Performance and survivability of totally enclosed motor propelled survival craft (TEMPSE) in ice and open water conditions

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(1)NRC Publications Archive Archives des publications du CNRC. Performance and survivability of totally enclosed motor propelled survival craft (TEMPSE) in ice and open water conditions Simões Ré, A.; Veitch, B.; Gifford, P.; Kennedy, E.; Kirby, C.; Kuczora, A.; Sudom, D.. For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.. Publisher’s version / Version de l'éditeur: https://doi.org/10.4224/21262965. Technical Report, 2012-05-01. NRC Publications Record / Notice d'Archives des publications de CNRC:. https://nrc-publications.canada.ca/eng/view/object/?id=e1396097-84b5-4981-a127-b1707733f262 https://publications-cnrc.canada.ca/fra/voir/objet/?id=e1396097-84b5-4981-a127-b1707733f262 Access and use of this website and the material on it are subject to the Terms and Conditions set forth at https://nrc-publications.canada.ca/eng/copyright READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site https://publications-cnrc.canada.ca/fra/droits LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. Questions? Contact the NRC Publications Archive team at PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca..

(2) OCRE-TR-2012-07. NATIONAL RESEARCH COUNCIL CANADA OCEAN, COASTAL AND RIVER ENGINEERING. Performance and Survivability of Totally Enclosed Motor Propelled Survival Craft (TEMPSC) in Ice and Open Water Conditions Technical Report António J. Simões Ré Brian Veitch Peter Gifford Edward Kennedy Craig Kirby Andrew Kuczora Denise Sudom May 2012.

(3) Report Documentation Page REPORT NUMBER. PROJECT NUMBER. DATE. OCRE-TR-2012-07. PJ2380. May 2012. REPORT SECURITY CLASSIFICATION. DISTRIBUTION. Unclassified. Unlimited. TITLE. PERFORMANCE AND SURVIVABILITY OF TOTALLY ENCLOSED MOTOR PROPELLED SURVIVAL CRAFT (TEMPSC) IN ICE AND OPEN WATER CONDITIONS AUTHOR(S). António J. Simões Ré1, Brian Veitch2, Peter Gifford3, Edward Kennedy1, Craig Kirby1, Andrew Kuczora1, Denise Sudom1 CORPORATE AUTHOR(S)/PERFORMING AGENCY(S) 1. NRC - Ocean, Coastal and River Engineering, 2Memorial University, 3Extreme Ocean Innovation. PUBLICATION SPONSORING AGENCY(S). Natural Resources Canada’s Program of Energy Research and Development (PERD) RAW DATA STORAGE LOCATION(S). PEER REVIEWED. Yes MODEL #. PROP #. EMBARGO PERIOD. N/A. N/A. 0 Months. PROJECT. GROUP. PROGRAM. PJ2380. Research. Marine Safety. FACILITY. N/A KEY WORDS. PAGES. FIGS.. TABLES. TEMPSC, ice, open water, performance, survivability, cold temperatures, wind, waves, fiberglass, propeller, nozzle, manoeuvrability, visibility, powering.. x, 47, App. A-E. 61. 6. SUMMARY. Lifeboats are a necessary fixture on all commercial vessels and fixed and floating offshore installations. They are the crew’s last line of defense in the event of an emergency. These craft are depended upon if vessel/installation abandonment is required. Despite this reality, there are no special design regulations if the intended area of operation of the craft experiences some level of ice coverage. This poses navigational and structural challenges since lifeboats operating in ice are exposed to higher loading then ones operating in open water. The majority of lifeboats built today are typically built from a combination of chopped strand mat and heavy woven roving. This results in a structure that is easy and economical to build but may not have sufficient mechanical strength to provide a safe haven during emergency evacuations in ice covered water. The ice trials showed that the conventional lifeboat tested is capable of operating in ice concentrations to a limit of between about 6 and 7 tenths concentration. Either way, the utility of the lifeboat was severely restricted by ice cover. The basic performance limits of this type of evacuation craft show the basic design requirements for any craft that is meant to complement or replace a conventional boat system. A simple impact model relating impact energy to the lifeboat hull material and temperature indicated a safe operating speed for the lifeboat at 2.0 knots. During the ice trials 2007, 2009 and 2010, this safe operating speed was exceed regularly without damage to the hull. This can be attributed to the conservative nature of the model plus a couple of other factors, namely ice strength and lifeboat bow area reinforcement. In the 2007 and 2009 the ice was relatively weak and in 2010 the lifeboat entire bow area was reinforced during the impact panel dynamometer and sea-chests installation. ADDRESS NRC - Ocean, Coastal and River Engineering - St. John's, Arctic Avenue, P. O. Box 12093, St. John's, NL A1B 3T5 Tel.: (709) 772-5185, Fax: (709) 772-2462.

(4) National Research Council Canada. Conseil national de recherches Canada. Ocean, Coastal and River Engineering. Génie océanique, côtier et fluvial. PERFORMANCE AND SURVIVABILITY OF TOTALLY ENCLOSED MOTOR PROPELLED SURVIVAL CRAFT (TEMPSC) IN ICE AND OPEN WATER CONDITIONS. OCRE-TR-2012-07. António J. Simões Ré Brian Veitch Peter Gifford Edward Kennedy Craig Kirby Andrew Kuczora Denise Sudom May 2012.

(5) ABSTRACT Evacuation from offshore petroleum installations and marine vessels in Arctic and sub-Arctic regions must operate in environmental conditions that include cold temperatures, remote locations, and a range of open water and sea ice cover. Field trials with a conventional lifeboat were carried out over the last four years to investigate the extent to which ice limits operational capabilities. The lifeboat was outfitted as a research platform. Measurements were made of ice loads in different types of ice conditions and in different types of operations. Changes in propulsion performance were investigated in light of major modifications to the propulsion system. Propulsion was also evaluated in open water to provide performance benchmarks. The field trials are described and some results are presented. Key Words TEMPSC, ice, open water, performance, survivability, cold temperatures, wind, waves, fiberglass, propeller, nozzle, manoeuvrability, visibility, powering.. OCRE-TR-2012-07. i.

(6) ACKNOWLEDGEMENTS Financial support to the research program by Natural Resources Canada’s Program of Energy Research and Development (PERD) is acknowledged with gratitude. The authors also thank the people at NRC/IOT and NRC/CHC who contributed to the design, fabrication and instrumentation of the lifeboat, the trials team in preparing and executing the field program and the analysis team that helped sort out data details. Special thanks are offered to the undergraduate and graduate students who made great contributions to the project team.. OCRE-TR-2012-07. ii.

(7) EXECUTIVE SUMMARY Lifeboats are a necessary fixture on all commercial vessels and fixed and floating offshore installations. They are the crew’s last line of defense in the event of an emergency. These craft are depended upon if vessel/installation abandonment is required. Despite this reality, there are no special design regulations if the intended area of operation of the craft experiences some level of ice coverage. This poses navigational and structural challenges since lifeboats operating in ice are exposed to higher loading than those operating in open water. The majority of lifeboats built today are typically built from a combination of chopped strand mat and heavy woven roving. This results in a structure that is easy and economical to build but may not have sufficient mechanical strength to provide a safe haven during emergency evacuations in ice covered water. The ice trials showed that the conventional lifeboat tested is capable of operating in ice to a limit of between about 6 and 7 tenths concentration. Either way, the utility of the lifeboat was severely restricted by ice cover. The performance limits of this type of evacuation craft show the basic design requirements for any craft that is meant to complement or replace a conventional boat system. A simple impact model relating impact energy to the lifeboat hull material and temperature indicated a safe operating speed for the lifeboat at 2.0 knots. During the ice trials of 2007, 2009 and 2010, this safe operating speed was exceeded regularly without damage to the hull. This can be attributed to the conservative nature of the model plus a couple of other factors, namely ice strength and lifeboat bow area reinforcement. In 2007 and 2009 the ice was relatively weak and in 2010 the entire lifeboat bow area was reinforced during the impact panel dynamometer and sea-chests installation.. OCRE-TR-2012-07. iii.

(8) OCRE-TR-2012-07. iv.

(9) TABLE OF CONTENTS Page ABSTRACT ................................................................................................................................. I ACKNOWLEDGEMENTS................................................................................................................II EXECUTIVE SUMMARY ............................................................................................................... III LIST OF FIGURES ......................................................................................................................VII LIST OF TABLES ....................................................................................................................... IX GLOSSARY ................................................................................................................................ X 1.0. INTRODUCTION ................................................................................................................. 1. 2.0. PROJECT OBJECTIVES ..................................................................................................... 1. 3.0. FIELD TRIALS ................................................................................................................... 2 3.1. 2007 Field Trials .................................................................................................. 2. 3.2. 2008 Field Trials .................................................................................................. 4. 3.3. 2009 Field Trials ................................................................................................ 4. 3.4. 2010 Field Trials .................................................................................................. 6. 4.0. TOTALLY ENCLOSED MOTOR PROPELLED SURVIVAL CRAFT (TEMPSC) –LIFEBOAT ......... 8. 5.0. INSTRUMENTATION ......................................................................................................... 12. 6.0. DATA ACQUISITION ........................................................................................................ 14 6.1. 7.0. Coordinate System ............................................................................................ 14. CALIBRATION ................................................................................................................. 15 7.1. Inclining Experiments and decay tests ........................................................... 15. 8.0. ENVIRONMENTAL CONDITIONS………………………………………………………………...16. 9.0. TEST PLAN……………………………………………………………………………………..16 9.1. Test methodology ............................................................................................. 17. 10.0 DATA ANALYSIS AND TECHNIQUES ................................................................................. 19 10.1 Open Water ........................................................................................................ 19 10.1.1. Bollard-Pull analysis .............................................................................. 19. 10.1.2. Resistance analysis ............................................................................... 20. 10.1.3. Speed and acceleration analysis ........................................................... 21. 10.1.4. Turning circle analysis ........................................................................... 23. 10.1.5. Pull-out analysis .................................................................................... 24. 10.1.6. Zigzag analysis ...................................................................................... 25. 10.2 Ice ....................................................................................................................... 26 10.2.1. Pack ice and broken channel level ice – 2007 ...................................... 26. 10.2.2. Level and Pack ice – 2009 .................................................................... 27. OCRE-TR-2012-07. v.

(10) 10.2.3. Controlled ice floes (freshwater ice) – 2010 .......................................... 29. 11.0 RESULTS........................................................................................................................ 31 11.1 Open Water ........................................................................................................ 31 11.1.1. Bollard Pull ............................................................................................ 31. 11.1.2. Resistance ............................................................................................. 31. 11.1.3. Speed and acceleration ......................................................................... 32. 11.1.4. Turning circle manoeuvre ...................................................................... 33. 11.1.5. Pull-out manoeuvre ............................................................................... 35. 11.1.6. Zigzag manoeuvre ................................................................................. 36. 11.2 Ice ....................................................................................................................... 37 11.2.1. 2007 Ice Trials – Triton Newfoundland .................................................. 39. 11.2.2. 2009 Ice Trials - Triton Newfoundland................................................... 41. 11.2.3. 2010 Ice Trials – Paddy’s Pond Newfoundland ..................................... 44. 12.0 DISCUSSION OF RESULTS ............................................................................................... 46 13.0 REFERENCES ................................................................................................................. 47 14.0 APPENDICES APPENDIX A – SUMMARY OF INSTRUMENTATION APPENDIX B – TEMPSC EQUIPMENT LOCATION APPENDIX C - SENSOR CALIBRATION (LINEAR & POLYNOMIAL) APPENDIX D – OPEN WATER AND ICE TRIAL LOGS APPENDIX E –ANALYZED INDIVIDUAL RUN RESULTS. OCRE-TR-2012-07. vi.

(11) LIST OF FIGURES Page Figure 3.1:. 2007 Field Trials sites for open water, pack and level ice ................................ 2. Figure 3.2:. Lifeboat open water speed trials and support vessel ........................................ 3. Figure 3.3:. Lifeboat heavy pack and rubble ice trials and support vessel........................... 3. Figure 3.4:. Lifeboat thin level intact ice trials ...................................................................... 3. Figure 3.5:. Ice conditions (level and pack) and ice thickness ............................................ 5. Figure 3.6:. Lifeboat transiting thin level ice and striking the ice edge ................................. 5. Figure 3.7:. Lifeboat remote operation set-up ...................................................................... 6. Figure 3.8. Ice thickness and layered structure .................................................................. 6. Figure 3.9:. Paddy’s Pond 2010 ice trials site and site preparation ..................................... 7. Figure 3.10:. Paddy’s Pond 2010 ice trials representative ice pieces .................................... 7. Figure 3.11:. Paddy’s Pond 2010 cleared area for concentration adjustment ....................... 8. Figure 3.12:. 2010 Open water field trials; July Speed run, August bollard pull..................... 8. Figure 4.1:. Trial 2007 lifeboat being towed to the testing site ............................................. 9. Figure 4.2:. Sea chest, 6-component dynamometer and acrylic panel conceptualization . 10. Figure 4.3:. Lifeboat hull preparation, sea chest construction and 6-component dynamometer .................................................................................................. 11. Figure 4.4:. Yanmar engine fitted to the lifeboat ................................................................ 11 Page. Figure 4.5:. Original and new propeller and nozzle arrangement ...................................... 12. Figure 10.1: Figure 10.2: Figure 10.3: Figure 10.4: Figure 10.5: Figure 10.6: Figure 10.7: Figure 10.8: Figure 10.9: Figure 10.10: Figure 10.11: Figure 10.12: Figure 10.13: Figure 10.14: Figure 10.15: Figure 10.16:. March 2010 Bollard pull results ...................................................................... 20 Open water towed resistance versus the tow speed ...................................... 21 Open water speed and acceleration – April 2007 ........................................... 22 Open water speed and acceleration – July 2009 ............................................ 22 Open water speed and acceleration – July 2010 ............................................ 22 Open water speed and acceleration – August 2010 ....................................... 27 Open water port and starboard turning circles 2007 ....................................... 27 Open water starboard and port turning circles 2010 ....................................... 24 Open water pull-out results, 2007 ................................................................... 24 Input and output signals for the 20-20 zigzag run ........................................... 25 System Identification results for the 20-20 zigzag run .................................... 25 Pack ice tests – 7ths concentration, 600 to 1000 shaft rpm ............................. 26 Broken ice channel tests, 500 to 700 shaft rpm .............................................. 27 Broken level ice 5-6ths concentration, 1000 shaft rpm ..................................... 27 Peak decelerations in “g” due to ice collisions ................................................ 28 Peak forces in kilo-Newtons due to ice collisions ........................................... 29. OCRE-TR-2012-07. vii.

(12) Figure 10.17: Fresh water trials 2010 – controlled ice floes: lifeboat transiting in 9ths ice concentration .................................................................................................. 30 Figure 10.18: Fresh water trials 2010 – controlled ice floes: lifeboat impact with large floe . 30 Figure 11.1: Bollard pull test results as a function of shaft speed ....................................... 31 Figure 11.2: Open water towed resistance versus tow speed ............................................ 32 Figure 11.3: Lifeboat speed over ground (SOG) versus shaft speed.................................. 32 Figure 11.4: Lifeboat acceleration versus shaft speed ....................................................... 33 Figure 11.5: Turning circle manoeuvre: Nominal 20° nozzle angle to port at 500 rpm .... 33 Figure 11.6: Turning circle manoeuvre: Nominal 20° nozzle angle to starboard at 500 rpm ........................................................................................................ 34 Figure 11.7: Turning diameter versus nominal nozzle angle .............................................. 34 Figure 11.8: Speed change during the port & starboard turning circle manoeuvre ............ 35 Figure 11.9: Lifeboat pull-out manoeuvre: assessment of dynamic stability on straight course ................................................................................................ 36 Figure 11.10: Lifeboat zigzag manoeuvre: Nomoto Indices K -assessment of turning ability................................................................................................... 36 Figure 11.11: Lifeboat zigzag manoeuvre: Nomoto Indices T -assessment of course stability ................................................................................................ 37 Figure 11.12: Field Trials 2007 pack ice: Measured impact forces versus impact speed ..... 38 Figure 11.13: Field Trials 2007 level ice: Measured impact forces versus impact speed ..... 38 Figure 11.14: Field Trials 2007 broken channel: Measured impact forces versus impact speed .................................................................................................. 39 Figure 11.15: Trials 2007 broken channel: Comparison of coxswain #1 and #2 .................. 39 Figure 11.16: Field Trials 2007 pack ice: Lifeboat path in 7ths ice concentration .................. 40 Figure 11.17: Field trials 2007 pack ice: Average SOG and shaft rotation through the ths 7 ice concentration run ................................................................................ 40 Figure 11.18: Field trials 2009 pack ice: Measured impact forces versus impact speed ...... 41 Figure 11.19: Field trials 2009 level ice: Measured impact forces versus impact speed ...... 42 Figure 11.20: Field trials 2009 broken level ice: Measured impact forces versus impact speed .................................................................................................. 42 Figure 11.21: Field trials 2009 level ice: Lifeboat path in weak unbroken level ice............... 43 Figure 11.22: Field trials 2009 level ice: Average SOG and shaft rotation through a level ice run .................................................................................................. 43 Figure 11.23: Field trials 2010 controlled floe size: Impact force at different impact speeds and ice concentrations ....................................................................... 44 Figure 11.24: Field trials 2010 controlled floe size: Front & side impacts ............................. 44 Figure 11.25: Field trials 2010 controlled floe size: Front & side impacts ............................. 45 Figure 11.26: Field trials 2010 controlled floe size: Distance and time performance measures ........................................................................................................ 46. OCRE-TR-2012-07. viii.

(13) LIST OF TABLES Page Table 3.1. Paddy’s Pond trial area water depth, ice and snow thickness summary .......... 7. Table 4.1:. TEMPSC, propeller and nozzle characteristics ................................................ 9. Table 7.1:. Summary of the lifeboat GM and roll period through all the trials ................... 15. Table 8.1:. Environmental conditions during trials ............................................................ 16. Table 10.1:. March 2010 bollard pull tests .......................................................................... 20. Table 11.1. Summary of the bollard thrust through all the trials ........................................ 31. OCRE-TR-2012-07. ix.

(14) GLOSSARY A/D. Analog-to-digital. BOA. Beam overall. GRP. Glass-reinforced plastic. IOT. Institute for Ocean Technology. LCG. Longitudinal centre of gravity. LED. Light emitting diode. LOA. Length overall. NTSC. National Television System Committee. SVHS. Super Video Home System. TEMPSC. Totally enclosed motor propelled survival craft. VCG. Vertical centre of gravity. VHS. Video Home System. OCRE-TR-2012-07. x.

(15) 1.0. INTRODUCTION. This report describes a series of field trials that investigated the performance capabilities of a 20-person conventional totally enclosed motor-propelled survival craft (TEMPSC) in natural ice and open water. The field trials were conducted from 2007 to 2010. The 2007 and 2009 ice trials were conducted in thin level intact ice and broken pack ice. In the 2007 trials, tests were also performed in heavy broken pack and rubble that included remnants of deteriorating icebergs. As the sea ice tests were done in spring, the ice was in the process of melting and was not as hard as might be expected in mid winter. The March 2010 ice trials were conducted in fresh water ice in a lake. For these trials a pool was cut in the lake ice, which allowed for the ice concentration to be adjusted in a process similar to that reported in laboratory tests with model lifeboats (Simões Ré & Veitch 2003, Simões Ré et al. 2006). In 2008 trials were limited to open water shakedown and seaworthiness after the major refit. At present there is limited information on the performance of emergency evacuation craft transiting and surviving ice-covered waters, wind and wave conditions. In 2006 BMT Fleet Technology led a research team that undertook a set of performance trials of a TEMPSC in icecovered water in the bays of New World Islands, Newfoundland and Labrador (Igloliorte, G. et al 2008). Earlier work, 2003, also conducted by BMT Fleet Technology Limited on behalf of Joint Industry Project (JIP) looked at a TEMPSC stranded in pack ice and how it drifted with the ice (Kendrick, A. 2004). In 2002, Seascape 2000 conducted a field trial with their craft off Twillingate, Newfoundland but most of the data was qualitative (O’Brien 2002). The field program was carried out by two NRC Laboratories, namely, Institute for Ocean Technology (IOT) and Canadian Hydraulics Centre (CHC) and Memorial University of Newfoundland Faculty of Engineering (MUN). The performance and survivability of a TEMPSC in environments in which cold temperatures wind, waves and ice were present was assessed. The field program was part of a larger research effort in the area of escape, evacuation and rescue in cold environments. Previous laboratory work was aimed at evaluating lifeboat evacuation capabilities as a function of ice conditions. That work undertaken to develop and refine measures of capability, or performance, that were specific to systems operating in ice environments and that had practical utility in the context of goal-based regulations. The research program involving research institutions, government departments, regulators, industry was developed to explore possible measures of performance, or benchmarks, might be used to evaluate the capabilities of marine emergency evacuation craft in environmental conditions in which they must be operated (i.e. pack and level ice, wind waves).. and that the and. The initial phase of this research consisted of a set of trial model scale experiments of three different TEMPSC hull designs in varying ice concentrations, piece size and wave heights to assess their performance with respect to transiting and manoeuvring. The intention of the research program was to provide some means by which decision makers can reasonably and defensibly judge various EER options, assess the performance and survivability in ice of the TEMPSC, and reproduce procedures used in the evaluation of physical model experiments in ice and wave environments. 2.0. PROJECT OBJECTIVES. The main objectives of the work reported here were to investigate the performance and survivability of a Totally Enclosed Motor Propelled Survival Craft (TEMPSC) in environments in which cold temperatures wind, waves, and ice are present. The work was intended to characterize the performance of TEMPSC with regards to construction materials, (fiberglass, aluminum, etc) propulsion systems (propellers, etc.), manoeuvrability, visibility (coxswain’s. OCRE-TR-2012-07. 1.

(16) position, forward/aft) and powering over a four (4) year field work program in which floating ice was present along with all other environmental conditions. 3.0. FIELD TRIALS. A four-year field campaign assessed the performance of a conventional lifeboat in cold temperatures and ice. The work characterized the performance of the TEMPSC with regards to construction materials, maneuverability, propulsion system and powering. 3.1. 2007 Field Trials. The 2007 field trials represented the first year of the four-year field campaign. These were preliminary trials and were intended to assess the performance of the lifeboat in open water, pack and level ice as delivered from factory, as well as work out logistical and operational requirements in advance of the remaining campaigns. The trials program encompassed a day for setting up the instrumentation on site, a day for open water trials, plus two days of ice testing: one in pack ice and one in level ice. The last day was used to decommission the lifeboat. In addition to the instrumented lifeboat, there was an accompanying fast rescue boat in attendance at all times, as well as a support vessel. The support vessel was a local fishing boat chartered for the trials. The trials were done off the North East coast of Newfoundland, in the vicinity of Triton and Pilley’s Island, during the first four days of May 2007. The site was chosen due to the local ice conditions in the region, and well as the excellent logistical support available. Open water trials took place at 49°30'12.85"N, 55°43'39.68"W. Pack ice trials were conducted some 2.25 Nm miles away in the bay between Triton Shipyard and Pilley’s Island harbour near 49°27'52.38"N, 55°44'6.97"W. Tests in level ice were done 2.5 Nm away in an inlet near Pilley’s Island at 49°29'46.70"N, 55°41'8.17"W. Figure 3.1 below shows the open water, pack and level ice sites.. Open Water 49°30'12.85"N 55°43'39.68"W. Level Ice 49°29'46.70"N 55°41'8.17"W. Pack Ice 49°27'52.38"N 55°44'6.97"W. Figure 3.1 – 2007 Field Trials Sites for open water, pack and level ice Figures 3.2 to 3.4 show the lifeboat in open water, pack and broken level ice conditions.. OCRE-TR-2012-07. 2.

(17) Figure 3.2 – Lifeboat open water speed trials and support vessel. Figure 3.3 – Lifeboat heavy pack and rubble ice trials and support vessel. Figure 3.4 – Lifeboat thin level intact ice trials Ice conditions in which tests were conducted included thin level intact ice and broken pack ice. As the tests were done in spring, the first year ice was in the process of melting and was not as hard as might be expected in mid winter. The flexural strength of the ice was evaluated by two. OCRE-TR-2012-07. 3.

(18) simple beam tests, which indicated strength of approximately 50 to 60 kPa. The ice was approximately 0.20 to 0.30 m thick. The ice strength was evaluated by four or more separate measurements of ice temperature, salinity and conductance during the trial. The measurements made on the ice samples indicated consistent values of temperature and salinity. The flexural strength was estimated according to Cammaert and Muggeridge (1988). The maximum and minimum brine volumes were used to estimate the flexural strength range. Additional tests were done in heavy broken pack and rubble that was partly made up of the remnants of deteriorating icebergs. Measurements were made of over 40 test runs during a four-day period, providing benchmark data on the performance of a conventional lifeboat in a range of conditions. 3.2. 2008 Field Trials. In 2008 the lifeboat went through a major refit and as a result only an open water shakedown trials was conducted in November to test the seaworthiness of the lifeboat, the functionality of the 6-component dynamometer, estimate the hydrodynamic effects of the two sea chests, practice deployment and retrieval of the lifeboat and train IOT’s trial team members on the operation of the lifeboat. No ice field trials were conducted in 2008. 3.3. 2009 Field Trials. The 2009 April field trials represent the second time the lifeboat had been in the ice and the first since the fitting of the 6-component dynamometer, impact panel and sea chest and the addition of remote control. Later the same year, in July the lifeboat went through another series of open water trials. The ice trials program took place from the 22-25 April in the vicinity of Triton and Pilley’s Island (Kenedy et al., 2010). During this trial, baseline open water tests were conducted for comparison with previous trials. In ice there were tests conducted in both level and in pack ice. Turning circles and zigzag manoeuvres were performed in the level ice as well as full and half speed impacts into the level ice sheet edge to maximize the loading of the impact panel. Similar type manoeuvres were also completed in pack ice. The logistical support was provided from a local fishing boat chartered for the trials and the Institute’s fast rescue craft. The ice strength was, as in 2007, estimated from several measurements of ice temperature, salinity and conductance during the trial. The measurements made on the ice samples collected indicated consistent values of temperature and salinity. The flexural strength was estimated according to Cammaert and Muggeridge (1988) and ranged from approximately 270 to 390 kPa. The maximum and minimum brine volumes were used to estimate the flexural strength range. The ice thickness at the field trials sites ranged from 0.13 to 0.20m. The first day of testing was conducted in a small cove that contained both level and pack ice that was approximately 0.14m thick. In this case, level ice refers to flat continuous ice and pack ice refers to broken level ice pieces. Figure 3.5 illustrates both level and pack ice and typical thickness.. OCRE-TR-2012-07. 4.

(19) Figure 3.5 - Ice conditions (level and pack) and ice thickness Due to relatively warm weather, the second day of trials was moved to an adjacent cove. The ice conditions (i.e. thickness and strength) were similar to the first day, however, in subsequent days the ice was in the weaker range. There were in excess of 100 runs performed in the level and pack ice the four days of trials. Figure 3.6 below illustrates the lifeboat progressing through thin level ice and impacting the ice edge.. Figure 3.6 - Lifeboat transiting thin level ice and striking the ice edge. OCRE-TR-2012-07. 5.

(20) Open water trials were also conducted in 2009, over a five-day period, 23, and 24, 27-29 July. In addition to manoeuvring (e.g. turning circles, zigzags) acceleration and speed trials, two days (23 and 24) were dedicated to lifeboat habitability trials looking at the effects of lifeboat internal temperature on occupants (NRC-IOT employees) wearing immersion suits, CO, CO2, light and noise levels over two hour run times. The NRC’s Research Ethics Board (REB) was consulted as to whether or not ethics approval would be required for this investigation. Since the NRC-IOT employees were performing activities that fell within their job descriptions, ethical approval was not deemed required. A total of 45 engineering runs were performed from the 27th to 29th with the lifeboat operated by the coxswain or remotely. The two photos below, Figure 3.7, show the lifeboat set-up for remote operation.. Figure 3.7 - Lifeboat remote operation set-up 3.4. 2010 Field Trials. The 2010 field trials represent the last year of the four-year field campaign. The trials were once again broken down into ice and open water trials. The ice trials were conducted in Paddy’s Pond in fresh water ice and in calm conditions. The setup mimicked model experiments conducted in IOT’s ice tank (Simões Ré & Veitch 2003, Simões Ré et al., 2006). Ice samples were taken from the level ice in the test area and transported in coolers to IOT’s cold room for testing. The results of the laboratory tests indicated ice with flexural strengths ranging from 200 to 1100 kPa and thickness between 0.30 and 0.40m. The large variation in flexural strength was due to the presence of stronger and weaker layers within the ice column (i.e. consolidated snow layer, porous snow layer, mid columnar layer and clear bottom layer). The average flexural strength and thickness was 565 kN and 0.34m, respectively. Figure 3.8 shows the thickness and different layers of the Paddy’s Pond ice.. Figure 3.8 - Ice thickness and layered structure. OCRE-TR-2012-07. 6.

(21) The Paddy’s Pond trials site consisted of a pool cut in the surrounding level ice. The pool extended for about 55m and had a width of about 32m. Prior to cutting the ice, three test holes (marked by red starts in Figure 3.11) where drilled to check for the ice and snow thickness and the water depth. The measurements are summarized in Table 3.1 below. The site location and initial site preparation are shown in Figure 3.9. Table 3.1 - Paddy’s Pond trial area water depth, ice and snow thickness summary #1 #2 #3. Location At wharf |20m NE of #1 |30m NNE of #2. Water Depth [m] 1.2 2.1 3.1. Ice thickness [m] 0.40 0.37 0.30. Snow thickness [m] 0.23 0.03 0.12. Figure 3.9 - Paddy’s Pond 2010 ice trials site and site preparation Ice pieces varying in size from 1.65u2m and 3.3u2m were cut from the original level ice cover, Figure 3.10. In preparation for the first tests, some of the ice pieces were cleared from the test pool leaving the test area with 9/10ths ice concentration, Figure 3.11. For subsequent tests at decreasing concentrations of 8/10ths to 5/10ths, additional pieces of ice were removed or pushed underneath the surrounding ice sheet. A total of 58 runs were performed over a five-day period, 22nd to 26th March, with no trials taking place during the 24th due to a snowstorm.. Figure 3.10 - Paddy’s Pond 2010 ice trials representative ice pieces. OCRE-TR-2012-07. 7.

(22) Figure 3.11 - Paddy’s Pond 2010 cleared area for concentration adjustment In order to capture and baseline the changes in the propulsion system two open water trials were conducted, one in July with the new propeller, nozzle and engine and a second one in August with the old propeller and nozzle and the new engine. Manoeuvring, speed and acceleration trials were conducted in addition to inclining, roll decay and bollard tests. A total of 63 runs were completed in four days of testing in July. An additional 70 runs were performed in three days of trials in August. In both trials engineering (i.e. force, accelerations, motions etc.) and human factors (i.e. temperature, CO, CO2, noise & light levels, etc.) were measured. Figure 3.12 shows the lifeboat during speed runs in July and bollard pull in August.. Figure 3.12 – 2010 open water field trials; July speed run, August bollard pull 4.0. TOTALLY ENCLOSED MOTOR PROPELLED SURVIVAL CRAFT (TEMPSC) LIFEBOAT. The lifeboat, or Totally Enclosed Motor Propelled Survival Craft (TEMPSC), is of glassreinforced plastic construction with the hull, inner-hull, and canopy moulded individually with poly-urethane foam as the buoyant material. It was built to the requirements prescribed by the Safety of Life at Sea (SOLAS) Convention (IMO 1997) and the International Lifesaving Appliance (LSA) Code (IMO 2003). In addition, tests were done according to corresponding guidance from the International Maritime Organization (IMO 1998).. OCRE-TR-2012-07. 8.

(23) The TEMPSC is 5.28m long, 2.20m wide, 2.70m high and has a moulded depth to the gunwale of 1.10m. This size facilitates storage and transportation to the trials location in a standard cargo container, or on its own trailer. The original TEMPSC was delivered with a 22 kW (29hp) engine, an electric starting system, conventional propeller inside a steerable nozzle, gear shift/throttle control, wheel, magnetic compass, on/off power switches and a 24V battery, as well as safety equipment (e.g., painter, oars, sea anchor, bailer). Prior to outfitting, the unloaded lifeboat weighed 2160 kg. It was loaded to its full complement, corresponding to 20 (75kg) people. The actual load was comprised of three operators (coxswain, plus two crew) weighing 258.7 kg, 50 bags of sand weighing 22.7 kg each, plus 111.3 kg of instrumentation for a total of 1505 kg. The fully loaded lifeboat weighed 3665 kg. Table 4.1 gives the lifeboat, propeller and nozzle characteristics while Figure 4.1 shows a 2007 picture of the lifeboat being towed to the testing site as outfitted for operation. Table 4.1 – TEMPSC, propeller and nozzle characteristics TEMPSC Length Overall LOA Beam B Height H Lightship 'Light Total Displacement ' Transverse Metacentric Height GMT Engine Propeller rotation / number of blades Propeller Diameter / Propeller Pitch D/P Nozzle inner / Outer diameter ID / OD. m 5.28 m 2.20 m 2.70 kg 2160 kg 3665 m 0.306 kW (hp) 22 RH / 3 m 0.457 / 0.279 m 0.50 / 0.52. Figure 4.1 - Trial 2007 lifeboat being towed to the testing site In 2008 the lifeboat went through a major refit. A 6-component dynamometer was conceptualized and designed using data collected during the 2007 field trials - see Figure 4.2 below for illustration. The dynamometer was fitted to the port sea-chest structure and tested for functionality in the lab. A 100 mm thick acrylic panel was machined with the same curvature as the hull and fitted to the dynamometer. A second acrylic panel was attached to a dummy dynamometer fitted to the starboard sea chest. Attached to the inner structure of the sea chests. OCRE-TR-2012-07. 9.

(24) were housings for video cameras (one on each sea chest). A grid of 100mmx100mm was marked on the acrylic panels. The sea chests were constructed of fibre reinforced plastic material and provided a watertight compartment that housed the 6-component dynamometer and dummy and prevented flooding into the lifeboat. The sea chests have an access panel on the upper side to allow for access to the equipment mounted inside. An air vent was fitted to the upper panel to permit instrumentation wires to be routed from the load cells and cameras to the data acquisition system. The access panel was located such that it is above the loaded water line of the lifeboat, allowing access to the instrumentation while the boat is waterborne.. Figure 4.2 – Sea chest, 6-component dynamometer and acrylic panel conceptualization At the same time the sea-chest were being constructed the entire forward portion of the lifeboat was reinforced. The extent of the reinforcement ranged longitudinally, from the stem to 1.4m aft of it, and vertically from the keel to the gunwale. At the 1.4 location a partial bulkhead was manufactured separating the bow area (sea-chest, 6-component dynamometer and dummy dynamometer) from the rest of the lifeboat. The reinforcement was accomplished by sandwiching a layer of polyurethane foam, 6 mm thick, between the existing fiberglass hull and a new layer of 6 mm fiberglass. The interior fiberglass layer replicated the lay-up of the fiberglass hull. Polyester resin was used in the hull reinforcement and the installation of the bulkhead The four pictures in the next page, Figure 4.3, illustrate the work conducted during the lifeboat refit. In 2009 the lifeboat went through an upgrade of the engine and propeller and nozzle. The original 22 kW (29hp) Bukh engine was replaced with a lightweight Yanmar 40 kW (54hp) low vibration and noise engine meeting EPA tier 2 emission standards, Figure 4.4 next page.. OCRE-TR-2012-07. 10.

(25) Figure 4.3 – Lifeboat hull preparation, sea chest construction and 6-component dynamometer. Figure 4.4 – Yanmar engine fitted to the lifeboat At the same time, the original 3-blade right hand propeller (0.457m diameter, 0.279m pitch, 0.61 P/D ratio) was replaced with a commercially available 4-blade right hand Kaplan propeller (0.457m diameter, 0.305 pitch, 0.67 P/D ratio) and the original nozzle (0.500m inner diameter, 0.521m outer diameter) was replaced with a custom made 19A-nozzle (0.464m inner diameter,. OCRE-TR-2012-07. 11.

(26) 0.556m outer diameter). In Figure 4.5, the left photograph shows the old propeller and nozzle and the right photograph shows the new propeller and nozzle.. Figure 4.5 – Original and new propeller and nozzle arrangement. INSTRUMENTATION. 5.0. The lifeboat instrumentation package was first developed for the 2007 ice trials and upgraded in 2009 reflecting the changes made to the lifeboat local load measuring system and new requirements for habitability data. The original instrumentation package fitted to the lifeboat for the 2007 trials consisted of the following components on 48 data channels: x Differential global positioning system (DGPS), main system, updated at 10Hz and a global positioning system (GPS), back-up system, giving information on latitude-longitude and time. x Three inertial motion measurement systems: o. Min-MotionPak: a miniaturized, low-powered inertial motion sensor unit, with surface mounted accelerometers and rates (for measuring angular speed) in the X-Y-Z directions, mounted along the centre line of the lifeboat and roughly at midships.. o. MotionPak 2: unit made up of 3 accelerometers and 3 rates mounted in the chest cavity of a training dummy seated in the aft portion of the lifeboat on the starboard side to measure the motions of a would-be evacuee.. o. MOTAN: unit made up of three servo accelerometers and three rate-angle sensors, mounted along the centre line of the lifeboat and roughly at midships. Note: For a more detailed description of MOTAN refer to Johnston et al. (2003).. x CO and CO2 monitors: sensors to measure gas levels set with human safety alarm thresholds. x Temperature sensors: three mounted in the lifeboat at the seat, shoulder and main canopy levels. x Two in-line load cells with a 5 kN range: Main load cell and back-up for measuring tow load in open water and ice and for measuring bollard pull. x Roll and pitch sensors: sensors to measure roll and pitch independently. x Yo-Yo potentiometer and tachometer: instruments to measure rudder angle and shaft speed.. OCRE-TR-2012-07. 12.

(27) x Anemometer: instrument to measure wind speed and direction, mounted on the lifeboat’s mast. x Magnetic compass and handheld GPS: instruments used by the coxswain to ascertain heading. x Data acquisition battery monitor. x Lifeboat video cameras (6): two looking down on the ice at the lifeboat’s shoulders, two aft looking down at the ice at the steerable nozzle longitudinal position, one forward mounted looking down at the ice at the bow, one at the stern looking down at the ice, one looking forward at the ice field, and one looking aft at the lifeboat track. x Additional cameras: one rover video camera and two digital cameras, one on the support vessel, one on the fast rescue boat. In 2009 the instrumentation package was upgraded from the original 48 channels to 114 channels. The new channels consisted of the following components: x Load dynamometer [impact panel] (1): three force transducers with a 10kN range measuring the force along the length of the lifeboat and one measuring the vertical force. Three force transducers with 50kN range measuring loads across the beam of the lifeboat. x Inertial motion measurement system: MotionPakTM: unit made up of 3 accelerometers and 3 rates on the lifeboat’s centreline between the two sea-chests housing the live and dummy load dynamometers. x Linear Variable Differential Transformer (LVDT): sensors to measure the displacement of the live dynamometer mounting frame and the relative displacement between the sea-chests. x Accelerometers (2): impact accelerometers mounted on the mounting frame of the force dynamometer measuring impacts in the X and Y-axis. x Air flow sensors (4): sensors installed over the lifeboat vent to measure airflow in and out of the lifeboat. x Temperature and humidity sensors (4): sensors to measure lifeboat’s internal and external ambient temperature (2) and humidity (2) levels. x Light sensors (3): sensors to measure the light levels inside the lifeboat. x Sound sensors (7): sensors to measure the noise levels inside the lifeboat. x CO sensors (9): sensors to measure CO concentration inside the lifeboat. x CO2 sensors (9): sensors to measure CO2 concentration inside the lifeboat x Sea-chests video cameras (2): one camera in each of the port and starboard sea-chests aligned with the three force transducers measuring loads across the beam of the lifeboat and looking through the acrylic impact panel to measure ice thickness. A summary of the instrumentation used throughout the tests is presented in Appendix A.. OCRE-TR-2012-07. 13.

(28) 6.0. DATA ACQUSITION. In the 2007 trials two different types of data acquisition systems (DAS) were used. During the open water and pack ice trials the DAS was a local area network of two laptops located in the galley of the support vessel. One laptop was running the IOT standard data acquisition server, acquiring data via one or more serial ports and making it available to client applications. The other laptop was running IOT’s Windows-based acquisition client that was used to retrieve data from the server and store it in standard DAC (data acquisition and control) file format. The client laptop was also used to monitor server channels in real time and to perform online analysis of acquired data. In the same trials but during the level ice trials the data acquisition system consisted of a laptop computer equipped with Bluetooth radio modems, running a stand-alone data acquisition program developed at IOT. The acquisition program captured the stream of data packets, which were telemetered from the embedded lifeboat systems by up to three (3) pairs of 900 Hz radio modems connected to the computer's serial ports, and saved the raw data to disc in comma separated value (CSV) format. Real-time calibration and monitoring of 12 data channels (e.g. carbon monoxide level) were available throughout the level ice trials. Video was transmitted via a high power 2.4GHz video transmitter. In 2009 and 2010 trials data acquisition was made through five (5) acquisition systems, sampling data at low, medium and high speed. The high-speed data acquisition systems (DAS) was a 3031 USB Daqboard while the medium and low speed DAS were programmable interface controllers (PIC). The low speed sample data at 10 Hz, medium at 100 Hz and high at 8000 Hz. A video acquisition system was also used. Once acquired, the data was post-calibrated by a separate calibration program and transferred to IOT’s main computer for analysis and archiving.. 6.1 Coordinate System The coordinate systems used in the analysis of the trials data are defined as follows:. x. Global Positioning Coordinate System. A global system using latitude and longitude obtained from the Differential Global Position System (DGPS) installed in the lifeboat. The origin of the X, Y grid was chosen at the DGPS antenna in the lifeboat. No vertical position Z was obtained from the DGPS unit. Note: DGPS- network of fixed, ground-based reference stations to broadcast the difference between the positions indicated by the satellite systems and the known fixed positions. These stations broadcast the difference between the measured satellite pseudo ranges and actual (internally computed) pseudo ranges. The DGPS is an enhancement to GPS that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations. The X-axis is defined North the Y-axis is defined to East.. x. TEMPSC Coordinate System A TEMPSC fixed system, with origin at the intersection of the transom, the keel and the model centerline. This right-handed coordinate system is fixed to the TEMPSC and moves with it. It defines the location of equipment in the TEMPSC and the location of all the instrumentation. All the instrumentation locations are summarized in Appendix B.. OCRE-TR-2012-07. 14.

(29) 7.0. CALIBRATIONS. All analog sensors were calibrated before the start of the experiments. The response of the sensor to a set of exciting loads was measured and a straight line or polynomial fitted through the data points by means of a least squares technique. For example the straight line is defined by two constants, A and B, which relate the integer analog-to-digital (A/D) converter reading (counts) to the physical quantities being measured according to the following linear transformation:. X A k

(30) u M - B k

(31)

(32) Where: X. = physical value in physical units,. M. = integer A/D converter reading,. A(k) = sensitivity of the sensor connected to the A/D channel, k in physical units per count, and B(k) = Zero offset of the sensor connected to A/D channel, k in counts. The purpose of this type of calibration is to calculate the constants A(k) and B(k), and to ensure that the sensor functions properly and has a linear response. The constant A(k) also represents the digital resolution of the measurement. The linear and polynomial sensor calibrations are presented in Appendix C 7.1 Inclining Experiment and Decay tests Inclining experiments and roll decay tests were conducted on the free-floating lifeboat prior to the start of any open water and ice trial. Inclining experiments were performed to determine the transverse metacentric height (GM) of the lifeboat for the full complement condition. Weights were used to induce a heel angle. An experiment was started with these weights on the lifeboat centerline. With the data acquisition system running, the weights were shifted a known distance to starboard and the heel angle of the boat recorded. The weights were shifted back to the centerline and the heel angle recorded again. The weights were then shifted to port a known distance and the heel angle recorded. Finally, the weights were returned to the centerline and the heel angle recorded to end the experiment. Roll decay experiments were performed to determine the natural roll period of the lifeboat for the full complement condition. The roll decay experiment was performed with the boat afloat and away from the wharf. The boat crew simply moved from side to side to induce rolling. The boat crewmembers then positioned themselves on the centerline and the roll oscillation was monitored as it decayed. The crew is part of the lifeboat ballast. These experiments were necessary to ensure that the metacentric height and roll period for the TEMPSC was realistic and consistent from trial to trial. Table 7.1 summarizes all the inclining experiments and decay test results for the all the field trials. Table 7.1 - Summary of the lifeboat GM and roll period through all the trials. GMT [m] Roll Period [s]. OCRE-TR-2012-07. 2007 May 0.306 3.56. Open Water trials 2009 2010 July July 0.311 0.308 3.53 3.54. 15. 2010 August 0.303 3.36. 2007 May 0.306 3.56. Ice trials 2009 April 0.305 3.53. 2010 March 0.308 3.54.

(33) 8.0. ENVIRONMENTAL CONDITIONS. The environmental conditions encountered during the open water and field campaigns are summarized in this section. The lifeboat trials were timed to accommodate IOT operational schedules. In addition open water trials were scheduled during periods when, statistically, the environmental conditions have the highest probability of being at their lowest values, with regards to wind and waves, and for ice trials during periods representing different stages of ice strength. The environmental conditions leading to lifeboat trials were monitored and forecast sought from local and national weather offices with regards to wave height, wind speed, ice concentration, thickness, precipitation etc. For open water trials, upper limits for wave heights and wind speeds were set at less than 0.4m and 10 knots, respectively. Ice trials were conducted in the conditions present at the time, which resulted in the lifeboat being operated in ice of different strengths, concentrations, thicknesses and both freshwater and sea ice. The general environmental encountered over the four years are presented below in Table 8.1 below. Table 8.1 – Environmental conditions during trials Open Water trials Location Date [month-year]. Ice trials. Triton. Holyrood. Holyrood. Holyrood. Triton. Triton. Paddy’s Pond. May-07. July-09. July-10. Aug-10. May-07. April-09. Mar-10. -1. Avg. wind speed [ms ]. 5.6. 2.9. 5.7. 1.8. 6.1. 1.1. 1.8. -1. Max. wind speed [ms ]. 8.9. 4.2. 7.7. 3.6. -. 4.7. 5.8. Temperature air [qC]. 1.6. 14.5. 19.5. 17.5. 1.3. 10.3. 3.6. Temperature water [qC]. 0.7. 8.2. 15.1. 16.0. 0.7. 0.4. 0.5. Temperature ice [qC]. -. -. -. -. -0.2. -0.1. -0.5. Wind Chill [qC]. -. 16.7. -. -. -. 7.8. 1.2. 97. 82.0. 88. -. 97. 75.7. 85. Ice [salt/freshwater]. -. -. -. -. saltwater. saltwater. freshwater. Ice type [unbroken (UL) & broken level (BL), pack (P)]. -. -. -. -. UL, BL, P. UL, P. BL. Ice concentration [10ths]. -. -. -. -. 5-7. Not specified. 5-9. Nominal ice piece size [m-m u m-m]. -. -. -. -. small to large. 1-5u1-4. 1.65-3.3 u2. Ice thickness [m]. -. -. -. -. 0.2-0.3. 0.13-0.2. 0.3-0.4. Ice strength [kPa]. -. -. -. -. 50-60. 270-390. 200-1100. Relative Humidity [%]. 9.0. TEST PLAN. The four-year field program was divided into a total of five (5) open water trials and three ice trials. In total, 396 runs were completed with 225 in open water, 99 in level ice, and 72 in pack ice. A total of 129 runs were performed in saltwater ice and 42 in freshwater ice.. OCRE-TR-2012-07. 16.

(34) Generally speaking trials were conducted over a four (ice trials) or five (open water) day window. For all the trials the first day was dedicated to setting up the instrumentation and debugging the various systems and the last day was used for decommissioning the lifeboat and preparing for the return to IOT. In the ice trials the second day was dedicated to pack ice and the third to level ice. In open water trials the second day was dedicated to manoeuvring (e.g. turning circles, zigzags) acceleration and speed trials, and the third dedicated to lifeboat habitability trials. Occasionally a fourth day was added to the habitability trials and the completion of remaining acceleration and speed trials. In 2007 and 2009 prior the start of the ice trials a series of open water trials was also performed. Open water and ice trials logs are presented in Appendix D. 9.1 Test Methodology Slightly different methodology was used in the calibrations, the decay tests, bollard tests and the general lifeboat open water and ice trials. The calibrations, turning circles, zigzags and crash stops followed institute standard procedures while decay, bollard, acceleration, speed tests and general tests followed the methodology presented below.. x. Launch the lifeboat ballast and check for trim and heel. Adjust as necessary.. x. Perform inclining, roll decay and bollard experiments on the free-floating lifeboat. These types of experiments were conducted at the beginning of every trial (open water and ice) to determine the static stability of the lifeboat, the roll period and associated damping and the lifeboat’s bollard pull.. After the calibration inclining, roll decay and bollard experiments tests were completed the remaining lifeboat open water and/or ice trials were performed. For the open water trials three nominal speeds, namely, full speed (6knots), half speed (3knots) and ice speed (1.5 knots) were selected. The methodology used in the open and ice trials was as follows: OPEN WATER. x. Turning circle/pull-out manoeuvre – adjust the throttle and course, set forward speed over the ground to the desired setting and initiate data collection. Once the lifeboat reaches steady state maintain for a short period of time and then have the coxswain sets the steering nozzle to the required setting. Hold the steering nozzle at the required angle until a heading angle change of 720q is observed and then return the steering nozzle to amidships. Terminate data collection if not pullout manoeuvre is planned. However, if a pullout manouevre is required continue data collection for a period of time after a steady heading angle is achieved and then terminate the data acquisition.. x. Zigzag manouevre – adjust the throttle and course, set forward speed over the ground to the desired setting and initiate data collection as per the turning circle instructions. Once the lifeboat reaches steady state maintain for a short period on a steady approach heading and then have the coxswain set the steering nozzle to the required initial angle (10q, 15q, or 20q). Hold the steering nozzle constant at the specified angle until a heading angle change equal to the magnitude of the steering nozzle angle is observed on the inboard portable GPS unit. Once the required angle is reached turn the steering nozzle in the opposite direction to the earlier specified angle. Each change in steering nozzle angle during zigzag manouevres is defined as one execute. After several steering nozzle executes with the associated heading angle changes are completed return the steering nozzle to amidships and stop the data collection.. OCRE-TR-2012-07. 17.

(35) x. Acceleration / speed – initiate data collection before adjusting the throttle from the clutched position to the desired shaft speed. Once the desired shaft speed was achieved the lifeboat was kept on course for two minutes, after which time the data acquisition was stopped.. Acceleration, speed, turning circles and zigzags trials were done in sheltered deep water, with sufficient room to maneuver. ICE. x. Unbroken level ice (bow impacts) – initiate data collection, adjust the throttle to the required setting and run the lifeboat into the unbroken ice. Once the lifeboat stopped making forward progress, maintain the throttle setting and oscillate the steering nozzle through relatively small angle changes port and starboard in attempt at making some forward progress. After a few angle changes reverse the lifeboat out of the ice field. Again adjust the throttle to the required setting, and manouevre the lifeboat into the notch in the ice made by the lifeboat in the previous attempt. Make a few more attempts and terminate data acquisition.. x. Unbroken level ice (glancing impacts) – initiate data collection, adjust the throttle to the required setting and run the lifeboat along the ice edge, periodically steering it into the ice edge such that contact point between the ice and the lifeboat is in the area of the impact panel. Repeat several times.. x. Broken level ice (uncontrolled size) – prepare the testing area by breaking a channel using one of the support craft. The size of the pieces was not controlled and varied from small to large pieces (similar in mass to the lifeboat). Once the channel was completed the coxswain was given instructions on the purpose of the run, the throttle setting, etc. before entering the channel. Starting in open water far enough away from the ice for the coxswain to identify the entrance of the channel, initiate data acquisition, adjust the throttle to the require setting and manouevre the lifeboat through the channel. Another type of test (i.e. turning circle) was performed in a field of broken ice prepared by the support craft. Starting from open water, the lifeboat data acquisition systems were started, the throttle setting adjusted to the required setting and the lifeboat manoeuvred into the ice field where turning circles were performed.. x. Broken level ice (controlled size) – the ice required preparation prior to starting. A saw cut measuring 32m wide by 50m long was made in the ice extending from the wharf. This cut formed the edges of the test area. The intact ice inside the test area was then cut into pieces approximately 2m wide and 1.65 and 3.3m long. This meant that 14 cuts were made longitudinally and 18 cuts transversely. This was done to control the ice piece size. The next step in the preparation of the test area was to remove some of the ice in order to change the concentration. In the first instance, enough ice was removed to go from complete coverage to 9/10ths coverage. This was done by moving ice near the wharf and removing it to shore with a backhoe. The same procedure was used throughout the test program to change concentration. The mass of the ice pieces was approximately 40 and 85% of the mass of the lifeboat. The ice floes were moved around by the trials team in order to mix the two ice floe sizes and get a qualitatively similar concentration of ice over the entire test area. Nominally identical tests were repeated two or three times, with the lifeboat navigating away and towards the wharf.. x. Pack ice (natural conditions) – give instructions to the coxswain with regards the target waypoint, initiate data collection, adjust the throttle to a nominal setting (e.g. full, half throttle) and manoeuvre the lifeboat through the pack ice natural conditions the best way. OCRE-TR-2012-07. 18.

(36) possible. If manouevring through the pack ice field to the target waypoint was unsuccessful and the lifeboat was unable to make forward progress terminate the run and the data acquisition. If the manoeuvring to the target waypoint was successful, once reached, stop the data acquisition and prepare for another run. Successful runs were defined as those for which none of the lifeboat, data acquisition, communications and video systems failed. 10.0. DATA ANALYSIS AND TECHNIQUES. Results from each test run were recorded and spot-checked at the time of testing to ensure the working status of the instrumentation and to isolate potential sensor problems that may produce unacceptable results. Some basic analyses were performed with statistics generated for each channel at the end of the day during transfer to IOT main system. These results were treated as preliminary results. After the completion of the trials, calibrations were applied to the data using IOT custom software. The calibration files included both linear and nonlinear curves and instrument offsets for each individual sensor. The linear and polynomial sensor calibrations for each channel are presented in Appendix C. The results presented in this report provide event statistics of open water calm conditions, speed acceleration, manoeuvring, (i.e. turning circles, zigzags) and operability capability for different lifeboat conditions (i.e. old propulsion system, new propulsion, old engine, new engine, etc.). The following sections describe the techniques used to analyze the test data. In some cases packaged software was used, while in others, task specific software was developed. In general all the data outputted by the IOT custom data acquisition software was calibrated and imported into IGOR Pro analysis package. Once all the files are loaded the analyst can select the relevant data file and tests type. Video records and selected runs representative of all different types of trials are presented in Appendix E along with the analyzed individual run results. 10.1 Open water Open water trials were performed to determine the lifeboat’s bollard pull, its open water towed resistance, its speed and acceleration and its maneuverability. 10.1.1 Bollard-pull Analysis The bollard tests were conducted by attaching one end of a 30m rope to the wharf’s bollard and the other end to a sacrificial link and inline load cell which in turn was attached to the lifeboat’s stern pull point. The lifeboat’s shaft speed was increased until full throttle was reached. The load cell and shaft revolutions per minute information were stored in ASCII format comma-space delimited (.CSV) files. Time histories were plotted and basic statistics (mean, maximum, minimum, and standard deviation) computed over the steady state portions of each shaft speed incremental change. These were treated as preliminary results. Once the data was transferred to the IOT computer systems all analog channels were put through calibration factors to convert measurements in volts to engineering units. The data was then saved in Igor Pro files. The time series data for the load cell and the shaft revolutions was plotted and the statistical average load in Newtons and shaft speed in rpm calculated for the steady state portion of the various throttle setting from clutched to full throttle. As an example the results of the March 2010 bollard tests are summarized numerically in Table 10.1 and shown graphically in Figure 10.1.. OCRE-TR-2012-07. 19.

(37) Table 10.1 - March 2010 bollard pull tests Shaft Revolutions [rpm] 411.3 560.2 704.5 844.6 980.8 1108.0 1167.8. Bollard Pull [N] 695 1244 1949 2656 3457 4250 4682. 5000N. 1200rpm. 4500. Bollard Pull Tests March 2010. 1000. 4000. 800. 3000 2500. 600. 2000 400. 1500. Shaft Speed [rpm]. Bollard Pull [N]. 3500. Load cell RPM. 1000. 200. 500 0 0. 50. 100. 150. 200. 250. 300. 350. 400. 0 450s. Time [s]. Figure 10.1 – March 2010 bollard pull results 10.1.2 Resistance Analysis The “Great Pumpkin” lifeboat was towed by the support vessel in calm protected waters to assess the lifeboat’s hull resistance through a range of tow speeds to a maximum of | 6.0 knots. The nozzle was set to 0° and the engine de-clutched allowing the propeller to windmill freely. There may have been some influence on the measured resistance by the wake of the towing vessel. The distance between the towing vessel and the lifeboat was maintained at 30m but it is possible that at the higher towing speeds the towing vessel wake influenced the measured lifeboat resistance. The data of interest was separated out and the information stored in ASCII format commaspace delimited (.CSV) files with time stamps that indicate when the data was pulled from the input buffer. No calibration factors were applied to the digital data. Time histories were plotted and checked for anomalies at the end of each run. The basic statistics (mean, maximum, minimum, and standard deviation) were computed over the steady state portion of the run. These results were treated as preliminary results. Once the data was transferred to the IOT computer systems all analog channels were put through calibration factors to convert measurements in volts to engineering units. The data was then saved in Igor Pro files. The time. OCRE-TR-2012-07. 20.

(38) series data for the load cell was plotted and the statistical average load in Newtons calculated for the steady state portion of the four towing speeds of interest. The towing speeds were calculated by first converting DGPS position data in latitude and longitude coordinates (degrees) to Universal Transverse Mercator (UTM) coordinates (Eastings (m), Northings (m)) and then differentiating the position vector to get the speed vector. The speed time series was then plotted and the statistical average calculated over the steady state portion of the run. Figure 10.2 below shows the lifeboat open water towed resistance versus the tow speed during the 2007 trials. 1500. Lifeboat Towed Resistance Towed Resistance [N]. 1450. 1400. 1350. 1300. 1250 5.1. 5.2. 5.3. 5.4. 5.5. 5.6. 5.7. 5.8. Tow Speed [knots]. Figure 10.2 - Open water towed resistance versus the tow speed. 10.1.3 Speed acceleration analysis The speed and acceleration of the “Great Pumpkin” lifeboat in calm water together with its trajectory are presented in this section for the open calm water conditions. During the speed and acceleration trials time histories of the critical channels were plotted and checked for anomalies. The initial step in the analysis was to convert the un-calibrated ASCII format comma-space delimited (.CSV) files with time stamps into calibrate Igor Pro files. The next step was to convert the DGPS position data in latitude and longitude coordinates (degrees) to Universal Transverse Mercator (UTM) coordinates (Eastings (m), Northings (m)) and then differentiating the position vector to get the speed vector with speed over ground converted to units of knots. The acceleration was obtained by differentiating the speed time series. Figures 10.3 to 10.6 illustrate speed and acceleration results for open water trials conducted in April 2007 July 2009, July 2010 and August 2010.. OCRE-TR-2012-07. 21.

(39) 8. 1200 SOG [knots] -1 Acceleration [knots.s ] RPM. 0.2. 1000. 6. 0.1. 4. 0.0. 600. 400 -0.1. 2 200. 0. -0.2. 0 0. 20. 40. 60. 80. 100. 120. 140. s. Figure 10.3 - Open water speed and acceleration – April 2007 8. 1200 0.15 1000. 0.10 6. 800. 0.00. -0.05. 600. 400. 2 -0.10 200 -0.15 0. 0 0. 20. 40. 60. 80. s. Figure 10.4 - Open water speed and acceleration – July 2009. Figure 10.5 - Open water speed and acceleration – July 2010. OCRE-TR-2012-07. 22. RPM. 4. Acceleration. SOG. 0.05. Acceleration. RPM. SOG. 800.

(40) Figure 10.6 - Open water speed and acceleration – August 2010 10.1.4 Turning Circle Analysis Turning circle analysis was conducted using IOT custom software, developed in IGOR Pro. Time series plots with both steering nozzle angle and heading angle were created, with the analyst interactively selecting the start and end of the run, the initial heading angle, the steering nozzle offset prior to the nozzle execute and the start of the nozzle execute and its return to amidships. The next step was to interactively smooth, apply a spline or remove isolated data glitches using linear interpolation or cubic spline. After glitches were removed the data was then smoothed. The data was then displayed in the X-Y plane giving the analyst the option of interactively correcting the data to take out the influence of wind, wave and current induced drift. Prior to generating the final turning circle data product the analyst had another opportunity to smooth or spline the X-Y position data. Figures 10.7 and 10.8 show typical port and starboard turning circles conducted in 2007 and 2010. The turning circle results from the different trials are presented in Appendix E.. Figure 10.7 – Open water port and starboard turning circles 2007. OCRE-TR-2012-07. 23.

(41) 20. 15 Advance - 19 m. Rudder Executed 15 Advance - 19 m. Transfer 7m. Approach Course 0. Y [m]. 360 5. 0. Tactical Diameter 22 m. Final Diameter 20 m 0. 270. 90. -5. Rudder Executed. 5. Transfer 10 m. Y [m]. 10. Approach Course. 10. 0. 360. Tactical Diameter 20 m. 90. 0. 0. Final Diameter 16 m 0. 180. -5. 0. 0. 270. 0. 180. -10. -10 -20. -10. 0. 10. -15 -15. 20. -10. -5. X [m]. 0. 5. 10. 15. X [m]. Figure 10.8 – Open water starboard and port turning circles 2010 10.1.5 Pull-Out Analysis Pull-out analysis was conducted using IOT custom software, developed in IGOR Pro. The analysis was performed after turning circles with opposite steering nozzle angles (i.e. port and starboard) of similar magnitude were completed. The analyst simply selected the pull-out analysis option for the matched port and starboard turning circles analyzed earlier. Figure 10.9 illustrates the results of a pull-out manoeuvre conducted in 2007. More examples of pull-out results are presented in Appendix E.. Figure 10.9 – Open water pull-out results, 2007 10.1.6 Zigzag analysis Zigzag analysis was conducted in two parts: first using IOT custom software developed for IGOR Pro and then exporting the data to MATLAB for final analysis. In IGOR the average of the heading angle during the steady state portion of the run (i.e. offset) was removed from all the heading angle values. The time series was subsequently cropped to coincide with the start of the zigzag manoeuvre. The run average speed (2.55 knots) for the nominal 20-20 zigzag was also calculated. The data was outputted in ASCII and imported into MATLAB where an initial analysis of the data was carried out. The standard non-dimensional Nomoto parameters K and T (Nomoto 1960) were derived using MATLAB’s system identification (SI) toolbox. This. OCRE-TR-2012-07. 24.