What is a Double Girder Bridge Crane?

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?

The girder acts as the supporting beam of an overhead bridge crane. It runs perpendicular to the runways that are built 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. It is also optimal for work areas where space is limited because there are fewer engineering requirements for lighter systems. 

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 choosing a particular crane. If 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 trolley that travels on top of the bridge, which elevates the hook height. This enables operators to hoist taller and longer objects and materials within a work area compared with a single girder crane that has an under-hanging trolley and hoist. 

Secondary Hoists on Each Girder

It’s possible to add additional hoists to individual girders which adds multiple lifting points to your overhead crane. These hoists can bypass each other because they are not on the same girder/bridge.

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.

Can double girder bridge cranes be under-running or top-running?

Double girder bridge cranes do not exclusively use top-running end trucks, but it is more common. 

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 load weight, headroom and building area, use cases, and your budget.

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!