It can take years to build a large ship, and months to build a small one. Large supply ships and floating docks can cost hundreds of millions of dollars. Large ships can be over 1,000 feet long and weigh up to 200,000 tons when at rest. As such, they cannot be lifted and lowered into the water like small boats. So, what are the methods of launching ships? How are they launched into the water?
The Evolution and Importance of Ship Launching
Launching is a crucial step in the shipbuilding process, marking the moment when a ship transitions from land to water. There are various methods of launching, each of which is suitable for specific types of ships, sizes, and site conditions. One of the most traditional methods is gravity launching, which relies on gravity to slide the ship down an inclined chute into the water. Float-out launching is a common method used in modern shipyards. The ship is built in a dry dock and then water is poured in to float it.
In addition, mechanical launching is usually limited by the size of the vessel and is usually suitable for small vessels. Airbag launching is a recent innovation that uses large inflatable rubber airbags placed under the hull to roll the boat into the water. Each method requires careful planning and design to ensure safety and minimize stress on the hull structure.
Gravitational launching
Let’s start with gravitational launching. This basically involves letting the boat slide into the water under the force of gravity. The boat is slid into the water via a ramp, which varies depending on the direction and the type of method used. There are generally three types of launching methods:
- Longitudinal oiled slideway
- Longitudinal steel-roller slideway
- Side oiled slideway
Longitudinal Oiled Slideway
The longitudinal oiled slideway is one of the oldest methods of launching a ship. It uses a lubricated slideway system to allow the ship to slide down into the water. Oil or wax is usually used to help the ship slide quickly. This method is relatively simple and does not require special tools. However, the disadvantage is that the lubricant can enter the water, and the bow of the ship will be subjected to a lot of pressure during launching.
Longitudinal Steel-roller Slideway
The longitudinal steel-roller slideway is launched in the same way as the oiled slideway. However, it uses steel rollers instead of lubricant, which makes movement much easier. On a wooden slideway, the steel units help the boat to move and prevent the steel balls from slipping. To prevent the steel balls from getting lost, there is a simple mesh bag at the end of the slideway. This method of launching boats works well, but the installation costs are high.
Side Oiled Slideway
A common method for launching large boats is to use an oiled slideway. The slideway can extend all the way into the water or it can be stopped at the water’s edge. The boat needs to balance itself as it slides into the water. This method of launching requires a sturdy boat with excellent stability.
On the other hand, this method is often used in narrow waterways and therefore requires extra care. If the boat hits the shore or wall, it may flood nearby roads and land, or damage the boat. Despite the dangers involved in launching this way, it is also the coolest way to launch a boat.
Floating Launch
This method involves building the boat in a dry dock. Once it is finished, the dry dock is simply filled with water and the boat floats to the surface. You can then safely move the boat to the sea. This is currently one of the most popular launching methods, and it is both simple and safe to operate, but it is also very expensive. It is worth noting that this is not technically a boat-launching procedure. However, most boatyards use this method. Because floating launching is simple, safe, and efficient.
Mechanical Launching
Mechanical launching is a very simple method that involves slowly lowering the boat into the water. This method is somewhat risky as it requires a crane or other type of lifting system. However, it is a common method for launching small boats. Therefore, it is not suitable for larger boats as they are too large and heavy.
Air Bags Launching
It is a safe way to launch boats of all types and sizes. It is like the airbags in cars that protect passengers. These rubber airbags provide support for the boat. Ship Launching Airbags are placed under the boat and then gravity is used to guide the boat into the water. This method does not require a slipway and does not require complex equipment or processes. Therefore, air bags Launching is, a simple, safe, and low-cost way to launch boats.
The Serious Consequences of Launching a Boat Incorrectly
Launching a boat involves a lot of calculations and adjustments to ensure a smooth launch. Launching from a longitudinal or lateral slipway also requires the internal structure of the hull to be processed to support the bow section.
However hard you try, mistakes are inevitable and the consequences can be very serious. These mistakes can take the form of a failed launch, some of which will go down in history.
For example, HMS Albion on June 21, 1898. This is probably one of the oldest launch photos. Although it is not clear how bad the situation was, the waves generated by HMS Albion destroyed the breakwater and killed 30 people.
Another example of a failed launch is the SS Principessa Jolanda. It was launched for the first time on September 22, 1907. After the launch, the ship began to sink and tilt to the left, which meant that it could not maintain its balance. As the accident could not be stopped, the ship could not be saved. It is believed that the cause of the error was a miscalculation of the center of gravity of the ship.
A more recent launch accident occurred on the luxury cruise ship SS Jiugang on September 29, 2011. The shipyard had opted for a vertical slide launch. But when they slid the ship into the water, it didn’t even float. According to Maritime Professional, $2.5 million eventually sank to the bottom.
Summary
Understanding the methods of launching a ship reveals that the maritime industry requires a great deal of creativity and engineering expertise. Whether it is launching by gravity, floating, mechanical, or airbag, each technique has been carefully designed to ensure that the ship enters the water safely and efficiently.
The choice of launching method depends on factors such as the size and type of ship and the capabilities of the shipyard. This shows just how versatile modern shipbuilding techniques have become. By mastering these methods, shipbuilders are constantly pushing the boundaries of innovation to ensure that every ship makes its maiden voyage successfully and safely.
FAQ
What are the different types of ship launching?
Common ship launching methods include gravity, float, mechanical, and airbag launching systems. Each technology has its own advantages and applications.
What factors influence the choice of ship launching method?
Common factors include the size and weight of the ship, shipyard facilities, and environmental factors. These all influence the selection of the most appropriate launching technique.
What are the risks associated with ship launching?
Risks include damage to the vessel or surrounding structures, personal injury, and environmental impact. Therefore, careful planning and execution are essential.
Can airbag launching be used for large vessels?
Although ship launching airbags are typically used for small vessels, they can also be used for large vessels if equipped with the appropriate equipment and planning. This provides a flexible solution for vessels of all sizes.
