Types of Ship Launching Methods

Types of Ship Launching Methods

In this article, we will be discussing various ship launching methods used by shipbuilders.

Ship launching is a moment of great anticipation, excitement, nervousness, and elation. It is perhaps the most crucial aspect and nail-biting part of the entire shipbuilding process.

The construction of the ship is a very elaborate affair, sailing in a ship and soaring high on waves is nothing less than a dream. After constructing a ship another important event is its launching in the ocean and that is some crazy stuff. Hence, getting a ship into water is, undoubtedly, the most crucial event of a sea voyage.

What Is Ship Launching?

The term ship launching means transferring a ship or a vessel into the water after the completion of its construction. It is also called ceremonial ship launching and is an important naval tradition across the world.

The ceremonial launching of a ship also involves several other traditions besides the transfer such as naming the ship and breaking a sacrificial bottle of champagne on its bow. This tradition has been going on for centuries, some of the oldest records being from as early as the 3rd century.

The seemingly easy process of transferring a ship into water actually involves many aspects of engineering and architecture and complicated calculations.

Hence, getting a ship into water is, undoubtedly, the most crucial event of a sea voyage. To make this tricky and tiresome job less complicated, shipyards use several different techniques for launching a ship. The procedures and methods used by them are hassle-free, secure, safe, and scientifically backed. These shipbuilding companies across the globe have been using slipways.

As you might be knowing that not all ships are made equally, they come in all sizes, ranging from a cozy family cruise to some giant cargo ships. Therefore, since the sizes are different so are the ship launching methods.

4 Types of Ship Launching Methods

Here we present you with some of the techniques and ship launching methods used by prominent ship construction companies in the world.

1) Floating-out Type Launching

Some ships are built in a narrow vessel or basin which is known as a dry dock. These ships are often launched by the floating-out technique. The modus operandi of this technique is flooding the dock with water so that the ship can ultimately float in the water. This technique is very effective and classic because it is simple, safe, and easy to perform. This ship launching method is one of the most widely used methods used by shipbuilding companies across the globe.

2) Gravitational Type Launching

This ship launching method harnesses the gravitational pull of the Earth to launch a vessel. It is further sub-classified into different ship launching methods:

a) Longitudinal oiled slideway launching

This is one of the oldest ship launching methods. In this method, oil and wax are used to help the ship slide on a slide-way to enter the water under its own weight. Ships with different tonnage and types can be launched through this method without any complex equipment.

There is a simplicity in this method but has some drawbacks also. The front part can come under huge pressure at the time of launch. Also, the oil and was used to smoothly slide the ship pollute the surrounding water thus making it not so environment friendly.

This method can only be used in seas or deep lakes.

b)  Side-Oiled slideway launching

Side oiled slideway
Side oiled slideway – Pic courtesy: https://www.wartsila.com/encyclopedia/term/launching

It is a variation of the oiled slideway method which is commonly used nowadays. Side oiled slideway is another very common technique used by shipbuilding companies. This method incorporates the use of oil and wax to aid the ship in slipping on its side through the slipway built near the water bodies. This method becomes very essential because it can help in launching ships of various sizes with the use of its weight and let the gravitation do its work.

The slipway/slideway extends into the sea and the ship slides its way into the water thus launching itself. The oils and waxes used in this technique have proved to be a pollutant to the ocean or water bodies. There are two methods of side oiled slideway launching methods. In the first system, the slideway extends to the water whereas, in the other version, the slideway doesn’t extend to the water. The ship slides into the water guided by the frames.

This method requires the ship to have the requisite buoyancy, stability, and strength to becomes steady when it slides into the water sideways. Sliding sideways can ship roll out to one side. The advantage of this method is that the ship can be launched in canals or waters with low depth.

c) Longitudinal Steel-Roller slide-way launching

Steel-roller slide way launching
Steel-roller slide way launching

In this method, instead of oil or wax, steel rollers are used to aid the ship slide into the water.

The slip-way is originally made up of wood and then a steel roller is installed on top of it which aids in sliding the ship into the water and the weight of the ship does the further process. This is one of the best methods used because it is very easy and effective. But it still has a limitation that is the expense of this process is very high.

This method is used when the shipyard is onshore.

3) Mechanical Type launching

This launching method spans a wide range of ships. This method incorporates a mechanical system such as a crane, winch, or a ship lift to launch a ship into the water. It comes with a variety of restrictions such as expenditure of setup and maintenance is prohibitive, and the controlling factors are also limited.

Of all ship launching methods, this one is most suitable for smaller vessels and not higher tonnage vessels.

It can also be further divided into these ship launching methods:

  • Longitudinal mechanized slide-way launching
  • Two points longitudinal mechanized chute launching
  • Wedge-shaped mechanized vehicles launching
  • Slope change transverse area mechanized vertical chute launching
  • High-low track slide mechanization launching
  • Mechanized comb slide lifting ship equipment

4) Air Bags Launching

Airbag launching
Airbag launching Pic courtesy: https://www.wartsila.com/encyclopedia/term/launching

Airbags are an interesting and unique way to launch ships. Not only this, but airbag launching is also the safest. Cylindrical airbags with hemispherical heads at each end made of reinforced rubber layers are used in this innovative process.

The airbags are first placed under the ship and then inflated. Then the ship slides down into the water safely without damaging either the ship or the environment with oil/wax. This method though needs a large area for the entire operation since the ship slides longitudinally with Bow facing first.

It is also one of the most cost-effective ship launching methods and can be used for ships of all types and tonnage.


Here were the most commonly used ship launching methods. Various new methods are constantly introduced by the shipbuilders to ensure higher success and safety. Please do share your views on these ship launching methods.


Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *