A raft is any flat structure for support or transportation over water.[1] It is usually of basic design, characterized by the absence of a
hull. Rafts are usually kept afloat by using any combination of buoyant materials such as
wood, sealed
barrels, or inflated air chambers (such as
pontoons), and are typically not propelled by an engine. Rafts are an ancient mode of transport; naturally-occurring rafts such as entwined vegetation and pieces of wood have been used to traverse water since the dawn of humanity.
Traditional or primitive rafts were constructed of wood, bamboo or
reeds; early buoyed or float rafts use inflated animal skins or sealed clay pots which are lashed together.[2]: 15, 17, 43 Modern float rafts may also use
pontoons,
drums, or
extruded polystyrene blocks.[citation needed] Inflatable rafts up to the 20th century used flotation chambers made of goat- or buffalo-skins, but since then have mostly used durable, multi-layered rubberized fabrics. Depending on its use and size, it may have a
superstructure, masts, or rudders.
Timber rafting is used by the
logging industry for the transportation of logs, by tying them together into rafts and drifting or pulling them down a river.[citation needed] This method was very common up until the middle of the 20th century but is now[when?] used only rarely.
Large rafts made of
balsa logs and using sails for navigation were important in maritime trade on the Pacific Ocean coast of South America from pre-Columbian times until the 19th century. Voyages were made to locations as far away as Mexico, and many trans-Pacific voyages using replicas of ancient rafts have been undertaken to demonstrate possible contacts between South America and
Polynesia.[3]
The type of raft used for recreational
rafting is almost exclusively an
inflatable raft, manufactured of flexible materials for use on
whitewater.
Natural rafts
In
biology, particularly in
island biogeography, non-manmade rafts are an important concept. Such rafts consist of matted clumps of
vegetation that has been swept off the dry land by a
storm,
tsunami,
tide,
earthquake or similar event; in modern times[when?] they sometimes also incorporate other kind of
flotsam and jetsam, e.g. plastic containers. They stay afloat by its natural
buoyancy and can travel for hundreds, even thousands of miles and are ultimately destroyed by
wave action and
decomposition, or make landfall.[citation needed]
Three Arks for a log drive on
Pine Creek, in Lycoming or Tioga County, Pennsylvania. The left ark was for cooking and dining, the middle ark was the sleeping quarters and the right ark was for the horses. The arks were built for just one log drive and then sold for their lumber. The line of the Jersey Shore, Pine Creek and Buffalo Railway can be seen on the eastern shore: the mountainside behind it is nearly bare of trees from clearcutting.[4]
^G. & C. Merriam Co., Websters New Collegiate Dictionary, 1976,
ISBN0-87779-339-5
^McGrail, Sean (2014). Early ships and seafaring : water transport beyond Europe. Barnsley: Pen and Sword Books Limited.
ISBN9781473825598.
^Smith, Cameron M. and Haslett, John F. (1999), "Construction and Sailing Characteristics of a Pre-Columbian Raft Replica", Bulletin of Primitive Technology, pp. 13–18
^Thomas T. Taber, III "Williamsport Lumber Capital", 1995, page 13
A raft is any flat structure for support or transportation over water.[1] It is usually of basic design, characterized by the absence of a
hull. Rafts are usually kept afloat by using any combination of buoyant materials such as
wood, sealed
barrels, or inflated air chambers (such as
pontoons), and are typically not propelled by an engine. Rafts are an ancient mode of transport; naturally-occurring rafts such as entwined vegetation and pieces of wood have been used to traverse water since the dawn of humanity.
Traditional or primitive rafts were constructed of wood, bamboo or
reeds; early buoyed or float rafts use inflated animal skins or sealed clay pots which are lashed together.[2]: 15, 17, 43 Modern float rafts may also use
pontoons,
drums, or
extruded polystyrene blocks.[citation needed] Inflatable rafts up to the 20th century used flotation chambers made of goat- or buffalo-skins, but since then have mostly used durable, multi-layered rubberized fabrics. Depending on its use and size, it may have a
superstructure, masts, or rudders.
Timber rafting is used by the
logging industry for the transportation of logs, by tying them together into rafts and drifting or pulling them down a river.[citation needed] This method was very common up until the middle of the 20th century but is now[when?] used only rarely.
Large rafts made of
balsa logs and using sails for navigation were important in maritime trade on the Pacific Ocean coast of South America from pre-Columbian times until the 19th century. Voyages were made to locations as far away as Mexico, and many trans-Pacific voyages using replicas of ancient rafts have been undertaken to demonstrate possible contacts between South America and
Polynesia.[3]
The type of raft used for recreational
rafting is almost exclusively an
inflatable raft, manufactured of flexible materials for use on
whitewater.
Natural rafts
In
biology, particularly in
island biogeography, non-manmade rafts are an important concept. Such rafts consist of matted clumps of
vegetation that has been swept off the dry land by a
storm,
tsunami,
tide,
earthquake or similar event; in modern times[when?] they sometimes also incorporate other kind of
flotsam and jetsam, e.g. plastic containers. They stay afloat by its natural
buoyancy and can travel for hundreds, even thousands of miles and are ultimately destroyed by
wave action and
decomposition, or make landfall.[citation needed]
Three Arks for a log drive on
Pine Creek, in Lycoming or Tioga County, Pennsylvania. The left ark was for cooking and dining, the middle ark was the sleeping quarters and the right ark was for the horses. The arks were built for just one log drive and then sold for their lumber. The line of the Jersey Shore, Pine Creek and Buffalo Railway can be seen on the eastern shore: the mountainside behind it is nearly bare of trees from clearcutting.[4]
^G. & C. Merriam Co., Websters New Collegiate Dictionary, 1976,
ISBN0-87779-339-5
^McGrail, Sean (2014). Early ships and seafaring : water transport beyond Europe. Barnsley: Pen and Sword Books Limited.
ISBN9781473825598.
^Smith, Cameron M. and Haslett, John F. (1999), "Construction and Sailing Characteristics of a Pre-Columbian Raft Replica", Bulletin of Primitive Technology, pp. 13–18
^Thomas T. Taber, III "Williamsport Lumber Capital", 1995, page 13