Seamanship: How To Get Ship’s Draft (example Problems And Solutions)

It is very important to know the current ship’s draft before navigation.

Here are the formulas for getting a ship’s draft:

Formula for getting Mean Draft:
MD = FD + AD / 2

Where:
MD for Mean Draft
FD for Fore Draft
AD for Aft Draft
/ 2 the result is to be divided by 2
x 2 to multiply by 2

Port meaning left ship’s side

Starboard meaning right ship’s side

Formula for getting Fore Draft:
FD = MD x 2 – AD

Formula for getting Aft Draft:
AD = MD x 2 – FD

Here is the Example Problem:
Fore Port = 12 feet
Fore Starboard = 14 feet
Aft Port = 16 feet
Aft Starboard = 18 feet

Find the ship’s Mean Draft, and here is the Solution:
Forward Port Draft 12’
+ Forward Starboard Draft 14’
is equals to 26’
/ 2 is equals to 13’

Aft Port Draft 16’
+ Aft Starboard Draft 18’
is equals to 34’
/ 2 is equals to 17’

MD = FD + AD / 2

MD = 13’ + 17’ / 2

MD = 30’ / 2

MD = 15’

Therefore, Mean Draft is equals to 15’


Another Example Problem:
Fore Port = 8.20 meters
Fore Starboard = 8.22 meters
Aft Port = 8.70 meters
Aft Starboard = 8.76 meters

Find the ship’s Mean Draft, and here is the Solution:
Fore Port Draft 8.20 meters
+ Fore Starboard Draft 8.22 meters
is equals to 16.42 meters
/ 2 is equals to 8.21 meters

Aft Port Draft 8.70 meters
+ Aft Starboard Draft 8.76 meters
is equals to 17.46 meters
/ 2 is equals to 8.73 meters

MD = FD + AD / 2

MD = 8.21 meters + 8.73 meters / 2

MD = 16.94 meters / 2

MD = 8.47 meters

Therefore, Mean Draft is equals to 8.47 meters


Another Example Problem regarding AD:
FD is 3.5 meters, and MD is 4.05 meters.
Find the AD

AD = MD x 2 – FD

AD = 4.05 meters x 2 – 3.5 meters

AD = 8.10 – 3.5 meters

AD = 4.60 meters

Therefore, Aft Draft is equals to 4.60 meters


Another Example Problem regarding FD:
AD is 24 feet, and MD is 22 feet.
Find the FD

FD = MD x 2 – AD

FD = 22 feet x 2 – 24 feet

FD = 44 feet – 24 feet

FD = 20 feet

Therefore, Fore Draft is equals to 20 feet.
 

.

Article Written by mantis36


Post Your Comment

Related Articles

  • Tae Kwon Do’s Best Kicks, But Can They Do It Not To Both Fall After Each Kicks?

    So far, those flashy flight kicks are good to see and feel power in every kicks but I seem notice that the kicker is the first to fall off the ground…

    And when their kicks are successfully landed hit their sparring opponent, but can still capable of a quick kick back response too, but if the kicker is the first to fall off the ground, I think he is in great danger.

  • Sacred Holy Water During First Rain On Month Of May Is Good For Exorcism

    My previous collection of Vendetta (Holy Water) is been egged by mosquitoes so I have to empty it and collect another new collection.

    I’ve been fun of waiting for that Month of May comes, until that I finally gather lots of pales of rains and store it, keep it safe until the exact time comes…

  • Seamanship: How To Find Ship Or Vessel Displacement In Sea Water And In Fresh Water

    Block Coefficient is the ratio of the actual volume of the underwater shape and a volume of a rectangular block, having the same extreme length, breath, and depth.

    The Coefficient is expressed as a decimal and varies from about .5 in the case of five lined yachts, gradually increasing through .6 to .75 in the case of fast passenger steamers and to .85 for slow, bluff, cargo type of vessels.

  • How Bathala (god) Named Kabunian Created Humans

    The Truth about Yesterdays….

    How Bathala (god) named Kabunian Created Humans

    Bathala Kabunian is the god of the Ifugao, and he’s very lonely because there is no existence of living creatures on this world, no such humans around.
    One day, Bathala Kabunian went to Pulog Mountain in order to create humans.

    Bathala Kabunian said: “I have to create humans, in order for them to guard and cultivate the beauty of the surroundings”

  • Ants, Fleas, Flies, Mosquitoes, Cockroaches, Anay, Rats, Mice: Kitchen Pests Exterminated

    Some of the common kitchen pests are ants, fleas, flies, mosquitoes, cockroaches, anay, rats, and mice. These pests endanger your health and destroy property. They live in dark, damp, and dirty places. Some live in pools of stagnant water, piles of garbage, decaying bodies of dead animals and empty cans. Cleanliness and sunshine will help keep them away.

  • Kyokushin Karate Versus Drunken Fist Kung Fu

    A very common sparring video clip between Karate’s Kyokushin against Drunkards Fist Kung Fu and I notify those basic errors committed by a Kung Fu black guy against his opponent Karateka.

    First of all, Karate is a Punching and kicking art, the first error movement of the Drunkard Fist is when he performs an attack, there is no such thing as follow-up movement, like a combo move.

  • Seamanship: Ship Or Vessel Displacement Problems And Solving Regarding Block Coefficient

    Find the Displacement of the ship whose
    length is 500 ft,
    breadth is 40 ft,
    mean draft is 20 ft,
    block coefficient is .7
    in sea water
    and in fresh water.

  • Is It 13 Fruits Or 12 Fruits On New Year’s Eve?

    It is already a well known to everyone that number 13 is a number of the Devil, and 13 is not applicable to any lucky fortune or any kind similar to it.

    Number 13 refers to the 13th floor to where a murder just happened there
    Number 13 refers to the 13th ghosts that according to legend, of all the ghosts, that 13th are the worst of them all
    Number 13 refers to the 13th creature and that is a Mantis, due to late, never enters heaven, a race on the 12 Animal Chinese Zodiac Signs
    Number 13 refers to the Omen Day and that is month of May Friday the 13th

  • Earning Traditional Passive Income: Trisikad (BMX Standard Bike With A Sidecar)

    A standard bike with a sidecar attached on bike’s right side.
    A side car attached to it can accommodate up to 2 regular body built passengers (sitting capacity) for public transportation fare fee of 5 Philippine pesos each, making it 10 pesos income on every round trip.

    No need to worry on gas, because it is driven through pedaling using driver’s feet (man power).

  • Highway 54 Before, Now EDSA, Tomorrow Corazon Aquino Avenue? (part 1)

    The present Avenue were once a wide, abundant long grasses on plain lands during those year 1940’s, and in 1945 after the known World War II, the avenue were named Highway 54, since most of the streets in the use were named in numbers, and 54 got its number because of the total length of the avenue is about 54 kilometers.