The transport of hay and grain from farms to markets and back has evolved from a strictly tractor-and-wagon unit to a range of large trucks, trailers, and semi-trucks. As farms grow in size and are more dispersed geographically, this has shifted how silage and grain are transported from fields to farmsteads and back again to markets. Farmers also maximize harvesting efficiency and transport efficiency while keeping labor costs down. Semi-trailer end dump trucks, pup trucks, truck and grain trucks, and regular and long-bed straight trucks are just a few of the large trucks and trailers that can be found on farms. These units will later be called large farm dump trucks or trailers. All farm dump trucks or trailers use a hydraulic lift to dump their loads. The same trailers and vehicles can also be used for transporting and dumping sand gravel, firewood, and debris.
What happens next?
The most dangerous situation is one that involves the use of large farm trailers and dump trucks on farms. Trucks and/or trailers can tip over when emptying loads. There are many reasons this can occur and we will discuss them in detail later. Another situation is when someone works underneath a trailer or truck bed. The person should not block the bed from falling unexpectedly. Third, if the truck or trailer bed is in direct contact with overhead electric lines, the driver or someone on the ground is electrocuted. This happens when the driver pulls away from the truck or trailer bed after emptying it. A person could be electrocuted or crushed within seconds in any of these three situations. Over the last 25 years, there have been twelve incidents. Sixteen of these incidents involved the victim being trapped between the truck bed frame and the truck bed. Other fatalities were caused by traffic accidents, falls from loaded trucks, and the tailgate falling onto victims.
Raised Dump Bed Dangers
Workers could be exposed to potentially hazardous conditions by raising the truck’s bed or trailer. These potentially dangerous conditions can all be avoided or controlled by using known solutions prior to, during, and after dumping loads. Below are some potential hazards associated with raised dump beds. These conditions can be controlled or eliminated.
Instability
The bed of a dump truck or trailer is more stable if it is raised than the ground. This is especially true if the ground is not perfectly flat. The risk of tipping over increases the longer the truck or trailer bed is, and the steeper the slope. When raising the bed, it is crucial that the load center gravity remains between the frame rails and the bed. It is best to keep the center of gravity in the middle. Even if the ground is flat, it is possible to create a slight slope by one set or more of tires setting in a hole, a deep set of ruts, or low tire pressure on one end. It is often a combination of all these factors that causes instability and tipping. Figure 2 illustrates the danger of tipping from elevated beds on sloped ground. Tip over risk is greater for longer beds than for shorter ones.
Lifting a bed on sloped ground can increase tip-over hazards. This risk is increased if the trailer is longer.
Instabilities can be caused by wind, off-center loads, and jack-knifed trucks. High winds can cause the trailer to tip over more easily because longer trailers have more surface area. If the trailer tips, jack-knifed rigs can often leave the cab in an unsound position. The risk of a trailer tipping is greater if it is uneven or blows high, or if the load shifts out of center while unloaded. Shifting loads and load distribution problems can be caused by a number of factors.
Unexpected Bed Lowering
Dump beds can fall unexpectedly and cause workers to be crushed to death. This could happen from inadvertently lowering the bed, failures of bed lift components (e.g. pins, bushings), or collapses of the hoisting cylinder. To check for unexpected noises and possible malfunctions and perform routine maintenance (e.g., greasing and repairs), a worker will most likely place himself or herself between a truck or trailer frame and a raised dump bed.
Co-workers or workers can accidentally lower a bed by accident. When a bed is raised, components such as hinge pins or bushings can fail, especially if the bed has a load.
Make sure to engage the lift arm support when you are placing your body underneath a raised bed.
Hydraulic hoists can suddenly lower the pressure in a cylinder. This can happen when components of the cylinder (hoses, valve rings, rings, etc.) wear out or leak due to excessive pressure or wear. If the original lift cylinder system was replaced or repaired, or if the truck/trailer bed is overloaded or significantly overweight, excessive pressure could occur. A lift arm support should be installed on truck and trailer beds to prevent the bed from falling. Figure 3 shows how to safely access the underneath of a raised mattress.
Contact Overhead Wires
Farms are at risk from overhead power lines. Although contact between overhead power lines and grain augers, hay, and grain elevators is more common, electrocution can also occur with trailer and truck beds. If the truck is being pulled forward with the dump bed still raised, contact between a raised dump bed and a powerline is most likely. This could be caused by forgetfulness or impatience on the part of the driver. The driver does not want to wait for the dump bed to drop completely before pulling away.
The truck tires provide protection from electric shock to the driver in such situations. Electrocution can only occur if the driver is in direct contact with both the truck and the ground while leaving the cab. Some drivers try to escape the cab, whether out of panic or ignorance. A person who touches any part of the truck, trailer, or another vehicle when it comes into contact with an overhead powerline can be instantly electrocuted.
Note: Jump as far as you can from the truck if there is an emergency, such as a truck on fire. To ensure your body does not come in contact with the truck and ground simultaneously, you should jump with both your feet.
Additional Hazards
Large farm dump trucks and trailers that haul large farms can pose additional dangers. Slips and falls can occur when you climb on or off the trailer beds. Opening and closing tailgate latches or tailgate hinges can cause fingers and hands to be crushed. As a helper, a driver may accidentally open or close the tailgate hinges or latches. These types of accidents can cause minor injuries, like a cut finger, or even serious injuries, such as being crushed between a trailer backing and a building. Another danger is stability.
Collapsing Lane Shoulders & Ditch Banks
Farm dump trucks and trailers of large size can put a lot of pressure on ditch banks and shoulders and lanes that run alongside fields. A 28-foot semi-trailer truck end-dump truck has a legal road travel Gross Vehicle Weight (GVW) of around 76,000 lbs. A large combine may weigh between 20-25 tons and 38 tons. The truck may tip over if the soil has been damaged by freezing, thawing, or prolonged rains. The shear line hazard is a hazard that can be caused by large combine or tractor operators operating near a ditch bank. Figure 4 shows the shear line for a six-foot ditch bank.
