Why a Ship’s bottom is Painted Red?

Ship’s bottom is Painted Red? The answer is a bit lengthy but very interesting Ships normally float in Water, Sea Water While the sea facilitates a ship to travel from one country to another…

it has its own downsides If you have seen a ship from the bottom a jetty or a pillar from the bottom. or anything that can stay in seawater
for long.

If it has been in Water for some time you’d see a lot of growth in it It’s usually barnacles, seaweed, Marine
grass, and alike although all of this marine growth is a good and positive thing for Marine life.

but it’s not good for the ships themselves Ships usually stay in water from their launch until the time they scrap except for 5 yearly dry-dock

The rest of their time is spent in the water, Which leads to the development of the growth on vessel’s hull

This includes barnacles, Seaweed, and Marine Grass, While marine growth is not harmful to the ship in any way, all of these growths lead to an increase in a vessel’s Drag Now,

What is Drag?

A Ship is usually Sailing in water with the help of her Engine & Propeller The “Marine Growth” on a ship’s hull reduces her Speed Simply Put, Drag is the friction between Water and Ship’s Hull A ship’s hull is quite Huge Extending from forwarding to Aft From one side to another And quite deeper than the area of hull you see above water or even deeper if she’s in loaded Condition

Marine growth in Such a big area leads to an increase in Fuel Consumption, The ship would need to exert more force to achieve the same speed & overcome Drag,

This means you’d need to Run her Engine at increased RPM (Revolutions per minute) And this means an increase in Fuel consumption Inevitably, an increase in drag leads to increased fuel consumption One solution to this problem is,

To Clean the Hull before every voyage A diving team can easily do this Job 2nd solution is, to coat your ship’s bottom with a paint that deters the growth of Marine organisms And that’s exactly where antifouling paints come in Antifouling paints deter Marine growth on
ship’s underwater hull and hence help in reducing a vessel’s Drag but, it’s important to mention here that …

The use of antifouling paints doesn’t guarantee ZERO marine growth however they help significantly in reducing this growth and you don’t need to clean the hull again and again if it’s coated with antifouling paint, But just to increase a vessel’s efficiency, owners do get the hull cleaned every 6 months or so.

By deterring Marine growth on ship’s hull it helps Ship’s achieve good Fuel average,

In today’s world, these Paints are available in a variety of colors, Now you can select any color of paint (mostly) that you like a Few years back there weren’t many choices With very few colors to choose from, owners usually selected RED

But, with plenty to choose from Nowadays.

You can pretty much make a selection of colors as you desire Cruise liners choose white, some choose Green Grey or Black … Just as they like

Why only RED then …
Why do most choose RED?

1st reason is that bottom of many ships was painted RED traditionally.

Some ships were fitted with Copper plates to avoid rotting & marine growth Over time, Copper sulfate would deposit
on them giving a RED tint.

Later they were painted with Copper-based paints, Reddish in color Both were applied to save wooden ships from Rot and Marine growth Slowly the painting systems and paints themselves changed.

The color RED was still chosen because of one more reason.

that is, many ships have a black hull, some have blue or grey too Shipowners usually choose Black hull as it looks beautiful and is easy to maintain this Bottom RED color meets the black hull at Plimsoll marks are usually the marks up to which your ship can be loaded.

The line where RED and Black color meet makes a visual demarcation line in exceptional cases this line can be above or below plimsol marks On ships where this demarcation line is at Plimsoll Marks.

You can visually make out if the vessel is overloaded or Not These are the 2 main reasons for which the bottom of a ship is Painted RED

However I must re-state, this paint does not prevent the Marine growth altogether Barnacles and Marine grass still grow, and hull cleaning may still be needed.

but all ports of the world don’t allow us to clean the hull in their water, This is actually not correct practice, Where will we clean the hull if not in ports.

Their environmentalist has a point that The ship carries barnacles that may have formed in some other part of the world releasing those barnacles in a new country can prove harmful to Marine life in that port or country.

If hostile, these barnacles and marine growth on a ship can completely alter the ecosystem of that port or country

Most of them ask us to clean the hull at the Open Sea.

Problem is, we can’t clean hull in the open Sea mostly, I don’t understand their reasoning at all. If the ports in the whole world don’t allow us to clean the hull then where should we?

Anyway, that’s the story for another day …

These are the two reasons why a Ship’s bottom is painted RED

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