Naval ships are impressive vessels. Commanding the seas worldwide, they require strength and durability. Alongside this, the most imperative component is their ability to float effortlessly on the waters.
Previously we covered where naval ships were built and how long it took, but when it comes to the actual construction, there are various materials used to ensure the safety and stability of these giant naval ships when carrying out their work. As an online chandlery, we find the topic of shipbuilding fascinating, so join us as we explore more about how giant naval ships are made.
Old Naval Ship Building
As depicted in historical movies about wars at sea, naval ships used wood within their construction. Wood was used for many centuries and even to this day is used for smaller boats and vessels. However, as time passed, this material proved ineffective as a reliable material for various reasons. Firstly, it can quickly deteriorate if left untreated, and while it may not take too long to treat a smaller sailboat, larger ships out at sea for months on end will promptly be subject to rot. This factor made naval ships unsafe for lengthy periods at sail.
Another issue was fastening the timber together. A ship must remain watertight, and slippage along fore-and-aft (front and back) flush seams was challenging to prevent. Large wooden ships required diagonal metal straps bolted to the planking to counteract slipping at the seams and to keep the hulls in shape.
Significant developments have been within wooden shipbuilding, with specialised glues and detailed techniques to prevent these material issues. However, other materials are favoured for durability and lower maintenance in the modern world.
Although not a new material, steel is modern in the history of shipbuilding. Steel has been used for over 150 years in ship construction due to its sought-after properties and low costs. Its strengths, rigidity and puncture resistance make it an ideal material for shipbuilding.
There are various kinds of steel, all offering similar benefits for shipbuilders, with stainless steel offering the best choice due to its corrosion resistance. This metal is ideal when taking large naval ships out to sea in all conditions with many corrosive environments, such as salt water and sunlight.
Mild steel containing 0.15% to 0.23 % carbon and high manganese content are used to construct a ship’s hull. Sulphur and phosphorus contents in mild steel are kept to a minimum (less than 0.05%) as higher contents of each hamper the welding properties of the steel. In addition, cracks can develop easily during the rolling process if the sulphur content is high. High tensile steels (higher strength than mild steel) are used for the more stressed regions of large tankers, container ships and bulk carriers. They are often used for the deck and bottom areas of larger tankers.
Sometimes, aluminium alloys are used in the construction of ships instead of mild steel for many reasons.
Firstly, aluminium is lighter in weight than mild steel, which is essential for the floatation of the ship and can save up to 60% of the weight. This can be essential for naval ships such as aircraft or cargo carriers, requiring more weight than crew. Also, much like stainless steel, aluminium is resistant to corrosion, making it ideal for challenging conditions. However, the issue with aluminium is the cost. It is much more expensive than steel per ton but regaining this cost with increased cargo can be beneficial.
Finally, due to the lightweight properties of this metal, the cost of fuelling the ship is much more efficient as there is less weight to pull.
How Are Naval Vessel Ships Held Together?
When shipbuilding first began, the standard way to hold the planks or sheets together was using rivets. These allow plates and planks to be secured and function as a watertight shield for the joins. Before modern-day technology, rivets were vital in keeping the vessel in one piece. Rivets can be seen in many applications aside from shipbuilding, including bridges and were common when constructing large structures such as the Eiffel Tower. They are usually made of steel (low carbon steel or nickel steel), brass, aluminium, or copper. Rivets can be created from various materials, but with the Titanic being a cautionary tale, cheap rivets will result in danger out at sea.
As progression has it, riveting, whilst an exciting and valuable technique, has made way for more efficient methods such as welding. This involves fusing the two workpieces to create one sheet of metal and is the much-preferred method due to the time and costs it saves.
How ever the ship was built, keeping up the maintenance is essential and imperative to keeping the ship in the same condition as it was built. Don’t forget you can buy all your marine supplies online, including our great selection of Unitor marine products, which will help keep your vessel in ship shape.