Calculating Reel Capacity
SHIPPING REEL CAPACITY
While it is virtually impossible to calculate the precise length of wire rope that can be
spooled on a reel or drum, the following provides a sufficiently close approximation.
Capacities In Feet Of Rope = (A + B) ACK
Example:
How much 1 1/4" diameter rope can be spooled on a drum having a 36" diameter
flange, 24" diameter drum and 30" width between flanges?
Using the above formula the number of feet equals
(6 + 24) x 6 x 30 x .152 or (A + B) x A x C x K
Answer - 821 feet
The value of "K" is taken from the previously calculated table of values shown below.
For 1 1/4 diameter this value "K" is .152
"K" FACTORS**
(0.2618 divided by rope diameter (squared)
Diam
(inches)
1/16
3/32
1/8
5/32
3/16
7/32
1/4
5/16
3/8
7/16
K
49.8
23.4
13.6
8.72
6.14
4.59
3.29
2.21
1.58
1.19
Diam
(inches)
1/2
9/16
5/8
11/16
3/4
13/16
7/8
1
1-1/8
1-1/4
K
0.925
0.741
0.607
0.506
0.428
0.354
0.308
0.239
0.191
0.152
Diam
(inches)
1-3/8
1-1/2
1-5/8
1-3/4
1-7/8
2
2-1/8
2-1/4
2-3/8
2-1/2
K
0.127
0.107
0.0886
0.0770
0.0675
0.0597
0.0532
0.0476
0.0419
0.0380
* This formula is based on uniform rope winding on the reel. It will not give correct
results if the winding is non-uniform. The formula also assumes that there will be the
same number of wraps in each layer. While this is not strictly correct, there is no
appreciable error in the result unless the traverse of the reel is quite small relative to
the flange diameter ("H").
** The values given for "K" factors take normal rope oversize into account.