Vessel towing services

Tugboats are of unquestionable importance in the day-to-day of any port. Below, we discuss all the key factors that make them essential.


What is a harbour tug?

Tug boats are a type of vessel designed to assist any floating craft or ship to perform the necessary manoeuvres within a harbour. Their efficiency depends directly on their type of propulsion. It is usually azimuth thruster or cycloidal, as it provides greater speed, simplicity and safety for each task.

For a tug to be effective, its strengths must include manoeuvrability, size according with its engine power, adequate fixed-point drive, perfect stability and the best possible view from the bridge. This type of vessel carries fenders, bridge equipment and sanitary equipment, in addition to the contents specified in a later section.

Functions of port tugboats

In any port area, and always combining their work with that of the pilot, their sole objective is to certify the safety of each manoeuvre. They are also in charge of preventing ships from colliding with the port structure or the quay. In the case of shallows, they help vessels to find the best route to make the mooring as safe as possible.

Tugboats play a crucial role in port operations worldwide. Learn about their functions and types here.
Its purpose is to certify the safety of each manoeuvre and to prevent vessels from colliding with the port structure or the quay. Photo by Freepik.

In some countries their use is mandatory for large ships to enter and leave ports. In addition, they have other functions such as:

  • Continuous assistance to the vessel during berthing and unberthing.
  • Assistance for a turning manoeuvre, especially in confined spaces.
  • To counteract the effect of wind, waves or currents to ensure that the concerned vessel does not encounter any problems in the harbour.
  • Stop the vessel gradually.
  • Towing, pushing or assisting a vessel which may have been left without an effective propulsion system or steering option.
  • To tow, from one part of the port to another part of the port area any floating device.
  • In cases of loss of steering, escort vessels with hazardous cargoes through areas susceptible to accidental fire.



Tugboat types

There are three types of tugs, and the choice of each will depend on the type of operation that needs to be carried out.

Harbour tug

It is the most common in port traffic. The minimum engine power is 400 hp, the maximum is 3000. A fixed-point traction ranges from six to 30 tonnes. Their length ranges from 20 to 30 metres. Its draught is between three and four and a half metres. It reaches a maximum speed of 13 knots.

Harbour and offshore tugboat

In addition to the aforementioned functions, there are others such as assisting large vessels, supertankers mooring to monobuoys or towing coastal offshore vessels. They are characterised by a length of between 25 and 40 metres. The maximum power is 5000 hp and includes a fixed-point traction of between 20 and 55 tonnes.

Deep-sea tug and salvage tug

It is the only one that can cope with ocean towing and even assist ships in distress at sea. Its maximum power is 20,000 hp and the fixed point pull ranges from 55 to 180 tonnes. The speed is 16 knots.

Most of these vessels are fitted with fire-fighting or pollution prevention equipment. They can be remotely controlled to extinguish fires more efficiently. They include bilge pumps systems for vessels with a casualty and everything necessary to start the corresponding engine, thus facilitating berthing.


Towage licence

Most ports rely either on direct agreement with the company providing the service or on rules established by the port authorities.

The port towage regulation began with the State Ports and Merchant Marine Law 27/1992 of 24 November 1992. It was partially modified by Law 62/1997 of 26 December 1997 and Law 48/2003 of 26 November on the economic regime and the provision of general interest services in ports. This was modified by Law 33/2010 of 5 August.

Before the various laws mentioned above, towing in Spanish ports could only be carried out by Spanish-flagged vessels and national companies. The law regulates all tugboats services and functions and includes a section that allows each port to establish its own rules.


Parties involved in port towage

Ship towing manoeuvres are carried out with the participation of the following parties:

  • The ship that wants to enter or leave port with its harbour master.
  • The harbour pilot.
  • The ship tugboat, with their respective skippers.


Maritime tugboats: Understanding their vital role in port operations and ship manoeuvring.
The law regulates all services and functions of tugboats and includes a section allowing each port to set its own rules. Photo by Freepik.

The ship’s captain, or officer of the watch, first contacts the harbour pilot on watch or the controller. If a tug, or several tugs, are required, he notifies the harbour master to request them.

The harbour pilot boards the vessel and gives instructions to the tug masters after listening to the captain. In the process, the captain knowledge of his vessel is combined with that of the harbour pilot to avoid possible collisions or accidents.

If you need a professional tugboat service, Suisca Group offers you everything your vessel might need when calling at a specific port. With an experience of four decades in the sector, we are your reliable maritime partner and work wherever you need us. We look forward to meeting you.