A bivouac shelter 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, or an officer. Etymology The word ''soldier'' derives from the Middle English word , from Old French ...

, or people engaged in backpacking,

bikepacking The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...

scouting Scouting, also known as the Scout Movement, is a worldwide youth Social movement, movement employing the Scout method, a program of informal education with an emphasis on practical outdoor activities, including camping, woodcraft, aquatics, hik ...

, or

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

. 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 is any product or physical matter stop changing it. Minerals and the metals that can be extracted from them (without further modification) are also considered to belong into this category. Natural materials are used as building ma ...

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

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

s, and similar material for

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

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 have fallen to the ground. This detritus or dead organic material and its constituent ...

) for insulation. Modern bivouacs often involve the use of one- or two-man 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. A bivouac shelter is colloquially known as a bivvy (also spelled ''bivy'' or ''bivvi'' or ''bivi'').

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 was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts e ...

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 material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

, 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 t ...

of the shelter and a second as the groundsheet. The 'roof' flysheet is suspended along in 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, including only woody plants with secondary growth, plants that are ...

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 vapo ...

. A basha is a simple tent, 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, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not ...

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

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

symmetry Symmetry (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definiti ...

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

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

. A drawback of a simple bivouac sack is the humidity that condenses 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 sack have a mesh screen at the face area to allow for outside visibility and airflow, while still protecting from insects. Fully zipping up a bivouac sack is poor practise, both from the obvious risk of hypoxia, and the dramatically increased levels of condensation that will form inside the bag.

''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 natural park in use for conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual ...

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

Examples

Count Henry Russell-Killough, the “hermit of the Pyrenees”, 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 in 1953 and was forced to bivouac alone on a rock ledge at 8000 m 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