Wire rope is an essential ingredient in most modern construction, and historically served a variety of purposes, leading to the development of shipping, railroading, elevators, telegraphs, mining, cable cars and airplanes. The earliest evidence of wire rope used in construction was found in the ancient ruins of Nemeveh near Babylon, dating back to 700 B.C. Evidence of modern use of wire rope in structural elements can be seen in the Brooklyn, Cincinnati, Williamsburg, Manhattan, George Washington and the Golden Gate Bridges.

## Take Measurements

### Step 1

Measure the length of the barrel and record it as the barrel diameter.

### Step 2

Measure the length from the top of one side of the flange to the bottom on the same side. Record as the flange diameter.

### Step 3

Measure the length of the space in between the top and bottom flanges, and record as the drum length.

### Step 4

Measure the distance between the top layer of the rope to the outside edge of the drum flange. Record the measurement as the freeboard measurement.

### Step 5

Measure the width of the cable and record.

## Online Calculator

### Step 1

Insert the recorded values into the appropriate spaces on the Ingersoll-Rand IR Drum Capacity Estimator.

### Step 2

Select the Metric Unit of Measure option located directly below the input fields.

### Step 3

Determine if your drum surface is smooth or grooved, and select the appropriate option located next to the Unit of Measure field.

### Step 4

Press "Calculate" button to calculate your total drum capacity, total working drum capacity, recommended working capacity, D/d ratio, minimum distance to lead sheave and maximum distance to lead sheave.

## Estimate Drum Capacity by Formula

### Step 1

Find the K value of the wire rope diameter in inches.

### Step 2

Subtract the barrel diameter in inches from the flange diameter in inches. Divide this number by two to find value A.

### Step 3

Allow the barrel diameter to stand for value B.

### Step 4

Allow the drum length in between the flanges in inches to stand for value C.

### Step 5

Insert the specific values into the following equation to estimate the approximate length of wire rope: (A + B) * A * C * K.

### Step 6

Convert the result in inches into centimeters by multiplying the output by 2.54.

### Tip

Stick to one type of unit of measure, English or metric, throughout the entire process in order to avoid miscalculation.

Find the K value online for accurate values.