Quercus Helix

Quercus Helix is to the entrance to a contemplative remembrance glade at the National Memorial Arboretum (NMA) managed by the Royal British Legion. The spiral concept was imagined by FIRA Landscape Architects who have been sensitively working with the NMA for 11 years. This is the first time a meditative memorial with horticulture at the heart of the design has been created and the helix forms the gateway that leads the visitor along a journey of remembrance to a second gateway and entrance into woodland glade which is set out in a perfect circle formed by white stemmed birch underplanted with bulbs and wildflowers with a polished stainless mirror in the centre flanked by a viewing bank.

We took FIRAs initial spiral concept as a starting point. Then delving into 20 years of knowledge and experience of steam bending long lengths of oak into complex curves designed the multiple spiral curved structure, and so Quercus Helix was born. We wanted to create a structure that was light, graceful and dynamic, with the smoothly flowing forms and multiple helixes suggesting life and progression.

Our choice of oak as a material was for a number of reasons. A native species with deep and rich cultural associations, oak is one of the wood species most suited to the steam bending process, is easy to work in its green state and is very durable in an outdoors environment.

The structure comprises four fifteen metre lengths, each assembled from three sections, each section made of three pieces of oak steam bent and glue laminated together. The main spiral of each length is a section of helix, and helixes of two different radii were used. For each five metre section we designed a jig that would dictate how the wood was bent and twisted in three dimensions. After designing and building the jigs came the highly physical stage of persuading five metre lengths of oak to take on a new form! The process was one of steaming, bending, letting cool, gluing and re-clamping. This in itself was a complex procedure that we have developing and refining over the years. It was a combination of applied experience and learning curve, responding to the behaviour of the wood and adapting our process. We bought top grade French green oak and milled it up ourselves into the 60×20mm laths for steaming. Five metre lengths of oak are rarely without blemishes and we had to contend with knots, shakes and short grain, as well as the hard to predict ways that green oak will behave when steam bent into complex shapes and then exposed to the hot sun and dry air of the sunniest spring on record. The separate sections were then half lapped and glued together and each helix/wave connected to the others with stainless screws and brass tubing. Moisture curing polyurethane glue was used, as well as lots and lots of clamps. The images show the entrance sculpture as a temporary installation outside our workshop. We will be installing it for real in the middle of June. The sculpture will float off the ground on minimal steel legs.