Commercial Fishing Boats: Types and Features

Human beings benefit from the food resources obtained from the sea since the first ages of history. According to the developing technological possibilities, fishing has changed its form and method and reached the modern fishing level of today. Fishing boats are the most important element of fishing technology and still the most valuable one among fishing gear. So do you know what are the types and characteristics of fishing boats?

Fishing types of fishing boats are generally defined by the name of the net and vehicle used by the boat. For example, a fishing boat fishing with a trawl net is called a trawl boat; where a ship using the surrounding net is called a purse-seine boat. In fishing statistics, fishing boats are classified according to both their physical appearance and the types of fishing they do as well as their capacity. The basic dimensions of the boat are length, width, and depth. These are the most important elements in determining a boat’s capacity.

General Features of Commercial Fishing Boats

It should be fast and maneuverable. These ships must have high speed in order to search for fish, to squeeze the fish found, and to ship the caught fish to the ports of the sale in a short time without losing its freshness. The boat’s length, width, depth, displacement, hull shape below the draft line, trim, and of course the power and type of the machine determine the speed of the ship.

During the operation of some fishing methods, it is desirable that the speed of the ship is very low (dead speed). Again, according to the hunting method, some hunting ships are required to have very high maneuverability. During the operation, the rudder should work effectively; the turnover circle should be quite small; The control of the drive mechanism for start, stop, forward and astern movements should be simple, fast, and safe. At medium speed, high speed, or low speed the speed of the machine should be smooth. Other features of commercial fishing boats include:

They must be resistant to strong winds and waves. The balance of the boat, swimming should be very good stern and wave oscillations should be less.
They should be able to cruise long distances and open seas.
It should be possible to preserve the fish caught in ice or frozen.
Fish must be able to be transported to the port of sale. Offshore fishing boats should have fish processing and canning machines.
In order for the fishing boat to achieve effective and economical results, fishing equipment and devices must be complete. These are fishing lines, log reels, winches, and pulleys that pull fiber and steel wire ropes, net pulling pulleys, special winches, purse seine net collection reel (power block), etc.

Types of Commercial Fishing Boats

Trawler Boats

Trawl boats can be grouped under two main groups according to their operation type. These are side trawlers and stern trawlers. Side trawlers are pulled from one side of the net boat. Towing ropes go to the crane by passing through the pulleys on the hangers on the starboard side of the boat. The bridge is at the stern. In stern trawlers, the towing ropes coming out of the winch pass through various pulleys on the stern deck and stern and go to the net being pulled from the stern of the boat. In small type boats, the pulleys were at the stern. It is attached to the hangers in the trawl. In large type boats, the pulling pulleys are attached to a crane or similar equipment located at the stern of the boat.

In these boats, the bridge is usually located at the front of the boat. A special stern (stern slope) has been made to the stern of medium and large trawlers for easy throwing and collection of the net. In some small trawlers, a large reel covering the stern is installed to reduce friction in the throwing and gathering of the net. The crane was placed immediately behind the bridge superior. It is ahead in small boats. Most of the large boats have freezers and cold storage. There are also factories that process fish caught in some of the large boats and make fish oil, flour, and canning.

Surrounding Boats

Fishing with the nets on these boats is based on the principle of catching the flock by wrapping it around. Surrounding fishing boats range from small open-top boats to large ocean-going boats. These boats are used for fishing surface fish. They have high maneuverability. The basic equipment is one or two winches that allow the net to be pulled at the stern of the boat and are powered by a rope from a hydraulic, electric, or winch suspended from a boom, and which shrink the bottom of the net with a net pulling reel. The fish caught is taken from the small pool formed in boating with a bucket or fish pump.

Purse-Seine Boats

After the fish flock is turned with the purse seine net, the shirring rope at the bottom of the net goes to the crane via the pulleys on the shirring hangers. When the crane pulls the shirring rope, the bottom of the net is closed. Thus, the fish is trapped in a net pond. We can divide purse-seiners into two types in terms of deck arrangement. One of them is North American type and the other is European type boats. On the North American purse seiners, the bridge and crew cabins are placed at the front. The net take-up reel is suspended at the end of the boom attached to the mainmast behind the bridge top. The winch is placed opposite the drawstring. The net is carried stacked at the stern of the boat.

On the European type purse-seiners, on the bridge and personnel cabins are placed at the stern. In the middle of the boat, there are warehouses for the fish caught. The net is usually carried on the upper deck. The net take-up reel is placed on the side of the bridge top. In addition, the net is stacked on the aft deck with the help of transport rollers or large rollers. The shrink rope is located at the front of the winch, opposite the full shrinkage davit.

Other Commercial Fishing Boats

Trammel Net Boats

Trammel nets are often used in boats on the shores. The further away from the shores, the larger the size of these boats. In the slightly larger ones, the bridge is either in front or behind. In small boats, the net is pulled by hand. Large ones have special hydraulic net pulling reels.

Trap Boats

These are boats used to carry aquatic creatures such as lobster, crab, squid, etc. with special baskets, pots, or similar tools made of net and place them in desired places in the sea. Generally, open-top boats are used along the coast, and 20-50 meters longboats are used at the borders of the continental shelf, there are davits, cranes, and booms for pulling baskets.

Hand Fishing Boats

If we think of hand fishing boats, hand fishing rods can be used in almost all kinds of marine vessels, from small crafts to small boats. There are fishing lines and storage places in these. There should be a suitable free space on the deck so that the fishing gear can be prepared and used easily. Fishing tackle can be used by hand, as well as some mechanical tools.

When we think of log lines, boats of various lengths are used according to the length of the log lines and the distance and conditions of the hunting area where they will be used. Bottom longlines are installed near the bottom or to the bottom. Surface loops and drifting logs are dropped from the water to a certain depth with the help of buoys. Fishing gear is pulled from the hull or one side of the boat by means of mechanical or hydraulic pulleys. It is then placed regularly in its special place at the stern. The bridge is located at the stern or the empty side. In large log line boats, it is usually at the stern. In large boats, many automatic or semi-automatic tools are used for attaching the baits to the hooks, throwing and collecting the log lines.

Multi-Purpose Fishing Boats

These types of boats are designed to use two or more different types of fishing gear sequentially. Without making much change in the equipment of the boat, they have arranged to hunt with other types of fishing gear when the main fishing gear cannot be used. For example, extension net boats can be used in fishing line and longline heron. Again, trawl boats are used in extension net fishing or purse seiners in trawl fishing with the help of additional equipment.

The deck arrangement and equipment of the trawl-purse-seine fishing boat are made to be able to apply both fishing methods. The boat must be strong as the boat will trawl. There is a crane on the bridge in front and just behind it. Reels, trawl hangers, purse seiners, net reel, etc. equipment is placed in the best possible way.

Factory Boats

In these boats, the fuel, food, fresh water, and consumer goods of the boats are provided on the one hand, and on the other hand, the fish caught and brought by the fishing boats are processed or stored in cold air storage. In addition to these, the health and social needs of the personnel on the fishing boats are met. The caught fish are taken to the ports where the fish are found in these boats.

The main boats can be classified among themselves as boats that keep the fish in cold storage after salting and freezing the caught fish, factory boats, and boats carrying hunting boats on their deck. The fresh fish caught by the fishing boats of the factory main boats can be frozen and stored in cold storage, as well as being canned in the factory inside the boat. In these boats, engine room and personnel cabins are at the stern. There are processing and freezing facilities in the middle.

Fish Transport Boats

These boats have freezers and cold storage depots. These are the boats that are used to transport the fresh fish brought by the fishing boats to the ports where there is a fish state, after being frozen in these boats and stored in the cold storage rooms.

Research Boats

Experimental studies on the determination of fish stocks in the seas, ie the experiences of fishing tools and equipment, and the easy removal of the fish caught from the sea are carried out by research boats. In these boats, the diversity of living things in the sea, lifestyles of sea creatures, sea pollution, and so on are researched.

Commercial Fishing Boats According to the Fishing Method

Purse-Seiners for Deep Sea Fishing

Knowing the length of the ship is sufficient for the manufacture of the ship in question by the construction masters. Of the ship; Other main dimensions such as width, depth, draft are determined on the basis of ship length. Commonly used values for these ships; L / B = 3.33 for length-width, D = 8.3310 for length-depth and B / T = 2.5 for width-draft. Although purse-seiners have shown some changes depending on the technological developments from the day they were first used to our time, in terms of their equipment, they can be grouped under three main headings as in-boat, on deck, and bridge equipment.

The stern of the boat is generally in the form of a mirror stern. In recent years, a significant change has been made in the stern design to allow the auxiliary boat to be placed and the net to slide easily into the sea. The engine room is located under the deck near the stern and generally includes the main engine, generator, and pumps. The propeller blades have 3 or 4 and can be single, double, or triple propellers depending on the number of main machines. The steering system is hydraulic or electronic. Fuel tanks are of capacity-dependent sizes and are placed symmetrically under the deck and close to the stern. Freshwater tanks are generally located under the deck at the fore or aft of the boat.

In purse-seine fishing in the seas; Freshwater tanks can also be found on the deck in small capacities since hunting areas are close to the beach and hunting is daily. The fish warehouse is usually located in the middle. Purse-seiners rarely need this hold as they usually have a carrier boat with them. However, purse-seiners fishing in the open sea is designed or modernized to have cold storage warehouses suitable for fish containment since they do not have carrier boats with them.

The tools required for the operation of the purse seine net are generally boom poles that can rotate around the main pole and an axis connected to the pole, the net collecting pulley operating with a mechanical or hydraulic system connected to the boom pole, the crane that pushes the ropes, and fixed and mobile pulleys where the wire and ropes are attached.

The area where the cabins of purse-seiners operating in the seas are located from the middle of the boat to the bow and occupy approximately 1/3 of the main deck. This area has a capacity to accommodate at least 15-20 people and includes spaces such as kitchen, washbasin, toilet, bathroom, and living area. The deck has at least two floors. There are navigation equipment, fish finders, and communication devices on the bridge.

Tools to Be Found on a Purse-Seine Boat

Purse-Seine Nets

The nets used for the production of pelagic fish, which enable them to be caught by circling the fish and trapping them in the net, are called turning nets. Purse-seine nets are the most characteristic of dialing networks. When the flock is turned around, the lead collar is shrunk and taken to the ship with the help of the rings on the lead collar and the wire rope passing through these rings. Then the cork collar and net are collected. Finally, the fish collected in the bag section is taken to the ship.

Utility Boat

Boats are 5-7 m long made of sheet metal and have 30-80 horsepower machines. These boats can be transported tied to the back of the net boat and can also be transported there by pulling to the special place built from the stern of the fishing boats built in recent years. Thus, the problem that the boat that swims in the back hinders the speed of the fishing boat is eliminated.

Fish Finder Devices

Echo-Sounder: Fishfinder devices send sound frequencies in kilohertz in vertical and horizontal directions to the aquatic environment in the form of pulses. These pulses, which are reflected from objects with different densities compared to the water in the environment, are received by these devices and give information about the object making the reflection. Devices that work only in the vertical direction are generally called “Echo-Sounder”. While these were used as navigation devices, they were later used in fishing and scientific research.

Sonars: The sonar, which was first mounted on a boat called G.O Sars in the winter of 1950, is the first of the sonars built as a fish finder. In the following years, sonars have also shown great improvements like Echo-Sounders. Sonars work according to the Puls-Echo system like Echo-Sounders, but the transducer used in sonars differs. Because the sonar can send its pulses at the desired slope. This slope can vary up to 90 ° from the water surface.

Net Pulleys (Power Block)

Net pulleys are of two types, mechanically and hydraulically, covered with smooth rubber inside, not damaging the net. Generally, the small ones and the very few that are in use are mechanical pulleys, and those used widely in large purse seiners are hydraulics. Mechanical ones are operated by means of a rope and with the help of a man or windlasses. Those of this type are found in small king and mullet purse-seiners. In these, the endless rope passing through the reel is connected to the capstans and allows the reel to rotate in the desired direction.

The working principle is similar to hydraulic pulleys and the same processes are done from it. Hydraulic reels, on the other hand, are the spools that make the rotation of the gears in the spool with hydraulic power. Their power source is generators because the main machines are stopped at the time of net assembly. Hydraulic reels have become increasingly common because they are used to pull webs that are larger, heavier, and require more power. A purse-seine fishing boat has three boom posts attached to the main boom pole. They carry the power block (net reel) that is used to collect the nets facing the stern. The net reel is connected to a small diameter reel placed at the end of this pole by means of a hoop system. With this system, the net reel is lowered on the stern with the help of a pulley when the nets are collected.

The upper arm of the net reel is opened and the head part (wing part) of the net is passed over the reel. The net reel is raised to the end of the reel pole with the help of a pulley. The net reel that has reached this state is ready to pull the nets. While the nets are passing through the reel, they are both controlled and the foreign objects caught in the net and the fish in the net are cleaned. For this reason, the reel can be stopped or operated backward when desired. The load on the reel is constantly controlled, otherwise, it is possible for the spool post to break under overloads. For this reason, the reel pole is connected to the main boom pole with metal pipes as in other poles, but these connections do not prevent the movement of this pole, it increases the carrying power because the pole has a movement area at a certain angle.

Windlass, Windshields, and Davits

Windlasses are aids that make hunting easier. These are of two types, the ones working mechanically and the ones working hydraulically. These vehicles, which previously operated mechanically depending on the main machine, have recently been transformed into hydraulic systems connected to very powerful generators. The winding of strong ropes on net pulleys is done by these tools. Hydraulic capstan can be managed by a single person, as well as winding the steel ropes it pulls on spinning wheels, and they are safe besides saving. There is a small moving reel on a pipe that allows the ropes to be wound properly on the reel. These windlasses can be moved at the desired speed.

The steel rope pulled for the purpose of pressing the bottom of the net rubs against the edge of the boat (handrail), causing both pulling force and abrasion due to friction. In order to eliminate this problem, davits are placed in the slot on the specially reinforced thick sheet plate for the starboard rail of the boat so that it can move in four directions. These davits, which are made of full pipe iron in L shape, are fixed in the desired direction with the help of a spring. There are rollers placed on thick chains at the ends of the mats that can be opened and closed by means of a hinge at the top. The steel rope passes through this reel and comes to the rope.

Trawl Boats for Mid-Water Fishing

The trawl of the ship changes according to the trawling with a single or double ship. It is up to 50-1000 gross tons. A 500 HP engine is used for a 300-ton ship. It has equipment such as radio and telephone, fish finder and direction finders, radar, crane, freezing facilities, and cold storage rooms. Staff varies between 12 and 50 people. It can stay at sea for 20 to 60 days. Their speed is 1–13 knots/hour.

Tools to be found on the Trawler Boat

It is possible to divide the tools and equipment used in trawl fishing into two parts. The first is the elements that provide the connections between the trawler and the trawl net. The other is the net bag in which the fish gather. One of the elements required for the connection between the boat and the net in a trawler is the main steel ropes connecting the equipment to the boat between the trawler and the trawl doors. These are two and their length should be at least three times the depth in which the trawl net will be released. The diameters of the ropes can vary between 10 mm and 32 mm, depending on the structure of the trawl net.

Fishfinder

The fish finders in the purse-seine boat and described above are also used in the trawler boats.

Roller Reel System

They are pulley systems used to move fishing gears. Various machines are used according to the hunting method. Most of them are used to collect fishing nets. According to their mechanisms, they are divided into two as friction rotating type and drum type, and they are also divided into net collecting and rope collecting reels. Since it is easy to use and can operate with little power, the friction rotating pulley type is more commonly used. It is a pulley system that rotates with a rope on it. The resistance at both ends of the rope overlaps the reel with the friction force.

Trawl Net

We can divide the trawl nets into two groups as bottom trawls and pelagic trawls in terms of their structures. Both bottom trawls and pelagic trawls can be with or without gates. In other words, bottom trawls and pelagic trawls are available both in one boat and in two boats. The doors provide a horizontal opening for trawl nets pulled with a single boat. It is located between the trawl wire and the mooring rope. Different gates are used for different types of trawls. Common door types are classic rectangular, oval, V-door, and super-exposed door. In the trawl equipment, the ropes that provide the connection between the door and the net form the ropes of the trawl.

The mooring rope connects the doors with the net. As the depth increases, the mooring rope is long and in shallow waters, shorter mooring lines are used. In modern nets, apart from the mooring rope, there are ropes extending from the core to the net, called the head rope, while in classical nets there are thick (several layers and 30 mm thick) three-piece or triple ropes between the mooring rope and the core. The head ropes free the wing nets from the limitation of the core, increasing the mouth height of the trawl net. The triple rope prevents the net from rising from the sea bottom.

The hydrolase rope helps to prevent the net from breaking down, dividing the caught product from the bag filled with the product into compartments and taking it into the boat in sections, and tying the bag mouth. It continues from the spades to the back of the bag. The core is hardware made of wood or iron that holds the head ropes.

Trawl nets consist of the wing, shoulder, tunnel (pipe), and bag sections. Wing or arm nets direct fishery products to be fished to the net. It is usually made of a wide mesh net. In classical nets, one piece is flat rectangular or the part coming to the core is narrow and the part coming to the shoulder is a wide trapezoid. Most modern networks have two or more pieces. The shoulder webs are located between the wing nets and the tunnel.

The shoulder section behind the lead collar is called the lower shoulder or abdomen, while the section behind the cork collar is called the upper shoulder. In bottom trawls, the lower shoulder starts further back than the upper shoulder. Thus, the fish entering the net are surrounded by the net when they come across a lead collar and see the net.

The section that connects the shoulder and the bag and allows the fish entering the net to direct the bag is called a tunnel. Since the area where the tunnel connects to the shoulder nets is wide and the area where it connects to the bag is narrower, this section looks like a complete cone. The mesh opening is narrower than the shoulder and wider than the bag. In classical nets, the shoulder, tunnel, and bag sections are at the same eye-opening.

The bag is the part where the caught product accumulates and it is the area with the smallest eye-opening. The width of the tunnel from the section where it connects to the end is the same. The last section where the fish accumulate in the bag is covered with a wide mesh cover made of thicker ropes in order to prevent it from rubbing against the seafloor.