Fourth Year Engineering
Design of Temporary Shelters for Refugees
(Structural Engineering Project, Rachel Battilana)
Emergency shelters currently used by the UN in cold weather situations are designed to have space-heating stoves inside them. Several hundred people froze to death in refugee tents in Afghanistan, when fuel supplies for their wood-burning stoves failed to materialise. Such shelters were also used in the Balkans in 1998, where temperatures during the winter months got down to -20°C, combined with Gale Force 6 winds, but the quantity of fuel required to bring the current design of tent up to even survival temperatures is colossal.
My project was to investigate the current tent design and come up with some recommendations to improve the situation. One of the main problems is that the tents are very draughty, so an obvious solution is to provide an internal liner. A materials company called Web Dynamics, who have worked on this project before, agreed to make some special, breathable, insulating fabric for a liner. The fabric was sewn up into a liner shape by H.M. Ashwell High Security Prison Textile Department: no mean feat as the material consists of 50 m2 of what essentially looks like a big white duvet.
Initial testing of the tent with liner was carried out using a brand new environmental test chamber belonging to the Ford Motor Company in Essex. This is normally used to test the performance of vehicles and is capable of simulating Arctic temperatures and howling winds. For a long weekend in February it was home to our refugee shelter, as we tested it under wintry Kosovan conditions, using thermocouples to map out temperatures in and around the tent, and a thermal image camera to observe where the heat was escaping. An electric heater was set up inside the tent to model the effect of a wood-burning stove with the "UN recommended" heat output. Results were better than I had hoped, with temperatures soaring alarmingly towards 50°C when using the tent in conjunction with the liner.
I have also conducted field trials in the grounds of my college where a number of volunteers agreed to spend a night in the tent so that I could log temperatures with the tent in use on a cold ground base. Apart from the issue of saving lives, the aim is also to calculate how many truckloads of fuel (or forests of trees) can be saved by use of the liner. If the extra insulation proves economically and logistically viable, the UN will be interested in discussing what has been done and generating some changes.