View source for Ice tank

{{more citations needed|date=January 2017}}
[[File:Aalto Ice And Wave Tank.jpg|thumb|alt=Aalto Ice and Wave Tank is a 40 m by 40 m water basin equipped with wave makers and a cooling system that can make model ice.|Aalto Ice and Wave Tank in Espoo, Finland]]
An '''ice tank''' is a [[ship model basin]] whose purpose is to provide a physical modeling environment for the interaction of ship, structures, or sea floor with both ice and water.  Ice tanks may take the form of either a [[towing tank]] or [[Ship model basin|maneuvering basin]].

Many un-refrigerated ship model basins use ice simulants such as paraffin wax, plaster, and mixtures of foam or plastic beads.  The cleanup and handling of such simulants often proves cumbersome. What differentiates an ice tank from other ship model basins is that an ice tank has purpose built provisions into its structure for handling such material conveniently. Use of a refrigerated basin containing mostly water allows freezing and melting to be a convenient method of model ice preparation and cleanup.

==Ice scaling==
Ship model basins often simulate full-scale processes in miniature. Ships and structures are reduced linearly in size, and cubic in mass, displacement, and volume.  The challenge in ice modeling is correctly reducing the ice properties of interest to provide an accurate simulation.

Many factors and properties are of interest when simulating ice.  The actual environment that will be simulated is of prime concern.  For example, ice pieces flowing then jamming a spring river would be modeled very differently from a ship model traversing a simulated arctic ice sheet.  Different again would be a ship traversing an area of loose broken ice pieces or pack ice.

==Weakened ice method==
One important factor in icebreaker model testing is the effect of changing ice strengths and thickness.  For example: if a 1 to 30 scale is chosen, then the ship model is 1/30 the size.  The ice used must also be 1/30 the thickness and 1/30 the strength.

If one was to use pure-water ice, the problem is that pure-water ice does not soften.

Many ice tanks simulate ice using a mixture consisting mostly of water and chemical additives called dopants, which are chemicals which reduce the melting temperature of pure water ice.  Common dopants used are salt, [[ethanol]], [[ethylene glycol]], and [[urea]].

By using a sufficiently cold temperature, both water and dopant are frozen in solution together forming an ice sheet.  This impure ice sheet is inherently softer than pure-water ice but may be much harder than the scale strength desired.  Once a desired thickness is achieved, the air temperature is raised to a tempering temperature.  As the temperature of the ice rises the dopants come out of frozen solution and form liquid brine pockets.  These brine pockets slowly drain out of the ice sheet thus weakening it.  Provided the ice-sheet isn't allowed to refreeze, the strength of the ice continues to decrease approaching an asymptotic value.  Choosing a correct ice scale then becomes a question of when to conduct the test.  This softening is often referred to as tempering.

Different ice simulants model ice differently.  For example, most [[icebreaker]]s break ice by riding upward unto the ice and breaking downward by the weight of the vessel. In this case, correctly modeling ice's downward [[flexural strength]] is most important.{{Citation needed|date=October 2016}} In the case of bridges or offshore structure, [[compressive strength]] or upward flexural strength may be of more interest.  The effects of ice on ship propulsion often require model ice density to be reduced by adding controlled amounts of gas or air during the freezing process.

==List of ice tanks==

{{Incomplete list|date=October 2016}}

{| class="wikitable sortable" style="width:100%; text-align:center;"
|-
! Facility
! Location
! Years
! Length
! Width
! Depth
! Technology
! class="unsortable" | Notes
! class="unsortable" | Ref
|-
| align="left" | [[Aalto University]]
| [[Espoo]], [[Finland]]
| 1980s–present
| {{convert|40|m|ft|0|abbr=on|sortable=on}}
| {{convert|40|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.8|m|ft|0|abbr=on|sortable=on}}
| Fine-grained with ethanol
| align="left" | 
| <ref>[http://icetank.aalto.fi/en/ Aalto Ice Tank]. Aalto University. {{retrieved|accessdate=2016-10-16}}</ref>
|-
| align="left" | [[Korea Research Institute of Ships & Ocean Engineering]] (KRISO)
| [[Daejeon]], [[South Korea]]
|
| {{convert|42|m|ft|0|abbr=on|sortable=on}}
| {{convert|32|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.5|m|ft|0|abbr=on|sortable=on}}
|
| 
| <ref>{{Cite web |url=http://www.moeri.re.kr/eng/study/institution08.aspx |title=MOERI - Maritime & Ocean Engineering Research Institute |access-date=2010-09-11 |archive-url=https://web.archive.org/web/20090514094235/http://www.moeri.re.kr/eng/study/institution08.aspx |archive-date=2009-05-14 |url-status=dead }}</ref>
|-
| align="left" | [[National Research Council of Canada]] (NRCC-OCRE)
| [[St. John's, Newfoundland]], [[Canada]]
| 1985 – present
| {{convert|90|m|ft|0|abbr=on|sortable=on}}
| {{convert|12|m|ft|0|abbr=on|sortable=on}}
| {{convert|3.0|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web |url=https://nrc.canada.ca/en/research-development/nrc-facilities/ice-tank-90-m-research-facility |title=Ice tank – 90 m research facility |date=19 March 2019 |website=canada.ca |publisher=Government of Canada |access-date=8 November 2019}}</ref>
|-
| align="left" | HSVA, Large Ice Model Basin
| [[Hamburg]], [[Germany]]
|
| {{convert|78|m|ft|0|abbr=on|sortable=on}}
| {{convert|10|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.5|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web|url=http://www.hsva.de|title=HSVA Home - Hamburgische Schiffbau-Versuchsanstalt|author=|date=|publisher=|accessdate=15 October 2016}}</ref>
|-
| align="left" | [[Aker Arctic|Aker Arctic Technology Inc]]
| [[Helsinki]], [[Finland]]
| 2006–present
| {{convert|75|m|ft|0|abbr=on|sortable=on}}
| {{convert|8|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.1|m|ft|0|abbr=on|sortable=on}}
| Fine-grained with salt
| align="left" |
| <ref name="40years">[http://akerarctic.fi/sites/default/files/page/fields/field_attachments/40_years_of_model_testing.pdf 40 Years of Model Testing] {{Webarchive|url=https://web.archive.org/web/20161022103448/http://akerarctic.fi/sites/default/files/page/fields/field_attachments/40_years_of_model_testing.pdf |date=2016-10-22 }}. Aker Arctic. {{retrieved|accessdate=2016-10-16}}</ref>
|- style="background:#FFFFFF;" 
| align="left" | [[Aker Arctic|Masa-Yards Arctic Research Centre]] (MARC)
| [[Helsinki]], [[Finland]]
| 1982–2006
| {{convert|77.3|m|ft|0|abbr=on|sortable=on}}
| {{convert|6.5|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.3|m|ft|0|abbr=on|sortable=on}}
| Fine-grained with salt
| align="left" | Wärtsilä Arctic Research Centre (WARC) until 1989; Aker Arctic since 2005.
| <ref name="40years" />
|- style="background:#FFFFFF;" 
| align="left" | [[Aker Arctic|Wärtsilä Ice Model Basin]] (WIMB)
| [[Helsinki]], [[Finland]]
| 1969–1982
| {{convert|50|m|ft|0|abbr=on|sortable=on}}
| {{convert|4.8|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.15|m|ft|0|abbr=on|sortable=on}}
| Saline water
| align="left" | Built inside an old air raid shelter
| <ref name="40years" />
|-
| align="left" | [[CRREL]]
| [[Hanover, New Hampshire]], [[United States]]
|
| {{convert|37|m|ft|0|abbr=on|sortable=on}}
| {{convert|9|m|ft|0|abbr=on|sortable=on}}
| {{convert|2.4|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>http://www.crrel.usace.army.mil {{webarchive|url=https://web.archive.org/web/20070203195746/http://www.crrel.usace.army.mil/ |date=2007-02-03 }}</ref><ref>{{Cite web |url=http://www.crrel.usace.army.mil/ierd/testbasin.htm |title=Ice Engineering Test Basin |access-date=2007-02-04 |archive-url=https://web.archive.org/web/20070610230218/http://www.crrel.usace.army.mil/ierd/testbasin.htm |archive-date=2007-06-10 |url-status=dead }}</ref>

|-
| align="left" | NMRI
| [[Mitaka, Tokyo]], [[Japan]]
|
| {{convert|35|m|ft|0|abbr=on|sortable=on}}
| {{convert|6|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.8|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web|url=http://www.nmri.go.jp/main/overview/facilities/facilities_e.html|title=National Maritime Research Institute - Main Facilities|author=|date=|publisher=|accessdate=15 October 2016}}</ref>
|-
| align="left" | [[Krylov State Research Centre]]
| [[St. Petersburg]], [[Russia]]
|
| {{convert|102|m|ft|0|abbr=on|sortable=on}}
| {{convert|10|m|ft|0|abbr=on|sortable=on}}
| {{convert|2|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web|url=http://krylov-center.ru/eng/|title=Krylov State Research Centre|author=|date=|publisher=|accessdate=15 October 2016}}</ref><ref>{{cite web|url=http://krylov-center.ru/eng/Activities/system_integration_in_civil_shipbuilding/experimental_facilities.php|title=Experimental facilities|author=|date=|publisher=|accessdate=15 October 2016}}</ref>
|-
| align="left" | HSVA, Environmental Test Basin
| [[Hamburg]], [[Germany]]
| 1971–
| {{convert|30|m|ft|0|abbr=on|sortable=on}}
| {{convert|6|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.2|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref name="40years" /><ref>{{cite web |url=http://www.hsva.de/ |title=Home |website=hsva.de}}</ref>
|-
| align="left" | [[National Research Council of Canada]] (NRCC-OCRE)
| [[Ottawa]], [[Ontario]], [[Canada]]
|
| {{convert|21|m|ft|0|abbr=on|sortable=on}}
| {{convert|7|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.1|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web |url=https://nrc.canada.ca/en/research-development/nrc-facilities/ice-tank-21-m-research-facility |title=Ice tank – 21 m research facility |date=19 March 2019 |website=canada.ca |publisher=Government of Canada |access-date=8 November 2019}}</ref>
|-
| align="left" | [[Arctic and Antarctic Research Institute]] (AARI)
| [[St. Petersburg, Russia]]
|
| {{convert|35|m|ft|0|abbr=on|sortable=on}}
| {{convert|5|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.8|m|ft|0|abbr=on|sortable=on}}
|
| align="left" |
| <ref>{{cite web |url=http://www.aari.ru/ |title=Home |website=aari.ru}}</ref>
|- style="background:#FFFFFF;" 
| align="left" | [[Arctic and Antarctic Research Institute]] (AARI)
| [[Leningrad]], [[Soviet Union]]
| 1955–??
| {{convert|13.4|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.85|m|ft|0|abbr=on|sortable=on}}
| {{convert|1.1|m|ft|0|abbr=on|sortable=on}}
| Saline water
| align="left" | World's first ice tank.
| <ref name="40years" />
|}

==References==
{{reflist}}

[[Category:Ship design]]
[[Category:Research]]
[[Category:Water ice]]