welded steel flotation units that were assembled like Legos, connected by special angle-iron pieces, called stringers. The flotation boxes and stringers were held together by special iron wedge pins. The flotation boxes came in two types: a rectangular basic unit measuring . The majority of NLPs were constructed using these. The second type had one side that was curved or angled to make a bow on the front of NLP barges or a ramp as needed. See also Float (nautical) Rhino ferry Seabee References "Navy's pin-up Boxes", February 1946, Popular Science illustrations of NPL units "Navy Lighterage", Global Security World War II military equipment of the United States Military bridging equipment Pontoon bridges in the United States Coastal construction Amphibious warfare Logistics Seabees