Overhead cranes are used in a wide variety of industries and they are designed into four different types. Selecting the most preferable set-up for your operations depend on your required capacity, duty class, and lifting heights. It could also be dependent on whether you are installing the crane in a new or old building. As you move on with the aim of selecting the type of overhead crane that is most suitable for your industry need and facility, here are some things you should always consider.
Top Running and Under Running Overhead Crane
The two main configuration options for overhead cranes are top running and under running (which is also referred to as underhung). On a top-running crane, the end truck rides on top of the runway beam, for an under-running crane, the end truck rides on the lower flange of the runway beam. Each has its own advantages over the other.
The under-running crane can allow a much better end approach for the hoist. This means it allows the hoist to get closer to the end truck or end of the runway than is possible when using a top running crane. Under running, cranes are usually more cost-effective than top running cranes. This could also be used if your operation calls for the ability to transfer hoists along bridges to interconnected monorails, you will need to make use of them under the running style of an overhead crane. The top running crane can lift a heavier load which is an advantage it has over the under running cranes. A top running crane also had greater headroom compared to them under the running crane.
Single Girder or Double Girder
The other two configuration options for cranes are single girders or double girders; both could be used with either top-running cranes or under-running cranes. It is known that the double girder crane has greater support for more capacities but is a more expensive type of overhead crane. It is also known that double guilder designs allow for a greater hook height than the single girder designs as the hoist could be fixed on top of the bridge instead of under it. Single girder crane has a lower cost but has lower capacities than double girder cranes. With a single girder crane, the hoist usually rides the bottom of the crane girder in both top-running and under-running configurations. This will create a wider cooperative envelop for the hoist and is a solution for applications where the headroom is not large enough.