Industrial Accidents: Investigation of incidents involving industrial and commercial equipment and operations. The forensic work included equipment inspection, testing, and accident reconstruction. Typical circumstances involve machine guarding, power isolation, control systems failures, and lockout-tagout. Various industrial standards and regulatory codes were also analyzed for relevance to each accident. The investigations involved accidents in which there was personal injury as well as fatality.
Sample engagements for industrial and commercial accidents include:
Lockout-tagout (LOTO) procedures and operations
Power presses and metal stamping equipment
Hydraulic compressors, air compressors, and pumps
Material moving equipment and systems
Oil & Gas drilling and production
Petrochem, refining, raw material processing
Conveyor and packaging systems
Sample forensic investigations engagements involving equipment and machinery include:
Boiler and burner explosions
Shock and electrocution
Battery recycler machine
Bridge crane safety
Subsea blowout preventer
Dual fuel boiler swithover
Foundry conveyor control
Ground fault detection
Lumber mill debarker
Elevator control system
Soot boiler controls
Paper roll band strapper
Transformer tap changer
Tire recycling machine
Vehicle assembly line
Steel tube extruder
Asphalt paving equipment
Accidents with machinery and equipment:
A common aspect of industrial accidents relates to lockout-tagout, often termed LOTO. This safety element relates to isolating all sources of energy from machinery and equipment while it is being maintained. Inadequate LOTO procedures and conformance to company policy often contributes to industrial accidents. A LOTO procesure should be prepated for every machine and process having the potential to injure an employee during a maintenance procedure. The lockout-tagout procedure can cover multiple pieces of equipment, or it can be specific to a single unit. Adequate and documented employee training on LOTO procedures is an essential aspect of lockout-tagout management.
Machine guarding is an important aspect of forensic engineering for machine and equipment accidents. OSHA 1910 Subpart O, also known as OSHA 1910.212, is an important guideline when considering machine guards such as light curtains, safety mats, movable barriers, and door interlocks. Another important industry standard is ANSI B11 which convers many aspects of machine design. NFPA 79 Electrical Standard for Industrial Machinery is another source of design and operation requirements that affect safe workplace conditions for manufacturing and process control.
The LOTO procedure must identify all sources of energy such as electrical, mechanical, chemical, heat, hydraulic, pneumatic, and gravity. The lockout-tagout procedure should identify all sources of energy and provide a clear method of both isolating the energy and verifying that it has been safely isolated.
A forensic investigation often includes evaluation of the mode in which the equipment was operated when the accident occurred. The requirements for normal production mode and maintenance mode are very different, but often misunderstood or misapplied. Also, employee training for lockout-tagout and general machine safety is also considered by the forensic engineer to determine if adequate workplace safety measures were in place.
Improper or lacking LOTO procedures can result in accidents such as physical injury, amputation, electric shock, electrcution, and chemical burns. Accidents can occur when a production worker, who is normally protected by machine guarding, peforms maintenance without first performing the required lockout-tagout procedure.
Accident reconstruction can be done using the original equipment provided that it was not damaged during the accident. Alternately, accident reconstruction can be done with substitute equipment, or computer modeling, to evaluate the accident as it occurred in real time.
One component of these investigations isa root cause analysis. The process is used to identify preventable causes of an accident or hazardous situation. The root cause is analyzed within the context of the accident as well as that of the operating environment in which it occured.
Copyright © 2022 Arthur Zatarain, all rights reserved. Some images are modified for confidentiality
or illustration clarity. This site should not be used as a technical or legal reference.