Anatomy of a Sail Boat - Part IX : RADAR

The sea has no roads...

With only the Sun or the Moon above your head...and clear blue waters till as far as your eyes can see...how do you navigate your prized yacht?...without getting lost or getting into a ship as huge as the horizon at night?...unless you know how to use the stars to guide you back home...WHAT DO YOU DO?


Radio Detection and Ranging - commonly known as RADAR - is the way to take you there !

NAVIGATION

Navigation is the science of getting ships, aircraft, or spacecraft from place to place; especially : the method of determining position, course, and distance traveled. (Courtesy : www.m-w.com)

From olden days, where techniques Mariner's Compasses were used to chart courses by seeing the stars, to modern-day satellite-coordinated techniques - navigation has come a long way.

RADARs estimate the distance between the SOURCE of the RADAR and neighbouring BODIES within its range.

WHAT, WHEN, WHERE, HOW ?

WHAT? - Radar is a system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for Radio Detection and Ranging.

Radar was originally called RDF (Radio Direction Finder) in Britain.



WHEN? - First instances of the use of a RADAR are as old as 1904, but the main development of this technology happened in the beginning of World War II, where the need for such a system precipitated.

WHERE? - A lot of countries can claim their contribution in developing the RADAR, but the British were able to develop some of the finest systems in comparison to the US, France, German and Hungary.

HOW? - RADARs work on a very simple principle - they send off waves that bounce back and return once they hit an obstacle - sounds as simple as a tennis ball bouncing off the floor.

Technically, electromagnetic waves reflect from a solid object in air or a vacuum. This is particularly true for electrically conductive materials, such as metal and carbon fiber, making radar particularly well suited to the detection of aircraft and ships.

At times, radar-absorbing material, containing resistive and sometimes magnetic substances, is used on military vehicles to reduce radar reflection. This is the radio equivalent of painting something a dark color. Technology like this is used in the Stealth Bombers and Stealth Ships for warfare.

PARTS OF A RADAR

Though it may look simple from outside - something more on the lines of a overgrown capsule - RADARs are a tad more complex.


A radar has different components:-

1) A transmitter that generates the radio signals of different frequencies.

2) A waveguide that links the transmitter and the antenna.

3) A duplexer that serves as a switch between the antenna and the transmitter or the receiver for the signal when the antenna is used in both situations.

4) A receiver. Knowing the shape of the desired received signal (a pulse), an optimal receiver can be designed using a matched filter.

5) An electronic section that controls all those devices and the antenna to perform the radar scan ordered by a software.

6) A link to end users.

With the amount of traffic in the seas increasing, a RADAR is a must in order to keep casualities and incidences out of sight.
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Anatomy of a Sail Boat - Part VII : The Deck

ALL HANDS ON DECK !

We're certain that all of us have heard these lines many-a-times in classic movies or the recently animated ones like Sinbad and many more.

Often mistaken for some other part of a ship or boat, a Deck is simply a permanent covering over a compartment of a ship. In something as small as a sailboat, it is the cover of the hull, which for the ordinary man would be wrongly termed as the 'body' of the sailboat.



Decks are both a structural and a functional form. It is the 'roof' for the hull which strengthens it and at the same time serves as the primary working surface.

DIFFERENT DECKS

The gargantuan cruise liners nowadays are more like skyscrapers on the sea and decks are the floors. These decks at times provide a specialised purpose - accomodation, entertainment, look-out, swimming pool and recreation and many more.


Materials such as wood, metal as well as modern day lightweight fibreglass are used. Due to safer technologies and good construction techniques employed, there are decks under the water level on some of the modern boats.

There are different kinds of decks depending on their placement and purpose. Some of these are Berth, Boiler, Flush, Main, Side, Upper and Lower Decks. Some fishing trawlers have a fishing deck.

SCANTLINGS

An important concept that is essential in the design of decks is the scantling. The critical dimensions of any element of the ship; so for the skin and deck of the hull it would be the thickness (of the planks, fibreglass layup, hull plating, etc.)

The thickness of the decking affects how strong the hull is, and is directly related to how thick the skin of the hull itself is, which is of course related to how large the vessel is, the kind of work it is expected to do, and the kind of weather it may reasonably be expected to endure.

DECK PLAN

Customers always like to 'touch' and feel what they are going to be in-for before they go ahead with dishing out huge sums of money for their cruise, and Deck Plans are the best illustrative method of giving them an idea of what to expect.


Deck Plans along with images about the finesse of the interiors of cruise ships allow prospective cruise-ers to visualise a ship that they mite chose to be on. As shown below, Deck Plans have a detailed layout of all the various decks of a ship and are detailed in a proper manner.

Next time you are aboard a floating vessel, you will have a better idea what ALL HANDS ON DECK means... Read more...