How big can a marine propeller reach?

 At present, the mainstream spiral slurry of marine vessels is made of copper-nickel alloy or copper-manganese alloy. Of course, there are stainless steel, cast iron, and even fiberglass reinforced plastic propellers, but the number is small.

Let's see how the copper-nickel alloy propeller is processed.

Propeller production process (figure from the website of China Sea Propeller Company):

Casting - The molten copper water is injected into the propeller mould, and the rough embryo of the propeller is obtained after cooling.

  Machining - Fine processing of propeller rough embryo through machine tools and other equipment to obtain the required precise size

Surface treatment - Surface burr treatment, polishing and marking. Shafting Composition - The propeller and the corresponding propeller shafting are matched. If the requirements are not met (the contact area is insufficient), further finishing treatment is carried out.

Considering only the processing capacity, the biggest limitation on propeller size is casting and machining equipment, that is, tens of meters of molds and hundreds of tons of heavy machine tools. With the current domestic manufacturing capacity, the production of this is the same as play. That is to say, copper-nickel alloy castings with a diameter of more than ten meters, which are half as large as the propeller in the title, can also be easily produced. In pursuit of the first, production capacity is not a problem, so the biggest is still stuck in the demand side.

The world's largest ships now under construction are 21,000 TEU container ships and 400,000 tons of ore dredgers. Their propellers are not much different from those in the title.

Larger propellers can also be built, but no one wants them at present.