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Final report for bluefin...

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Assignment 2: Zig-Zag Manoeuvre

Subject: JEE358 Bluefin: Maritime Engineering Lecturer: Dr Tom Mitchell Ferguson

Team Members: Harrison Whalley 423283 Blake Johnston 480367 Nicholas Toh 401887 Adrian Giudice 402323

Due Date: 05/10/18

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Abstract The manoeuvrability of a vessel is a vital factor for efficient and safe operation in a range of sea conditions that will be experienced through the life of the vessel. A range of manoeuvring trials must be completed by a vessel to comply with International Towing Tank Conference (ITTC) full scale manoeuvring trial standards and relevant maritime safety standards criteria. One manoeuvring trial which can be investigated is the zig-zag manoeuvre. On September 13, a 10/10 zig-zag manoeuvring trial was completed off Eddystone Point on the North East coast of Tasmania by AMC’s FTV Bluefin. This trial was completed by naval architecture students in co-ordination with the crew of Bluefin. The aim of this trial was to record a range of factors that effected the trial, as well as the response of the vessel throughout the trial. The recorded data was then successfully analysed for a detailed review of the vessel's performance under this specific trial. Calculations were completed which indicated whether the vessel passed the required International Maritime Organisation (IMO) Standards 2002a. Due to unfavourable environmental conditions encountered during the trial, the vessel does not comply with the required standards. This is considered an inaccurate representation of the vessel’s manoeuvrability aptitude and the data acquired from the trial provides insufficient conclusions to be made. Recommendations regarding the testing conditions are provided to improve the accuracy of the results obtained. It is also recommended that the trial is completed for five cycles as compared to the 1.5 cycles which were conducted during this trial. A reflective summary by all team members was made, outlining all achievements experienced throughout the voyage.

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Table of Contents Abstract......................................................................................................................................2 Table of Contents.......................................................................................................................3 List of Figures............................................................................................................................3 List of Tables..............................................................................................................................4 1 Introduction - Harrison.......................................................................................................5 2 Data collection methods – Nicholas...................................................................................7 2.1 Data collection and task allocation..............................................................................7 2.2 3 4

Procedure – Adrian...........................................................................................................14 Weather Conditions – Nicholas........................................................................................16 4.1 Testing conditions......................................................................................................16 4.2

5 6 7 8 9

Equipment used...........................................................................................................8

Limitations.................................................................................................................16

Results and Discussion – Harrison...................................................................................18 Recommendations – Blake and Harrison..........................................................................23 Conclusions – Blake.........................................................................................................24 References.........................................................................................................................24 Appendices........................................................................................................................25 9.1 Appendix A: Reflective Summary - Blake................................................................25 9.2

Appendix B: Reflective Summary – Harrison Whalley............................................26

9.3

Appendix C: Reflective Summary – Nicholas Toh...................................................28

9.4

Appendix D: Reflective Summary – Adrian.............................................................30

List of Figures Figure 1: Elements of a zig-zag manoeuvre...............................................................................5 Figure 2: Marine wind tracker....................................................................................................8 Figure 3: Marine GPS Navigator...............................................................................................9 Figure 4: JLN-203 Doppler Log................................................................................................9 Figure 5: Simrad S2016 Fish Finder..........................................................................................9 Figure 6: C Plot........................................................................................................................10 Figure 7: C Plot with Zig-Zag Manoeuvre track......................................................................10 Figure 8: Gyroscope and radar.................................................................................................11 Figure 9: Simrad AP70 Autopilot.............................................................................................11 Figure 10: Marine autopilot steering stand with gyro compass...............................................12 Figure 11: Caterpillar engine monitoring system.....................................................................12 Figure 12: Propeller pitch indicator.....................................................................................13 Figure 14: Beaufort wind scale................................................................................................16 Figure 15: Plot of heading and rudder angle compared to time for zig-zag manoeuvre..........19 Figure 16: Plot of speed over ground and speed through water compared to time for zig-zag manoeuvre................................................................................................................................20 3

List of Tables Table 1: Data collection method for Zig-Zag manoeuvring trial...............................................7 Table 2: Task allocation..............................................................................................................8 Table 4: Operation data during trial.........................................................................................18 Table 5: Vessel heading angle and rudder angle throughout the duration of the trial..............18 Table 6: Speed over ground and speed through water throughout the duration of the trial.....19 Table 7: IMO course-keeping ability criteria comparison.......................................................22

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1 Introduction - Harrison During the Bluefin voyage, the team was required to complete a zig-zag manoeuvre on FTV Bluefin. This manoeuvring trial was completed on September 13, 2018 at 2:20 pm off the North East coast of Tasmania around Eddystone Point. The trial was conducted under the control of the group with assistance provided by crew and peers. A 10/10 zig-zag manoeuvre was conducted whereby the rudder angle was adjusted by 10 degrees to investigate the heading deviation of 10 degrees from the original heading. A similar zig-zag manoeuvre which can be conducted is a 20/20 manoeuvre, also outlined in the ITTC and assessed against IMO Standards 2002a. The zig-zag manoeuvre investigates the course-keeping ability and yaw-checking ability of a vessel by measuring the response to counter-rudder applied in a certain state of turning, such as heading overshoot angle reached before the yawing tendency has been cancelled by the counter-rudder[CITATION PFu18 \l 3081 ]. An understanding of the information which can be derived from the test is required to appreciate its significance for vessel stability.

Figure 1: Elements of a zig-zag manoeuvre

With respect to Figure 1, the initial turning time measurement is the time between the first execution until the vessel reaches the specified 10 degree heading deviation angle and the reverse rudder heading angle is the heading angle at which the rudder angle has been reversed [CITATION PFu18 \l 3081 ]. As viewed in Figure 1, the overshoot angle was calculated as the difference between the specified 10 degree heading deviation angle and the maximum angle reached before the course is reversed [CITATION PFu18 \l 3081 ]. This data is required to be analysed for both the first and second overshoot angle. Furthermore, the time to check yaw is the time elapsed from the moment of the first or second execution to when the maximum change of heading is reached. The reach can be determined as the time between the first execute and the time when the vessel heading returns to the initial heading, and lastly, the time for a complete cycle is the time between the first execute and the instant when the 5

heading angle is equal to the initial heading after the third execute (see Figure 1) [CITATION PFu18 \l 3081 ]. The equipment used to complete the manoeuvre is outlined along with the procedure adopted to perform the trial which complies with ITTC trial standards. The report documents the weather conditions which were experienced during the trial and an analysis and discussion of the results obtained. Conclusions will be drawn from the manoeuvring trial to validate the course-keeping abilities of the vessel and finally, a reflective summary presenting the achievements made on board will be provided.

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2 Data collection methods – Nicholas 2.1 Data collection and task allocation The various components as listed in Table 1 were obtained from the zig-zag manoeuvring trial. These components required various collection methods which involved the utilisation of different tools which will be discussed in the ‘Equipment used’ section, and visual observation of the crew and students. It should be noted that the initial data which includes the true wind speed and direction, water depth, sea state and wave direction and water temperature are required to be obtained prior to the trial whereas the remaining data are obtained and calculated throughout the trial. Furthermore, the tasks were split amongst 8 people as listed in Error: Reference source not found. It can be seen that two people were tasked for the time recording. A mean time was obtained for each trial component to provide a more accurate time reading. Lastly, video recording of the trial was performed to obtain the various data sets required for the results.

Table 1: Data collection method for Zig-Zag manoeuvring trial Type of data

Collection Method

Data obtained

Units

True wind speed and direction

MR PB 200

True wind speed

knots

Radar

Display of wind speed and direction Total water depth

Sea State and wave direction

Visual observation

Sea state

Weather reports

Weather condition

Crew's observation

Sea state and weather condition

Water Temperature

C Plot

Water temperature

Vessel Speed

C Plot

True vessel speed

JLN-203 Doppler log

Apparent vessel speed

Stopwatch

Initial turning time

Time Lapse

Time to check yaw Time for reach Time for complete cycle

metres

℃ knots

second s second s second s second s

Radar

Panel display

Rudder angle

Rudder angle indicator receiver

Rudder angle

°

Heading Angle

Gyroscope/GPS

Heading angle

°

Radar

Panel display

Distance

C Plot

Distance

nm

Engine Revolutions

Caterpillar engine monitoring system

Engine revolutions

RPM

Yaw rate

Calculate from headings

Yaw

°/s

Propeller pitch

Obtained from crew

Propeller pitch

°

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Table 2: Task allocation Member Crew Adrian Harrison Blake Dane Harrison and Dylan Nicholas

Roles Operating vessel Video recording Record Speed (over ground and through water) Instructions for Crew Compass reading Time recording

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2.2 Equipment used The pictures below depict the aforementioned apparatus utilised throughout the zig-zag manoeuvre. Figure 2 displays the wind tracker which was used to observe the wind speed and direction and determine an associated Beaufort number. The apparent speed of the vessel was derived from the Doppler log shown in Figure 4 which presented the speed through water of the vessel. Figure 3 displays the marine global positioning system (GPS) navigator. The Simrad fish finder shown in Figure 5 was used to record the speed over ground (SOG). The C Plot in Figure 6 was used to record the water temperature during the trial in addition to tracking the vessel’s position and heading throughout the duration of the trial which is shown in Figure 7. The display panel which was recorded during the trial relayed the information from the radar and gyroscope (see Figure 8). The autopilot display and station where the rudder angle was altered can be seen in Figure 9 and Figure 10 respectively. The engine’s RPM was recorded using the monitor displayed in Figure 11. This was also used to observe the engine’s load, temperature and pressure throughout the duration of the trial to view if there was any mechanical issues present. Lastly, the propeller pitch was set and monitored using the control shown in Figure 12.

Figure 2: Marine wind tracker

8

Figure 3: Marine GPS Navigator

Figure 4: JLN-203 Doppler Log

Figure 5: Simrad S2016 Fish Finder

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Figure 6: C Plot

Figure 7: C Plot with Zig-Zag Manoeuvre track

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Figure 8: Gyroscope and radar

Figure 9: Simrad AP70 Autopilot

11

Figure 10: Marine autopilot steering stand with gyro compass

Figure 11: Caterpillar engine monitoring system

12

Figure 12: Propeller pitch indicator

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3 Procedure – Adrian A Naval architect conducts a zig-zag manoeuvring trial on a vessel to assess the handling characteristics and determine its safe operation in accordance to IMO Standards 2002a. The trial assesses the data of initial turning time, overshoot angle, time to check yaw, reach, time to complete one cycle, execute heading angle and reverse rudder heading angle. Before conducting the zig-zag trial the vessel and personnel's safety were taken into consideration. Due to the nature of the trial it was expected that the vessel would experience a change from normal operating behaviour to trial conditions that included sharp turning motions. Before the trial began, a verbal warning was given over the vessel’s public address (PA) system to ready the personnel on board for the upcoming trial, as well as previous warnings that were given 2 hours in advanced. The vessels safety was ruled to be approved by the vessels operating crew members. The following steps were taken to perform the zig-zag manoeuvring trial. Step 1. A one-minute warning announcement was given to all personnel on board over the vessels PA before the trial was undertaken. The following initial data was recorded a. True Wind Speed and Direction b. Weather reports (sea state) c. Water temperature Step 2. The vessel’s steady speed on ground (SOG) was set to 6 knots by crew, no further adjustment to the engine’ revolutions per minute (RPM) and propeller pitch was made until the conclusion of the trial. At the time the trial commenced, the following data was logged, and recording began. The data recorded consisted of: a. b. c. d.

Video of C Plot Initial headings Vessel speed for both through water and over ground Engine RPM and propeller pitch

Step 3. The rudder angle was then announced to be applied to an “angle of 10 degrees to port”. The announcement of “start time” was made to indicate to timers to start recording. The time taken for the vessel to reach this rudder angle was recorded. The vessel changed its yawing motion which results in the heading change. The following data was then recorded. a. b. c. d.

Started timing Time for the vessel to turn 10 degrees as indicated by compass. Yaw rate (Calculated after the trial) Vessel speed for both through water and over ground

Step 4. Once the heading angle of vessel was reached the rudder was reversed to the opposite side of “starboard 10 degrees”. This changed the vessel’s yawing along with heading. The following data was then recorded. 14

a. Verbally announced “lap and 10 degrees starboard rudder.” b. Time recorded c. Vessel speed for both through water and over ground Step 5. As the vessel continued to turn port, the overshoot angle was recorded (first overshoot). This was achieved by monitoring the heading angle. The following data was then recorded. a. Maximum overshoot angle and announced “lap” b. Time recorded c. Vessel speed for both water and ground Step 6. Once the heading turned 10 degrees to Starboard, the announcement of “lap” and “change the rudder heading to 10 degrees port” were made, this indicated to the crew to change the heading as well as the timers to record the time difference between headings. The overshoot angle was recorded (second overshoot), this was achieved by monitoring the heading angle. The following data was then recorded. a. Maximum overshoot angle b. Vessel speed for both through water and over ground Step 7. Once the rudder achieved ten degrees port, the announcements “lap” and “change the rudder heading to 10 degrees starboard” were made, this indicated to the crew to change the heading as well as the timers to record the time difference between headings. The overshoot angle was recorded (third overshoot), this was achieved by monitoring the heading angle. The following data was then recorded a. Maximum overshoot angle b. Vessel speed for both water and ground Step 8. To conclude the manoeuvring trial, when the vessel’s original heading was achieved, the announcement to the crew was “return the vessel to its original heading and speed” and “stop recording” to indicate to the crew and timers that the trial had concluded. The following was then completed. a. Stop video recording b. Announced trial completion c. Take photo of phone stopwatch to log data in visual format

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4 Weather Conditions – Nicholas 4.1 Testing conditions The weather conditions were recorded before the trial commenced through several methods. Firstly, the weather reports were printed prior to the trial, and the daily weather forecasts and warnings were obtained from the announcements on the radio on the morning of the trial. During the trial, visual observations were conducted to match the obtained wind speed with the sea state chart as listed below in Figure 13. In addition, observations from the crew on the state of the weather conditions were obtain...