View source for Length between perpendiculars

{{Short description|Form of ship length measurement}}
[[File:Ship size (side view).PNG|thumb|right|300px|Graphical representation of the dimensions used to describe a ship.]]
'''Length between perpendiculars''' (often abbreviated as '''p/p''', '''p.p.''', '''pp''', '''LPP''', '''LBP''' or '''Length BPP''') is the length of a [[ship]] along the summer load line from the forward surface of the [[Stem (ship)|stem]], or main bow perpendicular member, to the after surface of the [[sternpost]], or main stern perpendicular member.  When there is no sternpost, the centerline axis of the rudder stock is used as the aft end of the length between perpendiculars.<ref>{{Cite web |url=http://www.globmaritime.com/martech/naval-architecture/general/6766-perpendiculars-and-length-between-perpendiculars |title=Perpendiculars and Length Between Perpendiculars |access-date=2012-12-07 |archive-date=2016-04-04 |archive-url=https://web.archive.org/web/20160404135216/http://www.globmaritime.com/martech/naval-architecture/general/6766-perpendiculars-and-length-between-perpendiculars |url-status=dead }}</ref>

Measuring to the stern post or rudder stock was believed to give a reasonable idea of the ship’s carrying capacity, as it excluded the small, often unusable volume contained in its overhanging ends. On some types of [[Marine vessel|vessels]] this is, for all practical purposes, a waterline measurement. In a ship with raked stems, naturally that length changes as the [[draft (hull)|draught]] of the ship changes, therefore it is measured from a defined loaded condition.

==See also==
* [[Length overall]]

==Citations==
{{reflist}}

==References==
* {{cite book |last=Hayler |first=William B. |author2=Keever, John M.  |title=American Merchant Seaman's Manual |year=2003 |publisher= Cornell Maritime Pr |isbn= 0-87033-549-9 }}
* {{cite book | last=Turpin | first=Edward A.|author2=McEwen, William A.  | title=Merchant Marine Officers' Handbook| edition=4th | year=1980  | publisher=Cornell Maritime Press  | location=Centreville, MD | isbn=0-87033-056-X }}

==External links==
* [http://www.globmaritime.com/martech/naval-architecture/general/6766-perpendiculars-and-length-between-perpendiculars Perpendiculars and Length Between Perpendiculars]

{{Ship measurements}}

[[Category:Shipbuilding]]
[[Category:Ship measurements]]