The boom running rope on the Crawler Crane failed and dropped the boom. I don’t have any more info at this time, but the “experts” are investigating.
From our experience in the certification business we know that boom ropes are;
1. Hard to inspect and a precise method is necessary to inspect them properly.
2. Failure mode is usually “Crushing” on the Drum WHICH CAN BE SEEN and “Embrittlement” of the wires in the rope causing fatigue failures of the wires WHICH ARE HARD TO SEE.
One reliable way of knowing your wire ropes are in good working condition is to keep track of the time the wire rope has been on the crane and the condition and maintenance of the wire rope. Gottwald Harbor Cranes have an hour meter on their hoist which shows the actual time the ropes have been spooled in and out on the drum which causes the damaging fatigue. Presently, they say to change the wire rope at 8,000 hours of operations. No other manufactures to my knowledge has given an hourly replacement criterion.
The method we follow when making an inspection on the critical Boom Luffing Ropes is;
- Get the date the rope was installed, they don’t know, deficient.
- Get the Wire Rope certificates, must have.
- Check to see it’s the correct rope, if wrong, deficient.
- Boom must be put on the ground and ropes slack for inspection, if you can’t, deficient.
- Inspect per my presentation, which I will go over at out next newsletter.
The “attentive” crane owner is well aware of the importance of inspecting the wire rope on his crane, but the problem is that some are becoming accustomed to having third party inspection companies perform their annual inspections, This is the only time the wire rope is thoroughly inspected. However, the new OSHA construction standard 1926.1413 requires written monthly wire rope reports completed by a “competent person” to be performed and documented. What does it mean to be competent?
The definition of “competent person” in OSHA is thirty five words long! But what says is, someone who knows what there are looking for, and has a good track record of finding it!
However, this written report is most often missing from the crane file when we (as required) review the files during our annual inspection. Let’s all try harder to improve ourselves in these inspections of this critical component, Boom Luffing Ropes.