Overhead Crane

In the simplest of terms, an overhead crane is a machine, or piece of equipment, that allows you to lift and move heavy materials from one location to another in a precise manner. There is no “one size fits all” approach to defining an overhead crane, as each overhead crane is carefully designed and engineered for a specific purpose or application to suit a business' material handling needs.

Clean Floor space
Your floor space is cleared up because your supports for the crane are out of the way. Typically your crane provider can come up with a column design that is freestanding and can be aligned with your building columns or along walls. You can choose a ceiling mounted crane (typically on new building designed for the loadings) or you can support the crane from the floor. Sometimes a combination of the two can be used with some supports from the floor and some from the ceiling of your building.

Safety
The crane operator can put himself into the optimum location to safely move the load. The fork lift creates blind spots which are inherent with the structure around the operator. The fork lift can be prone to overturning (which is the leading cause of death with a forklift), Pedestrian can be struck by a forklift, driver or employee can be crushed by a forklift, or the driver can fall from the forklift. Overhead bridge cranes can also be outfitted with anti-collision devices to keep them from colliding with cranes in the same bay or end stops.

Customizable and adaptable
Overhead bridge cranes are very versatile when it comes to below the hook accessories. The types available are limitless. Below the hook accessories include spreader bars, c-hooks, weight scales, custom designed lifting tooling, manipulators, and vacuum lifts to name a few. Many cranes have several different below the hook tools which are changed out for the particular job.

Heavier payloads
Heavier loads can be handled while keeping your plant personnel away from the load. Forklifts require your operator to be within close proximity to the load. With an overhead bridge crane the operator can rig the load and then move away from danger when using the above referenced radio or independent traveling pushbutton station.

Complete coverage
Your entire plant can be covered with no dead spots of coverage. A crane can travel right over the load, even without a clear path or aisle. This allows the most flexibility when setting up your plant design.

Inexpensive operating costs
Operating costs are very inexpensive with a bridge crane. From no energy requirements for a completely manual system, to a very economical three phase system. There is no need to charge batteries or have tanks filled. The bridge crane is always ready to work!

Capacity and Service Rating
The load rating capacity is the maximum load weight a crane can handle. It's important to note the load capacity and frequency of operation. Operating a crane above its load rating capacity is extremely dangerous and can cause serious damage to your new system. Be sure that the maximum weight requirements of your application are less than the load rating capacity of the crane. Knowing this information will also help you to identify the right service rating classification for your new crane.The CMAA offers six different service-rating classes. Each service rating is used to describe the type of service performed and frequency of use. The service rating helps users to select a crane designed for their particular application.

Structural Components
Most overhead cranes are made from welded steel plates or aluminum sections. The more steel, the heavier the crane. Consider your service classification and compare it to the type of crane you are interested in purchasing. Spanco A-Series Gantry Cranes, for example, can either be steel or aluminum. Whereas aluminum gantry cranes are designed for lightweight applications and total portability, a steel gantry crane will provide a higher load rated capacity and is designed for heavier applications. Understanding these options will help you to make the best choice for your operation and control some of the structural elements that impact the weight of the crane and its cost.

Mechanical & Electrical Components
Overhead cranes in general provide a variety of options beyond design and structure. Choosing the best mechanical and electrical options can be a daunting task without the right approach. But, if you consider the needs of your application and facility first, you can eliminate some of that confusion. There are multiple mechanical and electrical component options for each type of overhead crane we manufacture. Knowing what each component does and how it will impact your particular application will help you to decide which options are necessary.

Motor Controls & Operator Controls
Another important option to consider when choosing the right system for your operation is the use of motor controls. Electrical control systems allow you to manipulate bridge and trolley motions for increased precision and safe, controlled lifting. These components also impact the cost of the crane, so making the best choice for your operation is crucial. If you choose to purchase a motorized system, ask your supplier if they provide speed control. A variable frequency drive, for instance, is an adjustable-speed drive used to control motor speed and torque by varying motor input frequency and voltage. VFD provides cushioned acceleration and deceleration, which is especially important when handling fragile or oversized loads. At Spanco, we provide VFD technology on every motorized system that we manufacture. Knowing what your supplier provides with each system and how it will benefit your application is a fundamental step in your buying process.

Regular Inspections
Inspections conducted on a regular basis assist find possible problems before they develop into serious ones. Daily, monthly, and yearly inspections can be planned.Before the start of each shift, daily inspections involve looking for any loose or damaged parts, wear, or strange noises. Furthermore, the operation of safety tools like limit switches and emergency stop buttons can also be checked.A more thorough inspection of the crane's parts is performed during monthly inspections. This entails inspecting electrical connections, checking wire ropes and electric chains for damage, and looking for breaks or abnormalities in structural components. Here, it is important to use thorough inspection checklists and to adhere to the manufacturer's service and maintenance recommendations.

Stick to the Manufacturer's Guidelines
Installing an overhead crane in your plant entails significant financial investment, and to assist you in maintaining it effectively, the crane manufacturer always provides a comprehensive handbook or maintenance schedule book. This resource contains service advice tailored to the specific crane's duty cycle and capabilities.It is crucial to strictly adhere to the manufacturer's guidelines when it comes to crane maintenance, including lubrication schedules and inspection intervals. By following these recommendations carefully, you can ensure the optimal performance and longevity of your crane.

Lubrication and Cleaning
To reduce friction and stop premature wear, the working elements of the crane must be lubricated often. Areas like wire ropes, sheaves, gears, and bearings should be lubricated. Additionally, routine crane cleaning helps get rid of corrosive substances, dirt, and other things that can harm its components.

Operating Environment Considerations
The operating environment plays a vital role in determining the lifespan of overhead cranes and their components. To safeguard the crane against adverse environmental conditions such as excessive heat, chemical exposure, fumes, steam, dust, or high moisture levels, special metal coatings may be necessary.Failure to consider these factors during the design and quotation phases can lead to corrosion, oxidation, and accumulation of dirt and grime on crane components. Taking proactive measures to address environmental challenges is crucial to ensure the longevity and optimal performance of overhead cranes.