answersLogoWhite

0

It is not so much of a failure but an Heading offset caused by

"Speed Error"

The speed error is an error generated when a vessel/aircraft in which a gyrocompass is installed transits a course other than east or west. Its value is determined depending on the ship's speed, course, and latitude. (It is not related to the kind or type of gyrocompass.)

The north-seeking tendency of a gyrocompass is based on the earth's rotation. When a ship sails, the resultant motion of the ship's motion and the earth's rotation acts on the north-seeking tendency of the gyro. If the course of the ship deviates towards the north or south, the direction of the resultant motion deviates north or south and thus an error occurs because the north-seeking force of the gyro acts perpendicular to this resultant motion. That is, the speed error is the angle of the difference between this resultant motion and the east-west direction.

Determining Speed Error

ϕ: Latitude

K: Speed of the earth's rotation at the

equator (About 900 kt)

V: Vessel/Aircraft speed (kt)

θ: Gyrocompass course

δ: Speed error

In the figure above, AC = Vcos θ = Kcos ϕ • sin δ

Since δ is a small value,

sinδ = δ (radian) = 1/57.3 δ (unit: degree)

From these equations, δ = 57.3 Vcos θ/900 cos ϕ

If we assume, for example, that the ship is at the equator ( ϕ = 0), the gyrocompass course is N ( θ =

0), and the ship's speed is 30 kt, then

δ = 57.3 × 30/900 = 1.91 degrees = 1°54'

When the value of θ is between 270° to 90°, the compass indication increases. Therefore, the

ship's true course is as shown below.

0° − 1°54' = 358°6'

As seen above, if the compass course deviates towards the north, the true course can be obtained by subtracting the speed error from the compass course, and if the course deviates towards the south, the true course is obtained by adding the speed error to the compass course.

Most modern Gyros can automatically compensate for this error when interfaced to a GPS/SatNav/GLONASS (position/Speed) and w or w/o a Speed Log (speed). These values can also be entered in Manually to calculate speed error. See CMZ900 by Yokogawa and marketed by AGMarine. Just a little plug if that's alright?

In the same location when we compare 2 vessels have same heading; we can come to that conclusion from formula "57.3 Vcos θ", higher speed will cause bigger speed error.

User Avatar

Wiki User

13y ago

What else can I help you with?

Related Questions

What is one cause of heart failure?

Plants cause heart failure


Can steroids cause kidney failure in dogs?

i dont think they would cause kidney failure, but it would cause lots of other problems.


List the cause and effect connections between the Chinese invation of the Magnetic compass and Zheng He's voyage?

The cause is the Chinese invention of the magnetic compass. The effect is the voyage of Zheng He. The invention of the magnetic compass allowed Zheng He to make his voyage.


What is the Cause of magnetic compass failure in higher latitude?

The continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods such as the current epoch by relatively shallow seas (known as shelf seas) and gulfs. The continental rise is below the slope, but landward of the abyssal plains. Its gradient is intermediate between the slope and the shelf, on the order of 0.5-1°. Extending as far as 500 km from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. Sediment cascades down the slope and accumulates as a pile of sediment at the base of the slope, called the continental rise. Under the United Nations Convention on the Law of the Sea, the term continental shelf was given a legal definition as the stretch of the seabed adjacent to the shores of a particular country to which it belongs. See the Territorial waters page for more details.


Do renal angiomyolipomas cause kidney failure or mean that you are already in kidney failure?

It is a very unlikely cause of kidney failure(if it is large and bilateral or affect the only existing kidney) .


What is the cause of the mid-latitude westerlies?

The mid-latitude westerlies is caused by flow patterns. This pattern is known to be strong.


Which of the following is perhaps the most frequent cause of difficulty or failure when studying economics?

Failure to understand the basic definitions is perhaps the most frequent cause of difficulty or failure when studying economics.


Can pentasa cause kidney function failure?

The medication Pentasa can cause kidney function problems but not complete failure. It also can cause chest pain and trouble breathing.


Is weightlifting a cause of heart failure?

No not at all, if you take steroids they can lead to heart failure.


Can a powertain control module failure cause transmission problems?

yes a power train control module failure can cause transmission problems.


Can warm currents cause isotherms to be deflected towards the south pole?

Yes, warm currents can cause isotherms to be deflected towards the south pole by transferring heat energy from lower latitudes to higher latitudes. This can result in a warmer climate in regions that would otherwise be cooler due to their higher latitude.


What drugs cause heart failure?

cocaine