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Mine Safety and Health Administration MSHA's Accident Prevention Program
Safety Idea

Safe Access: Beware of Appearances

Safety Something YOU can live with!
Mine Type: All Surface
Category: Maintenance

While running conduit in a preparation plant, an electrician fell into an operating cyclone sump while working from a perforated plate screen that covered the top of the sump. The fatal accident occurred when a section of the screen gave way under the weight of the worker.

Photo of hole in floor Photo of hole in floor showing screen
The purpose of the screen was to keep extraneous material from getting into the sump. The screen was not designed or intended to be walked upon and over time it had been weakened by corrosion. There was an access ladder to the top of the sump, but it was only intended to provide a vantage point for checking the pumps and pipes.

Photo of protected accessTo prevent such accidents, mine operators should do the following:

1) Where persons need to work above a sump or other open vessel, provide a safe means of access.

2) Beware of situations where a worker may assume that it is safe to walk on a cover that is not intended or engineered to support their weight.

3) Where a cover on a sump or other open vessel is not designed or intended to support personnel, make sure that warning signs are provided and access blocked.

4) Where safe walkways are not available for performing maintenance activities, ensure that workers use appropriate fall protection.

5) Check with the vessel manufacturers on what options they can provide for safe access. Manufacturers can provide covers of corrosion-resistant material, such as stainless steel, designed to safely support the weight of personnel.

6) Ensure that elevated walkways are engineered with adequate strength and provided with proper guard rails.

7) Check walkways regularly for corrosion or other damage that would make them unsafe.

8) Shut down sumps when performing maintenance activities in or around them.

Reissued: 10-10-2002 
Tag # AP2002-S037