By Francis Rioux
Technical representative at
Premium Industrial Group inc.
Key takeawaysTo increase an overhead crane's lifting height, you generally need to consider five factors :
Before modifying the equipment, the starting point is almost always the same: identify what is actually limiting the available height – the hook position, below-the-hook devices or obstructions in the building). |
Insufficient lifting height on an overhead crane is more common than you might think, and it can get expensive. What really affects lifting height? More importantly, how can you gain a few valuable extra inches?
At Premium, we regularly see this issue on our projects. It should not be taken lightly, because it can affect operations for the entire service life of the installation or create unexpected costs.
In this article, we look at the 5 key factors that determine an overhead crane’s lifting height and how to act on each one.
Why is lifting height so important?
In an overhead crane project, lifting height is often a central concern. In a plant, every inch matters. A lack of height can complicate handling, limit load travel, or force a company to change how certain operations are performed.
For example, you may need to move a load over a rack or a machine. Or you may need enough height to load a part onto a trailer, etc.
The goal is not simply to lift higher. The priority is to understand which elements have a real impact on the available height, so you can choose a configuration that matches the operation, the building, and the budget.
Where to start: a quick hierarchy
When space is limited, this is the most logical order to analyze the problem :
- Clear height / obstructions (often a major impact)
- Overhead crane type (single- vs. double-girder)
- Structural design (fine adjustments depending on context)
- Hoist (headroom, overall dimensions and configuration)
- Below-the-hook accessories (loss of "real" lifting height)
1. Clear height
Clear height is the distance between the floor and the lowest obstruction above the runway. It determines the highest point where lifting equipment can be installed.
Before looking at the overhead crane options themselves, you need to verify whether the building imposes a physical limit. If an obstacle prevents the overhead crane from being installed higher, the lifting height will inevitably be reduced.
What can you do?
In some cases, you can gain clear height by modifying the environment around the overhead crane. For example, a garage door track, a duct, or a secondary structure can sometimes be moved, adjusted, or installed differently. This type of change can provide a more direct gain than changing equipment.
See also : Overhead crane obstructions: a costly but preventable problem.
However, in many buildings, the available height is fixed. In that case, you need to work within that constraint and optimize the other elements of the system.
2. The overhead crane type
The overhead crane type directly affects lifting height because it determines where the hoist sits relative to the girders. There are two main configurations : single-girder and double-girder overhead cranes.
Single-girder overhead crane
A single-girder overhead crane has one main girder. The hoist travels under this girder. This configuration is common, but it reduces lifting height because the girder and the hoist take up space between the runway and the hook.
Double-girder overhead crane
A double-girder overhead crane has two girders. The hoist generally travels on top of or between them, which makes it possible to achieve better lifting height. This is often the configuration to consider when you need to maximize available height, although it involves higher cost and a more complex design.
You also need to consider the load to be lifted. If the load is very bulky, the girders themselves can become a constraint and may require below-the-hook devices that reduce the actual lifting height.
3. Structural design
Structural design can also influence lifting height. Depending on span, required capacity, and building configuration, it may be possible to adjust the girder or structural proportions. For example, a girder that is wider but not as tall can sometimes free up space. For a longer span, a box girder’s width and height can be adjusted.
Girder or box girder structure
An optimization that depends on context
This factor is not automatic. On a double-girder overhead crane where the hoist travels above the girders, girder thickness may have little or no impact on hook height. This option needs to be validated against the complete overhead crane configuration.
4. Hoist selection
Hoist selection is one of the most important factors for maximizing lifting height. Two hoists with the same rated capacity can have very different headroom. Some models are specifically designed to allow the hook to go higher.
Standard chain hoist Low headroom chain hoist Ultra-low headroom chain hoist
Chain hoists
With chain hoists, there are standard, low-headroom, and ultra-low-headroom models. Some use an offset motor to reduce the space above the hook, which can make a significant difference in a low-height building.
Wire rope hoists
With wire rope hoists, lifting height also varies by model. A hoist designed for heavier loads may have larger overall dimensions, which can reduce the available lifting height. The hoist must be selected not only for capacity, but also for the available space and the lifting height you need.
Lifting height vs hook heightKey takeaways : Hook height : distance between the floor and the hook in the highest position.Lifting height : height reached by the top of the load in the highest position.The difference often comes from below-the-hook devices (slings, spreader beams, etc.) that take up space and reduce the actual height available for the load. |
5. Below-the-hook devices
Below-the-hook devices are often underestimated, but they have a direct impact on real lifting height. Even if the hook travels high enough, a spreader beam, long slings, or a bulky rigging arrangement can significantly reduce the space available for the load.
One hook with a spreader beam vs. two hoists without a spreader beam
What can you do?
It may be wise to adapt the rigging setup to minimize height loss. For example, you can review the sling type or use a lower-profile device. You can even consider adding a second hoist to avoid using a spreader beam and gain lifting height. These adjustments are often less expensive than replacing the entire overhead crane, but they must be analyzed rigorously, because below-the-hook devices are an integral part of lifting safety.
Example of an ultra-low-headroom spreader beam
Conclusion: analyze the full system (and avoid false solutions)
Increasing lifting height does not come down to changing one single element. You need to analyze the entire system :
- the building's clear height;
- the type of overhead crane;
- the structural design;
- the hoist;
- below-the-hook devices.
Each factor can contribute to the result, but its impact depends on the context.
Next step : if you are short on height, start by identifying the real limitation (obstruction, hook position, or rigging).
See also : What does not increase an overhead crane’s lifting height (common misconceptions) — to avoid investing in the wrong place. (Coming soon !)
And finally, if needed… Talk to a Premium specialist to validate your configuration before manufacture.
