Space Frame Trellises

My new and original plant support system was inspired by Buckminster Fuller (1895-1983), the inventor of the geodesic dome. The key feature of the SFT system is its variability, which is made easy with my deceptively simple universal connector.

Form
The structural shapes of the SFT are modelled on molecules. Why look at molecules? – Nature is always the sublime teacher of structural economy.

Lawrence Bragg pioneered in 1912 the x-ray diffraction technique to ‘see’ the three-dimensional arrangement of individual atoms in crystals. The conjecture by a few scientists that graphite-like sheets (hexagonal lattices) could be bent into geodesic structures was indeed confirmed. These carbon-cage molecules, which form very stable structures, are referred to as ‘fullerenes’ in honour of Buckminster Fuller who first explored and applied these geodesic structures in his architectural designs.

A geodesic is the shortest curve between two points on a curved surfaces laying wholly on the surface. We find geodesic patterns in very different things and very different orders of magnitude and in many disguises. They are present in:

• Fullerenes
• Double helix of DNA
• Protein shells of viruses
• Pollen grains
• Skeletons of various tiny marine organisms
• Shapes of various species of fungi
• Compound eyes in various species of insects
• Conical helices in various species of shells and horns of animals
• Muscular fibres, for example the circular and longitudinal muscles of the mammalian heart
• Helical twists in many climbing plants

Geodesic space frame structures are efficient regardless of scale.
What is a space frame? – A three-dimensional frame, usually triangulated in all directions, composed of struts and ties interconnected so that they all share in carrying any load.

Application
Trellises are used as obelisks, screens, arches, arbours and pergolas. Trellises have a particular relevance to today’s smaller gardens and ‘gardens in the sky‘. Obelisks and arches can be used to frame a view, define an entrance or path. Obelisks can give instant height to a border. An arbour can partly hide a sitting area.

Trellised walks are surely among the most delightful features in the garden. Their use goes back to antiquity. Imaginative trellises can also be used as sculptures in the garden. Generally, trellises have a rustic appearance and are heavy in every sense, physically and aesthetically. The structural form of 21st century trellises should be minimal, lightweight and almost invisible!

My SFT system, analogous to a Meccano kit, can be used in a new garden project and also to rejuvenate an existing area of the garden. A unique feature of my SFT system is that individual struts can be threaded through the branches of an established plant and assembled into a very strong and unobtrusive trellis.

Cost
My space frame trellises are inexpensive to make as they use standard off the peg materials. They can be fabricated by any blacksmith or any DIY enthusiast.

Arbour in full bloom

Arbour in the form of half an icosahedron plus two tetrahedra. (The icosahedron and the tetrahedron are two of the five Platonic solids).

The trellis of this arbour has the form of half an icosahedron plus two tetrahedra. (The icosahedron is the basis of Fuller’s geodesic domes).

The rose festooned arbour has a long history. Many years ago someone planted ‘New Dawn’ next to the boundary wall of St. George’s Fields, near Marble Arch, just opposite Hyde Park.

Gradually this vigorous climber grew up the wall and along the ground forming a tangled mass. In order to save and rejuvenate this old rose, I designed the trellis in the form of a modified geodesic dome, made from 17 equal length struts.

First, the tangled rose was lifted and held up by means of a few T-shaped wooden poles.

Next, the trellis was erected piece by piece under the raised rose. Once fully assembled the props were removed.

The massive climber dropped perfectly over the trellis and covered it completely. The rose responded magnificently to its raised support and flowered profusely.

To extend the flowering season an evergreen clematis armandii was planted and trained over the rose. It quickly spread over the arbour and up the wall of the neighbouring house. In full bloom the sight is spectacular. It was most gratifying to see that neglected climbing rose transformed into a garden treasure!

The assembled arbour. The minimal space frame is very stable, yet it touches the ground lightly.

The space frame trellis is doing its work, whilst being invisible!

To photograph this sight one had to be very quick.

Arch Pergola

The Arch Pergola is formed from four pyramidal units bent into an arc and propped by two internal V-shaped supports.

This space frame trellis is a hybrid between an arch and a pergola.

It is formed from four pyramidal units bent into an arc and propped by two internal V-shaped supports.

The structure works like a three-hinge arch, which makes it not susceptible to differential settlements of the foundation – pegs in this case.

The space frame trellis is almost invisible amongst the branches of the plants.

The dynamic and minimal space frame trellis is accentuated by the snow.

The universal connector, using off the peg materials.

Another view of the connector.

Sphere

St. George’s Fields sphere

This geodesic sphere in stainless steel can be found in St. George’s Fields, near Marble Arch and opposite Hyde Park. It is constructed from ten great circles. (The shortest line between two points on a sphere is an arc of a great circle). This oversized ‘football’ can be moved about in the garden till the ideal spot for it is located. As it is not fixed to the ground cutting the lawn underneath the sphere is not a problem.

This sphere was placed in the shady part of the garden. An ivy was planted where the sphere touches the ground.

Helical Obelisk

Helical Obelisk

Helical Obelisk

In this obelisk the tetrahedra are joined face to face to create a twisted column with triangular faces. The edges of this arrangement follow helical lines, it is referred to as a tetrahelix. Note, it forms right-handed helices like in the structure of DNA. The tetrahelix space frame is a beautiful geodesic structure expressing life and growth, which is most appropriate for the support of plants.

Sixteen of these 21st century obelisks were erected in a double rose border over 100 metres long at the RHS Garden Harlow Carr. This project was first shown on the BBC Gardener’s World Roadshow on 09.07.05 and again in Gardener’s World on 02.09.05. A similar photo was included in the RHS poster in 2006 to excite garden lovers to join the RHS.

Tetrahelix

Obelisk in the form of a ‘stretched’ tetrahelix.

Leaning and branching obelisk in the form of a tetrahelix. Space frame trellis with a double cantilever, analogous to the branching of a tree.

Twin Domed Pergola

Note that geodesic domes with a fourfold symmetry can be augmented, analogous to orthogonal plane tessellations.

Twin Domed Pergola

Twin Domed Pergola

Twin Domed Pergola

Geodesic Dome

A fourfold symmetry adaptable to plans with right angles, which is the norm.

Geodesic Dome

Geodesic Dome

Saddle Shaped Pergola

These surfaces are referred to as Schwarz’s periodic minimal surfaces, in honour of the mathematician H.S. Schwarz who first explored them in 1867. These periodic minimal surfaces can be tessellated into hexagons and heptagons consisting of equal length edges, The design of this highly efficient structure was inspired by recent research in Fullerenes.

Saddle Shaped Pergola

Saddle Shaped Pergola