Trench Shield Inspection | NAXSA
An important responsibility of a competent person is to inspect all the shoring and shielding equipment at the job sites. OSHA requires these inspections to be conducted at the beginning of work and as often as needed during the day.
For example, we will inspect this aluminum trench shield which is eight feet tall and ten feet long. It has got four adjustable spreaders, and it weighs around 1,200 pounds. The first step would be to inspect the shield by ensuring all the components are in place.
Next, we need to examine the top rail at the top of the sidewall, the bottom rail at the bottom of the sidewall, and the two ends to ensure no signs of excessive deflection. Sometimes the steel shields undergo the ‘waffling effect,’ where they are subject to extreme loads, and the skin of the shield presses into the sidewall. The waffling effect is a cosmetic problem as it may rip or tear the skin of the shield. Hence, it is essential to examine each side wall.
The next step is to investigate the spreaders, as they are prone to get hit by excavator buckets. Hence, we need to ensure that the pins and keepers on these spreaders are in good condition. Manufacturers consider the pins as structural items. Therefore, the pins should either be supplied by the shield manufacturer or meet that manufacturer’s specifications. Nails, welding rods, or a piece of scrap can hamper the functionality of a keeper. This shield’s spreaders are attached to the sidewalls via these vertical whalers. Since these vertical whalers will either be riveted or welded to the sidewall of the shield, we need to examine the rivets and wells. This particular shield has four pins on the lifting lugs.
As we discussed, we will check the pins, wells, and the condition of the D rings on the lifting logs. Many a time, steel sheets have stack pockets. Therefore, when the sheets are mounted at the ends of the sidewalls, it is crucial to inspect the state of the stack pockets, welds, and pins. The final step is to examine the manufacturer’s tabulated data to ensure that the information remains at the job site at all times.
There are several ways in which this information can be given; a plate that is welded or riveted to the sidewall, a sticker on the sidewall, or a paper form. The format is not essential; it is crucial to ensure that this information is at the job site with depth ratings and answers to questions. The shield manufacturer or the shield distributor is responsible for answering questions raised in the inspection process. Hence, the inspection process increases the safety standards and ensures that OSHA’s inspection requirements are met.
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