Maintenance Man

During Longwall setup procedures, two service representatives from shield manufacturer were installing yield valves on shields. The deceased was positioned behind leg jacks installing yield valves on tilt jack, while second representative began to install yield valves on leg jack. Plugs from both jacks were removed causing the shield canopy to collapse crushing the victim.

On Friday, December 2, 2016, at approximately 11:00 a.m., a 36-year-old shield designer and engineer was fatally injured when the longwall shield he was working on collapsed and fell on him. The victim was in the process of installing hydraulic components on the tilt cylinder. His co-worker, who was working with the victim, removed plugs from both support cylinders which depressurized the hydraulic system and caused the shield to collapse. The victim was asphyxiated by the weight of the shield.

1. The contractor did not have an effective procedure to ensure persons working on longwall shields were properly task trained. The contractor used the sales manager/translator as a maintenance assistant, but the translator was not trained in the task of installing the longwall shield. He did not have practical knowledge of safe work procedures for the task and did not recognize the hazard created by depressurizing both support cylinders at the same time.

   Corrective action: The contractor will ensure that all its personnel performing work in the mine are properly trained.

2. The mine operator and contractor did not have an effective procedure to ensure the longwall shield was blocked against motion at all times while work was performed in an area where the shield could collapse onto a miner. Both of the support cylinders of the shield were depressurized while the victim was in the pinch point performing maintenance on the tilt cylinder.

   Corrective action: The mine operator submitted a revision to the roof control plan that requires a 4-point wood crib to be installed to block the shield against motion while work of this type is performed. MSHA approved this plan revision. The operator and the contractor have retrained all longwall installation personnel on the proper procedure to block the longwall shield canopy when repair, maintenance, or installation of the longwall shield would cause both support cylinders to depressurize.

Findings from MSHA's final investigation report, which supersedes the preliminary narrative above.

Activity at time of incident

Machine Maintenance

Subunit / location

UNDERGROUND

Underground location

FACE

Mining method

Longwall

Accident type

Caught in, under or between collapsing material or buildings

Source of injury

LONGWALL SUPT,JKS & CHOCK

Nature of injury

CRUSHING

Body part affected

MULTIPLE PARTS (MORE THAN ONE MAJOR)

Total mining experience

13 years

Experience at this mine

0 years

Experience in this job

13 years

Degree of injury

FATALITY