Mooring lines are of utmost value in the marine world. They ensure the safety of ships and vessels by securing them with docks or buoys. However, there are different types of mooring lines for ships. Those types vary in terms of their materials, functions, and constructions.
These lines are not just used on large vessels, but are also helpful for small boats. Their role is more crucial if the vessels face harsh weather conditions. Are you unfamiliar with mooring lines and their types? Worry not! This article is dedicated to mooring lines. You’ll get a basic overview of all of their types. So, let’s get started!
What are Mooring Lines in Ships & Vessels?
Let me introduce you to mooring lines before discussing their types.
Mooring lines are chains or ropes used to secure ships, vessels, or boats. They are heavy-duty, durable, and strong enough to keep the ship from drifting. Their primary purpose is to ensure the safety of the vessel. Without them, ships won’t be able to stay at one point.
Imagine a ship that doesn’t have mooring lines. It won’t be able to stay at one point. If it docks, it will keep moving and collide with the docking structure. As a result, it can get damaged as a result of this collision. Additionally, this ship can further collide with nearby boats or vessels, which can worsen the conditions.
In harsh conditions, ships face heavy tides and waves. If boats don’t have mooring lines, they would drift due to strong tides. In short, these lines ensure the stability, control, and safety of the ships and vessels. Remember, ships can also use these lines when staying with any boias marítimas. These lines are robust and durable, holding the boat securely in place.
Types of Mooring Lines for Ships (In terms of Materials)
Interestingly, mooring lines are divided into subtypes depending on various factors. Some types are based on the materials they produce, while others are based on their functionality. In this article, we’ll look at those types of mooring lines. Let’s start with types that differ from each other in terms of the materials.
1- Nylon Rope
Nylon mooring lines or ropes are generally used on small boats and ships. Manufacturers use high-quality polyamide fibers (synthetics) to make these ropes or mooring lines. This synthetic fiber is elastic, which imparts elasticity to these mooring lines. What I love about these ropes is that they can absorb the shocks. During tides, the ropes generally feel the sudden jerks.
The nylon-made mooring lines can efficiently withstand those jerks. These lines are resistant to various weather conditions, including high temperatures and chemicals. They don’t deteriorate when kept in harsh conditions. However, their only drawback is that they become heavier when they get wet. I don’t recommend using these ropes for heavy-duty vessels.
2- Polypropylene Rope or Lines
As I said earlier, nylon ropes or mooring lines are generally heavier. So their usage, handling, and management can be challenging. However, these polypropylene ropes are lightweight and very easy to use. If you throw them into the water, they will remain on the surface of the water instead of sinking to the bottom.
Additionally, their colors are also sharp (red or yellow), which keeps them visible from a distance. The main reason for the popularity of polypropylene ropes is their affordability. However, their durability, strength, and temperature resistance are not ideal. Therefore, I recommend using them only for small ships or boats.
3- Polyester Rope
Made from polyester fiber, these mooring lines are used on commercial ships or cargo vessels. This is due to their ideal strength and lack of elasticity. Generally, the ropes lose their strength over time and become very weak. However, these polyester ropes maintain their strength, quality, and integrity in the long run.
They have less stretch, which helps achieve stable tension when used in mooring operations. These ropes are resistant to moisture, temperature, chemicals, rot, and UV rays. As a result, they can be used in extreme conditions and remain stable, with a better lifespan. However, these lines are more expensive than those made from nylon or polypropylene.
4- Steel Wire Rope
Are you looking for ropes that are highly rugged and strong? If so, these steel wires or ropes will meet your needs. They are made using steel (metal) strands looped or wired together. This creates a chain or rope that exhibits no stretch but exceptional ruggedness and strength. However, their weight is too high, making their handling challenging.
These ropes can be used where tension is needed. However, these ropes can become rusty if neglected for a prolonged period. It is highly recommended to clean them regularly and paint them periodically to maintain their good condition. As these ropes are strong, they are used in heavy-duty applications. These include the mooring of oil tankers, containers, and larger ships.
5- Kevlar Ropes
These ropes are made from aramid fibers (synthetics) and are known for their temperature resistance. They remain in good shape if the temperature rises to 500 degrees Celsius. Their weight is also low, and they outperform all other synthetic fibers and ropes in terms of their strength.
Interestingly, these mooring lines are three to four times stronger than the steel wires, which makes them stand out. However, their weight is lower than that of steel wires. They fall between steel and HMPE ropes in terms of strength and weight. Remember, these ropes are not better than HMPE.
However, their pricing is lower than that of HMPE ropes, which makes them a decent option for many. What I love about these ropes is that they are abrasion-resistant. Even if used in rocky coastal zones, they won’t wear out quickly. These ropes are sensitive to UV rays and moisture and are protected by an additional coating.
6- High-Modulus Polyethylene (HMPE)
The ropes that are generally strong have a higher weight. On the other hand, lightweight mooring lines have compromised strength. This mismatch makes it challenging to choose the mooring lines that are both rugged and lightweight.
In such cases, high-modulus polyethylene (HMPE) ropes are handy. They are made of synthetic fibers and are very lightweight. However, their lightweight does not mean that they have compromised strength. Instead, they can be used in mooring operations for heavy-duty vessels.
The reason is that they have very low stretch (elongation) and an excellent strength-to-weight ratio. I consider them stronger and more durable than those steel cables. They’re used where mooring failure is intolerable, like LNG carriers and military ships. However, the prices of the HMPE mooring lines are very high, which is a big drawback.
Destaque rápido: These HMPE ropes are around seven to ten times stronger than steel wires or ropes. However, their weight is almost 75 to 85% lower than that of the steel wires. Due to this, many people prefer using HMPE despite their higher price. The ideal strength-to-weight ratio of these HMPE lines is well worth the investment.
Types of Mooring Lines or Ropes by Construction
In the above portion, I discussed various types of mooring lines by their materials. However, other types of lines are distinguished by their construction. Let’s dive in and discuss these types of ropes (by their construction).
- Double-Braided Mooring Lines: These mooring lines are made by braiding two ropes together. One rope acts as the inner core, and the other Rope remains as the outer covering. The combination of these rope braiding improves the strength and wear resistance.
- Three-Strand Twisted Mooring Lines: These lines are made by twisting three strands of fibers. The first three bundles of fibers are made, and then these are twisted together to make mooring lines. This construction reduces the weight of ropes while also making them flexible and preventing them from kinking.
- Eight-Strand Plaited Mooring Lines: As the name suggests, these lines are made by eight strands. The four strands are located on the right side, while the other four are positioned on the left side, forming a square pattern. These mooring lines are easy to coil and don’t kink or tangle as well. Their eight strands make them durable and ideal for heavy-duty use.
- Twelve-Strand Braided Mooring Lines: These lines consist of 12 strands of Rope, making them highly durable and robust. What I like about these lines is that they have no stretch or elongation. The presence of 12 standards makes them strong and heavy-duty for large vessels and oil tankers.
Types of Mooring Lines By Function
Have you ever heard people say to use a specific mooring line to stop a ship from drifting forward? That’s because some mooring lines are based on their functionality. Some stop ships from drifting forward, while others prevent them from drifting backward. Here is a table indicating the types of mooring lines based on their functionality:
| Type (based on function) | Function |
| Headlines or Head mooring lines | Prevent backward movement |
| Stern Mooring Lines | Prevent forward movement |
| Spring Mooring Lines | Prevent forward/backward movement |
| Breast Mooring Lines | Prevent side-to-side movement |
Perguntas frequentes
How many types of mooring lines are there?
There are a total of six types of mooring lines that differ in terms of their materials. These include:
- Nylon Rope
- Kevlar Ropes
- Polyester Rope
- Steel Wire Rope
- Polypropylene Rope
- High-Modulus Polyethylene (HMPE)
What is the strongest mooring line?
I consider High-Modulus Polyethylene (HMPE) as the strongest mooring line used in marine operations. Their weight is also lower, which makes them very easy to handle and use. Kevlar and steel wire ropes are also good alternatives after HMPE ropes.
What is the best rope for mooring lines?
It depends on what you’re mooring. Generally, nylon ropes are considered the best for mooring lines on smaller ships and boats. On the other hand, steel wire, Kevlar, or HMPE mooring lines are ideal for heavy-duty vessels.
Conclusão
As I said earlier, mooring lines are must-haves for marine operations. Without them, ships or vessels cannot stay at one point. However, there are different types of mooring lines available in the marine industry. Some of them are cheaper but less strong and effective. So, they are used on small boats or ships.
On the other hand, some mooring lines are made from durable materials and last for many years. Their strength is ideal, and they are used in large vessels. Their pricing is also higher, which can be a drawback. In this article, I’ve explained all the significant types of mooring lines and their unique value propositions. Remember, each type of mooring line has specific pros and cons.