Product Announcement from RUD Chain, Inc.
SEEING EYE TO EYE
by an Pelton, Editor Canadian Metalworking Magazine
Industrial accidents, and fatalities, occur due to incorrect eyebolt installation
Whether it's a matter of not wanting to spend the time or the money, many mold making plants--and other facilities that deal with heavy lifting--are being less than vigilant in their rigging practices when it comes to hoisting and lifting.
There was one incident where two workers were injured, one fatally, when an eyebolt failed during an attempt to hoist a mold weighing about 65,000 lbs.
Four shoulderless eyebolts, 2 1/2 inches in diameter, had been screwed in, close to the four corners of the mould. Four six-foot, 10-inch chains were hooked into the eyebolts and attached to the hook of a 40-ton overhead traveling crane.
One eyebolt snapped before the mould lifted off the floor. The chain, with part of the eyebolt attached, swung up and struck the first worker, then hit the second worker as it came down.
Another accident resulted in the death of a worker who was attempting to lift a motor/pump assembly, weighing 440 pounds, with a one-ton manual chain hoist. The hook was inserted through the eye of a shouldered eyebolt threaded into the electric motor.
The location of the centre of gravity of the pump set in relation to the eyebolt resulted in a force being applied to the eyebolt outside the plane of the eye. The eyebolt failed and the worker was killed.
A properly installed shouldered eyebolt has the shoulder firmly seated against the mould, with the plane of eye aligned in the direction of the pull. "They are never really aligned, unless it's a coincidence," claims Brian Mills, a sales rep for Century Tool and Machinery Ltd. who frequently visits such plants in his line of work. "And it's not a coincidence that commonly happens."
To properly align the eyebolt, Mills says flat shims or washers need to be installed on the shaft of the bolt, below the shoulder. This allows for the eye to be aligned, and the shoulder is squeez-ing the shims against the mould.
"(Shimming) has to be done," says Mills, "and if you don't do it, what you effectively have is an unshouldered eyebolt. This is a different product altogether that is much lower rated and it's definitely not supposed to be used for any kind of angular lift." He also says that he hasn't seen any such shims or proper washers in any of the plants he has visited.
The problem with shims is there is a lot of trial and error involved with each installation. In an age when everyone seems to be in hurry and the equation of "time is money" is increasingly a company philosophy, many mould handlers just leave the shoulders unseated, or not aligned.
"If a guy has all the right shims and washers, I could see the whole process taking about 15 minutes," figures Mills. "The problem is that they never have them around.
"You can go any mold place, you will not find any shims around. They may have a few washers, but they all seem to be the same size. You need to have various sizes."
A second hazard comes into being when handlers are careless with, or negligent of, thread depth specifications.
Specs call for a toolmaker to make the hole 1.5 to two times the thread diameter. If the toolmaker bores any deeper, he or she is often accused of wasting time.
The trouble is that machinery eyebolts may have much longer threads than the specs call for. It's common for a one-inch eyebolt to have a thread protrusion of 2 ½ inches, and a 1 ½ -inch eyebolt to have threads that are 3 ½ inches long.
The manufacturer's instructions say the bolt cannot be cut or altered in any way.
What results is that the shoulders are not seated on the object being lifted, and strength is severely compromised.
Some people put spacers, drilled blocks, and even nuts, on the threads to ensure something is seated. This, unfortunately, causes the eye to move further away from the object, giving the lifting force more leverage to break the already de-rated and poorly-seated bolt.
There are even instances when some gamblers dispense with eyebolts ltogether and apply the hooks to hex nuts.
WARPED INSPECTION PRIORITIES? Mills contends that health and safety inspectors may be missing the point. They tend to be more concerned with the state of the lifting tools rather than thelifting procedure.
If the bolts and chains, for instance, are up to standard, the inspector issues a passing grade. Perhaps not enough attention is paid to how they are applied and how well they perform.
In fairness to eyebolt manufacturers, it has to be said that they forward reams of literature that meticulously explain the do's and don't's of eyebolt installation and usage.
It just seems that industry isn't paying enough attention.
On a brighter note, Mills says that about half the companies in Ontario have stopped using the side-loaded eyebolt method and have switched to safer modes of lifting and hoisting--such as swivel hoist rings--when the load warrants it.
There is one factor, however, that deters more companies from following. The swivel hoist rings cost almost ten times than the eyebolts.
"The companies that don't have a strong health and safety committee, or owners that care, end up using (side-loaded eyebolts)."
For cost-conscious plants, there are more stable alternatives that don't carry as hefty a price tag.
The purpose of the adapter is allow the attachment of self aligning lifting points onto equipment that has existing large threaded holes designed for shouldered eyebolts.
Eyebolts are de-rated by 75 per cent when side loaded, so large eyebolts are used and large holes are bored and tapped into the work. Hoist rings and swiveling lifting points have much higher ratings, for the same thread size,than side loaded eyebolts.
A large swiveling fitting that fits the hole is expensive, cumbersome and not required. A smaller thread-sized fitting would have an equal or better WLL than the eyebolt it replaces. By using these inexpensive adapters, users can use a smaller, lighter, and less expensive, safe fitting.
Designed for side-loading applications, Starpoints can also be used for straight pull and angle lifts, and will always adjust to the direction of the pull.
What is very important is that they will always be seated properly, thanks to the adapter.
Users can realize further cost savings, Mills points out, by asking for the free drawing and making the adapters themselves in their shops.
The adapter is designed for permanent installation into moulds or other equipment, into threaded holes designed for forged eyebolts. The existing threads must be cleaned and cleared with a blind tap.
An appropriate thread-locking compound is recommended, or later tack welding.
The suggested procedure is to thread the adapter onto a short bolt, and flat washer, that matches the ID of theadapter, with the flange up against the washer. The assembly is threaded into the hole, and torqued using the head of the bolt. The Flange must seat firmly against the work after being torqued to a recommended 50 ft./lbs.
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