The Penetration Test (PT) is one of the three test methods stated in Appendix 2 of the International Maritime Solid Bulk Cargoes Code (IMSBC Code) used to determine the Transportable Moisture Limit (TML) of Group A or liquefiable solid bulk cargoes. The two other test methods stated in Appendix 2 of the IMSBC Code used to determine the TML of Group A or liquefiable solid bulk cargoes are the Flow Table Test (FTT) and Proctor/Fagerberg Test (PFT). The PT constitutes a procedure whereby a material in a cylindrical vessel is vibrated. The Flow Moisture Point (FMP) is determined on the basis of the penetration depth of an indicator..
The Penetration test was developed in Japan by Tamaki Ura and Masato Tanaka at the Research Institute of Marine Engineering for determining the TML of coal . Research began on the Penetration test in 1989  and it was adopted by the International Maritime Organization, in 1994, for determining the TML of ore concentrates and coal .
|1987||Analysis of Capsizing of Bulk Carrier due to Liquefaction of Ore Concentrates with Height Moisture Content||Published|||
|1988||Determination of flow moisture point||Published|||
|1988||Study on the Liquefaction Characteristics of Coal||Published|||
|1989||Development of Test Method of Transportable Moisture Limit for Coals||Published|||
|1989||Development of The Penetration Method for Mineral Concentrates||Published|||
|1990||Development of new criteria against shifting of bulk cargoes||Published|||
|1990||Tentative results of international co-operation experiment on the penetration method||Published|||
|1990||Supplementary data for determining the conditions of the penetration method for mineral concentrates and similar materials||Published|||
|1991||Development of a Test Method to determine Flow Moisture Point of Bulk Cargo||Published|||
|1994||Code of Safe Practice for Solid Bulk Cargoes (BC Code)||Introduced|||
|Cylinder size||Inner diameter||Depth||Wall thickness|
|small||146 mm||202 mm||9.6 mm or more|
|large||194 mm||252 mm||10.3 mm or more|
Temperature and HumidityEdit
The test material required should be collected as a representative sample of the cargo being shipped. Experience has shown that more accurate test results will be obtained by ensuring that the moisture content of the test sample is increased rather than decreased towards the FMP.
Consequently, it is recommended that a preliminary flow moisture test should be conducted, generally in accordance with the following, to indicate the condition of the test sample, i.e. the quantity of water and the rate at which it is to be added or whether the sample should be air-dried to reduce its moisture content before commencing the main flow moisture test.
Preparation of Test SampleEdit
Preliminary Flow Moisture TestEdit
It is noted that “tamping does not affect the result of the Penetration Test, because the sample is quickly consolidated by vibration from the vibrating table regardless of the pressure of tamping conducted prior to the test” .
|Typical Cargo|| Bulk Density
| Maximum Cargo Depth
| Tamping Pressure
| Force on 30 mm Diameter Head|
|Iron Ore Concentrate||4,000||2||80||5.7|
|Iron Ore Concentrate||4,000||5||200||14.1|
|Iron Ore Concentrate||4,000||10||400||28.3|
|Iron Ore Concentrate||4,000||20||800||56.5|
|Lead Ore Concentrate||5,000||2||100||7.1|
|Lead Ore Concentrate||5,000||5||250||17.7|
|Lead Ore Concentrate||5,000||10||500||35.3|
|Lead Ore Concentrate||5,000||20||1,000||70.7|
Note: Extrapolation of the tamping pressure from the graph above is not part of the procedure stated in Appendix 2 of the IMSBC Code, 2013 Edition. The graph is shown just as a visual guide to the data given in the table above.
After the tamping pressure has been calculated and the tamping procedure performed:
Main Flow Moisture TestEdit
Concerntrates and Similar MaterialsEdit
The Flow Moisture Point (FMP) of the material is (in gross water content by weight):
- FMP = Flow Moisture Point (%),
- m3 = the exact mass of the sample just above the flow state,
- m4 = the exact mass of the sample just above the flow state, after drying,
- m5 = the exact mass of the sample just below the flow state and
- m6 = the exact mass of the sample just below the flow state, after drying.
- TML = Transportable Moisture Limit (%) and
- FMP = Flow Moisture Point (%).
|Material||Typical TML values determined using the Penetration Test (% GWC)|
|Iron Ore Fines||5.90 - 11.50 (Average = 7.55)|
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- Munro, M. and A. Mohajerani, 2015, Management of Hazardous Effects of Liquefaction of Iron Ore Fines during Transportation in Bulk Carriers, Journal of Environmental Management
- International Maritime Organisation, International Maritime Solid Bulk Cargoes Code, 2013 Edition, London: International Maritime Organization.
- Munro, M., & Mohajerani, A. (2016). Moisture Content Limits of Iron Ore Fines to Prevent Liquefaction During Transport: Review and Experimental Study. International Journal of Mineral Processing, 148. doi: http://dx.doi.org/10.1016/j.minpro.2016.01.019
- Tanaka, M. and T. Ura, Development of The Penetration Method for Mineral Concentrates. International Maritime Organization, Sub-Committee on Dangerous Goods, Solid Cargoes and Containers, BC 30/5/12, 1989
- IMO: Code of Safe Practice for Solid Bulk Cargoes (BC Code), IMO, 1994 edition
- URA, Tamaki, Analysis of Capsizing of Bulk Carrier due to Liquefaction of Ore Concentrates with Height Moisture Content, IMO, BC28/INF.4, (1987.1), pp.1-25.
- TANAKA, Masato; URA, Tamaki, Determination of flow moisture point, IMO, BC29/5/11, (1988.5).
- URA, Tamaki, Study on the Liquefaction Characteristics of Coal, IMO, BC30/5/2, (1988.8).
- TANAKA, Masato; URA, Tamaki, Development of Test Method of Transportable Moisture Limit for Coals, Journal of Japan Institute of Navigation, No.80, (1989.3), pp.125-131.
- URA, Tamaki; TANAKA, Masato, Development of new criteria against shifting of bulk cargoes, IMO, BC31/3/2, (1990.10).
- URA, Tamaki; TANAKA, Masato, Tentative results of international co-operation experiment on the penetration method, IMO, BC31/INF.4, (1990.12).
- URA, Tamaki; TANAKA, Masato, Supplementary data for determining the conditions of the penetration method for mineral concentrates and similar materials, IMO, BC31/INF.5, (1990.12).
- URA, Tamaki; TANAKA, Masato, Development of a Test Method to determine Flow Moisture Point of Bulk Cargo, Journal of Japan Institute of Navigation, No.84, (1991.3), pp.45-51. (Download PDF)
- Munro, M. and A. Mohajerani, Determination of Transportable Moisture Limit of Iron Ore Fines for the Prevention of Liquefaction in Bulk Carriers. Marine Structures, 2015. 40(1): p. 193-224.