Tug boat are vessels used for moving ships and all Sea structures. Large vessels that are in the narrow channel, harbor or cannot move alone are possible with the help of towing vessels. These vessels also a rescue vessels and pulling structures without propulsion systems.
The tug boats are designed to push and pull all kinds of ships and are divided into different types based on volume and power.
The general applications of tug boat are as follows:
- Tugboat is used as a means of separating ships from the docks
- Pushing and pulling other ships in a harbor
- As a guide for large ship in harbor
- To put a barge (without propulsion system) in required position
- As a Firefighting vessel for firefighting Tugboat
- Any operation in ship construction and repair in dock yard
Different types of tugboats in terms of their application and their propulsion system:
The following figure shows the category of tugboat:
Figure 2- Type of Different Tug Boat
The most commonly tugboat that used in towing operation
- Sea Tug
Sea tug have a wide range of different applications because they have no restrictions on port performance.
Among the effective sea tugs are:
Salvaging or towing a vessel in case of breakdown, grounding or collision are some sea tugs operation. These vessels can operate offshore and are designed to stay in the sea for long periods.
Figure 3-Sea tug
- Escort Tug
This type of tug boat is used for moving large vessels on narrow and dangerous roads. These facilities are only used for large vessels whose propulsion system is not capable of maneuvering on dangerous roads and waterways because of shallow water and low maneuverability.
Figure 4-Escort tug
- Harbor Tug
Harbor tug are multipurpose vessels that are used in ports and waterways for aiding and towing operating the vessels in and out of ports. They are also used to move barge and carry goods.
The Harbor tugs are highly maneuverable because they have to move large ships in small, confined areas.
Figure 5-Harbor tug
- Push Boat
These types of tug boats are used to push barge and rail barges. Push Boats usually have a square shape of Bow and due to their low draft, are used in shallow areas. In the bow of this type of tug boat, plates are mounted to move high altitude vessels. Push Boats are commonly used in rivers and waterways.
Figure 6-Push Boat
- Azimuth thrusters
Different Types of azimuth thrust systems:
- ATD(Azimuth Tractor Drive)
These types of tugboats are used to pull barges and are usually used for berthing large vessels and tankers in ports .This type of tugboat is »Tractor tug« that to provide the maneuver required for vessels that lack the maneuverability.
These types of vessels, which have a propulsion system with azimuth thruster, are used for docking and construction operations.
- ASD(Azimuth Stern Drive)
ASD’s are commonly used for harbor tugboats. This propulsion system Equipped with two stern engines that can generate a 360°, all directional propulsion force. ASD usually have a towing winch forward. These tugboats able to towing both, Bow-to-Bow and stern- shoulder.
Pulling and pushing mode provides good working conditions for this type. The average bollard pull of ASD Tugs around 65 tonnes that be increased.
- ART(Advanced Rotor Tug)
In this type of tugboat, two diesel azimuth thruster are mounted on bow of vessel and one on the aft. The ART have high maneuverability and also have excellent traction force in the indirect direction. In terms of Stability, these tugboats have very good performance.
Figure 7- from left to right respectively: ATD, ASD and ART
The advantages of azimuth thrust system:
1- Rotation 360 degree
2- No need for a rudder
3- Reduce maintenance costs
4- Better use of floating space
5- These vessels do not require tugboat to reach the repair basin.
6- High electrical efficiency
7- High maneuverability
- VOITH Schneider Propeller (VSP)
The Voith Schneider propeller (VSP) is used mostly for Harbor tugs. In addition to being highly maneuverable, these propulsion systems can quickly change direction of movement.
In this system, a number of vertical blades that are hydrofoils shape, rotate around a circular plane and around a vertical axis. The inner gear changes the angle of attack of the blades, so each blade can produce a thrust force in each direction. Each blade can also rotate separately around a vertical axis.
The advantage of VOITH Schneider Propeller system:
1-High efficiency and reduced fuel consumption
3- In all directions, it generates the thrust force quickly.
Figure 8- Voith Schneider propeller (VSP)
- Screw Propeller
The screw propellers are generally divided into two categories of fix-pitch and controllable-pitch. The pitch of fixed-pitch, cannot be change during on operation. The pitch of a controllable-pitch propeller can be changed at any time, subject to bridge or engine room control. The controllable-pitch propeller can reverse the direction of a ship without requiring a change of direction of the drive shaft. According to above explanation there are two type of screw propellers:
- Controllable-pitch propeller (CPP) – The pitch angle is easily controllable and the pitch angle can also be switched from maximum forward to reverse. The controllable-pitch propeller can reverse the direction of a ship without requiring a change of direction of the drive shaft.
- Fixed pitch propeller (FPP) – Propeller with blades rigidly attached to the hub.
The advantages of Screw Propeller system:
– Low Cost
– Easy maintenance
Figure 9-Screw Propeller
Marinnor have able to designing and manufacturing of any type of tug boat with best operation condition according to navigation area. Good quality of used material and equipment with low cost and minimum delivery time are one of our best solution. for more information please contact us. you can see Tug and Workboats manufactured by Marinnor company in our products page.