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Association of American Railways (AAR) 2011 Intermodal Cargo Securement Loading and Securing Manual

Entry DateOctober 22, 2012
Issue Number12-034-VEH
NameSean McAlister
AgencyOrca Road Safety Consultants, Ltd
AddressUnit 1, 103 Maclaren StreetOttawa, ON, K2P 0K5CanadaMap It (opens in a new tab)
Phone613-680-1580
Email[email protected]
CommitteeVehicle Committee
StatusClosed
Summary of Issue

The Association of American Railways (AAR) updated in 2011 their intermodal cargo securement loading and securing manual and a couple of issues have emerged. First AAR has tested a number of rubber mats which have Coefficient’s of Friction (COF’s) ranging from .9g to 1.25g (i.e.: NRI and Allegheny).

Justification or Need

There is a need to clarify the relationship between two principles in the cargo securement standard and regulations. The first principle was if a cargo securement device manufacturer was prepared to mark and rate their product they would be given full credit for that marking and rating. The current rule or standard only gives credit for .5g for use of rubber mats.

Request for Action

The new AAR loading diagrams for split loads have been updated to remove blocking/bracing. Blocking and bracing remains only when the load might tip. In the standard only .5g is acknowledged for these mats to prevent shifting in all horizontal directions. I would like to know if a mat is properly marked and rated for .8g or greater will it be given credit for that rating in preventing shifting of the load in all 4 horizontal directions? Moreover, is there still a requirement in split loads to provide additional blocking in the forward direction? I have seen these mats and the marking. For roadside purposes, if the mat is marked and indicates “COF > than .8g” will that be acceptable for enforcement purposes?