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
23.11.2020.
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