Investing in a double girder bridge crane is a serious undertaking, which is why you need to be sure it is the most suitable option for your lifting requirements. So how do you know what type of overhead crane is best for your needs? In this article, we will cover weight capacity, span, and hook approach to help you decide.
What is the purpose of a girder on a bridge crane?
![Overhead Bridge Crane with Wire Rope Hoist](https://pwiworks.com/wp-content/uploads/2020/06/overhead-bridge-crane-wire-rope-hoist-1200x900.jpg)
The girder acts as the supporting beam of an overhead bridge crane. It runs perpendicular to the runways that can be either freestanding or integrated into the building structure. The girders that form the bridge move along the runways using end trucks.
Single Girder Benefits
Single girder overhead cranes are suited for mostly light applications. They are a cost-efficient solution for handling loads of up to 15 tons and with a limited span.
The light load capacity also allows the crane to operate at faster speeds and allows for more efficient production. The deadweight (or total system mass) of a single girder bridge crane is also less, meaning that it will put less strain on the runway and building frame making it a more cost-effective solution where multiple cranes are required.
Double Girder Benefits
Capacity
Load capacity is often the main reason for using a single or double girder crane. If you need to lift loads greater than 15 tons in a constant duty cycle, a double girder bridge crane is a cost and space-efficient solution.
Improved Hook Height
Double girder bridge cranes feature a hoist and trolley that travel on top of the bridge, which elevates the hook height. This enables operators to lift taller and longer objects and materials within a work area compared with a single girder crane that has an under-hanging trolley and hoist.
Span Longer Distances
A double girder bridge crane can also span longer distances because the parallel girder design has greater combined strength than a single girder.
![Overhead Crane Workshop](https://pwiworks.com/wp-content/uploads/overhead-crane-workshop-1200x800.jpg)
Can double girder bridge cranes be under-running or top-running?
![](https://pwiworks.com/wp-content/uploads/double-girder-cranes-1200x795.jpg)
Double girder bridge cranes do not exclusively use top-running end trucks, but it is more common. There are certain low headroom applications where under-running end trucks can be used as well.
Do you need a single or a double girder bridge crane?
Back to our question of whether you need a single or a double girder bridge crane. As always, the answer is dependent on a number of factors. You need to factor in the maximum span, capacity, headroom in order to get the right solution for your application.
If you are still unsure as to whether you require a single or double girder bridge crane our team of experts at PWI is here to help. Contact our team and we will steer you in the right direction. And if you’re certain which system is best for your needs, you can get a free quote today!