In a technical sense, the turning circle of a ship is the locus traced by the vessels pivot point while applying a definite turning moment towards a particular side. Merchant ships usually turn in a circle having a diameter of about 3-4 times the length between perpendiculars (LBP). The circle is the path of the ship's pivot point as it executes a 360 turn. Calm weather conditions free from any disturbance and a normal sea state. Transmitting . %PDF-1.4 % 0000142428 00000 n angle made by the tangent to the curved path of any point with the fore-and-aft line is known as the drift angle at that point at any given instant. Turning Circles and Stopping Distances The advance of a ship for a given alteration, of course, is the distance that her compass platform moves in the direction of her original line of advance, measured from the point where the rudder is put over. Maintaining a desired course or trajectory. The culmination of all these factors leads to a greater increase in the force parameters and a greater degree of effort to turn the effort. Any ship must be able to turn or change its directional sense as and when required. Moreover, wave patterns are created at the fore and aft regions. Therefore, taking into consideration her ability to turn within a constrained space is something that should not be overlooked. Save my name, email, and website in this browser for the next time I comment. The Oxford English Dictionary describes turning circle as "the smallest circle within which a ship, motor vehicle, etc., can be turned round completely". Lastly, the turning circle or the turning tendency is also affected by external conditions, as expected. This turning moment, as we know, is caused by the application of a rudder force or any other turning mechanism it has. What is Port Disbursement Account (PDA) in Shipping? A vessel of fine form will take longer to stop as compared with a buff-formed vessel of similar draft length. The views constitute only the opinions and do not constitute any guidelines or recommendations on any course of action to be followed by the reader. The radius of this circle is the turning radius of the ship. How will this affect the anchor in . As a result, the wheel needs to be spun at a point before where the ship needs to turn. During an Inertia or simple stop manoeuvre carried out in open sea it may be necessary to take into account the currents, if any, as the current might continue to carry the ship. A large vessel is unable to turn around at a single point. Advance is measured from the point where the rudder is first put over. Sailing in meandering courses like rivers, channels, canals, etc. Aamira, (LNG Carrier, IMO 9443401) Ship Details, sea trials finalizing the shipbuilding process, Maximizing Your Shipping Efficiency with FCA Shipping Terms, Maximizing Equipment Performance: A Guide to Understanding Capacity Plates on Boats, The Best Maritime Colleges and Academies in the US, Magnetic Compass Maintenance And Safe Adjustment, Navigating the World of Ship Brokering: Comprehensive Guide, Understanding the Phenomenon of Hogging and Sagging in Ships. It is usually quoted for a 90 change of heading. It is essential for a vessel to determine her wheel-over position which is dependent on her turning radius before making a turn in order to avoid getting off her intended new track. Stopping the engines to allow the eddies to subside, and then starting again with reduced revolutions, is more likely to be successful. ]3}>)\ymiSx /l}?5Y}5|{9i/)c0\Pp&Zkmt%NYU"/K;_[cr.%-=XVffff7 xKi-o9P{#&W5z#g~x"cXA0V+t n2d:=D}Ga]u RbO A) gained at right angles to the original course B) gained in the direction of the original course C) moved sidewise from the original course when the rudder is first put over D) around the circumference of the turning circle. There appears to be no published information at all dealing with this, but the present analysis shows a significant effect to be present. without incurring significant time costs. 0000004898 00000 n After a steady approach at full test speed, the track reach and time to dead in water realized in a stop engine-full astern maneuver are measured. The effects are likely to be particularly pronounced in ships where the propeller slipstream does not play directly on to the rudder. Or even simpler, start running on a football field or an open ground. On a general cargo ship or tanker the difference between the turning qualities when lightly laden and when fully laden is very marked. Learn the difficult concepts of sailing described in a easy and story-telling way. Normal Turns If for example our ship of 67,000 t displacement enters and continues a turn at a constant rpm for slow ahead, both forces balance to give a turning circle as shown . We get commissions for purchases made through links on this website from Amazon and other third parties. 0000004222 00000 n 5. gYpV:+ 1. Similarly, the greater draft of a vessel also creates a greater turning circle. Size and motive power of the main machinery. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". You can find me on, Aamira, (LNG Carrier, IMO 9443401) Ship Details, Maximizing Your Shipping Efficiency with FCA Shipping Terms, Maximizing Equipment Performance: A Guide to Understanding Capacity Plates on Boats, The Best Maritime Colleges and Academies in the US, Magnetic Compass Maintenance And Safe Adjustment, Navigating the World of Ship Brokering: Comprehensive Guide, Understanding the Phenomenon of Hogging and Sagging in Ships. So, when a certain angle turns the rudder to a particular side, it exerts a moment that manifests itself in causing the vessel to turn in that same direction. One more interesting phenomenon that takes place in a turning circle is the effect of the centrifugal force that acts on the ship .The physics involved here is quite simple: any body undergoing a revolution has an additional centrifugal force that acts from the geometric centre of the circle it traces. Radius of curve keeps reducing & by the time ship's head is 90 degrees away from original, a steady radius of turn is reached. It is also generally acknowledged that maneuvering performance is affected by the shape of a ship's bow profile below water and by the presence or absence of a bulbous bow. The author and Marine Insight do not claim it to be accurate nor accept any responsibility for the same. 2. a) Ships head is inwards by an angle equal to drift angle. What does "Good Time" in Colreg Rule 8 "Action to Avoid Collision" paragraph c means? Conversely, a ship with a small turning radius will be more agile but may be less stable in rough seas. As the moment due to the rudder force turns the ship's head, the lateral force on the hull builds up and the ship begins to turn. TURNING CIRCLE :when a vessel is made to turn under a contionous helm through 360 deg it will follow a roughly circular track called turning circle, ADVANCE : It is the distance travelled by ship along original course line when she alter her course through 360 deg, TRANSFER : It is the distance travelled by the ship measued from original course line to the point when she alter her couse by90 deg, TACTICAL DIAMETER : It is the distance travelled by the ship measured from original course line to the point when she alter her course by 180 deg, DRIFT ANGLE : It is the angle between the ship fore and aft line and tangent drawn to the turning circle. This translates to a larger turning circle. 1 How do you calculate the turning circle of a ship? Visit our About Us page for our team and goals. The turning circle of a ship, or the diameter of the smallest circle it can make at full speed, is a key aspect of maritime navigation. In crash stop manoeuvre the ship is stopped by applying astern power. But opting out of some of these cookies may affect your browsing experience. This article will explain what the wheel over position is, how it is affected by the ships turning radius, and its impact on a ships maneuverability. hb``e``]Abl,;t``q`@)"C'N ; >^ j`iAS 1\XV0h1u24Lv: @&F \ Iu;+.0k'0^Qh !07 2mL@,v@Hs3wm[2hH2l0 N3 In rougher sea states and weather conditions, the effort required to turn the vessel increases manifold due to increased hydrodynamic and wind forces and pressures. 0000005646 00000 n Can we turn the ship by giving rudder movement while we are drifting ? 10 ECDIS questions SIRE inspectors ask and how to deal with it? The effect of the drag of the rudder and the sideways drift of the ship will result in a progressive loss of speed while turning, even though the engine revolutions are maintained at a constant figure. If youre unsure about what type of training will work best for you, just tell us a little more about your needs. endstream endobj 125 0 obj <>stream Turning Circles. PHASE 3: Data and charts, if used, in the article have been sourced from available information and have not been authenticated by any statutory authority. A B. @ ~ u-J<7"N. 69% Seafarers Suffering Extreme Financial Crisis, Says C L DUBEY EXERCISE 11 (Grain Stability), C L DUBEY EXERCISE 02 : Simpsons Rule. With a smaller rudder angle the ship will make larger turning circle and gain more speed. Our encyclopedia covers a great collection of study materials and detailed notes in subjects such as Navigation, Cargo work, Ship operation technology, Meteorology, ROR and Ship Stability etc. What is the effect of reduced under keel clearance to the size of turning circle of ship? R,rjed0(niT$RJN^("ukP!p+zZ:c0TA*US3jZ.3kPv) 1I:qA)ioTA}Baq(207u0:;3tUUQS?u:HN'fPEf~/`fjLqv7Nd(%d*"k*$:5R/!MMb"^ Ts|/x]vyWt9/G'L?y;\KO># mHsf26C8jo&,Lvh?` + By continuing to use the website we will assume you're happy to receive all cookies. Changing its course or heading from time to time. {jz`,b+Qu]6 Na"YJ~ml Q5Z- D7w?Dl! q `q Q1!x$@8IUn4G0=d9yb v`U}%o\yEcL4&c the locus traced by the vessels pivot point while applying a definite turning moment towards a particular side. 0000007326 00000 n startxref Turning radius = SOG/ROT , that is 1.0 NM. This is the distance the ship travelled in the direction of the original heading, measured from the point at the moment when helm was Fixed is not really correct, because it moves forward or aft as the vessel moves through the water as stated below: 1. Present in the Navigation bridge, it displays detailed information of manoeuvring characteristics of the ship including turning circle, stopping and manoeuvring characteristics of the vessel. Subhodeep is a Naval Architecture and Ocean Engineering graduate. Required fields are marked *. 0000066796 00000 n Steering Mariners 42.8K subscribers Join Subscribe 264 13K views 2 years ago Contents of this video will benefit. For alterations of course of up to 20 degrees the reduction of speed may not be very great, but for those between 20 degrees and 90 degrees the speed usually falls off rapidly. d) Tactical diameter is approximately equal to 4-5 ship lengths. Some common manoeuvring trials are turning circle, zig-zag, spiral, reverse-spiral and full astern stopping tests. A student must understand that there is no standard stopping distance, which is true for all ships.Following observations are important in relations to stopping distance. Maneuverability is described as a vessels ability to adjust its route or path. 7 Q The term "shift the rudder" means _____. What action must a navigating officer take when a NUC vessel is seen from stern making way through water? Because a ship must endure extended trips in a variety of weather situations, it is critical that its performance throughout the day-to-day aspects of its voyage is not jeopardized on: A navigators understanding of the turning circle is critical since these measurements indicate whether there is enough sea room for the ship to avoid the danger being encountered. HTK0Wv8/)@ZuOvUY`HZ 6+^)yl}R-j@tyMgKbfRr w9KA^M 3Jm)L+ c@e&x1h\infJye"76A"Yds2#Bk8t5icgq" 08K(l:KL Da3r&H 0000002205 00000 n Some Turning Basics Turning Circle - A ship's turning circle is the path followed by the ship's pivot point when making a 360 degree turn. The wheel-over position is therefore the location at which a ship needs to commence a turn in order to come on the desired new track safely. 0000234746 00000 n Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. Working of Hygrometer & Stevensons Screen. This is from simple Newtonian principles of inertia: the higher the motion and greater the mass. It has also been observed that when there is a trim by the stern, the diameter of the turning circle also increases considerably for the vessel. The circle is the path of the ships pivot point as it executes a 360 turn. 5 Q Interested in the intricacies of marine structures and goal-based design aspects, he is dedicated to sharing and propagation of common technical knowledge within this sector, which, at this very moment, requires a turnabout to flourish back to its old glory. When the vessel is trimmed by the head, the tactical diameter of turn is decreased. The main purpose of this paper is to analyse the influence of wind on ship manoeuvrability. Eddies may build up that counteract the propeller forces and the expected action of the rudder. North East Coast Inst of Engineers & Shipbuilders, The National Academies of Sciences, Engineering, and Medicine, Copyright 2023 National Academy of Sciences. But from the simpleton laws of nature again, the smallest circle traced by any object or body is directly related to the size of the body. H\0E|U"-e1Mf>F r"?V4H *N]?dqha2oc s 0000000016 00000 n This cookie is set by GDPR Cookie Consent plugin. Nowadays the precise course & speed over ground may be read directly on a GPS receiver. The cross-track distance should either be zero or kept to a minimum because there is less available sea room. Turning characteristics depend on the ship size. For a vessel, the turning circle measures its turning ability as the extent of the smallest circle made by applying a constant turning moment. Staying on a predetermined path/trajectory. The shape of the underwater part of the hull aft, particularly the cut-up area, as shown in Figure, has a most important effect on the size of the turning circle. "Advance. The information provided by turning circles and stopping distance (speed trials) is critical for those in charge of todays ships. Necessary cookies are absolutely essential for the website to function properly. Turning radius formula for ship - In this video, I explain the meaning of turning circle of a vessel Practical calculation of a ship's squat: . What changes were done couple of years back for FUJAIRAH anchorage approach? In shallow water, the rate of turn is likely to be decreased, so the vessel will have a larger turning circle. . It was named for John Williamson, USNR, who used it in 1943 to recover a man who had fallen overboard. 0000003296 00000 n In relation to the turning circle of a ship, which describes the term "kick"? Because of transverse thrust, right-handed propellers have a tighter turning circle when turning to port. The article or images cannot be reproduced, copied, shared, or used in any form without the permission of the author and Marine Insight. 0000006271 00000 n This turning moment, as we know, is caused by the application of a rudder force or any other turning mechanism it has. Determination of the wheel over position coupled with the use of the ships turning radius is a technique used as a means to ensure the ship stays on the desired track during and after the course alteration so as to minimize the cross-track distance and keep the vessel at a safe distance from prospective hazards. It is essential for a vessel to determine its wheel-over position before making a turn. And we already know that the turning circles for any vessel are directly proportional to the depth and draft. In shallow water, the rate of turn is likely to be decreased, so the vessel will have a larger turning circle. it must undergo full-scale trials after the ship is fully ready. The effect of speed on tactical diameter will vary from one type of ship to another. The effects of shallow water on steering in restricted waters such as canals or rivers are usually worse than in the open sea and are more likely to have dangerous results. Searchable index include more than 2000 nautical topics in expected MMD written and oral exams with pinpoint answer, making our site a good all around tool for MMD exams preparation. The larger the rudder, the smaller will be the Turning circle diameter (TCD). It is usually Tactical Diameter refers to the distance nearly equal to its paths geometric diameter. This turning moment, as we know, is caused by the application of a rudder force or any other turning mechanism it has. Manoeuvers required by IMO standards include turning circle, zig-zag and full astern stopping tests. 2. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); google_ad_client = "ca-pub-7136153532409610"; 0000002603 00000 n (A) The lateral slide away from the direction of turn upon putting the helm hard over o (B) The distance gained in the direction of the original course when the helm is hard over o (C) The distance around the circumference of the turning circle The effect of a list is to hinder a turn in the direction of the list and assist a turn away from it. What was the turning circle of the Titanic? Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. 0000009657 00000 n Drift Angle is the angle between ships fore and aft line & the tangent to turning circle at any given moment. The advance, the tactical diameter, and the transfer are given as multiplicity of ships length. Start turning towards a side. Shipping Container Dimensions: 20ft vs 40ft Size Comparison, What is Length Between Perpendiculars: Understanding the Importance in Shipbuilding. The collaborative and constantly updated encyclopedia is free for everyone to use and perfect for candidate who are preparing for MMD written or oral exams such as Second mate, Chief mate or Masters. 7 How does cargo distribution affect the turning circle? Currently employed as Marine Surveyor carrying cargo, draft, bunker, and warranty survey. The diameter will vary, based on the speed, the amount of rudder used and the trim. How does cargo distribution affect the turning circle? Stopping distance is the distance, which, a ship will continue to move after action is taken to stop engines and till the ship comes to rest. Top 10 Largest Dry Bulk Carrier Operators. gYpV:+ All Rights Reserved. This essential tool assists a coxswain in steering a course safely. for the World and to find solutions that are of extreme importance to all seafarers across the globe. This cookie is set by GDPR Cookie Consent plugin. Your email address will not be published. You ship has a right handed propeller and you can turn either way. Turning Circles The circle is the path of the ship's pivot point as it executes a 360 turn. Lets say your ship is doing 14 knots and your R.O.T is also 14 deg/min. This cookie is set by GDPR Cookie Consent plugin. It is a metric for determining how maneuverable a vessel is. ship is considered stopped when she is stopped w.r.t water in which she is floating. Required fields are marked *. The ability of a ship to turn tightly and come exactly on the new intended track after altering course is an important issue in passage planning because of safety considerations. The transfer of a ship for a given alteration, of course, is the distance that her compass platform moves at right-angles to her original line of advance, measured from the point where the rudder is put over. This podcast on the maritime matters will provide value to the listeners. 0000006728 00000 n This space is larger than the turning circle, because at each point of the turning circle the ship is positioned at certain angle (drift angle) to the tangent to the path of the centre of gravity (CG). What is turning circle of ship? What is meaning of Interaction between two ships ? Chapter 12: Rising & Setting Of Celestial Bodies, EXERCISE 29 RISING/SETTING AZIMUTH -SUN, EXERCISE 30 LATITUDE BY MERIDIAN ALTITUDE SUN, EXERCISE 35 LATITUDE BY MERIDIAN ALTITUDE STAR, EXERCISE 37- LONGITUDE BY CHRONOMETER STAR, Previous Years MMD Function wise Questions, Naval Architecture MEO CLASS 4 WRITTEN PAPER, GENERAL ENGINEERING KNOWLEDGE MEO CLASS 4 MMD PAPER, Motor Engineering MEO CLASS 4 MMD PAPER. Transfer: This is the distance travelled by the ship's centre of gravity in a direction perpendicular to the ship's initial course. It may be provided for loaded & light conditions. google_ad_slot = "8641225286"; Due to the lesser clearance between the bottom of the vessel and the river or seabed for shallow waters, the flow patterns and the entire hydrodynamics is affected. Consider the paths described by various parts of a ship turning under rudder when steaming ahead, see figure above. ship, freight transport, sailor | 22K views, 417 likes, 29 loves, 5 comments, 132 shares, Facebook Watch Videos from Marine Insight: |EP-10: Turning Circle of a Ship| Maritime Shorts- Knowledge in a. It should be mentioned that the International Maritime Organization (IMO) has its own yardsticks, (IMO resolution MSC.137(76) Standards for Ship Manoeuvrability), for determining the maximum permitted limits of turning ability for a ship, failing which the entire design is scrapped and subjected to review. Marine Gyaan Encyclopedia is a free online resource aims to document all maritime subjects and queries to replace bulky reference books. Theangle made by the tangent to the curved path of any point with the fore-and-aft line is known as the drift angle at that point at any given instant. Moreover, the results from the model and full-scale trials should be congruent with some minor differences within acceptable limits. The altered pressure patterns on the hull cause angular acceleration for turning. We will get back to you as soon as possible with the answers you need! It is a benevolent reference work for Maritime community in an exhaustive manner. Also known as the execution point wherein the ship starts to turn. The information provided by turning circles and stopping distance (speed trials) is critical for those in charge of todays ships. In restricted visibility, are we expected to see lights. Knowledge of the rate at which a ship gains or loses speed in different circumstances is invaluable when maneuvering in congested waters. Furthermore, there is a dramatic reduction in speed. A balance of all forces, moments and pressures leading to all unbalanced accelerations becoming zero and the turning attaining a. . It is a metric for determining how maneuverable a vessel is. Conversely, the turning circle diameter decreases when there is a trim by bow. Does Annabeth have blonde hair in the books? Shiphandling: Terms Turning Circle Kick Final Diameter Tactical Diameter 30. In addition to our massive store of reference material for fellow mariners, we are providing online bookings for various Maritime courses in maritime institutes across India. First, it is ensured that the vessel is heading forwards in a straight line with a steady approach speed. We also use third-party cookies that help us analyze and understand how you use this website. The diameter will vary, based on the speed, the amount of rudder used and the trim. As obvious, a small boat encountering an obstruction shall be able to evade the same much more quickly than a bulk carrier. When trials are conducted in condition other than full load, manoeuvring . However, you may visit "Cookie Settings" to provide a controlled consent. Turning trajectory Effect of Ship's Parameters on Turning and Course Keeping Normally in calm water a fully loaded ship at speed about 5 knots with a rudder hard over (35 deg) will turn round 180 degrees in less than 4 ship's lengths. For starting up also after the first movement is given a loaded tanker will come to the designed speed slower than the same tanker when it ballasts. 0000190589 00000 n Turning Circle. The drift angle increases: with increase in speed when the helm angle and rudder area are constant; Watchkeeping officers should be fully aware of the effect of speed on the turning qualities of their ship. Stopping the engines to allow the eddies to subside, and then starting again with reduced revolutions, is more likely to be successful. <<94F6F8DBAE06B942A288670076816AEB>]/Prev 273039/XRefStm 1436>> The parameters at any instant of the turn are defined as: Figure 8.5. The path described by the ships pivot point as it moves through a full 360 degrees under full helm is known as the turning circle of a ship. Circling some point like a port or terminal or an island due to unavailability of berths, tidal conditions, rough sea or weather conditions, or marine traffic. Some refer to it as the path traced out by the centre of gravity. Ship manoeuvring performance is very important in navigation safety, especially when ships operate in shallow water. Transferis the lateral distance of the centre of gravity from original course line or it is the effective distance travelled by centre of gravity of the ship, in a direction 90 from original direction measured when the ships head is 90 from original heading. The terms used and the geometry of the circles are defined. How Does A Rudder Help In Turning A Ship. Helm Angle. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. The turning circle trial is conducted with the ship at full speed and the rudder helm set at 35. In shallow water, the rate of turn is likely to be decreased, so the vessel will have a larger turning circle. For example. endstream endobj 124 0 obj <>stream You are going to leave a crowded anchorage by making a 180 degrees turn. Track Reach: Is the total distance travelled along the actual path followed by the ship. Often higher speed may lead to a greater tactical diameter because the rudder may stall. The ship may start to vibrate. 4. Shiphandling: Terms Turning Circle: The path described by a ship's pivot point as it executes a 360 turn. A change from right (left) to left (right) rudder an equal amount. Once trials of a new ship are complete, operators will need to know how the vessel can expect to perform in a variety of sea conditions. Length of ship from bridge to hawse pipe = 122 m. Length of cable = 6 shackles (6 x 27.5) = 165 m (+) Depth of water = 12 m (-) Swing circle radius of the vessel = 275 m. The main engines should be kept in a state of readiness at all times . Turning radius formula for ship - Turning radius formula for ship can help students to understand the material and improve their grades. The corresponding rates for one ship will differ largely from those of another, and the rates for a particular ship may change considerably with her condition of loading. Though, the ships speed with which a turning circle is made, does not have much effect on the diameter of the turning circle. 0000234488 00000 n Your email address will not be published. Merchant ships usually turn in a circle having a diameter of about 3-4 times the length between perpendiculars (LBP). 151 0 obj <>stream the turning circle of a vessel making turn of over 360 degrees is the path followed by the center of gravity The distance a vessel moves parallel to the original course from the point where the rudder is put over to any point on the turning circle is called the advance Details of a Turning Circle with Advance, Transfer, Tactical Dia, Final Dia, Drift & Pivot Point. When maneuvering at slow speed or turning at rest in a confined space in shallow water, the expected effects from the rudder and the propellers may notappear. The balance between the rudder force and the lateral resistance plays a crucial part in shaping all turning circles. Slowly start turning the steering wheel and keep it fixated at a certain position. In shallow water, the rate of turn is likely to be decreased, so the vessel will have a larger turning circle. We get commissions for purchases made through links on this website from Amazon and other third parties. 0000190690 00000 n This website uses cookies to improve your experience while you navigate through the website. The reverse will happen when the tanker is on ballast that is it will travel a lesser distance. google_ad_width = 336; Manoeuvring tests. Turn Circle: When a vessel alters her course under helm through 360 degrees, she moves on a roughly circular path called a turning circle. Turning around an obstacle such as a landmass or any other type of maritime vehicle. (TR = SOG/ROT) = 1.0 nm). The only way to regain control is to reduce speed drastically at once. Each point in the ship must follow a path approximately concentric with that described by the center of gravity. This cookie is set by GDPR Cookie Consent plugin. The shape of the underwater part of the hull also plays an important part. Now, lay two lines parallel to both the initial course and final course with a distance of Turning Radius i.e 1NM between them. A light draft vessel, with lot of windage area is influenced a lot by prevailing wind conditions. Structural design and length of the ship. the ship has changed its heading by 180 degrees. Though there are no hard and fast standards, minimum advance criteria are always sought for a given ship type and speed. The ship will undergo transfer, advance, drift angles, and angle of the heel during the TCD maneuver (see Figure). It does not store any personal data. F,|fwMQ\ZVt"cm erkVu7-^ 1`[ !}`3{Eiu{uU}&]n!qSFA8s[u pRr[.*u 3Yrn } bXw>vT4aL ). A list to port decreases the tactical diameter of a ship turning to starboard and vice versa. 0000214390 00000 n h) In the next quarter, there is further loss of speed, reaching 55% to 65% of original speed. 0000046081 00000 n