Inventory Management and Warehouse Operations.


Loading Dock Safety:  Education and Equipment can increase safety in your loading dock. 

By Dave Piasecki

It is easy to come to the conclusion that the loading dock area is very likely to be the most hazardous part of your operation when you consider the combinations of hazards and the volume of activities that occur in this area.  For the lift truck operator, ramps and inclines, overhead obstructions, dissimilar surfaces often wet and slippery, poor lighting in trailers, other vehicular traffic, pedestrian traffic, restricted views, sheer drops, trailer creep, congested staging areas, and accumulations of empty containers, pallets, and debris are hazards which can all be present at the same time within a very confined area.  While OSHA does require training of lift truck operators on these types of hazards, many operations fail in providing detailed hazard assessment, operational procedures, and day-to-day enforcement of safety issues.  In addition, those employees that do not operate lift trucks are rarely trained on dock safety issues even though they share many of the same risks as the lift truck operators.

The biggest reason to put a priority on dock safety is not so much related to the frequency of accidents in dock areas as it is to the potential severity of injuries that can occur in these types of accidents.  Injuries sustained when lift trucks tip over or fall from docks, or those that occur when pedestrians are impacted by a lift truck, falling load, or tractor-trailer, tend to be very serious and sometimes fatal.  Prevention of these types of accidents can be achieved through proper equipment, proper training, and enforcement of safe operating procedures.

Wheel Chocks 

When people think of dock safety the first thing that will generally come to mind is the wheel chock.  Wheel chocks are wedge-shaped blocks placed in front of the rear wheels of a trailer to prevent the trailer from moving away from the dock while the trailer is being loaded.  Trailer creep (also known as trailer walk, dock walk) occurs when the lateral and vertical forces exerted each time a lift truck enters and exits the trailer cause the trailer to slowly move away from the dock resulting in separation from the dock leveler.  Factors that affect trailer creep are the weight and speed of the lift truck and load, the grade of the drive the trailer is parked on, the softness of the suspension, the type of transition (dock levelers, dock boards) being used, and whether the trailer has been dropped off (spotted) or if it is still connected to the tractor.  Separation from the dock also occurs when a driver prematurely pulls away while the truck is still being loaded/unloaded. 

OSHA regulations require the use of wheel chocks or other vehicle-restraining device when loading and unloading trucks and trailers (NOTE: this may have changed. see update at the bottom of this page).  The effectiveness of wheel chocks is an often hotly debated issue. Depending on the surface conditions and type of chock being used chocks can sometimes slip thus reducing their effectiveness in preventing trailer movement. Also, requiring people to walk in between trailers to set and remove the wheel chocks creates additional safety issues.  A bigger problem with wheel chocks is, however, not so much related to their physical characteristics as it is to the difficulty in enforcing their use.  Often, companies feel that by chaining wheel chocks to the outside of their dock and putting up a couple of signs reminding the drivers to use them they have done their part in dock safety.  In reality this approach will provide minimal if any usage of the chocks.  If you’re going to use wheel chocks you must require your lift truck operators to verify the chocks are in place, and be prepared to frequently verify that your operators are doing this.  You should also make sure your operators have an easy way of verifying the chocks are in place.  Many dock designs do not provide visibility to the trailer wheels from inside the building.  Windows, mirrors and cameras can resolve this.  Enforcement of this type of a policy is critical; if you do not regularly confirm compliance and discipline non-compliance, the chocks will simply not be used.  You also need to keep spare chocks on hand as chocks are often casualties of theft and snowplowing operations.

It's also a good idea to require your delivery drivers to move the tandems all the way back before backing into your dock. This helps to ensure that the trailer doesn't slip forward from the tandems when the wheels are chocked. It also makes the trailer more stable. The delivery drivers may not like this requirement, so once again, enforcement is critical.

Other Vehicle Restraint Devices.

There are a great variety of alternative vehicle restraint systems available and their popularity is growing.  Of these, one of the most popular is the ICC bar type restraint system.  These systems incorporated a device that engages the ICC bar (rear impact guard) on the rear of the trailer preventing it from moving away from the dock.  These devices may be mechanically or hydraulically operated and may vary significantly in design and functionality from one manufacturer to another.  There are also other types of restraints such as those that automatically engage the rear wheels of the trailer.  As with the ICC bar restraints, the wheel engagement restraints also vary significantly from one manufacturer to another.  There is not a one system fits all solution for vehicle restraints. ICC bar systems may not work with damaged ICC bars, lift gates, and low-boy trailers.  Wheel engagement systems are more expensive and may have problems in northern climates due to snow or ice. 

Dock Levelers

It’s also important to note the importance of the dock leveler in dock safety.  Dock levelers provide a bridge to the trailer as well as a ramp to facilitate the transition in height from dock to trailer.  Dock levelers are rated by weight capacity and by the service range.  The service range also known as the height differential rates the safe range above and below dock level you can use the leveler to transition to the trailer height.  Differences in trailer width, height, floor level and the recent popularity of air-ride suspensions are forcing more attention on the functionality of dock levelers and their ability to safely handle the variety of vehicles serviced. 

Dock levelers come in mechanical and hydraulic models. The mechanical models require the operator to pull a chain and then walk down on the leveler to engage it, while hydraulic models provide automatic functionality from push buttons usually mounted on the wall next to the dock door.  Hydraulic models also offer a smoother transition when entering vehicles with soft suspensions (such as air-ride). Mechanical levelers use a mechanical safety mechanism to prevent the dock from bottoming out if it disengages from the trailer floor, the side-effect of this safety mechanism is that when you enter a trailer with a soft suspension the main portion of the leveler will not always drop with the suspension, leaving only the hinged lip to make up for the height differential.  Hydraulic levelers incorporate a hydraulic velocity fuse as a safety mechanism, this still allows for full functionality of the leveler as the trailer height changes.

The advantages in using automatic dock equipment with electronic controls include the ability to incorporate all of the equipment into signaling devices.  Signaling devices such as signal lights will let your lift truck operators know that the restraint mechanism and the dock leveler are properly engaged signaling that it is now safe to enter the trailer, while at the same time signaling the truck driver that it is unsafe to pull away from the dock.

Additional Equipment

Other dock equipment includes stand-alone barriers and barriers built into dock levelers to prevent driving off the edge of the dock when the dock is empty, fixed and variable height ramps to raise trailers to a level closer to that of the dock, and a variety of dock doors and dock seals.  It’s very important to use the operating instructions provided by the manufacturer of dock equipment as operating procedures will vary based upon the type of equipment used.  Some hydraulic dock levelers may allow you to leave the leveler engaged as the trailer departs while most mechanical levelers should be fully disengaged and returned the stored position prior to trailers departing.

Additional Recommendations

The following are additional recommendations that can improve safety in your dock operation.  Some of these are equipment related while most are simply procedural.

  • Use portable jack stands in addition to the forward landing gear of spotted trailers when loading and unloading to prevent potential tipping.  Also note that spotted trailers (dropped trailers) are more susceptible to trailer creep.
  • Make sure lift trucks used to load/unload trailers are equipped with spotlights, also use dock mounted lights to supplement the lift truck lights or when manually loading/unloading trailers.
  • I highly recommend side shifts as standard equipment of forklifts. Not only do they increase productivity, but they also help to prevent product damage and promote safety by allowing the lift truck operator to perform the task with fewer movements and eliminates the need to ride right against the wall of a trailer.
  • Have all equipment maintained in accordance with manufacture's recommendations.  This includes lift trucks, dock levelers, vehicle restraining devices, dock doors and seals, and automatic signaling devices.
  • Do not allow pedestrians in trailers while a lift truck is loading/unloading.  The likelihood of being crushed by a forklift is greater in tight spaces. 
  • Perform a visual inspection of the trailer prior to driving a lift truck into it.  Damaged and rotting floorboards are common in older trailers and even though I have never heard of a lift truck completely falling through the bottom of a trailer, a wheel breaking through is fairly common.  Also be aware that the lift truck wheel breaking through the trailer floor will probably not be as dangerous as the execution of the ingenious plan your warehouse personnel will devise to try to get the lift truck unstuck.
  • Caution is advised when using lift trucks to unload straight trucks (small delivery trucks).  Make sure the straight truck has the capacity to handle the weight of the lift truck and loads.  I generally recommend using hand pallet jacks rather than lift trucks to unload straight trucks whenever feasible.
  • Use physical barriers at open edges of docks and ramps and to protect pedestrian walkways.
  • Use paint or tape to designate staging areas, through aisles, and loading lanes.  Make sure employees recognize the designations.
  • Keep the dock areas clean and free of debris.  Now I’m not one to tell you that the floor should always be spotless and that employees should immediately pick up every little scrap of paper that may appear.  Loading areas should be completely swept at least once per day or once per shift, large pieces of debris such as broken pieces of pallets should be picked up immediately.
  • Designate areas for storage of used pallets, containers, and trash.  Also limit the stacked height of used pallets and containers.
  • Limit the stacked height of materials in staging areas, especially if pedestrians will be working around the material.  Also leave sufficient access aisles between rows of staged material if employees may be required to inspect or otherwise access the material.
  • Use traffic cones or portable barricades to temporarily block off staging lanes where pedestrians are working.
  • Special attention should be given when large loads are being handled that may obstruct the view of the lift truck operators.  While normally a lift truck operator would be driving in reverse with these loads, this option is not available when loading trucks.  Both lift truck operators and pedestrians working in the loading area must be aware of this.
  • If you require your employees to install or remove security seals for truckloads and containers you should designate a safe area away from the dock to do this.  Never allow an employee to stand between a trailer and the dock.
  • When loading small vans such as those used by small parcel carriers I highly recommended doing this at a street level dock or a specially designed ramped dock (you can also add ramps to existing raised docks).  If you must use standard raised docks, you may want to consider temporarily or permanently blocking off adjacent docks to eliminate risk from trailers backing into areas where people are working.  Also, use the dock closest to the building access and use chocks behind the van’s wheels to prevent the van from rolling back potentially crushing someone between the van and the dock.
  • Instruct employees not to climb on docks or to place any part of their bodies outside of the dock door.  I recently read a story about a local warehouse worker who was crushed between a trailer and the dock seal.  Apparently he was hanging out of the dock probably trying to signal a driver or get a view of another dock when the trailer backed up.
  • If employees need to climb down into the dock area make sure proper ladders or stairs are provided.
  • Train all employees that work in dock areas on the hazards.  Do not make the mistake of limiting training to lift truck operators only.
  • Enforce compliance to all procedures.  Plant safety is directly related to the enforcement of safety procedures.  If you don’t enforce it, it won’t happen.

Update: OSHA Wheel Chock Requirements.

I don't have a particular document to cite, but I've seen mention on OSHA's site and other sites that OSHA will no longer enforce their wheel chock requirement for commercial vehicles already covered under the Federal Motor Carrier Safety Administration (FMCSA), FMCSA only requires the use of a parking brake for most vehicles (vehicles that fall under FMSCA and meet the parking brake requirement). Here is their parking brake requirement:

"The parking brake shall be capable of holding the vehicle or combination of vehicles stationary under any condition of loading in which it is found on a public road (free of ice and snow). An agricultural commodity trailer, heavy hauler or pulpwood trailer shall carry sufficient chocking blocks to prevent movement when parked."

And here is a note on OSHA's site:

"Due to the DOT brake regulation, OSHA does not cite for failure to chock trailer wheels if the vehicle is otherwise adequately secured. DOT's regulation preempts enforcement and DOT has jurisdiction. However, if the vehicle is an intrastate truck, OSHA has jurisdiction. Only another Federal agency may preempt OSHA's jurisdiction"

So what does this mean. It means things are a bit more confusing now. Many vehicles that are loaded with a lift truck at a dock are probably covered under this, but some may not be.

More importantly, you still need to define your own requirements. Just because OSHA or FMCSA doesn't require it, doesn't mean you shouldn't require it. My problem with the parking brake requirement is that there is no easy way for the lift truck operator to make sure the parking brake is engaged and is operating effectively. Remember, government safety requirements should be considered as "minimum" requirements. By themselves, they may not be enough to ensure a safe operating environment.

Also read my article on Lift Truck Safety and see the Dock Equipment Pics page.  

Go to Articles Page for more articles by Dave Piasecki.

Further Reading:

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 Warehouse Safety: A Practical Guide to Preventing Warehouse Incidents and Injuries.    I just can't say enough good things about this book.  Highly comprehensive in dealing with a broad range of safety issues within a warehouse environment, Warehouse Safety is an excellent source for information on safe operating procedures.    Available at Amazon  or The Government Institutes.  Read full review at The Inventoryops Book Shelf


Dave Piasecki, is owner/operator of Inventory Operations Consulting LLC, a consulting firm providing services related to inventory management, material handling, and warehouse operations. He has over 25 years experience in operations management and can be reached through his website (, where he maintains additional relevant information.

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