49 CFR §176.174

1. (a)Fixed magazines may be built within a shipboard barge. Freight containers may be used as magazines within a barge.
2. (b)Shipborne barges may be used for the carriage of all types of Class 1 (explosive) materials. When carrying Class 1 (explosive) materials requiring special stowage, the following requirements apply:
   1. (1)Class 1 (explosive) materials in compatibility group G or H must be stowed in freight containers.
   2. (2)Class 1 (explosive) materials in compatibility group K or L must be stowed in steel magazines.
3. (c)Class 1 (explosive) materials of different compatibility groups may not be stowed within the same shipborne barge unless under § 176.144(b) of this subpart they are authorized to be stowed in the same compartment.