3D does not offer rubber bumpers as a standard option on our pushback systems. The reason for this is two-fold:
While these bumpers do in fact reduce noise, when properly loading and unloading pushback lanes, you cannot hear the carts over the sounds of even an electric forklift. Furthermore, if an operator unloads a lane improperly (ie. too fast) creating a “bang”, we think it’s a good idea if other staff/management nearby know, so that they can remind the driver that he is to control the loads when emptying the lane.
It should also be noted that standard rubber bumpers offered by our competitors only work as noise reducers for the bottom cart, as the bumper is attached to the beam and only the bottom cart makes contact with it. Subsequent carts on 3-6 deep systems all make steel to steel contact, thus offering no noise suppression.
This simply is not true. In order to withstand loads of 2500# or more coming in contact with the bumpers, the rubber must be constructed from very high-density material. Because of this fact and because they are relatively short (typically 1"-2"), the incoming cart decelerates within 1/16”-1/8” of an inch. This extremely short deceleration distance is essentially the same as coming to a dead stop, and therefore, there is no "cushioning".
It should also be said that this advertised feature may give a false sense of security to operators, thinking they can back out in an uncontrolled manner, and everything will be OK. Operators should always control the loads when backing out of a pushback lane.
If you have any questions or comments regarding why we don't like rubber bumpers on pushback racking, please give us a shout. We'd love to hear from you.