pylon competition

England, UK | Competition

OSCILLATIONS introduces a pylon which is not a singular entity but instead an element that changes across the landscape. Its design, while remaining true to the efficiency of the truss, varies on a theme - keeping consistent design clearances and and fabrication rules while at the same time producing different expressions within one family - differing ‘phenotypes’. Designed with algorithmic digital technology, it expresses a controlled complexity which represents our current technologically based culture. Current fabrication technology facilitates this variation. The result is ‘Oscillations’, a network of related elements, each of which delights. One or other may be favoured by individuals but each produces a different expression and can be found in a specific place on the landscape. 

OSCILLATION

Oscillation is a pattern of repetitive variation around a point. The point around which it varies is  often an equilibrium point. Oscillation is associated with both the natural and physical world: the sine wave is one of the most common examples of oscillation. Oscillation occur in electrical energy transmission (AC current) as well as in the movement of light and sound waves, movement of natural organisms as well as in mathematic analysis of structures. Oscillation occurs in technological systems but also in natural systems. Oscillation occurs where energy is transmitted, giving it a special relationship to the pylon.

Where oscillation provides variation, it also provides a predictable pattern with repetition. This also allows repetition in fabrication across the landscape.

OSCILLATION IN DESIGN

The oscillation in the design occurs in two ways. The first is that the angle between the two top support points oscillates: tilting in one direction then reversing to switch to the other side. The oscillation occurs in steps of 15 degrees. Some steps are excluded where the design is unfeasible due to flatness, since this doesn’t allow the angle to the lightning ground. At points, the pylon reaches equilibrium and a symmetry occurs in the design. 

The other oscillation occurs over the landscape - the height of the element varies across the landscape as the oscillation in the angle occurs. As children, we often drive down the road watching the hydro lines on the side of the road from the window. Because of the speed of the car, the images we see are wires, somewhat blurred, oscillating up and down with a rhythm. This design incorporates this sense of speed and time by its variation. This also makes reference to the example of a sine wave where one axis of the graph is amplitude while the other is time. The graph allows the introduction of a static representation of an energy by plotting time along an axis. Similarly, although the towers are static structures, the idea of energy can be introduced: the towers, while not changing location, show a change in amplitude in each instance and the landscape is the axis of time. 

STRUCTURAL CONSIDERATIONS

The truss as a structural system has stood the test of time and for good reason: it is highly efficient and easy to construct. Another advantage of the truss, which has been demonstrated in recent years in various dynamic projects, is that curves and varying forms can be introduced and the truss facilitates these new forms. The truss allows fabrication of complex forms in a relatively simple manner because it is fabricated out of smaller and thinner elements. This design is set up to take advantage of the truss in all these ways, and in doing so, it also pays homage to the historic pylon - referring to its structure but bringing in the new advantages of the truss.

The structure proposed is one with four ‘legs’, each of which is a triangular trussed structure which is then ‘zipped’ up its centre by another set of diagonals. This ‘zipping’ produces a mega truss with the legs as the top and bottom chords. The legs are composed of specially rolled angles with an angle of 60 degrees (as opposed to 90). The angles are then bent into the form of the tower. All other elements of the tower are straight angles. 

All splice connections required on the legs and all connections of the tower are bolted for ease of fabrication. The design can easily adjust to varying terrain.

The cables, which are used to suspend the hydro lines, are triangulated to equilibrate the forces on them and prevent asymmetric forces from affecting the tower. They also function structurally to provide light post tensioning to the tower, helping resist lateral loads.

TECHNICAL DESIGN CRITERIA

The arrangement of the tower support cabling system was based on the italian design TERNA ELECTRIC PYLON which was designed by the architecture firm Hugh Dutton Associés. The hydro lines, rather than hanging and being free to swing, are strung onto cables and suspended in place away from each other and away from the tower. Since this type of system was not explicitly addressed in the documents, we have made assumptions and understand that some of these assumptions may need to be modified or adjusted for this type of system.

The clearance to the cables from the tower was taken from the documents at 3.1m and from this we produced three dimensional spheres which were then placed in space and the clearance around these wires was maintained in each phenome. The curvature in the tower is the curve required to fit the clearance spheres. The clearance around these cables is set at the distance given in the documents provided but could be modified, in the case that this is insufficient or excessive.

Similarly, the angle of the grounding wire to the tower has been maintained at 35 degrees as required and as a result certain steps of the oscillation which are too ‘flat‘ were dropped from the sequence. 

Where a tension tower is required to take loading as the hydro lines turn a corner, the design can adjust by a change in the distance between the four legs so a wider triangular stance results. A phenotype such as those which have one wire above and two below may be selected and refined for the design loading. If necessary, cables may be braced by angles at these location.

Since the design is parametric, the technical constraints are taken into the design as parameters and the resulting design becomes modified as the constraints change. The technical criteria for the pylon was used  to provide a framework for the variations in the design. Alternate criteria can be incorporated and the design adjusted for these criteria.

DESIGN DEVELOPMENT

To adequately represent the state of technological advancement in today’s power industry as well society at large, the use of a digital parametric process was used.The design proposed is developed through the use of algorithmic programming in 3D modelling software. The algorithm allows different inputs and from these inputs, the structure is generated. Input can be constraints around distances or angles or many other factors. The generation of structure through this process as well as the resulting form represents our current digital technology and its relationship to culture and landscape.