Tent

From Wikipedia, the free encyclopedia

A tent is a shelter, consisting of sheets of fabric or other material draped over or attached to a frame of poles and/or ropes. Some tent styles are free-standing, while others are attached to the ground using guy ropes tied to stakes (pegs). Tents were first used as portable homes by nomadic peoples, but today, their main application is for recreational camping. Modern tents are usually made of fire-retardant material.

Tents range in size from those barely large enough for one person to sleep in up to huge (circus) tents capable of seating thousands of people. The bulk of this article is concerned with recreational camping using tents capable of sleeping from 1 up to about 10 people. Larger tents are discussed in a separate section below.

Tents for recreational camping are generally transportable by car. Depending on tent size and the experience of the person or people involved, such tents can usually be assembled (pitched) in between 5 and 25 minutes; disassembly (striking) takes a similar length of time (some very specialised tents have spring-loaded poles and can be 'pitched' in 2 seconds, but take somewhat longer to strike).

Smaller tents may be sufficiently light that they can be carried for long distances on a person's back, or on a touring bicycle, a boat, or even a pack animal.

The military organizations of most nations use tents to temporarily house troops living and working under field type conditions.

Contents 1 General considerations 2 Parts of a modern tent 3 Design factors 4 Shelters 5 Current tent styles 5.1 Rigid poles 5.2 Flexible poles 6 Older tent styles 7 Larger tents 8 See also 9 External links

[edit] General considerations

Tent fabric may be made of many materials including cotton (canvas), nylon, and polyester. Cotton absorbs water, so it can become very heavy when wet, but the associated swelling tends to block any minute holes so that wet cotton may be more waterproof than dry cotton. Nylon and polyester are much lighter than cotton and do not absorb much water; with suitable coatings they can be very waterproof, but they tend to deteriorate over time due to a slow chemical breakdown caused by ultra-violet light. Since stitching makes tiny holes in a fabric, it is important that any seams are sealed or taped to block up these holes.

Rain resistance is measured as a hydrostatic head in millimetres (mm). This indicates the pressure of water needed to penetrate a fabric. Heavy or wind-driven rain has a higher pressure than light rain. Standing on a groundsheet increases the pressure on any water underneath. Fabric with a hydrostatic head of 1000 mm or less is best regarded as shower resistant, with 1500 mm being usually suitable for summer camping. Tents for year round use generally have at least 2000 mm; expedition tents intended for extreme conditions are often rated at 3000 mm. Where quoted, groundsheets may be 5000 mm or more.

Many tent manufacturers indicate capacity by such phrases as "3 berth" or "2 person". These numbers indicate how many people the manufacturer thinks can be crammed snugly into a tent with just sleeping bags. These numbers do not allow for any personal belongings such as luggage, inflatable mattresses, camp beds, cots, etc. Experience indicates that camping may be more comfortable if the actual number of campers is 1 or even 2 less than the manufacturer's suggestion.

Tents can be improvised using waterproof fabric, string, and sticks. This allows them to be easily built and moved.

[edit] Parts of a modern tent

• There are three basic types of tents (but each type may appear in many different styles):
  • Single skin (USA: single wall). Only one waterproof layer of fabric is used, comprising at least roof and walls.
  • Single skin with flysheet. A flysheet or rain fly is suspended over and clear of the roof of the tent; it often overlaps the tent roof slightly, but does not extend down the sides or ends of the tent.
  • Double skin (USA: double wall). The outer tent is like a flysheet, but extends right down to the ground all round. One or more'inner tent's provide sleeping areas. The outer tent may be just a little larger than the inner tent, or it may be a lot larger and provide a covered living area separate from the sleeping area(s). An inner tent need not be waterproof.

When a flysheet or outer tent is used, it is important that there be no contact with the inner tent it is protecting; this keeps the inner dry even if the outer is wet. Expedition tents often have extra poles to help ensure that wind does not blow the two layers into contact. The double layer may provide some insulation.

• A 'groundsheet'is used to provide a waterproof barrier between the ground and a sleeping bag. With double skin tents, the inner tents normally have a sewn-in groundsheet, but a separate flat groundsheet may be provided for any living area. With single skin tents, the groundsheet may be sewn in or separate. Normal practice with sewn-in groundsheets is for the groundsheet to extend some 15 cm (6 in) up the lower part of the walls (sometimes called a bath-tub arrangement); this copes with a situation where water seeps under the side walls of the tent. Separate groundsheets allow loadsharing when backpacking, and may make it easier to pitch and strike a tent, but they provide less protection against insects etc. getting into the sleeping area; also, if any part of a separate groundsheet protudes from under the side walls, then it provides a ready path for moisture to flow into the tent.

• The poles provide structural support.They may be collapsible for easier transport and storage. Some designs use rigid poles, typically made of metal, or sometimes wood. Other designs use semirigid poles, typically made of fiberglass, or sometimes of special metal alloys.

• Stakes or pegs may be used to fasten the tent to the ground. Some are attached to guy ropes that pull outward on the poles and/or fabric to help shape the tent or give it additional stability. Others are used to anchor the bottom edge of the fabric to the ground. Pegs may be made of wood, plastic, or metal. A mallet may be needed to drive thicker pegs into the ground. Skewer metal pegs consisting essentially of a length of thick wire with a hook on one end can usually be inserted by hand, except if the ground is very hard, but may not be as strong as more substantial pegs. Pegs used for guy ropes should not be driven vertically into the ground; instead for maximum strength they should be driven in at an angle so that the peg is at right angles to the guy rope attached to it. Lighter free standing tents may need some guy ropes and pegs to prevent them from being blown away.

• Multiple air vents should be provided to help reduce the effects of condensation. When people breathe, they expel quite a lot of water vapour. If the outside of the tent is colder than the inside (the usual case), then this vapour will condense on the inside of the tent, on any clothing lying about, on the outside of a sleeping bag, etc. so that everything is damp in the morning. Hence it is important to have plenty of ventilation to help dispel the vapour and get it outside the tent, even if this lets in cold air and makes the tent feel a little cooler. Many inner tents are made of some 'breathable' material so that water vapour can more easily pass through it.

• An optional tent footprint or groundsheet protector may be used. This is a separate flat groundsheet which goes underneath the main groundsheet, and is slightly smaller than that groundsheet. The intention is to protect the main groundsheet, especially when camping on rough terrain, since it is much cheaper to replace a separate footprint groundsheet than it is to replace a sewn-in groundsheet.

[edit] Design factors

Many factors affect tent design, including:

• Financial Cost.
• Intended use.
  • Backpacking/tramping, having to carry the tent all day. Weight and size are the most crucial factors.
  • Touring, having to pitch and strike the tent every day or so. Ease of pitching/striking the tent then becomes important.
  • Static, staying at one campsite for a week or two at a time. A comfortable camping experience is then the target.

• Camping season.

A tent required only for summer use may be very different from one to be used in the depths of winter. Manufacturers label tents as one-season, two/three-season, three/four season, four season, etc. A one-season tent is generally for summer use only, and may only be capable of coping with light showers. A three-season tent is for spring/summer/autumn and should be capable of withstanding fairly heavy rain, or very light snow. A four-season tent should be suitable for winter camping in all but the most extreme conditions; an expedition tent (for mountain conditions) should be strong enough to cope with heavy snow, strong winds, as well as heavy rain. Some tents are sold, quite cheaply, as festival tents; these may be suitable only for camping in dry weather, and may not even be showerproof.

• Size of tent.
  • The number and age of people who will be camping determines how big and what features the sleeping area(s) must have.
  • To allow for inclement weather, some covered living space may be desirable. Alternatively, cyclists on a camping trip may wish for enough covered space to keep their bicycles out of the weather.
  • To allow for sunshine, an awning to provide shade may not go amiss. Some tents have additional poles so that the fabric doorways can be used as awnings.
  • Internal height. Manufacturers quote the maximum internal height, but the usable internal height may be a little lower, depending on the tent style: ridge tents have a steeply sloping roof so the whole height is rarely usable, dome tents slope gently in all directions from the peak so something close to the whole height is usable in the centre, tunnel tents have a good usable height along the center line. Frame and cabin tents have gently sloping roofs and near vertical walls, so both the wall height and the maximum height must be considered.

Height is significant in connection with moving around in a sizable tent, and in changing clothing in any tent. There are basically four useful heights to consider: lie down only, sit, kneel, stand. The exact heights at whch these apply depend on the heights of the campers involved; those over 182 cm (6 ft) are likely to have less choice of tents than those who are somewhat shorter. As a starting point, sitting height is often between 90 and 105 cm (3 ft to 3 ft 6 in), and kneeling height may be between 120 and 150 cm (4 ft to 5 ft).

• Number of sleeping areas.

Larger tents sometimes are partitioned into separate sleeping areas or rooms. A tent described as viz-a-viz usually has two separate sleeping areas with a living area in between.

• Tent colour.

In some areas of some countries (e.g. Lake District in England), there may be restrictions as to what colour tents can be, there by reducing the visual impact of campsites. The best colors for low visibility are green, brown, or tans. It is important to check for any such restrictions

• Setup effort.

Some styles of camping and living outdoors entails quick setup of tents. As a general rule, the more robust the tent, the more time and effort needed to setup and dismantle. The style of the tent also has a great impact on its ease of use.

[edit] Shelters

Shelters are not normally used for sleeping. Instead they may act as a store or provide shelter from sun, rain, or dew.

• A flysheet consists of a single rectangular sheet of material. Two opposite sides are held up in the middle by poles, or sometimes just a rope between conveniently placed trees. The tops of the poles are attached via guy ropes to pegs, in order to keep the poles upright. Additional guy ropes are attached to the lower edges to pull them outwards away from the poles.

• A gazebo uses a framework of metal poles to support a roof. This structure provides a lot more usable space than does a flysheet, since the gently sloping roof allows for a reasonable amount of headroom even at the edges (like a frame tent). Because a gazebo is free-standing, it is often used as a shelter for a temporary shop at a fair or street market.

• Beach tents are often a simplified form of dome tent and provide a useful (relatively sand-free) place to temporarily store beach equipment, but are at most showerproof. Some beach tents use specially treated fabric which is opaque to ultra-violet light, and so provide some protection against sunburn. Maximum height is typically about 120 cm (4 ft), and they are usually not large enough for an adult to lie down in.

• Fishermen's tents are also modified dome tents, often with a projecting awning high enough to sit under, but sometimes with no closable doorway.

[edit] Current tent styles

With modern materials, tent manufacturers have great freedom to vary types and styles and shapes of tents.

• The poles effectively hold the tent in the required shape.
• Poles which dismantle for ease of transport are either colour-coded or linked by chain or cord, so there is little doubt as to which poles connect where.
• Relatively few guy ropes are needed (sometimes none).
• The exact positioning of any guy ropes is not too critical.

[edit] Rigid poles

Many tents which use rigid steel poles are free-standing and do not require guy ropes, though they may require pegs around the bottom edge of the fabric. These tents are usually so heavy (25 to 80 Kg) that it takes a rather strong wind to blow them away.

• Frame tents are double-skin tents. They have a living area and one or more nylon/polyester inner tents. The outer tent is draped over a free-standing steel frame, and may be made of canvas or polyester (the latter often has a hydrostatic head of 3000mm, i.e. three season camping). The living area is generally at least as large as the sleeping area, and there may be a specific section with window and extra air vents for use as a kitchen. The walls are nearly vertical and are typically about 150 to 180 cm high (5 ft to 6 ft). The center of the gently sloping roof is often 210 cm (7 ft) high or more and provides reasonable headroom throughout. The smaller 2-person models were less than 3 metres square (10 ft), but these have largely been replaced by dome or tunnel tents. The larger 8-person models may exceed 5 metres (16 ft) in length and/or width.

• Cabin tents are single-skin tents used mainly in the USA. They often have nylon walls, polyester roof, and a polyethylene floor, plus an awning at one or both ends. With a hydrostatic head of only 1000 mm, they may best be considered as summer tents. Removable internal dividers allow the cabin to be split into 'rooms'. Sizes may range from 13 ft by 8 ft (2 rooms) up to 25 ft by 10 ft (4 rooms), with wall and roof heights similar to those of frame tents. There are three separate pole units, with each unit consisting of two uprights and a connecting ridge. These pole units support the centre and ends of the roof, and are usually outside the tent.

[edit] Flexible poles

Flexible poles used for tents in this section are typically between 3 and 6 metres long (10 and 20 feet) and are normally made of tubes of fibreglass with an external diameter less than 1 cm (1/3 inch). For ease of transportation, these poles are made in sections some 30 cm to 60 cm long (1 to 2 ft), with one end of each section having a socket into which the next section can fit. For ease of assembly, the sections for each pole are often connected by an internal cord running the entire length of the pole.

• Dome tents have a very simple structure and are available in a wide variety of sizes ranging from lightweight 2-person tents with limited headroom up to 6 or 9-person tents with headroom exceeding 180 cm (6 ft). These may be single wall, or single-wall with partial flysheet, or double wall. Depending on the pole arrangement, some models pitch outer-tent first, while others pitch inner-tent first. The former helps keep the inner tent dry, but the latter is easier to pitch.

The basic dome has a rectangular floor and two poles which cross at the peak; each pole runs in a smooth curve from one bottom corner, up to the peak, and then down to the diagonally opposite bottom corner. There are usually special fittings at each corner which fit into sockets at the ends of each pole - pole tension keeps everything in shape. The poles usually run outside the tent fabric, which is attached to the poles by sleeves. In some new models clips are also used. Dome tents do not require guy ropes and pegs for structural integrity, but must be pegged down in high winds.

The basic dome design has been modified extensively, producing tents with three poles, tents with irregularly-shaped bases, and other unusual types. A common variation is to add a third pole going from corner to corner on one side; this is angled away from the tent, and supports an extended flysheet or outer tent to give a porch/storage area.

• Tunnel tents may offer more usable internal space than a dome tent with the same ground area, but almost always need guy ropes and pegs to stay upright. These are almost always double wall tents. Sizes range from 1-person tents with very limited headroom up to 8 or 10-person tents with headroom exceeding 180 cm (6 ft). Tunnel tents have a low end profile making them great for high wind situations.

A basic tunnel tent uses three flexible poles, arranged as three parallel hoops, with tent fabric attached to form a tunnel. The most common designs have a sleeping area at one end and a porch/storage/living area at the other. Smaller designs may use only 2 poles and larger designs may use 4 poles; the latter may have a sleeping area at each end and a living area in the middle.

• Hybrid dome/tunnel tents are now common. One variation is to use a basic dome as the sleeping area; one or two hooped poles to one side are linked by a tunnel to the dome to provide a porch. Another variation is to use a large dome as the living area, with up to 4 tunnel extensions to provide sleeping areas.

• Geodesic tents are essentially dome tents with 2 or more extra poles which criss-cross the normal two poles to help support the basic shape and minimise the amount of unsupported fabric. This makes them more suitable for use in snowy conditions. To help withstand strong winds they are rarely more than 120 or 150 cm high (4 to 5 ft).

• Single-hoop tents use just one flexible pole and are often sold as light-weight 1 or 2-person tents. These are the modern equivalent of older style pup tents, and have the same feature of somewhat limited headroom. Different styles may have the pole going either along or across the tent.

[edit] Older tent styles

Most of these tent styles are no longer generally available. Most of these are single-skin designs, with optional fly sheets for the ridge tents.

All the tents listed here had a canvas fabric and used a substantial number of guy ropes (8 to 18). The guys had to be positioned and tensioned fairly precisely in order to pitch the tent correctly, so some training and experience were needed. This made these styles relatively unsuitable for casual or occasional campers. Pup tents might use wooden or metal poles, but all the other styles mentioned here used wooden poles.

• A pup tent is a small version of a ridge tent intended for 2 or 3 people. It usually has a rectangular floor of size ranging from 4 ft by 6 ft up to 6 ft by 8 ft, and ridge heights ranging from 3 ft up to 5 ft. The side walls are usually about 1 ft high. There are guy ropes for each pole, at each corner, and in the centre of each side, and these guy ropes help to maintain the required shape. Earlier versions had a single upright pole at each end, while later versions often have two poles at each end, arranged rather like an 'A' shape, in order to make access easier. Some models have a horizontal ridge pole joining the tops of the end poles to support the centre of the tent.

• A ridge tent can sleep 5 to 8 people. They usually have a rectangular floor of size ranging from 8 ft by 10 ft up to 10 ft by 16 ft, and ridge heights around 6 ft to 7 ft. The side walls are usually about 3 ft high. They normally have a single upright pole at each end with the tops joined by a horizontal ridge pole. Longer models might have an additional upright pole in the centre to help support the ridge pole. They often have two guy ropes at each corner, and guy ropes every 2 ft along the sides. If strong winds are expected then two additional storm guy ropes are attached to the top of each pole.

• A square centre-pole tent was often used for family camping in the first half of the 20th century. Despite the use of 9 poles and 12 guy ropes, such a tent could be pitched by an (experienced) family of four in some 10 to 15 minutes. These tents had a square floor of size ranging from 8 by 8 ft up to 15 by 15 ft. There were poles about 5 ft high at each corner and in the middle of each side, and a 10 ft or 12 ft pole in the centre - the walls were vertical and the roof was pyramid-shaped, so there was plenty of headroom over most of the tent.

• A Sibley tent (bell tent) had a circular floor plan some 10 ft to 15 ft across, a single central pole some 10 ft high, and walls about 3 ft high. Guy ropes were connected every 2 ft around the top of the walls - these had to carefully tensioned to hold the pole upright and keep the tent in shape.

[edit] Larger tents

These larger tents are seldom used for sleeping.

• "Party tents" or "marquees" are common for large wedding, fairs, and other gatherings. They are made from tough vinyl. These tents are very expensive and require specilized equipment and skill to erect, so they usually must be rented. Many corporate companies own marquee tents but have them installed and maintained by qualified professionals. The larger party tents are held down with tensioned rachets. Sizes range from 10' x 10' to 150' x 400'. Properly installed party tents are dramatic and very strong.
• Traditional Pole Marquees - Consist of Canvas and more recently PVC, under tension by means of centre poles, side poles and guy ropes which are attached to ground stakes hammered into soft surfaces only such as a lawn or field. Hand made of white cotton canvas, traditional poled marquees are more attractive but much less practical and versatile than aluminium frame marquees. The modern PVC traditional pole marquee was introduced due to the material being easier to clean than woven canvas and giving them a longer hire life span.
• Aluminium Frame Marquees - Aluminium frame tents have no centre poles or guy ropes, can be erected on any surface and adjacent to buildings or annexe tents. Much more stable and can span a much wider area over pools, flower beds or trees.
• Marquee tents typically have interchangeable parts, which allow for a rental company to easily expand to larger sizes. Tents can be ordered in a variety of colours, however white is by far the most popular colour. Skylights can also be built into the fabric, which allow a greater amout of light to enter and is useful if walls are being used. Walls can also be ordered with clear vinyl windows in them.
• "Bail Ring Tents" are usually tents that are 100' to 150' feet wide and expandable to any length. They can be made from either vinyl or canvas. The purpose of the bail ring style is to raise an enormous amount of material "the tent" off the ground without using heavy machinery. Initially, the center poles are raised and guyed out to stakes after which the tent is spread out and connected to the bail ring using shackles. Once the outside of the tent is raised a crew of men can go under the tent and start raising the bail ring up the center pole using a system of pullies. This style of tent is not as popular as it was in the past due to the advancement of forklifts and skidsteers. There was a time when even smaller tents 40' to 100' were often raised and set using a bail ring.

• The four Major golf tournaments have tents set up they are usually 40x40.

• A "Rub Hall" is a large tent used primarily as emergency warehousing.

• A circus tent usually has one or more oval or circular arenas surrounded by tiered seating which might accommodate thousands of people. Nowadays such large tents are made of some artificial fibre (polyester or vinyl) and are often erected with the help of cranes. In earlier times it was common for the circus elephants to be used as a source of power for pulling ropes to haul the canvas into position.

• Denver International Airport's main terminal building is a tent style building.

• See also: carpa.

[edit] See also

• Bivouac sack
• List of types of lodging
• Traditional tent types
  • Fly (tent)
  • Tarpaulin
  • Tipi
  • Wigwam
  • Yurt
  • Sibley tent
• Tensile architecture

[edit] External links

• Backpacking Tents - Information and comparison of tents.
• The Gear Junkie - review of some lightweight tents.
• Red Lion Marquees - a marquee hire company based in Bedfordshire, England. The site includes many images of both tradtional and modern clear span framed marquees.