Reels for wire rope

Steel rope loads a reel differently

Steel wire rope packs a lot of mass into a small diameter. Compared with an electrical cable of the same outside size, it is denser, stiffer and far less forgiving if the reel gives way. A reel carrying rope must hold the full weight on its arbor and drum without the flanges spreading, and must do so while the rope is under tension during spooling, when the outward pressure on the flanges is at its highest.

That outward push is the thing to understand. When rope is wound tightly in layers, each layer squeezes the ones below and presses sideways against the flanges. A weak or cracked flange can bow out, the rope can drop into the gap at the edge, and the next layers crush it. Strong flanges with all their plies sound, and through-bolts that hold the flanges square to the drum, are what stop that.

Drum size and rope life

Rope makers express the bending limit as a ratio between the drum or sheave diameter and the rope diameter, often called the D/d ratio. A higher ratio means gentler bending and longer rope life. The right figure depends on the rope's construction, so take it from the maker's literature for the rope you have. For storage reels the bend is static rather than cycling, which is less punishing than a working sheave, but a drum far too small still puts a permanent set in the rope.

In practice, steel rope buyers ask for reels with generous drums for their flange size, then work out how much flange depth is left for the length they need. If the length will not fit, the answer is a larger flange or a wider traverse, not a smaller drum.

Who uses empty reels for wire rope

The steady buyers are rope distributors and rigging shops. They take long master lengths from the mill and cut them to the lengths crane owners, elevator contractors, logging and mining crews and marine operators order. Each cut leaves on a reel, and a supply of sound used reels in two or three sizes keeps that cutting line moving. Sonoco lists elevator and marine cable among the markets its wood reels serve, and the same reels suit rope.

Other buyers come and go with projects: a crane company storing spare hoist rope, a marine contractor holding mooring wire between jobs, a ski lift or tramway crew handling a haul rope change, a dredging firm keeping spare rope on site.

Grading a used reel for steel rope

Because the load is high, we grade reels headed for rope as if they were going under power cable. A reel that is fine for light rope or a building-wire offcut is not necessarily fine for steel.

• Arbor hole round and unsplit, with any steel arbor plate tight. Steel rope through a split arbor is a reel waiting to collapse on the stand.
• Flanges free of through-cracks and ply separation, and square to the drum. Sight along the rim; a flange that leans out at the top will lean further under rope.
• Through-bolts all present and tight. On a nailed reel, missing bolts let the flanges walk apart.
• Drum staves complete and flush. Rope finds every gap and seats into it, which kinks the bottom layer.
• Drive holes intact if the reel will be powered by a reeler or take-up stand.
• No rot near the bottom rim. Rope reels often stand outside at docks and yards, so check the low edges for soft wood.

How much rope a reel holds

Rope suppliers use the same formula cable makers do, written L = (A + D) × A × B × K. L is feet of rope, A the depth of rope space in inches, D the barrel diameter, B the traverse between flanges and K a constant for the rope size. Paducah Rigging, Kulkoni and Industrial Rope print identical K tables, and Paducah notes that its K values take normal rope oversize into account, which is why they run a little below the 0.2618 / d² used for round cable.

Paducah's own example puts 1-1/4 inch rope on a reel with a 36-inch flange, 24-inch drum and 30 inches between flanges: (6 + 24) × 6 × 30 × 0.152 = 821 feet. That example uses the full 6 inches of flange depth. Industrial Rope says clearance should be about 2 inches unless rope-end fittings need more, and Kulkoni asks for at least one rope diameter. With 2 inches off, the depth is 4 inches and the same reel holds about (4 + 24) × 4 × 30 × 0.152 = 511 feet. Both sources say the figures assume uniform winding.

K values from the Kulkoni, Paducah Rigging and Industrial Rope tables. Use your rope supplier's table if it differs.

Rope weight and reel choice

The weight check is simple arithmetic and it should be done every time. Take the rope's weight per foot from the maker's table, multiply by the length, and add the reel's own weight. Compare that total with what your forklift, crane or stand is rated for, and with what the reel is built to carry. If the reel stencil gives a load figure, use it; if not, be conservative and choose a heavier reel.

Long lengths of large diameter rope quickly reach weights where only the biggest reels, 60 inches and up with multi-ply flanges and plated arbors, make sense. Short cuts of small rope will sit happily on 24 to 36 inch reels. Between those, the traverse is the variable to play with: a wider traverse holds more rope at a lower stack height, which keeps the outer layers further below the flange rim.

Transferring rope between reels

When rope is moved from a shipping reel to a storage reel or onto a machine drum, the standard rigging practice is to keep the bend in the same direction. That means paying off from the top of one reel to the top of the other, or bottom to bottom. Running top to bottom bends the rope one way and then the other, which is a reverse bend and can make the rope twist or kink.

Keep back-tension on the paying-off reel with a brake so the rope winds tight on the new reel. Loose winding lets the upper layers cut down between the lower wraps, which crushes the rope. Both reels should be on shafts through their arbor holes, never rolled on the ground while paying off.

Selling rope reels

Rope reels come back from jobs scuffed, greasy and often stencilled with a mill name. None of that bothers us. Grease on the drum does not stop a reel being reused, though a buyer winding cable or fiber will want it wiped. Count the reels by size, check the arbor holes, and send a photo of a typical reel. Large steel-rope reels are heavy, so tell us what lifting equipment you have.