What is a semi gantry crane?
A semi-gantry crane, is also called a half gantry crane, a device that has only one side of the steel column in structure, and classified under the certificate ISO 4301 compliance. Semi gantry crane has neither the overhead dual-runway systems, nor has the full gantry crane two-leg structure. This gantry crane can be used outdoors and indoors. Semi gantry crane combined one side of the foundation rail and one side of an overhead runway system together. When you have a workshop that is limited or small, you can consider the semi-gantry crane to help you save space and operate effectively.
Comparison between Semi Gantry Crane vs Full Gantry Crane vs Overhead Crane
1.Semi-gantry crane: you can see the semi-gantry crane as a half of the overhead crane or a half of the full gantry crane. As we have talked about it above, you can prefabricate a foundation to install the gantry crane system’s rail and the overhead crane system’s single runway at your workshop outdoors or indoors.
2.Overhead crane: an overhead crane should always need dual runways at a workshop. There is no need to consider the two or one legs to support an overhead crane to operate. There are some crucial points you need to consider, such as span, lifting height, and lifting capacity. But most essentially, you have to confirm the duty class to match your site situations. That means whether you will use your overhead crane often or use it infrequently.
3.Gantry crane: a gantry crane is often used outdoors and indoors. Some critical points are that you have to prefabricate two sides of the rails. Of course, you have to know your site situations in order to select the right span, lifting capacity, and lifting height. The same is true for the overhead crane. You should definitely select the right duty class to match your workshops.
Types of the semi-gantry crane: BMH vs. BMG Semi Gantry Crane
There are two types of the semi-gantry crane: BMH and BMG Semi Gantry Crane. You can see them below:
BMH Single Girder Semi Gantry Crane is always used in light-load circumstances, typically under 16 tons and under 20 m span. This type of semi-gantry crane is adopted with CD/MD hoists to lift and travel. Duty class is A4, so you should not consider this duty class when under the heavy-duty class sites.
BMG Double Girder Semi Gantry Crane is a double girder semi-gantry crane device. If you want the heavy-duty class semi-gantry crane, then BMG is better for you to select. Typically, when the lifting capacity is beyond 16 tons, A5-A7 duty class above, you can choose this BMG semi-gantry crane.
Application scenarios
Semi-gantry cranes have various application scenarios, such as wall-side production lines, old factory renovation, indoor/outdoor stockyards, precast concrete plants, steel fabrication workshops, harbor auxiliary operations, and working under existing overhead cranes.
There is a case of a customer in Thailand who bought the semi-gantry crane products from us. And they have an 8 m of an old factory that needs to be rebuilt, and they inquired about our 7 m span , 5 m lifting height of a semi-gantry crane. We provided the foundation and crane drawings for them to confirm. And they are satisfied with our solution. After 3 years, they had no accidents or other problems happen at their site or workshop.
So, we received good feedback from them.
Site Assessment Checklist before decision-making
You should make a checklist before you make any decisions to buy or to purchase the semi-gantry crane.
Let me help you to make the checklist:
1. Wall to wall clear width
2.Column spacing
3.Clear height
4.Floor bearing capacity
5.Construction structural type
Core requirements you should confirm:
1. the maximum weight of a single item
2.Lifting or travel frequency or working hours
3.Dual-speed mode and VFD control
4.The plans to rebuild or expand your workshops
Of course, you need to confirm the most important thing: certificates and regulations on the crane industry.
Cost Analysis: TCO
One of the most important considerations when purchasing a crane is the TCO (Total Cost of Ownership). We need to keep this cost within the minimum feasible range, without compromising quality assurance. The most cost-effective crane is the most qualified product. Therefore, you need to consider the following aspects:
Equipment price
Civil works (track foundation, ground reinforcement)
Installation & commissioning
Annual maintenance
Downtime cost
So, we must achieve the right cost upfront to reduce maintenance costs and downtime later on. Only then can we make full use of the crane and ensure the safety of our personnel.
Frequently Asked Questions (FAQ)
1.Is a semi-gantry crane always better than a full gantry crane?
→ Depends on building structural strength and space constraints; there is no absolute superiority.
2.Can a semi gantry crane be installed in an old factory building?
→ Yes, but the load-bearing capacity of columns/walls must be verified.
3.What is the minimum workshop width for a semi-gantry crane?
→ There is no absolute minimum; it must be calculated based on leg width + safety clearance + aisle requirements.
4.Does a semi-gantry crane require less floor reinforcement?
→ Usually, yes (only one side has a rail), but structural reinforcement is needed on the building side.
5.Can it work under an existing overhead crane?
→ Yes — this is one of the core advantages of a semi gantry crane.
