Code of Federal Regulations Title 46. Shipping § 46.45.173 Eligible barges

(a) Unmanned, river service, dry-cargo barges;

(b) Barges that have been designed and built to at least the minimum scantlings of the American Bureau of Shipping River Rules which were in effect at the time of construction;

(c) Barges with a length-to-depth ratio less than 22;

(d) Barges on the Milwaukee route must not be more than 10 years old;  and

(e) All weathertight and watertight closures (dogs, gaskets, covers, etc.) must be in proper working condition.