Explanation of the Leeward and Windward Sides of Ships
Wind plays a vital role in sailing. In the Age of Navigation, which lasted nearly 400 years, wind was the main force that propelled ships (from commercial to military). Although the wind’s effect on sailing ships as the basis of propulsion has been replaced by mechanical propulsion systems over the years, its influence on everything from maneuverability and sailing ability to resistance characteristics is still important.
Understanding wind and its movement
In the movement of wind, the flow of wind always has a direction. For example, when the wind blows from the geographical north, we call it a north wind; when the wind blows from the east, we call it an east wind.
In real life, at any location in time and space, due to the complex interaction of meteorological and physical factors, the wind mainly flows from random directions to varying degrees, and the wind vector component with the greatest intensity is the one that is felt most strongly.
Therefore, when we say that there is a “weak south wind” blowing, the wind component from the south direction is dominant, while other wind vectors appear to a lesser extent.
In addition, the effect of wind is a very relative concept. In the above example, we can only feel the effect of this south wind when we are facing it, that is, when we are in a position where the wind’s influence is obvious. Now, let’s assume that in this case, there is a mountain or cliff behind us and another person on the other side.
This person will not be affected by the wind force that we experience. For example, after a while, a person feels the wind blowing, and for him, it is a north wind, but for us, it is not.
2. Wind and Leewind
This is similar to understanding the up and down directions. If the direction in which the object floats is the same as the direction of the water flow, it is said to move with the flow, and if the direction in which the object floats is the opposite of the direction of the water flow, it is said to move against the flow.
Similarly, when we move against the wind, we are said to move against the wind, and when we are in the same direction as the wind, we are said to move with the wind.
So, from the perspective of the physics of the action of wind, there are two very important definitions: 1) upwind wind and 2) downwind wind. What are these? The windward side of the body is the side that faces directly towards the wind.
On the other hand, the windward side is the side that faces the opposite direction of the wind’s action. For any reference point, the leeward side is called the leeward side, and the leeward side is called the leeward side.
3. In the case of ships
On a ship, the side facing the wind, or more precisely, the direction facing the wind source, is called the leeward side, and the side facing away from the wind is called the windward side.
For example, a ship is sailing north-south, and the sea breeze blows from the east. The starboard side of the ship is the windward side, and the port side is the leeward side.
But let’s consider another ship sailing south along the same route. For this ship, the port side is the leeward side, and the starboard side is the windward side.
Similarly, imagine that on a ship, a gust of wind blows from the bow, or the opposite direction of the bow’s heading. In this case, the bow area is called the windward area, and the stern area is called the leeward area.
Thus, if one is standing on the main deck, directly forward, against the wall, over the bow, then one is essentially into the wind, whereas if one is standing further aft, facing the propeller wake behind him, then one is into the wind.
In the age of steam ships, the effect of the wind on the ship is decisive only when the wind is strong enough, because the air resistance of the exposed parts above the waterline increases. In extremely bad weather conditions, the ship usually needs to change course to counteract the maximum effect of the wind.
If the high-intensity wind force is strictly in the longitudinal direction, i.e., from bow to stern, the importance of the leeward and windward sides is different from when their components are at another angle.
In the first case, if the windward side is in the bow area, the bow bulge is affected by the increased air resistance. On the other hand, when the windward side is in the stern or stern area, the propulsion efficiency of the ship is further improved by this additional force, depending on its intensity.
When any component of the wind force acts transversely, it often becomes very critical to keep the ship on course.
For example, if a strong wind acts on the port side (windward port and leeward starboard) of a ship on a set course, its effect tends to cause the ship to yaw slightly to the right. In this case, it is usually necessary to correct the course by applying rudder torque to the right.
In strong winds, it is usually recommended that crew and passengers on the weather deck stay away from the windward side of the ship to avoid injuries and accidents. Any cargo handling or shipboard operations involving work and equipment on the leeward side of the deck are suspended.
From the perspective of lateral stability, if the larger wind forces act on the side of the ship, causing the ship to tend to roll, then the side that sinks and has the largest draft is the windward side. In this case, roll cages, stabilizers and other anti-roll devices must counteract the wind forces acting from the windward side.
Ship and Earth Mass
When a ship is close to land or the coastline, an interesting set of nomenclatures emerges that are based entirely on the physics of reference points. When we are talking about a ship close to land, the windward side of the ship is always the side facing the sea or away from the coast, regardless of changing weather conditions. The side of the ship facing the land is the windward side.
Now, for a person on land, anywhere on the coast where the ship can be seen, it is on the windward side because that side faces the sea. However, for a person on the ship, the same person on land is on the windward side because his position is in the leeward quadrant of the ship’s reference point.
When islands are involved, the situation becomes more interesting and complicated. For simplicity, assuming that the island is a round object, the naming system is based in part on the direction of the wind at the time.
As in the previous example, from the reference point of the ship, the leeward and windward sides remain the same. Also, the side of the island facing the ship is the windward side. However, for an observer on the island watching the ship, everything depends on the nature of the prevailing wind. If the wind is blowing from any direction other than the direction of the ship, then the wind is to leeward of the island from the reference point of land.
If the high-intensity wind force is strictly in the longitudinal direction, i.e. from bow to stern, the importance of the leeward and windward sides is different from when their components are at another angle.
In the first case, if the windward side is in the bow area, the bow bulge is affected by the increased air resistance. On the other hand, when the windward side is in the stern or stern area, the propulsion efficiency of the ship is further improved by this additional force, depending on its intensity.
When any component of the wind force acts transversely, it often becomes very critical to keep the ship on course.
For example, if a strong wind acts on the port side (windward port and leeward starboard) of a ship on a set course, its effect tends to cause the ship to yaw slightly to the right. In this case, it is usually necessary to correct the course by applying rudder torque to the right.
In strong winds, it is usually recommended that crew and passengers on the weather deck stay away from the windward side of the ship to avoid injuries and accidents. Any cargo handling or shipboard operations involving work and equipment on the leeward side of the deck are suspended.
From the perspective of lateral stability, if the larger wind forces act on the side of the ship, causing the ship to tend to roll, then the side that sinks and has the largest draft is the windward side. In this case, roll cages, stabilizers, and other anti-roll devices must counteract the wind forces acting from the windward side.
Bowl-Shaped Masses and Continental Masses
When a ship is close to land or the coast, an interesting set of nomenclature emerges that is based entirely on the physics of reference points. When we are talking about a ship close to land, the windward side of the ship is always the side that faces the sea or away from the coast, regardless of how weather conditions change over time. The side of the ship that faces the land is the windward side.
Now, for anyone who can see the ship along the coast, he or she is on the windward side, because that side faces the sea. However, for the person in the ship, the same person is on the windward side when on land, because his position is in the leeward quadrant of the ship’s reference point.
When the situation is an island, it becomes more interesting and complex. For simplicity, assuming that the island is a round object, the naming system is based in part on the direction of the wind at the time.
As in the previous example, from the reference point of the ship, the leeward and windward sides remain the same. Moreover, the same side of the island that faces the ship is still the windward coast.
However, for an observer on the island watching this ship, everything depends on the nature of the wind at the time. If the wind is blowing from any direction on the island other than from the direction of the boat, then the wind is on the leeward side of the island from a land reference point.
