Manual for

N55 SPACEFRAME


N55 SPACEFRAME, 1999. Music by Anders Remmer

Introduction:

The N55 SPACEFRAME is a low-cost, movable lightweight construction that can easily be transformed. It is dimensioned as a living unit for 3-4 persons and demands practically no maintenance. The construction can be erected by anybody in a short time.
The N55 SPACEFRAME is configured as a truncated tetrahedron with an indoor ground floor of approx. 20 m2. According to needs and economy, the size and configuration may be changed, and extra floors and rooms may be included: it is easy to add to the construction in stages.
The entire unit is constructed from small lightweight components which all can be handled without the use of cranes or other heavy machinery. All components are materially minimised, have a low degree of manufacturing and are produced by a few simple machines, which anybody can operate. When stacked, the components take up very little space. The construction is assembled by hand. It can be erected directly onto the ground, since a cast foundation is not necessary. The structure can be dismantled and rebuilt many times over without damaging any of the components. The construction can be moved either fully assembled, or partly dismantled.



Technical background:

By constructing spaceframes one is able to utilize geometry to achieve very strong, self-load-bearing structures and at the same time save materials and work.
The building system in N55 SPACEFRAME is configured as a space lattice known as the common space lattice, the octet truss, or the octahedron-tetrahedron complex.
The geometry of this space lattice does not depend on gravity for strength or integrity, and therefore is suitable for employment in satellites and space platforms, in big halls etc, but is rarely employed for housing and other small-scale purposes.
The distribution of tensile and compressive forces, the rigidity and the ability of the structure to deform locally makes it safe under extreme conditions like earthquakes or sudden impacts. Because of the geometry, loads are distributed well throughout the construction.
All the struts in the construction are of equal length, ensuring an economic production with few different components.
The octet truss is among the structures in which one obtains the greatest strength using the least materials.

Construction:

The struts used in the building system for the N55 SPACEFRAME are acid resistant stainless steel, highly durable, prepared for numerous reassemblies and chemically immune to most conditions. The equal-length struts are bent in 70° angles for tetrahedra and 110° angles for octahedra. The struts are assembled by hand using stainless acid resistant bolts and nuts that are tightened with a screwdriver. Two tetrahedra and one octahedron make the basic building "brick", with which one can build walls, foundation and roof.
The structure can be thinned out to use fewer struts. The resulting space enclosure has walls of 50 cm, inclining at angles of 70° and 110°. The walls can be filled with insulating material, or be used as cupboards, to hide electrical installations or for growing plants inside.
On the outside the construction is covered with plates in acid resistant stainless steel, which need no maintenance.
Inside planes are covered with moisture-absorbing plaster-fibreboard plates. The floor is made of birch plywood and polycarbonate is used for windows. The window frame is covered with plates of insulating, light-reflecting polyethylene foam.
The door is a plate of honeycomb aluminium. Polycarbonate is used for skylight. If the walls are properly insulated, there should be no need to heat the room except under extreme conditions. Lighting, sun radiation, cooking and normal activities will provide sufficient heating. All kinds of insulating material can be used: Rockwool, sheep wool, paper, polystyrene, and so on.



During assembly one may climb in the structure, using a climbing harness for security
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Assembly:

Alternating tetrahedra/octahedra are put together to form girders which are combined to form the base. The walls are built onto the base one girder at the time. During assembly, the struts are bolted only loosely together, and the bolts are finally tightened when all the parts of a layer are in place.

The construction is built using two kinds of struts: Tetrahedra are assembled using 6 pc 70° struts. 12 pc 110° struts for octahedra are then attached to the tetrahedra.

Two tetrahedra, one octahedron: the "brick" in the construction. This configuration fills space in all directions.

The struts are overlapping each other in a regular pattern.

Fishplates are bolted onto all meeting points in order to increase rigidity of the inner and outer plane (“stressed skin”).

Foundation: Polyethylene plastic tanks are built into the lowest level in the construction. The tanks are each filled with approx. 90 liters of water, together adding about 3 tons to the total weight of the construction. One can also use earthspears or fill the lower level with sand. Shields may be attached to prevent moisture and scavengers from entering from below.

Roof: The roof is covered with plates of stainless steel and polycarbonate, mounted with draught strips and rubber. The roof has one central summit and one in each corner. The height and decline of the plates is regulated with wedges and long screws.

Door: The entrance is a hexagonal hole which is closed with an aluminium honeycomb plate. The door is closed by pulling the rubber handle and turning the key.

Outside plating: The construction is faced using stainless acid resistant steel triangles and squares. The plates overlap and the tightness is regulated with wedges. This surface demands no treatment or maintenance.

Windows: The construction is slightly dynamic and is influenced by temperatures. Glass is therefore not suited for windows and polycarbonate is used instead. A slight deformation of the material will not cause it to break. The windows are opened and closed by regulating the long fixture screw at their low corners.

Window frames: The window frames are covered with plates of polyethylene-foam, which is easy to cut and mount and reflects light.

Inside plating: Plaster-fiberboard plates are used to cover the inner walls. The plates are treated with varnish and mounted with draught strips.

Floor: Birch plywood, varnished, mounted with wedges and draught strips.

The octahedron-tetrahedron complex has been discovered and formulated within various contexts: chemistry, physics, mathematics and other. A construction system (the "octet truss") which makes use of this geometry was patented in the 1940´s by R. Buckminster Fuller, USA. The system was used as a curved space frame for building the Ford Rotunda in Detroit.