A bivouac shelter or bivvy (alternately ''bivy'', ''bivi'', ''bivvi'') is any of a variety of improvised camp site or shelter that is usually of a temporary nature, used especially by

soldiers A soldier is a person who is a member of an army. A soldier can be a conscripted or volunteer enlisted person, a non-commissioned officer, a warrant officer, or an officer. Etymology The word ''soldier'' derives from the Middle English word ...

or people engaged in

backpacking Backpacking may refer to: * Backpacking (travel), low-cost, independent, international travel * Backpacking (hiking), trekking and camping overnight in the wilderness * Ultralight backpacking, a style of wilderness backpacking with an emphasis on ...

, bikepacking,

scouting Scouting or the Scout Movement is a youth social movement, movement which became popularly established in the first decade of the twentieth century. It follows the Scout method of informal education with an emphasis on practical outdoor activi ...

mountain climbing Mountaineering, mountain climbing, or alpinism is a set of outdoor activities that involves ascending mountains. Mountaineering-related activities include traditional outdoor climbing, skiing, and traversing via ferratas that have become mounta ...

. It may often refer to sleeping in the open with a bivouac sack, but it may also refer to a shelter constructed of

natural materials * A ″ natural material a substance that comes from plants, animals, or the earth, and has not been made by humans.. Minerals and the metals that can be extracted from them (without further modification) are also considered to belong into this ...

like a structure of branches to form a frame, which is then covered with

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

s and similar material for

waterproofing Waterproofing is the process of making an object, person or structure waterproof or water-resistant so that it remains relatively unaffected by water or resists the ingress of water under specified conditions. Such items may be used in wet env ...

and duff (

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen to the ground. This detritus or dead organic material and its constituen ...

) for insulation. Modern bivouacs often involve the use of one- or two-person tents but may also be without tents or full cover. In modern mountaineering the nature of the bivouac shelter will depend on the level of preparedness, in particular whether existing camping and outdoor gear may be incorporated into the shelter.

Etymology

The word ''bivouac'' is French and ultimately derives from an 18th-century Swiss German usage of ''Beiwacht'' (''bei'' by, ''Wacht'' watch or patrol). It referred to an additional watch that would be maintained by a military or civilian force to increase vigilance at an encampment. Following use by the troops of the

British Empire The British Empire comprised the dominions, Crown colony, colonies, protectorates, League of Nations mandate, mandates, and other Dependent territory, territories ruled or administered by the United Kingdom and its predecessor states. It bega ...

the term became also known as ''bivvy'' for short.

Construction

Artificial bivouacs can be constructed using a variety of available materials from corrugated iron sheeting or

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

, to groundsheets or a purpose-made basha. Although these have the advantage of being speedy to erect and resource-efficient, they have relatively poor insulation properties. There are many different ways to put up a bivouac shelter. The most common method is to use one bivouac sheet as the

roof A roof (: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of tempera ...

of the shelter and a second as the groundsheet. The 'roof' flysheet is suspended along its ridge line by a cord tied between two

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s which are a suitable distance apart. The four corners of the flysheet are then either pegged out or tied down to other trees. Care must be taken to leave a gap between the ground and the sheet to ensure that there is enough air flow to stop

condensation Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...

. A basha is a simple

tent A tent is a shelter consisting of sheets of fabric or other material draped over or attached to a frame of poles or a supporting rope. While smaller tents may be free-standing or attached to the ground, large tents are usually anchored using g ...

, made from one or two sheets of waterproof

fabric Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, and different types of fabric. At first, the word "textiles" only referred to woven fabrics. However, weaving is no ...

and some strong cord. Generally a basha is made of reinforced

nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

with eyelets and loops or tabs located along all four sides of the sheet and sometimes across the two central lines of

symmetry Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...

. The basha is an extremely versatile shelter that can be erected in many different ways to suit the particular conditions of the location. (The word also sometimes refers to a special type of bivouac sack described below).

Bivouac sack

A bivouac sack is a smaller type of bivouac shelter. Generally it is a portable, lightweight, waterproof shelter, and an alternative to larger bivouac shelters. The main benefit of a bivouac sack shelter is speed of setup and ability to use in a tiny space as compared to tent-like shelters. A bivouac sack is therefore a common choice for hikers, cyclists or climbers who have to camp in tight areas, or in unknown areas. A bivouac sack will usually have a thin waterproof fabric shell that is designed to slip over a

sleeping bag A sleeping bag is an insulated covering for a person, essentially a lightweight quilt that can be closed with a zipper or similar means to form a tube, which functions as lightweight, portable bedding in situations where a person is sleeping o ...

, providing an additional 5 to 10 °C of insulation and forming an effective barrier against

wind chill Wind chill (popularly wind chill factor) is the sensation of cold produced by the wind for a given ambient air temperature on exposed skin as the air motion accelerates the rate of heat transfer from the body to the surrounding atmosphere. Its va ...

and

rain Rain is a form of precipitation where water drop (liquid), droplets that have condensation, condensed from Water vapor#In Earth's atmosphere, atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is res ...

. A drawback of a simple bivouac sack is the humidity that

condense Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...

s on the inner side, leaving the occupant or the sleeping bag moist. Moisture severely decreases the insulating effect of sleeping bags. This problem has been alleviated somewhat in recent years with the advent of more waterproof, but breathable fabrics, such as Gore-Tex, which allow some humidity to pass through the fabric while blocking most external water. A traditional bivouac bag typically cinches all the way down to the user's face, leaving only a small hole to breathe or look through. Other bivouac sacks have a mesh screen at the face area to allow for outside visibility and airflow, while still protecting from insects.

''Boofen''

In the German region of Saxon Switzerland in the Elbe Sandstone Mountains, climbers refer to overnighting in the open air as ''Boofen'' (pronounced "bo-fen"). The spot selected for overnight stays usually comprises an overhang in the sandstone rock or a cave, the so-called ''Boofe'' ("bo-fe"). This has often been adapted with a sleeping area and fireplace. In the

national park A national park is a nature park designated for conservation (ethic), conservation purposes because of unparalleled national natural, historic, or cultural significance. It is an area of natural, semi-natural, or developed land that is protecte ...

itself, ''Boofen'' is only permitted at designated sites and only in connection with climbing, although in this case lighting fires is absolutely forbidden. The colloquial

Saxon The Saxons, sometimes called the Old Saxons or Continental Saxons, were a Germanic people of early medieval "Old" Saxony () which became a Carolingian " stem duchy" in 804, in what is now northern Germany. Many of their neighbours were, like th ...

word ''boofen'' was derived from ''pofen'' (to sleep soundly and for a long time).

Examples

Count Henry Russell-Killough, the "hermit of the

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

", is broadly accredited with the invention of the bivouac in extreme, inhospitable places. He would bivouac in the open, creating a blanket of rocks and earth or using a simple bag. An example of a bivouac being made in a time of urgency was shown when the climber Hermann Buhl made his ascent of

Nanga Parbat Nanga Parbat () (; ), known locally as Diamer (), is the ninth-highest mountain on Earth and its summit is at above sea level. Lying immediately southeast of the northernmost bend of the Indus River in the Gilgit-Baltistan region of Pakistan-a ...

in 1953 and was forced to bivouac alone on a rock ledge at altitude, in order to survive until the following morning. Modern bivouacs have evolved to offer heightened levels of comfort for climbers and explorers. Modern portaledges (the vertical camping version of a tent) are a more comfortable, safer, and sturdier option to hanging hammocks.

References