Following the UN ICAO Technical Instructions 2017/2018 Edition, the 58th Edition DGR removed Engine and Machinery from UN 3166 and thus made UN 3166 only for Vehicles with differing fuel source. Vehicles remained intact as Class 9 regardless of the fuel type used. Under the provisions of DGR 9.4.3 or under USG-13 regulations, Class 9 remains exempted from the requirements of accessibility when loading on CAO. So, there was no problem with Vehicles.
However for Engine and Machinery which were purged from UN 3166 are now assigned to the Class and Division applicable to the fuel used. Engine and Machinery using flammable liquid fuel is assigned to UN 3528 Class 3, and Engine and Machinery using flammable gas as fuel is assigned to UN 3529 Division 2.1. Due to the change in Class and/or Division assignments, there were other rules which needed review and amending. Special Provision SP A208 was introduced allowing a grace period until 31 March 2017 to allow continuous shipments of Engine/Machinery using the old UN 3166 Class 9. The U.S. presidential election posed a new phase with President Trump issuing numerous Presidential Orders which delayed the issue. Finally, we saw a revision to USG-13 which listed UN 3528 and UN 3529 on the list of substances exempted from the CAO accessibility rule. Now, however, DGR 9.3.4 remains not amended. The USG-13 revision has jumped ahead of the ICAO Technical Instructions. UN 3528 Engine/Machinery (Class 3) and UN 3529 Engine/Machinery (Division 2.1) will have to be loaded in an accessible manner on CAO until the DGR rules are changed. Until DGR 9.3.4 gets amended, UN 3528/UN 3529 must be loaded in a Class C Cargo Compartment (DGR 126.96.36.199 (a)) or follow DGR 188.8.131.52 (c) and load in an accessible condition.