Tents: the State of the Art in Deployable Shelter
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580 SEEKING THE CITY Tents: The State of the Art in Deployable Shelter ROBERT CORSER University Of Kansas INTRODUCTION: DEPLOYABLE SHELTER and a locking mechanism (H2, foglio 30v, 31r) as FROM PRE-HISTORY TO DAVINCI AND seen in Figure 1. It is unlikely that either the tent TODAY or this structure, described simply as a “padiglion” (pavilion) was intended for emergency use. It is Tents have been a primary form of human shel- clear however that DaVinci is speculating about ter, especially for nomadic cultures, hunting par- systems of deployment that would be far more ties and military expeditions, for as long as we self-contained than a traditional tent’s assemblage have records of human activity. Cave paintings of loose parts. These proposals for more highly supply the earliest evidence of tents dating to the integrated systems may well be the fi rst example Cro-Magnon period in Europe, ten to twenty thou- of what we would today call self-contained, rap- sand years ago.1 Although nomadic peoples have idly deployable shelters. Unfortunately, no other largely disappeared, the plains of Eurasia still host graphic material exists to help further explicate numerous bands of yurt-dwelling shepherds who DaVinci’s thinking, and as with nearly all but the utilize traditional portable shelters. In antiquity, most recent deployable structures, no physical tents came to occupy a central role in the rise evidence of any kind remains. Beyond these in- of empires and in the development of numerous vestigations, there is little evidence of efforts to cultures. The basic unit of the Roman legions was signifi cantly transform age-old approaches to tent the “contubernium,” a party of eight men sharing design until well into the 20th century. Why has a tent and a packhorse.2 The description of the the tent proved to be such an enduring solution portable temple contained in the book of Exodus and why has innovation been so rare? might serve as the archetypal description of tent technology spanning the period from biblical times ARE TENTS THE BEST STRATEGY FOR until very recently.3 In almost every recorded DEPLOYABLE SHELTER? example, tents consist of a loose assemblage of posts with layers of fabric skins held taut by lines The example of history indicates that the tent, in or cables in tension. one form or another, has long been the most wide- spread solution to the problem of deployable shel- Historical evidence of attempts at innovation in the ter. Prior to the 20th century, it is nearly impos- area of tents and temporary structures is sparse at sible to identify any other signifi cant approach to best. Leonardo Da Vinci’s more than 5000 pages of the problem. In general, tent construction offers extant drawings record studies of everything from numerous advantages, among them: simplicity, human anatomy to fl ying machines, siege engines extreme portability, and economy of means. Tents and churches. The collection “Manuscript H” con- are easy for individual users to carry, construct, tains some of his few known sketches for tents or modify if necessary, and maintain. Of course tents portable shelters.4 One view seems to show a sys- also suffer from numerous drawbacks in compari- tem for rapidly raising a fairly traditional tent with son with other possible systems, including relative a tension cables set in a ring. (H1, foglio45r) An- structural instability in severe weather and very other shows a three-dimensional view and details limited thermal performance. Since expeditions, indicating a framework that is foldable with hinges wars and emergencies are generally hoped to be TENTS: THE STATE OF THE ART IN DEPLOYABLE SHELTER 581 Because the western culture of mobility is typically associated with automobiles or aircraft, it should not be surprising that approaches to deployable shelter have also taken a vehicular track. Camp- ers, trailers, and hybrids like pop-ups all share the distinction that they are based on a fi xed chassis on wheels with much or all of their enclosed vol- ume delivered in fi nished form. The advantages of vehicular systems are that they are potentially the most stable and durable approach to deploy- Figure 1 - Roman military tents from the Column of able shelter, and they offer the possibility of the Trajan (L) and details of folding pavilion Leonardo Da most complex layered construction for potentially Vinci, Manuscript H (R) the best thermal performance. The disadvantages, however immediately outweigh the advantages for most situations, because they are the most costly, temporary situations of extremity, little interest least effi cient to deploy, and least fl exible in their has traditionally been focused on comfort or lon- use. As the FEMA trailers of hurricane Katrina so ger-term durability. But as wars, man-made and clearly illustrated, campers are slow to deploy in natural disasters and their associated population large numbers, expensive, wasteful of resources, displacements become more widespread and their and far from user-friendly. Although they might effects longer lasting, rapid shelter technology be the longest lasting option, compared with their needs to respond with better performance. high cost, they are uneconomical in the extreme.6 Do other deployable systems rise to the challenge It is still the case that the most advanced military of offering higher performance shelter than tents? forces in the world rely on tents not only for imme- Panelized, fl at-pack or folding systems, like that diately deployable and temporary shelter, but as shown in one of DaVinci’s sketches, offer some is the case with the Persian gulf wars, also as long advantages because they are potentially more term housing for personnel. The only innovations stable and durable than tents. By virtue of their evident in today’s military tent-cities appear to be more robust construction, they also offer the pos- the adoption of a semi-circular ‘Quonset hut’ form sibility of more complex layered enclosure sys- for simplicity and structural integrity, and the ad- tems for potentially better thermal performance. dition of hugely wasteful air conditioning systems. The disadvantages of panelized systems seem According to a Louisiana National Guard unit, typ- to be their increased complexity, higher costs, ical army tents of today: “…measure about 100 x greater risk of construction diffi culties and more 25’ long and sleep 60 people cot-to-cot. As tents limited portability. In recent designs, the desire go, they are comfortable and robust. About every to alleviate some of theses disadvantages has third cot there is a heating/air conditioning unit.”7 produced mixed results. For example, the Global Village Shelter (GVS) by Ferrara Design, is the In the civilian sphere, the two largest organiza- most widely heralded new approach to deployable tions engaged in global disaster relief are the Unit- shelter.5 It is a fl at pack system of custom shaped ed Nations (UN) and Oxfam, and each agency’s plastic-impregnated cardboard panels that as- long-standing choices for deployable shelter are semble like a large box, approximating the shape noteworthy. In response to both natural disasters of a small hut. While this system, intended to last and long-term population displacement, Oxfam for 18 months, is marginally more durable than has maintained a policy of stockpiling corrugated a good tent, its structural geometry, like a house sheet metal for quick delivery to affected areas. of cards, is highly ineffi cient. Further, the GVS Local inhabitants and aid volunteers are then free still requires the addition of plastic tarps to water- to fl exibly deploy this economical material that proof the roof. Perhaps the greatest advantage combines structural stiffness with basic moisture of the GVS is its comforting domestic appearance. protection.8 The UN has long preferred supplying Beyond that, it offers scarcely any more stability, simple 13 by 16 foot blue plastic tarps, for similar insulation or fl exibility than existing tent designs. reasons of simplicity, immediacy, cost-effective- 582 SEEKING THE CITY ness, and fl exibility. In fact, in current practice, structural systems and the development of new even tents are judged to be too complex by these tent fabrics. agencies. According to the UN High Commission- er for Refugees Handbook for Emergencies: FORMAL AND STRUCTURAL GEOMETRIES “Except for tents in certain circumstances, pre- A basic rectangular plan shape with some sort of fabricated or special emergency shelter has not triangular roof pitch has long been the most com- proved to be a practical option on either cost or cultural grounds… Refugee housing should be cul- mon structural geometry for tents in the western turally and socially appropriate and familiar. Suit- world. This form has its roots in both traditional able local materials are best, if available… (and) house forms, and also in the rectangular shape Wherever possible, refugees should build their of the woven fabrics produced on hand- and ma- own housing…” 9 chine-operated looms. Since the basic cladding material often comes in rectangular pieces, the Given the priorities and attitudes of these agen- most labor effi cient way of producing tents has cies, it is nearly impossible to imagine any system long been to use these raw materials in rectangu- more complex than a tent gaining widespread ac- lar layouts. Civilizations that produced tents pri- ceptance. Their insistence on fl exibility and the marily from animal skins or felted, as opposed to importance of hybridizing the supplied systems with local materials and ingenuity are also key woven, fabrics, have tended to maintain circular concepts for future deployable shelter designs. plan forms. In Native American building cultures, Given the inherent drawbacks of panelized and examples of round teepees and wigwams far out- vehicular systems, the tent appears to remain the weigh what little evidence there is for rectangu- 10 most likely model for the provision of immediate lar tent forms.