The tactical diameter of a ship is the distance: travelled on sea surface; during a turning circle test; with maximum rudder angle; by the center of gravity of a ship; taken perpendicular to the initial track followed at approach speed; when the heading has changed by 180° e) Quicker turn is possible at higher speeds time wise but diameter of turn will not vary in that proportion. Tactical Diameter. Transfer is the horizontal displacement of the ship during the same period of time.

The internal diameter of the turning circle where no allowance has been made for the decreasing curvature as experienced with the tactical diameter is the final diameter. Advance, transfer and tactical diameter. Advance and Transfer.

Transfer – 90° change of heading as additional measure of some interest.

b) Tactical diameter is less than & not equal to maximum transfer. When the vessel is trimmed by the stern, the tactical diameter of turn is increased Added: 2014-11-01 Last modified: 2014-11-01 Terms used when describing a ship's turning ability. Tactical diameter – 180° change of heading. This is the transfer for a turn of 180°, which is almost equal to the max transfer and about the maximum advance. Tactical diameter definition is - the perpendicular distance between a ship's course when the helm is put hard over and its course when she has turned through 180 degrees. The diameter will vary, based on the speed, the amount of rudder used and the trim.

Advance is the forward progress made between the time that the rudder is put over and the time the ship is steady on her new course. Diameters The greatest diameter scribed by the vessel from starting the turn to completing the turn (ship’s head through 180°) is the tactical diameter. Transfer The advance, the tactical diameter, and the transfer are given as multiplicity of ship’s length.

c) Advance is approximately equal to 3 to 4 ship lengths but may be 5 ship lengths for faster ships. IMO standards for Deep water: Tactical diameter must be less than 5L

Advance and Tactical Radius - posted in Surface Operations - Part 1: I have been talking with a friend in the Netherlands who works at a Naval Simulation facility, where they do work on modeling performance for Naval Architects, and the various EU Navies. Advance – distance until 90° change of heading. And we got around to talking about things like Advance and Tactical Turning Radii. d) Tactical diameter is approximately equal to 4-5 ship lengths.