Torsion detection in rope: this is how it works!

Rope: an indispensable item in maritime operations. Every ship has meters, possibly kilometers, of it on board. So many ropes, even more characteristics, and often it’s not entirely clear how a rope should be used best. HoendeRope - part of Hoenderop’s own rope assortment - is equipped with torsion detection. But how does torsion detection work exactly, and why is it so important?

Firstly, it’s important to realize that rope is often used as mooring lines. Although that may seem relatively simple, ropes are subjected to considerable forces. After all, mooring lines are constantly at work, absorbing the shocks of the moored ship. These shocks are caused by waves, wind, tides, currents, and passing ships. Therefore, it’s crucial for a ship to be as securely moored as a house. By ensuring that there is no torsion in the mooring lines, not only the lifespan of the rope is increased but also safety is enhanced.

Both the HoendeRope ORKA 12-pro and the HoendeRope HMPE feature torsion detection. The ropes are braided straight and consist of two colors: blue and white. “The colors make it easy to track the strands,” explains Patrick Gerritsma, account manager at Hoenderop. “If the rope is twisted, those strands no longer run in a straight line, indicating torsion.”

Breaking Load
When the rope is twisted, gaps, also called lays, appear in the rope. As a result, part of the strands is not loaded, but they still wear due to friction. For the overloaded strands, they wear out faster as well. Loading ropes with torsion reduces the breaking load. As a rule, with four lays per meter, the breaking load decreases by 10 to 30 percent [1]. Gerritsma: “When you consider that this affects meters-long mooring lines, you can imagine the significant impact. By detecting and addressing torsion before loading, the rope lasts longer, and unsafe situations are prevented. Fortunately, the human brain naturally wants to straighten things out, so HoendeRope automatically ensures that people don’t have to think about it, but the rope is automatically laid correctly.”

Splicing
Preventing torsion also applies when splicing the HoendeRope ORKA 12-pro and HoendeRope HMPE. “HMPE is a collective term and stands for High Molecular Polyethylene. It’s also better known as Dyneema, which is, by the way, a brand name. However, HMPE is just as strong and has no stretch. Therefore, splicing must be done very accurately. The rope must not lay, as uneven loading of the strands can occur,” says the account manager. Every year, Hoenderop organizes a splicing course in Bremen in collaboration with rope manufacturer Gleistein. “What many people don’t know is that there is no splicing machine. Every splice, large or small, is purely manual work!”

Both the HoendeRope ORKA 12-pro and the HoendeRope HMPE are suitable for all types of vessels, from pleasure craft to the largest seagoing vessels. Both types of ropes are available in various lengths and diameters. The HoendeRope is also supplied on rolls of 220 and 1000 meters or as complete mooring lines with two spliced eye splices. The HoendeRope HMPE, in addition to standard lengths, is available on rolls of 1000 meters. The ropes are delivered as standard in blue and white colors, with the HMPE distinguished by the orange thread in the rope.

Source:
[1] Gleistein Mooring Rope Manual