TABLE OF CONTENTS When a vessel is completed, various trials take place in order to confirm that the ship's performance is as specified by the shipowner when the Memorandum of Agreement was signed. These trials are also known as Acceptance Trials.
Part of these trials are Speed Trials over the measured mile. This is one nautical mile of 1852m. This is undertaken to verify that the new vessel can attain a certain speed for a given shaft or brake power.
Due to the displacement being lower than the fully loaded displacement, the Trial speed is about 0.75 1.00 kt greater than the specified designed service speed. See later worked example to illustrate this.
In order to obtain reliable results during Ship Trials, the following precautions should be observed:
The vessel should be dry-docked immediately before the trials. The hull should be cleaned and painted. The number of days out of dry-dock prior to the trials should be noted.
Trials should be carried out in calm weather, with little or no wind. The presence of wind requires a correction factor that is difficult to estimate.
Trials should be carried out in water where the depth of water will not influence the ship's resistance. A ship is said to be in deep water when the depth of water is greater than the depth of influence (F D). Table 18.1 and Figure 18.4 in Chapter 18. show depths of influence (F D) for several types of Merchant ships.
Because the trial displacement is less...
