need for a simple, sturdy crane.

Even as telescopic crane development exploded in Europe, many U.S. companies continued to manufacture long lattice booms. Apparently, construction sites in the U.S. were much larger, making lattice booms much easier to use. Also, road regulations within the U.S. varied from state to state making it difficult to transport the telescoping mobile cranes.

[edit] Technology Advancements

[edit] Wind Farms and Crawler Cranes

According to an October 2006 issue of Cranes & Access magazine, the wind power industry created resurgence in crawler crane manufacturing. With a global warming crisis at the forefront of many minds, alternate sources of energy were, and still are, being sought after. Hydroelectric power plants have been built around the world and many nations are utilizing wind power as the newest source of energy to harness.

“A wind turbine now produces more than 180 times the electricity at less than 50 percent of the cost per kWh unit than its equivalent 20 years ago. And in good locations, wind can now compete with the cost of both coal and gas-fired power.”[4]

This has resulted in the building of wind farms, which consists of many tall wind turbines, generally about 109 yards (100 m) apart, connecting to a source power plant. These tower turbines require a mobile crane to build them.

Crane manufacturer Liebherr was the first to introduce a crawler crane specially designed for wind farm construction. These first cranes were less than 5.5 yards (5 m) wide capable of traveling on narrow wind farm roads. So, the crane could travel from turbine to turbine in about two hours because they didn’t require rigging and re-rigging, which could take an entire day or two.

Liebherr also attached outriggers to provide increased stability and aid in maneuverability. The outriggers lifted the crawler tracks entirely off the ground and then rotated them to face the direction of travel.

Kobelco entered the wind farm crawler development too. They designed retractable crawler tracks that could extend to 8.3 yards (7.62 m) for stability and retract to less than 5.5 yards (5 m) for travel.

[edit] Other Types of Crawler-Mounted Cranes

In the 1920s, industrial wheel tractors such as those built by Fordson and McCormick-Deering were adapted to power a wide range of machinery. In one example, half-swing shovels and cranes were built by several manufacturers around the tractor's engine and power train, and the wheels were replaced with crawlers.

As crawler tractors came into widespread use in the 1930s, a number of manufacturers began producing attachments for them, including a variety of lifting devices. Side-mounted booms were initially used primarily for pipelaying, hence the term "pipelayer," and are now often used for cleaning up railroad derailments; they are ideal for this work because of their compact size, mobility, and considerable lifting capacity. Swing booms mounted atop the engine compartment were also available. Hyster Company and R. G. LeTourneau offered end-mounted booms; Hyster's was also convertible to a shovel, backhoe or dragline. But none of these machines were not crawler cranes in the strictest sense of the term.

[edit] Features/How it Works

Crawler cranes travel on crawler tracks, similarly to a crawler tractor. However, because of their great weight, these machines move very slowly.

They are available with a telescopic arm, which is easy to extend with the use of hydraulics, or a lattice boom, that must be manually assembled by adding multiple sections.

Typically, the crane is powered by one engine and controlled by two or more cable operated drums.

[edit] Common Manufacturers

[edit] Additional Photos

Sumitomo C52 4.8-ton Crawler Crane
Mantis 2010 10-ton Hydraulic Crawler Crane
2003 Manitowoc 555 Series II 150-ton Self-erecting Crawler Crane

[edit] References

  1. Bachman, Oliver; et al. The History of Cranes. KHL Int.: 2004. 86.
  2. Bachman, Oliver; et al. The History of Cranes. KHL INT.: 2004. 87.
  3. Bachman, Oliver; et al. The History of Cranes. KHL INT: 2004. 170.
  4. PDF. Vertikal. 2008-09-24.