Blender to UDK help?

I have created a simple model and the collisions for it and named them all correctly. Using fbx export and then import into UDK. Collsions are not working at all, unable to get them to work after many attempts. Can someone please help me find a fix? Many thanks and find attached the blender file. MiddleBridge.blend (1.15 MB)

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moved to Game Engine Support and Discussion
because it does not belong to the BGE