Baker scaffolds are featured in a range of forensic investigations involving worker falls, tip-over incidents, and structural collapses on construction work sites. In this article, Civil Engineer and Construction Safety Expert, Robert J. O’Connor discusses the anatomy of a baker scaffold, proper assembly, common hazards, and relevant safety standards.
Construction Safety: Baker Scaffolds - Expert Overview
Baker scaffolds are a prefabricated manually propelled mobile scaffold commonly used on construction sites for performing overhead work tasks. They are particularly useful when working at the interior of buildings for accessing higher ceilings or upper portions of walls, painting larger ceiling areas where ladders would need to be repeatedly repositioned, and where workers are handling larger materials such as full sheets of drywall or long sections of ductwork. This type of scaffold is intended to be quickly assembled using matching manufactured components, and easily moved around using wheels at the base of the scaffold. They also have work platforms which can be readily repositioned at various heights.
A baker scaffold is relatively smaller than other types of scaffolds used on construction sites, with a length of about 6 feet and a width of less than 3 feet. They are also limited in height, with the scaffold typically consisting of either one or two levels or tiers, with each level being about 5 feet to 6 feet tall. However, just like other types of scaffolds used on construction sites, the use of a baker scaffold can present potential safety hazards to workers if not properly set up and utilized.
A basic baker scaffold configuration with a single level or tier consists of a wood work platform, typically plywood with metal edges, which is placed on and supported by metal braces on each of the longer sides of the scaffold. The side braces are attached to narrow fabricated metal frames at the ends of the scaffold, which have horizontal bars for stability and to facilitate access to the work platform, with the end frames typically having wheels or casters at the base which are installed for moving the scaffold around. The wheels should have a mechanism to lock them in place and help prevent the scaffold from moving around while workers are on the platform.
Baker scaffolds can also be supplied with other components such as additional end frames and platforms, “outriggers” which are side extensions at the base of the end frames used to help stabilize the scaffold, as well as “guardrails” or safety railings which can be installed around the work platform to help protect workers from falls. The outriggers and guardrails are typically installed when a second level or tier of scaffolding is being used with a significantly elevated work platform.
A baker scaffold is assembled by first installing the wheels to the end frames. An engaging rod or stem on the wheel assembly is inserted into the base of the end frames and then a pin with a retention device, or snap pin, is used to secure each of the wheels to the end frames. Two side braces are then attached to the end frames at the desired height, with the side braces having spring loaded locking pins to hold them in place. Then the work platform is placed on the side rails, with the side rails typically having spring loaded latching pins to hold the platform in place.
Additional end frames can be installed on top of the first level or tier of the scaffold, with the open socket like base of the upper end frames slid over an engaging rod or stem at the top of the lower end frames, and which are often secured with swivel lock pins or snap pins. The additional end frames are used to either provide a hand hold for workers climbing onto a work platform installed near the top of the first level, or to install additional work platforms with side rails at a higher level. When a second level or tier of the scaffold is installed, with a significantly elevated work platform, manufacturers typically require that outriggers be installed at the base to help stabilize the scaffold and that guardrails be installed to help protect workers on an upper platform from falls.
Like other types of scaffolds used on construction sites, the use of baker scaffolds can present potential safety hazards to workers. These hazards include falls from an elevated level, scaffolds tipping over, and scaffold failures or collapses which can result in a worker becoming seriously injured. Construction industry safety standards, including OSHA standards contained in 29 CFR Part 1926 and ANSI standards in A10.8 related to scaffolding safety, contain numerous requirements for contractors to protect their employees who use scaffolds. There are also requirements for general contractors overseeing work on a construction site where scaffolds are being used.
Construction industry safety standards require that workers on construction sites utilizing scaffolds have basic training in recognizing common jobsite hazards, such as falls, as well as additional training related to the particular type of scaffold being used. It is also required that scaffolds be assembled and utilized by or under the direct supervision of a qualified competent person who has significant training or experience related to the type of scaffold being used.
Falls from a scaffold are particularly hazardous for workers, and construction industry safety standards such as OSHA regulations and ANSI standards require that workers on a scaffold at a height greater than 10 feet be provided with fall protection. That fall protection can consist of either personal fall protection, such as a safety harness with a lanyard attached to a hanging lifeline, or substantial guardrails on any open sides of the scaffold.
Some local construction safety standards, such as the New York Labor Laws and Industrial Code, as well as some jobsite specific safety programs have more restrictive provisions and require that workers on a scaffold be protected from falls when at a height of 7 feet or 6 feet. Furthermore, manufacturers of baker scaffolds often require that guardrails be installed on upper work platforms whenever the baker scaffolds are stacked, or a second level or tier with an upper work platform is used, with that platform at a height of about 6 feet or more.
Concerning the stability of baker scaffolds to help prevent those scaffolds from tipping over, it is required that the height of the work platform not exceed four times the narrow dimension of that scaffold. A typical width of a baker scaffold without outriggers installed is about 30 inches, or 2-1/2 feet, in which case the maximum height that the work platform could be placed at is 10 feet. When a work platform for this scaffold is placed above 10 feet, industry standards would require outriggers be installed at the base of the baker scaffold to increase the width and stability. However, manufacturers of baker scaffolds often require that outriggers be installed whenever the baker scaffolds are stacked, or a second level or tier with an upper work platform is used, which means that outriggers would be required with a work platform at a height of about 6 feet or more.
Concerning the wheels at the base of a baker scaffold, industry standards require that those wheels be securely attached to the scaffold frame to prevent them from accidently falling out, which could occur if the wheels were not secured and the baker scaffold is lifted up over items on a floor such as extension cords or pipes. The wheels also need to have a locking mechanism to prevent movement of the scaffold while a worker is standing on the platform. The locking mechanism typically includes a metal bracket above the wheel, which a worker can push down or lift up with a foot or hand to easily lock or unlock the wheel. Unexpected movements of a baker scaffold can cause a worker on that scaffold to lose their balance and fall off the scaffold becoming injured.
Construction industry safety standards also have provisions related to the safe use of baker scaffolds on work sites including that they be placed on a firm and stable surface, that the scaffold and work platform be reasonably plumb and level, and that safe access be provided to any work platforms. There are also limitations on moving a baker scaffold while a worker is standing on that scaffold.
CONSTRUCTION SAFETY INVESTIGATIONS
The use of baker scaffolds on construction sites can present potential safety hazards to workers if they are not properly setup and utilized. These hazards include falls from an elevated level, scaffolds tipping over, and scaffold failures or collapses which can result in workers becoming seriously injured if proper precautions are not taken to train and protect those workers. The Construction Safety experts at Robson Forensic have worked at every level within the industry, and have done the work central to your case. They can testify regarding the hazards, risks, and responsibilities in the construction industry.
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Civil Engineer & Construction Safety Expert
Robert is an expert in civil, structural, and construction engineering with a diverse background in construction and consulting. He has more than 35 years of experience with private and municipal projects involving forensic investigations, construction safety, construction defects, condition inspections and evaluations, construction failures, premises safety, construction project management, jobsite supervision, project engineering, preparation of contract documents, civil engineering designs, enforcement of construction regulations, construction inspection, and construction testing. This includes matters related to the construction and general industrial provisions of the New York Labor Law, NYCRR Regulations, OSHA Regulations, ANSI Standards, and other related industry standards.