Rib (nautical)
{{Short description|Structural element of watercraft}}
File:Arviat Qulaittuq 1995-07-02.jpg
On a vessel's hull, a rib is a lateral structural member which runs between gunwales and sprouts from the keel.{{cite book |title=The Oxford Handbook of Maritime Archaeology|chapter=Illustrated Glossary of Ship and Boat Terms |date=December 2013|first= J. Richard |last= Steffy|editor3-first=Alexis |editor3-last=Catsambis |editor2-first=Donny L |editor2-last=Hamilton |editor1-first=Ben |editor1-last=Ford |publisher=Oxford Handbooks|doi= 10.1093/oxfordhb/9780199336005.013.0048}} They are called "ribs" because they resemble the human rib. The ship's outer planking and inner sheathing are attached to the ribs. For ships that are too large for a rib to be made out of a single piece of wood, the ribs are made of multiple sections called futtocks that are scarfed together.{{cite book |last1=Van Gaasbeek |first1=Richard Montgomery |title=A Practical Course in Wooden Boat and Ship Building |date=1919 |publisher=F.J. Drake |pages=222–23 |url=https://books.google.com/books?id=MvsOAAAAYAAJ |access-date=29 November 2020}} The ancient writers Polybius and Plato held that, since the ribs of a ship were the most important part of the ship's framework, then if the ribs were new, then the ship as a whole was new.{{cite book |last1=Torr |first1=Cecil |title=Ancient Ships |date=1894 |publisher=University of Michigan Press |pages=39–40 |url=https://books.google.com/books?id=mD8EAAAAMAAJ |access-date=29 November 2020}} Iron was first used in shipbuilding to make the ribs and frames, with wood sheathing attached to them, but this proved inadequate compared to replacing the wood sheathing with iron plates.{{cite book |last1=Fairbirn |first1=Sir William |title=Treatise on Iron Ship Building |date=1865 |publisher=Longmans, Green, & Company |location=London |page=71 |url=https://books.google.com/books?id=HltGAAAAYAAJ |access-date=29 November 2020}}