Chances are, you’re looking for a gantry crane, or you wouldn’t be reading this. When you say ‘crane’ most people think of the enormous tower cranes used in urban construction. There’s something grand about their enormous scale that sticks in your mind and makes you think of great things. As Archimedes once said, “Give me a place to stand with a lever and I will move the world.” As humans, we celebrate the supremacy of brains over brawn in achievements from pyramids to gothic cathedrals and from skyscrapers to the local mechanic’s garage.
Cranes of all shapes and sizes played an important part in those accomplishments. But… in principle tower cranes are no more amazing than more humble-appearing types. All cranes use clever tricks to create a mechanical advantage. More importantly, cranes are idiosyncratic, that is they are designed to meet a specific need. Their beauty lies, not in size, but in the perfect fit of tool to need, within budget.
Since no two jobs are exactly the same, there is a huge variety cranes in all sizes and shapes. At first glance, choosing one can be daunting, but keeping in mind that all cranes must obey the laws of stability and conservation of energy, choosing an ideal or near-ideal crane is usually a matter of calculation. It’s not (usually) art, but like all engineering it can be a bit like rocket science. Simplify the process by focusing on the task, not the assortment of cranes available in the marketplace.
That is, first spec the job, and then try to find the tools to do it. There are many crane-calculators available online to help you match tools to your job and your budget. Crane vendors can often help there, too. Use them. More than anything else, sloppy thinking blows the budget. Experts can save you money by helping you match the tools to the job.
In turn, you can help the vendor by being specific about the job you want to accomplish. Some considerations are more obvious than others, of course. Lifting and load capacity spring to mind immediately, as do area of hook coverage and length of lift, but there are other important aspects to the investment in new plant and equipment, as well. In particular, doing a refit is usually more constrained than doing an install to new construction. Some other questions might include the following:
- What will you be lifting? Picking up pipe is not the same as lifting engine blocks.
- What is the range of weights to be lifted?
- How often will the system be used?
- How long do I want the system to last?
- Are all of the tasks performed at the same height, or will I need an adjustable system?
- Can I use the new system to improve overall safety in my plant and cut costs?
- How many axes of rotation do I actually need?
- Is this acquisition part of a renovation/replacement, i.e., constrained by existing construction limits, or is it new building to meet a specific need?
- Is the system portable, or easily movable to another location? And, of course,
- How much should I spend on the system?
The vendor understands that the object of the exercise is not to just spend money on a lifting system, but to improve efficiency, grow the business, avoid costly accidents, protect the workers, and increase shareholder wealth. They can help you make good choices, whether you need a custom overhead bridge system or monorail, a rolling (floor-based) gantry, or a mobile jib. Careful exploration of the available options can make a world of difference in the bottom line, both now, and far into the future.
Peter Parker writes on behalf of R&d Ergo, a company which purely focuses on gantry cranes.