Can an overhead crane be operated above its rated capacity?

Sometimes, a production or maintenance manager wants to lift a very heavy machine or part, for maintenance purposes for example. But what if none of the overhead cranes has the capacity to lift it? Can an overhead crane still be operated above its rated capacity for occasional lifts?

This subject that can even extend to a new crane project. Indeed, one might ask: should I buy higher capacity lifting equipment just to be able to lift this part, even if it’s one lift a year? Or should I use an overhead crane that matches my frequent operations to exceptionally lift a load in excess of its rated capacity?

It’s a complex question, because excessive lifting could lead to serious consequences, such as major breakage or serious injury.

But rest assured, there are clear answers to this question, whether you’re considering your current installations or deciding on new installation projects.

As a supplier of lifting equipment for over 15 years, we are often asked this question. Our in-depth knowledge of standards has enabled us to respond to numerous requests on the subject, in a wide variety of environments and industries.

In this article, we answer the following questions :

1. Is it allowed to lift a load greater than the rated capacity of a piece of lifting equipment?
2. If so, what conditions must be met during the operation?
3. How to choose the right equipment for frequent operations, while considering an exceptional lifting need?

After reading this article, you’ll know exactly how to choose the right solution to this dilemma, whether for a future acquisition or for your current installations. You’ll be able to make the best decision without hesitation, in line with current standards.

Let’s start by checking the main question: is it permitted to lift more than the rated capacity of the lifting device?

Is it permitted to lift a load in excess of the overhead crane’s rated capacity?

Normally, it is not permitted to lift a load with an overhead crane if the weight of the load exceeds the rated capacity of the hoist. However, there is a provision in the CSA-B167-16 standard, known as controlled overhead lifting, which allows this type of operation to be carried out in certain situations.

The CSA B167-16 standard refers to the ASME B30 standard, which specifies the conditions to be met for this type of lifting. These are always special operations that must follow precise rules. Let’s take a closer look.

What conditions must be met when lifting a load in excess of the crane’s rated capacity?

First of all, this type of operation should be regarded as occasional and special, since it involves additional risks compared to a normal lift. When a controlled overload lift is to be carried out, the following conditions must be met :

1. Maximal capacity : 125%

The capacity should not exceed 125% of the equipment’s rated capacity.

1. For example, if a 5,000 kg overhead crane is to be overloaded, a load of no more than 6 250 kg can be lifted.
   
   

2. Frequency : 2 times in 12 months

This type of lifting should not be carried out more than twice in a period of 12 months.

3. Lifting plan in collaboration with the manufacturer

An overload lifting plan must be drawn up by a competent person and approved by an engineer, in collaboration with the equipment manufacturer. This plan must include warning all persons present in the area when the lift is to take place.

4. Summary of the overhead crane’s history

A written summary of the crane’s history should be prepared. This should include previous controlled overload lifts, structural repairs carried out and any major modifications the equipment has undergone.

5. Inspection before and after operation

The equipment must be inspected by a competent person before operation to detect and repair any problems beforehand. A new inspection should be carried out after overload lifting to check and treat any new anomalies before the equipment is used again.

6. Inspection and approval of the structure supporting the overhead crane

The design of the crane runway must be examined, inspected and approved by a competent person. Design calculations must take into account any deterioration or damage related to the load to be lifted.

7. Short-distance breaking test

Before proceeding with the full maneuver, the operator should perform a short test run to evaluate the load brake and ensure that it is holding the load securely.

8. Creation of a controlled overhead lifting register

A log should be added to the equipment logbook, including calculations, inspections and lifting distances for each overload lift performed.

It’s true that this procedure can seem complicated. That’s why an equipment owner might wonder whether it wouldn’t be better to have a device capable of doing this type of lifting without constraints. In other words, how do you choose the right capacity? Is it better to buy an overhead crane adapted to everyday needs, or to get one with a higher capacity so you can lift heavier loads without having to follow all those rules?

How do you choose the right equipment for frequent operations, while considering the need for exceptional lifting?

The answer to this question lies in a precise analysis of your needs. Why is this so important? The acquisition of a higher-capacity overhead crane will obviously cost more. But that’s not the only problem. It may well be that such equipment is not suited to your regular operations. Indeed, the lifting and travel speeds may not match your needs.

On the other hand, what if your higher-capacity lifts aren’t so occasional? Here again, you need to select the right solution for you! You may need 2 pieces of equipment. Or maybe you’ll decide to employ the services of a machinery moving company or rent a crane that can lift and move a part or machine too heavy for your equipment.

Here are the questions to ask yourself when analyzing your needs :

1. what are my daily lifting needs? To determine them clearly, consult the article “I need an overhead crane!” What information to I need to pass on to my supplier?
2. What are my occasional lifting needs? What is the maximum weight I’ll need to lift?
3. How often do these occasional lifts need to be carried out?
4. Will our operations and organizational structure allow us to apply the 8 conditions listed above when the time comes to carry out controlled overload lifting?

 

The answers to these questions will help you determine which solution to choose. Let’s look at some examples.

On a daily basis, you feed a machine with parts weighing up to 5 tons. But once a year, you need to maintain a large machine weighing 6 tons. You might consider acquiring a 5-ton capacity overhead crane, since controlled overload lifting would not exceed 125% of the overhead crane’s rated capacity, and special lifting would only take place once a year. If you can afford the other 6 conditions, then this could be a wise choice.

However, if in this same scenario the machine has to be lifted every quarter and weighs 7.5 tons, other conditions will have to be met. Or if the lifting conditions complicate your operations and affect your productivity, another option could be considered. You could assess the cost of using an external service or evaluate the characteristics of a 7.5 ton overhead crane in terms of cost and speed, for example. A similar assessment can be made for existing installations.

Here again, it’s a matter of assessing your specific needs. And this is where the expertise of an overhead crane specialist comes in handy.

A specialist to guide you towards the right option

We’ve seen that, although no load may be lifted heavier than the rated capacity of an overhead crane, current standards do allow it in special circumstances. However strict conditions must also be met. But the challenge is to know which is the best option: choosing a piece of equipment based on daily operations, or one whose capacity allows for these exceptional lifts. How do you decide?

The first step is to consult a lifting specialist who will analyze your specific needs with you. Whether for existing installations or a new overhead crane project, an expert will be able to guide you in your decision. The Premium Industrial Group team offers this service and can advise you. If you wish, you can fill in the form at the bottom of the page, and a Premium representative will contact you to help you determine the right solution for your needs.