What is the purpose of a yard ramp? The two basic applications for yard ramps are (1) ground to trailer and (2) ground to top of dock. The ground to trailer approach is used to load and unload product while ground to top of dock is used to bring equipment into the warehouse or equipment down to street level. For this equipment to function at its finest, proper measurements must be taken.
Which Measurements Matter
When determining the right yard ramp for your application three most important measurements are length, width, and capacity. Length is important to maintain the proper grade for equipment traveling up the ramp. The width of the ramp cannot be wider than the trailer opening or dock door depending on the application. This is due to the front apron of a ramp which needs to sit on the bed of a trailer or the top of a dock (commonly called lip purchase). Further, the capacity of the ramp will be determined by the total weight of equipment and the load of product traveling across the ramp. The yard ramp must be capable of holding the weight and withstand the use of the user.
For loading or unloading from a truck
Length can be dictated by the height of the floor of a trailer above the ground. Most over-the-road trailers range from 48” to 55” in height with refrigerated and containers coming in slightly higher. The standard length of a ramp in this application is 30’ of incline to allow proper grade for the forklift to operate. It is also recommended to include a level-off portion on the ramp (typically 6’ in length). This allows the forklift to enter the trailer with forks level enough to remove pallets in an end-load position. In short, the ramp for this application would be 36’ in total length, 30’ of incline (for proper grade), and 6’ of level (for proper entrance of trailer for forklift).
Most over-the-road trailers (sometimes called vans) have an inside width of 102”. The front apron of the ramp will sit on the trailer floor with a lip purchase up to 16”. The most common ramp width for this application has an overall width of 84” with a usable width (area in which forklift can drive on) of 78”. This allows for the proper lip purchase onto the trailer floor and allows for the forklift to have maneuverability while traveling on the ramp.
The easiest way to determine ramp capacity is to take the lifting capacity of the forklift and multiply by 3 for a 4-wheel forklift or multiply by 4 for 3-wheel forklift. This will allow for the total weight of the forklift and the total weight of any product that it may carry to be captured.
For Dock to Ground
The length of a yard ramp for a dock-to-ground application is going to depend on dock height and the type of vehicle traveling on the ramp. A typical dock height is 48” to 51” tall. For forklift traffic, it is recommended to maintain approximately a 14% to 15% grade. A 30’ all-incline ramp will accommodate this. In lower profile (ground clearance) vehicles the grade may need to be lowered to prevent it from bottoming out when transitioning on and off the ramp.
The width of a yard ramp for a dock-to-ground application will be determined by a couple of factors; width of the overhead door and the type of vehicle traveling the ramp. It is important to remember that the front apron of the ramp will sit on the dock floor so the ramp cannot be wider than the door opening. Another thing to keep in mind is with the ramp sitting on the dock floor and with up to 16” of lip purchase, the overhead door may come down on top of the ramp not allowing it to close properly. Thus, measuring how far the overhead door is positioned from the edge of the dock is important as well. There are design changes that can be done (recess side curbs) or extra equipment (dock extension) to accommodate this situation.
If the yard ramp is being used by forklifts, the capacity is factored into the above criteria (lifting capacity). However, vehicles such as utility vans, service trucks, or passenger vehicles carry their load across the ramp calculating a different capacity. If these vehicles are utilizing the ramp, Total Gross Vehicle Weight (TGVW) is the required measurement.
Work with an industry leader
The critical measurements discussed above are a great start to effectively specify a yard ramp for common applications.
Understanding measurements for yard ramps are an important piece of finding solutions that work best for the end-use customer. When it comes to yard ramps, correct measurements assist in finding the best solution, even if that means customization. For the right ramp for your application, consult with Bluff Manufacturing on our yard ramps solutions.