What is the significance of measuring in both horizontal and vertical planes while aligning shafts?

Measuring in both horizontal and vertical planes while aligning shafts is crucial because it allows for the detection of angular misalignment in all dimensions. This type of misalignment can occur if the shafts are not aligned along their axes correctly, leading to increased wear on bearings and other components, as well as possible equipment failure. By assessing alignment in multiple planes, technicians can identify angular discrepancies that may not be evident if only a single plane is considered. Proper alignment is essential to ensure optimal performance, reduce vibration levels, and extend the life of the machinery.

The other choices do not address the technical needs for alignment. Visual alignment does not ensure precision, minimizing footprint is unrelated to shaft alignment, and while safety regulations are important, they do not directly dictate the necessity of measuring for angular misalignment.