Devices, systems and methods for compacting a charge of composite material across an edge are disclosed herein. The devices include a vacuum compaction device including a compaction force transfer structure, a sealing structure, and a vacuum distribution manifold. The compaction force transfer structure includes a first barrier structure, a second barrier structure, and a junction support that extends at least partially between the first barrier structure and the second barrier structure. The junction support is configured to maintain the first barrier structure and the second barrier structure at an angle with respect to one another and to permit limited angular motion of the first barrier structure and the second barrier structure relative to one another. The systems include composite structure fabrication systems that include the vacuum compaction device. The methods include methods of operating the vacuum compaction device.