Technology OverviewUse of metrical ropes on imperial cranes and of imperial ropes on...

# Use of metrical ropes on imperial cranes and of imperial ropes on metrical cranes

When using mm-ropes on inch-cranes or vice versa, often the wrong rope diameter is selected. Here the following selection table is valid.

The table is to be used in the following manner:

### Case 1

The crane has a sheave or drum that is dimensioned for imperial ropes (unit: inch) and a metrical rope (unit: mm) has to be installed.

For the inch-diameter in the left column the nominal rope diameter can be chosen in mm from the right column if it is shown in the same color.

Example: If the sheave or the drum was laid out for a nominal rope diameter of 11/4 inch, a rope can be used with the nominal rope diameter of 32 mm. If the rope diameter in the right column is shown in a different color, the next smaller nominal rope diameter has to be chosen in mm, presumed the demands for minimum breaking strengths are fulfilled.

Example: If the sheaves or drums are laid out for a rope of the nominal diameter 1 inch, a metrical rope of the nominal rope diameter of 25 mm has to be used.

### Case 2

The crane has a sheave or drum that is dimensioned for metrical ropes (unit: mm) and an imperial rope has to be installed. For the mm diameter in the right column the nominal rope diameter can be chosen in inch from the left column if it is shown in the same color.

Example: If the sheave or the drum was laid out for a 32 mm rope, a 1-¼ inch rope can be used. If the rope diameter on the left side is shown in another color, the next smaller nominal rope diameter of the inch column has to be chosen, presumed the demands for minimum breaking strengths are fulfilled.

Example: If the sheave or the drum was laid out for a rope of the nominal diameter of 26 mm, an imperial rope of the nominal diameter of 1 inch has to be chosen.

Previous article