Elevator Mechanic Practice Exam

The DBG is 6'6" using 15lb rails with ¼ shim on the brackets, what is DBB?

1. 6'6" ½"

2. 6'6" ¾"

3. 7'1 ½"

4. 7'2"

The correct answer is: 7'1 ½"

To determine the DBB (Distance Between the Brackets), it is essential to understand the relationship between the DBG (Distance Between Guides), the rail weight, and the shimming used. In this case, the DBG is given as 6'6", with 15lb rails and a ¼" shim on the brackets. The standard adjustment for determining the DBB from the DBG usually involves considering the shim height and adding a specific offset based on the rail type used. For 15lb rails, the typical offset is approximately 6 inches when accounting for shimming and rail weight. Since a ¼" shim is added, this additional height has a minor effect on the overall calculation. Starting with the DBG of 6'6”, we add the necessary offset for the 15lb rails, as well as considering the height of the shim. This leads us to calculating that the DBB should be approximately 7'1½", which corresponds with the understanding of how the measurements translate due to shimming and rail specifications. Therefore, the choice indicating 7'1½" aligns correctly with this calculation approach and setup used in elevator systems, confirming the appropriate DBB based on the provided DBG and specifications.