What are the signs your loading dock bumpers require replacement?
Like all material handling equipment, loading dock bumpers wear out. That's why, to prevent damage, you may need to replace your dock bumpers sooner rather than later.
Most dock bumpers are made from resilient, compressed rubber that is cut to uniform pads, anchored between steel angles and adjoined with heavy duty tie-rods.
A new bumper has approximately 1.5 inches of exposed rubber surface. If the exposed rubber is extremely worn and/or compressed, it does not provide sufficient space between your building and trailers. This reduced space increases the likelihood of structural and equipment damage from trailer impact forces.
What do you need to check?
- Are there deep gouges in the rubber surface?
- Is the rubber compressed or uneven?
- Is the metal bumper frame bent or rusted?
- Is the exposed rubber worn close to the metal frame?
- Is there metal to metal contact occurring?
Curb Angle Steel
- Are the anchors loose?
- Are the plate welds cracked or rusted?
- Are there visible cracks in the concrete?
- Is the concrete crumbling and loose?
What do you need to know?
A good place to start is to consider the repeated impact forces that dock bumpers receive. Consider the amount of traffic you see at your loading dock on an average day.
What amount wear-and-tear is okay?
When the depth of the existing rubber is 50 percent of a new bumper or 0.75 inches from the metal frame, it has reached the end of its usable wear. It is time to replace.
The typical weight of an unloaded tractor-trailer is approximately 35,000 lbs. Average payloads, bring the total weight to about 40,000 lbs. (Far below the 80,000 lbs. load limit for Class 8 trucks).
If the average payload (40,000 lbs.) enters the dock at the low speed of 4 miles per hour, it can transmit 150,000 lbs. of force upon contact. That is an average. Keep in mind that an approaching vehicle, depending on weight and speed, can generate up to 300,000 lbs. of impact force.
That's a lot of force; and for one load! Now, multiply that force by the number of loads you receive per day. It’s easy to see why dock bumpers are essential for the protection of your building and equipment.
In fact, dock bumpers that are in good condition can absorb over 80% of the impact force from an entering trailer. Whereas worn bumpers absorb less than 15% of the impact force (for the same truck traveling at the same speed).
Without enough protection, the repeated impact can cause significant damage to other structures. Like, concrete pit sidewalls, curb angles, door jams, headers, tracks, and your building.