As floods,
hurricanes, earthquakes and volcanoes destroy or damage urban areas with growing
frequency large numbers of people will need to be rehoused. The proportion of
people living in towns and cities is expected to keep growing – it is already
over 50% - and many of these extreme natural events occur in or near them
because they tend to be built close to
- Tectonic fault lines – because mineral wealth is concentrated in such places
How do you rehouse the population of a large shanty town flooded as the sea level rises? How do you rebuild a large part of a modern city demolished by an earthquake?
It is too late to undo the damage done by man already,
in the sense of accentuated climate change and of shoddy architecture in the wrong
places. Millions of people are likely to need rehousing in the coming decades
as extreme climate events increase even faster than predicted and as people
continue to flock into cities. Providentially, a new kind of building
technology is evolving fast and could be ready for serious, in-field use within
a decade: 3 dimensional printing of houses.
3D house printing is achieved in a manner similar in
principle to the 3D printing already being used. For example, aircraft wings
can be designed on a computer and printed layer by layer by extruding the
appropriate material through a computer controlled nozzle. There is even a
widely available 3D printer costing about a $1000 available to consumers,
called the Cube.
It enables you to print out real, physical objects instead
of symbols on paper. The set-up for constructing a house would require an
overhead gantry from which the printing nozzle would be suspended. The movement
of this nozzle, and the rate of supply of composite fibre concrete to it, would
be controlled by software defining the structure of the house. This special
concrete, which retains its shape while still wet, would be deposited layer by
layer, gradually building up the walls. At intervals the printing would be
paused to allow floors, insulation, wiring, plumbing and drainage pipes to be
installed. The whole process should take less than a day. An engineering professor, Behrokh
Khoshnevis, at the University of Southern California, is behind this idea.
See this news item.
Apart from helping communities to
recover from disaster the 3D printing principle could be used for house
building in normal situations. There are large numbers of people living with
minimal protection against the elements and deprived of comforts most people
reading this have come to expect. There must be some way of combining this
method of building with the installation of sewage systems and power grids.
Khoshnevis also proposes using 3D printing as a way of
building space colonies in advance of the intended inhabitants. I have not
looked into this but it could be more cost effective than transporting
prefabricated modules if you wanted to build a colony. It would be a matter of
transporting one gantry plus the material rather than numerous modules which
would have to be skilfully handled and put together. I suspect that the total freight
storage space needed to transport the modules would be larger than for the 3D
printing system.
One potential of present small scale 3D printing is its use as a basis
for custom manufacturing units in shops to help regenerate High Streets. It could possibly be combined with skilled craftsmanship to finish off a basic form.
This is powerful technology and it is difficult to imagine
it not being used in a big way somehow.
John
Author, 2077 AD
Reach me at cosmik.jo@gmail.com
