ArticleThe experts at Robson Forensic investigate many industrial mishaps to understand how they occurred and to determine the responsibilities of the parties involved. These investigations involve a range of engineering issues from in-running nip hazards to falling objects and maintenance procedures. Through the course of their training, education, and experience, our engineers and industrial safety experts have developed expertise in conveyor systems and the relevant workplace safety standards.
This article provides a 101 style overview of conveyor safety and is one part of a series on machine guarding and industrial safety.
CONVEYOR SYSTEM INJURIES & MISHAPS
From small family owned stores to supermarkets, warehouses and distribution centers, factories and process industries, the conveyor is a widespread means of transporting materials, components and products. When properly designed, installed and commissioned, conveyors will safely transport materials without presenting hazards to users and others present. This article focuses on the type of conveyor that most of us are familiar with - the belt conveyor.
ANATOMY OF A BELT CONVEYOR
COMMISSIONING BELT CONVEYORS
Typical conveyor installations include a commissioning process, which takes place after the conveyor is installed and is typically conducted by the installer. The commissioning process is a comprehensive hands-on review of the entire conveyor system. Typical steps in the commissioning process will ensure that:
- all temporary installation materials have been removed and the conveyor is free from obstructions;
- all belt splices are intact;
- all steel work is secure and free from sharp edges;
- all guards and safety devices have been installed and are operative;
- all idlers and pulleys are securely fastened and aligned
A common hazard encountered in our conveyor investigations is the in-running nip hazard. This hazard will typically occur between the belt and the head pulley or the belt and the return pulley. As seen in the anatomy illustration, these pulleys are found at the ends of the conveyor and are often referred to as rollers by the layperson. The various pulleys found along the underside of the conveyor can also present in-running nip hazards.
Conveyors typically move materials along various lengths, and those materials can be heavy. Therefore, it is essential that the belt does not slip on the pulleys and that conveyor motors have sufficient power to drive the belt. To ensure sufficient power, conveyor motors are of industrial strength. Because of this robust construction, entrapments between the belt and a pulley are unforgiving and can result in serious injury. It can be difficult, if not impossible, to withdraw entrapped body parts from these hazards.
Industrial Machine Safety
Manufacturers must assure that hazards are engineered out of the product during the design process. If a hazard is inherent and cannot be designed out of the machine, system, or process, the hazard must be guarded. In all cases, the user must be warned or instructed about dangers of the product. These steps form the fundamental principles and rules of practice for the safe and appropriate engineering of products, and are sometimes referred to as the hierarchy of hazard control.
The requirement for guarding and, more broadly, machine safety is reinforced by a number of government and industry oversight organizations. In the section below we reference one of the earliest standards on conveyor safety.
Robson Forensic possesses an extensive technical library that houses standards and reference materials dating throughout the modern industrial era. In many forensic investigations, our experts are able to reference industry specific resources to establish the relevant standard of care at the time that a piece of machinery or equipment was designed, built, or modified.
CONVEYOR SAFETY STANDARDS
As early as 1922, the American Standards Association recommended a safety code for conveyors. After several meetings, invitations to various industry entities, formation of committees and subcommittees, the first standard was issued in 1947. That standard was designated as ASA B20.1-1947 American Standard Safety Code for Conveyors, Cableways, and Related Equipment. That early standard advised as follows:
- 602 Pulleys, Sprockets, Sheaves, Drums, Blocks
- All mountings for pulleys, etc., when located in a working area where operators (other than maintenance men) are present shall be arranged to prevent the possibility of injury due to hands or parts of clothing being caught between the belt and pulley, or chain and sprocket, or cable and sheave, drum or block. When these mountings are located in areas where maintenance men only have access then such arrangement of frames or guards will not be required if provisions are made to stop and lock out the conveyor before maintenance men work on the conveyor.
The conveyor standard has been revised many times since its inception and OSHA incorporates the standard by reference. Additionally, CEMA (Conveyor Equipment Manufacturers Association) provides additional standards and guidelines for conveyors.
Workplace Safety & Machine Guarding Investigations
The industrial safety experts at Robson Forensic have designed, built, maintained, and operated a broad variety of industrial machinery. Moreover, our experts have investigated countless mishaps over the years involving all manner of equipment. By retaining Robson Forensic, you are securing the full weight of our collective experience, knowledge, and resources toward the resolution of your case.
For more information visit our Industrial Safety practice page.
Industrial Engineer & Machine Safety Expert
Harry has worked as an Industrial Engineer since 1978. He has been responsible for the design and manufacture of consumer products, as well as commercial and industrial equipment. Harry provides technical investigations, analysis, reports, and testimony toward the resolution of litigation involving product liability, and mechanical, industrial and construction accidents.
Harry has extensive experience in the area of compliance with safety standards; he has worked closely with Underwriters Laboratories, Canadian Standards Association, as well as overseas safety agencies. Harry has been responsible for product development, product testing, Quality Control, as well as factory floor safety. He has a broad background in machine guarding, industrial safeguards, personal protective equipment, training, and supervision.