Finding the ideal crane for every job
Published in: Construction Equipment
Date: 11/15/1992
By: Landberg, Lynn
Service and utility cranes vary in range and applications. These cranes are generally used for loading and unloading trucks, move shop parts and supplies around and carry jobsite materials. For small shops, free-standing or self-propelled cranes are commonly used. The articulated cranes from Europe can load and carry materials. For higher structures, telescoping cranes with greater vertical access can be used.
Service and utility cranes come in all sizes for almost any lift in the shop or field
If you have a “light” lifting job, there’s a service or utility crane that can handle it. While service and utility cranes are no match for heavy-lift versions and most will be used in light-lifting applications, some can go after loads weighing in excess of 30 tons.
While the range and application of utility and service cranes is astounding, typically they’re used to load and unload trucks, move components around the shop, and place materials on the jobsite.
Free-standing cranes
Free-standing or self-propelled cranes are generally used in and around the shop. These cranes include small carrydeck or yard models, gantry cranes, or manual cranes. They’re economical and maneuverable, and usually can be used indoors or out because of their low profiles. Some lift a surprising amount of weight relative to crane size. These types of cranes, however, are not highly mobile and must stay pretty close to home.
For use in the field and elsewhere, a truck-mounted crane is preferable. The two types are articulated or knuckleboom cranes, and telescoping-boom cranes. Each is unique as to its uses.
Articulated cranes
Articulated cranes, while popular in Europe, are still catching on here. These units fill a particular niche and have distinct advantages over telescoping cranes in certain applications.
Articulated cranes are designed for load-and-carry operations. Usually, the load would be placed on the flatbed of a crane-equipped truck for transport. An advantage of the articulated crane is that it can be folded away against the back of the truck cab, leaving maximum room on the truck bed for the load. Also, the favorable weight to capacity ratio of the articulated crane allows for a greater payload. Articulated cranes usually are operated from the ground, using a remote control setup.
Articulated cranes are rated in foot-pounds, a practice common in Europe where the articulated crane originated. The foot-pounds measurement is a function of radius times capacity. If you know one, you can calculate the other. For example, if the articulated crane is rated at 20,000 foot-pounds and the object to be lifted weights 2,500 pounds, the maximum radius at which the object can be lifted is 8 feet (8 X 2,500 = 20,000).
The rating is accurate at short boom lengths, which are typical of articulated cranes. However, as boom lengths grow longer, the rating’s accuracy decreases, which disqualifies it for use with telescoping-boom cranes. Telescoping cranes are rated by the weight they can lift.
Telescoping-boom cranes
The telescoping crane has greater vertical reach than the articulated unit and is, therefore, used to lift loads to upper stories or roofs of structures. Some smaller versions can be mounted on a flatbed with room left over for a load.
In recent years, truck-mounted telescoping cranes have taken on features previously seen only on larger hydraulic cranes. Boom reach has been extended so that now some units exceed 100 feet. Full 360-degree rotation makes it possible to better maneuver the crane and truck into position. And load moment indicators provide that margin of safety common on larger cranes.
New designs and materials also have reduced crane weight while maintaining capacity. The payoff here is that the overall weight of the truck-crane combination is reduced, allowing for greater payload. The crane may also carry more boom and have more capacity with the same weight as previous units.
What you can expect to pay
The cost of utility and service cranes ranges from $1,000 to more than $100,000, depending on size and type. Articulated and telescoping units are comparably priced when the packages are put together.
For example, a crane with a 10-ton capacity might run about $40,000 with a two-axle truck costing between $25,000 and $30,000 for a $65,000 to $70,000 setup. Higher capacity cranes and specific applications might require a tandem-axle truck, which can cost $40,000 or more. A tandem axle truck with a GVW in excess of 33,000 pounds is subject to a 12 percent federal excise tax, so it’s important to figure your needs carefully for greatest dollar savings.
The Best Crane for the Job
Manual Cranes
Small and economical, manually-operated cranes generally are used in and around the maintenance shop. Depending on the size of the crane, units can lift from a few hundred pounds to several thousand. Shop floor models are manually positioned and may be hydraulically or electrically operated. Some versions mount on pickup trucks for field use.
Gantry Cranes
Gantry, or straddle, configuration allows these cranes to achieve high capacity lifts relative to crane weight. These highly stable cranes come in many sizes and have a variety of applications. For repetitious movement, they often are positioned on tracks. Gantry cranes are most typically used indoors or on hard surfaces outdoors.
Articulated Cranes
Good weight to capacity ratios and the ability to work in confined areas contribute to the growing popularity of these cranes, which originated in Europe where they are very popular. Also called knuckleboom cranes, these units are designed for lifting materials on and off trucks and fold away to use minimal space when not in use. Articulated cranes are highly maneuverable but limited in reach.
Telescoping Cranes
The strong point of a telescoping-boom crane is reach, making it deal for lifting and placing materials at heights in excess of 100 feet. Smaller versions are used on service and maintenance trucks. A larger telescoping crane is not well-suited for loading onto its own truck because of retraction limitations.
COPYRIGHT 1992 Reed Business Information