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Friday, January 1, 2021

futuristic ship designs ... .. getting back to wood !!

Of the various effects of lockdown following Corona, is closure of Marina beach – that has denied watching the Bay of Bengal, its waves, the big majestic ships that sail on the sea. 

The first things that strikes the mind – is ‘ships float’ – boats also float .. but boats are made of wood.  We know that wood floats in water but when a steel rod is put on water, it just sinks in ! ..  for understanding this, one needs to know upward thrust, buoyancy and some Science as also the principle of density. Density describes how much something weighs relating to its size, or mass per unit volume. In technical terms, the density of a body is defined as the weight (mass) of the body in kilograms (kg) divided by its external volume in cubic metres (m3). The formula for density is:  density = weight/volume (kg/m3).

There are various types of ship – oil tankers, cargo ships, car carriers, container carriers and more .. .. .. a  cargo ship or freighter is a merchant ship that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year, handling the bulk of international trade. Cargo ships are usually specially designed for the task, often being equipped with cranes and other mechanisms to load and unload, and come in all sizes. They  are almost always built by welded steel, and with some exceptions generally have a life expectancy of 25 to 30 years before being scrapped.  The earlier cargo ships were purpose built to carry cargo in bulk.  Containerization changed the way goods are shipped and handled.

In understanding the anatomy of any ship – the  hull of a ship is the most notable structural entity of the ship. To define the hull, it can be said that it is the watertight enclosure of the ship, which protects the cargo, machinery, and accommodation spaces of the ship from the weather, flooding, and structural damage. But this alone does not suffice our requirements of understanding all the aspects of a ship’s hull. The hull is the most exposed part of a ship to the water. It’s generally waterproof in most cases and dictates the various components in ship’s motion.  Also, the hulls depending on whether they are single in number (monohulls) or more (multihulls) determine the turning area. 

For easy understanding – a Ship is a mega version of a mechanized boat – have seen lot of fishing boats in some ports and more specifically in Kakinada, East Godavari, Andhra Pradesh. Have heard from builders that they use ‘ayini’ or known as ‘anjili’ – wild jack - Artocarpus hirsutus logs for building the keel and the hull superstructure.  In the folklore of fishermen of coastal Andhra,  ‘Ranee of Hyderabad’ was a charmer.  I have heard the story of the  boat “Ranee of Hyderabad” pristine at its peak, built of teak and having copper hardwarde built somewhere in 1966  but continued its operation during 1990s also. Amidst the  ripe stories, was one of this boat getting carried away in stormy weather,  from Kakinada coast and found once in 24 paraganas and in Bangladesh (or was it Burma) but with all its crew safe and that some local astrologer finding out its whereabout in a betel leaf !! Strange are the ways at SEA.        

Now read this interesting article in BBC Future  on the construction of a small sized ship. The shipping industry's climate impact is large and growing, but a team in Costa Rica is making way for a clean shipping revolution with a cargo ship made of wood. In a small, rustic shipyard on the Pacific coast of Costa Rica, a small team is building what they say will be the world’s largest ocean-going clean cargo ship.

Ceiba is the first vessel built by Sailcargo, a company trying to prove that zero-carbon shipping is possible, and commercially viable. Made largely of timber, Ceiba combines both very old and very new technology: sailing masts stand alongside solar panels, a uniquely designed electric engine and batteries. Once on the water, she will be capable of crossing oceans entirely without the use of fossil fuels.  “The thing that sets Ceiba apart is the fact that she'll have one of the largest marine electric engines of her kind in the world,” Danielle Doggett, managing director and cofounder of Sailcargo, states. The system also has the means to capture energy from underwater propellers as well as solar power, so electricity will be available for the engine when needed. “Really, the only restrictions on how long she can stay at sea is water and food on board for the crew.”

Right now, Ceiba looks somewhat like the ribcage of a gigantic whale. When  it was visited in the shipyard in late October 2020,   construction has been going on for nearly two years. The team is installing Ceiba’s first stern half frame – a complicated manoeuvre to complete without the use of cranes or other equipment. Despite some hold-ups due to the global pandemic, the team hopes to get her on the water by the end of 2021 and operating by 2022, when she will begin transporting cargo between Costa Rica and Canada. With the hull and sail design based on a trading schooner built in the Åland Islands, Finland, in 1906, from the horizon Ceiba will have the appearance of a classic turn-of-the-century vessel, when the last commercial sail-powered ships were made. 

For her builders, one of the ship’s main attractions is to provide a much-needed burst of (clean) energy in an industry long dragging its heels on climate. The global shipping sector emitted just over a billion tonnes of greenhouse gases in 2018, equivalent to around 3% of global emissions – a level that exceeds the climate impact of Germany’s entire economy.

Ceiba is small for a cargo ship – tiny in fact. She will carry around nine standard shipping containers. The largest conventional container ships today carry more than 20,000 containers. She is also relatively slow. Large container ships typically travel at between 16 and 22 knots (18-25 mph/30-41 kph), according to Gilliam. Ceiba is expected to be able to reach 16 knots at her fastest, says Doggett, and easily attain 12 knots, although the team has conservatively estimated an average of 4 knots for trips until they can test her on the water.  And while Ceiba is small compared to most container ships, she is still around 10 times larger than the most established fossil-free sailing cargo vessel currently in service, the Tres Hombres. Sailcargo hopes this means she can help bridge the gap between these smaller ships and even larger emissions-free ships in the future. 

But, being a world-first, there are some aspects of Ceiba’s design that have yet to be proven at sea – including her specific combination of wind power and an electric engine. Ceiba has a regenerative engine: when she is travelling using her sails, her propellers can be used as underwater turbines to capture excess energy, similar to how regeneration mode in an electric car can capture excess kinetic energy when you brake. The electricity, along with that generated by the solar panels, can then be stored in the battery until it is needed to drive the ship. Importantly, and unlike many other ships that already use some kind of electrical engine, Ceiba’s engine is purely electric and does not have diesel as a back-up option. She is genuinely fossil free. 

Sailcargo has pledged that 10% of its profits will go to back to the planet, including donations to AstilleroVerde as well as other charities. In addition to this pledge, it aims to ensure Ceiba is “carbon negative” by planting 12,000 trees in Costa Rica before she is launched, giving each four years of care after planting. One in every 10 of those trees will be destined for building future ships, while the rest will overcompensate for the wood used to build Ceiba. Most of these trees are native species, which are slow to mature. It takes about 50 years to grow the trees from which Ceiba is built to maturity.  

Interesting ! 

With regards – S. Sampathkumar


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