There’s a reason that developing an adequate material handling solution
is so difficult. Even following OSHA’s published lifting limit of 50 pounds
doesn’t fully protect employees. This is because material weight alone is
not the only factor that contributes to MSD risk, especially during physically awkward or fast-paced tasks.
Though many loads weighing less than 40 lbs. are safe to move manually,
one OSHA study specifically analyzing the MSD risk of lifting tasks discovered that injury is still possible when transporting materials as light as 35
lbs. With such conflicting information, the confusion fabricators experience when trying to protect their employees is completely understandable.
Coming up with the right ergonomic motorized equipment for a specific
application is a complicated process. In addition to load size and weight,
engineers have to account for any inclines, rough surfaces, or outdoor
conditions that could inhibit the proposed equipment’s ability to operate safely. Entire workplace processes and systems must also be looked at
in-depth, because some safety risks go beyond transporting a load from
point A to point B.
For example, shifting materials onto shelving or raising them up to work
table height presents MSD risks that should not be overlooked. Facility
layout and storage systems are another factor. Fabricators in particular
can run into problems when trying to find a cart that is long enough to
carry industrial shafts and sheet metal, but maneuverable enough to pass
through tight workspaces.
Every fabricating environment is unique and can change with each new
project, especially in low-volume, high-product-mix environments. Here’s
where that all-important walk-through comes into play. Walk-throughs reveal how employees are operating and help identify any additional issues
with workcell structures, storage systems, and operational logistics.
Quite often some type of motorized platform cart is needed to accommodate the lengthy or unusually shaped materials. Standard motorized carts
can improve matters, as can scissor-lift carts with adjustable heights—
especially helpful when tackling ergonomics for a group of employees with
varying heights and body types.
Transporting exceptionally heavy or long materials often calls for a heavy-duty motorized transfer cart that can handle very large payloads. When
designing these custom carts, a fabricator needs to consider the level of
maneuverability. For example, in a facility with tight workcells and storage
aisles, the cart might need to be engineered to rotate 360 degrees around
Engineers can get creative in tailoring the final product to the needs
of the fabricator by customizing the platform size, safety features, drive
systems, and deck add-ons such as racks or shelving. Heavy-duty transfer
carts can be designed to operate wirelessly, while the “driver” stands a
safe distance away from the cart itself. Wireless control is ideal for a fabrication facility with space limitations or additional safety concerns that
limit where employees can travel throughout the workspace.
Consider one fabricator that invested in a motorized transfer cart with
side-mounted controls and steering to accommodate the length of the
materials onboard. When beams, tubing, or extra-long components that
will naturally extend beyond the platform of just about any motorized cart
are transported, side-mounted controls help maximize platform space on
both ends of the cart.
For appropriate applications, electric tuggers can be a versatile, cost-effective way to prevent MSDs. Tuggers operate similarly to an SUV towing a trailer, meaning pulling is usually easier than pushing or backing up.
Though maneuverability is more limited with a tugger than a motorized
cart, a tugger can pull multiple carts at once. With the proper hitching
method, a standard tugger can hitch to and move a variety of manual cart
types within its payload capacity.
Research, Education, and Engineering
Each of these ergonomic equipment categories is as diverse as the transport problems it is designed to fix, and it takes quite a bit of research,
creativity, and expertise to find out which one is going to work for a specific application. Though every facility has its own challenges, one thing is
clear about every fabricating operation: The most important step in combating musculoskeletal injuries isn’t simply going out and buying a piece of
equipment. It’s the preliminary research, education, and engineering that
allow fabricators to master the physics of their own workspaces.
Raymond Erbe is president of Electro Kinetic Technologies, W194 N11301 McCormick Drive,
Germantown, WI 53022, 262-250-7740, www.ek-tech.com.
MANAGEMENT » CHIEF CONCERNS
The most important step in combating
musculoskeletal injuries isn’t simply going out
and buying a piece of equipment.
It’s the preliminary research, education,
and engineering that allow fabricators
to master the physics of their own workspaces.