Contributed by Bob Kozickie, Technical Sales Support Manager
Edited by Christy Kutchma, Product & Marketing Associate
Utilizing alloy chain slings to lift heavy loads has been the general industry practice for well over a century. There are a variety of mass-manufactured master links and hooks which are either forged or welded available in the market that can lift conventional loads on a repetitive basis. Those fittings simply get placed onto the crane hook then attach to the load making it easy to move a product from point to point. Sometimes, however, there are circumstances that require a special device to lift the load. There may not be hoist rings, lifting lugs, or other attachment points available to accept a conventional sling hook or foundry hook or have choking availability in order to safely make the lift. These are the conditions where a custom lifting attachment or device are required.
The most important point to keep in mind is that these types of attachments and lifters are custom. Advanced planning is a requirement to allot adequate time for the design and manufacture of a device that will work as needed.
Submitting an request
When the initial RFQ is submitted to the estimators, it’s important to include as much information as possible. If it doesn’t provide enough detailed specifications to begin compiling a quotation, the estimator has to go back to the requester for additional information. The most important factors to be sure to included are:
- Critical dimensions
- Center of gravity location
Pictures do speak a thousand words as they offer the engineers a visual image of the load. They can also help by showing the way the product or load is currently being rigged and lifted. This visual can depict additional critical obstacles which have to be overcome during the design phase.
Turnaround time on Quote
The complexity of the device will determine the amount of time it will take to receive the initial quotation. Throughout the quoting process, the estimators will likely need to source components and processes from outside suppliers which can include:
- Special machining
- Special threading
- Material such as rubber pads
- Machined plastic
- Rubberized coating
All these additional steps take time to receive costing back from third party vendors. Once this information is received, then an accurate quotation and lead time can be established.
The good news is that there are options available to lift a wide variety of non-standards loads. The sizes and capacities can range from a custom bent bar product to lift a small motor all the way up to a custom engineered attachment used to dump a ladle of molten steel. The two main points to remember are that the entire process takes time and as much of the required information as possible, if not the component itself, be provided to the estimators with the original inquiry. Consideration must be taken in the fact these attachments require time to develop a concept, engineer an appropriate device, and then manufacture the device in accordance with the safety standards spelled out by OSHA and other Standards.
We will examine this process in detail in a future blog article and take a look at the steps involved through the completion of a finished product.