Having been delivered by barge crane from the River Thames, Head above Water made a brief, but dramatic addition to the London Skyline for the duration of the festival and is estimated to have had more than 28,000 visitors over five days adding to the hundreds of thousands of daily visitors to the area. Supporting mental health campaign Time to Change it was developped to engage and stimulate the discussion to eradicate mental health-related stigma and discrimination.
The ‘Head’ was deliberately gender, ethnicity and age neutral and stood as a symbol of hope, bravery, compassion, positivity and change, for those who have come through or are still confronting mental health issues, and the people who support them.
At night, lighting displayed the mood of the city. People were encouraged to tweet their feelings and emotions. In real time, the changing colours of the sculpture reflected the mood of those engageing with the project. The result was a two-way interactive experience with Head Above Water both triggering and receiving states of mind. Consulting engineers and lighting design specialists Hoare Lea were the masterminds behind the lighting scheme.
A model of sustainable, smart design and build, Steuart Padwick first sculpted the head in clay and then developed the concept using precision engineered, renewable and sustainable, PEFC-certified cross-laminated timber panels, provided by Stora Enso. To realise the structure Steuart Padwick worked with structural engineering expertise, Ramboll.
Head Above Water was delivered to an incredibly tight deadline of 15 weeks from concept to installation. At design stage, it was necessary to consider the complex logistics of installing CLT panels from the River Thames by barge crane, with the limitations of the crane’s load and reach capacity and its ability to only achieve the necessary height during high tide.
“The design of the sculpture presented several interesting engineering challenges.” Says structural engineer, Alan Dowdall. “There was no existing information available about the pier, so a key part of the design process was to understand the capacity of the existing structure and, by doing so, define the maximum height limit of the sculpture.”
To achieve the programme dates, the design process needed an approach that could fast track the design output and allow completion of information that could be used by Stora Enso for production purposes. A digital workflow approach was required to allow the design to be developed while the pier site investigation was ongoing. This was set up to develop the design using parametric models and create an instantaneous design output, ready for when the site investigation results were completed.
From the outset the design philosophy was for the structural design for the CLT to be similar to a typical CLT building design. The aim being to create a complex design using simple techniques such as platform construction, proprietary connection elements and limited number of panel types.
Where possible the design was developed to align with the principles of CLT production to minimise wastage. The layout of the floor levels was set to maximize the width of a typical motherboard panel to a typical wall and the height of the plinth structure is the height of a typical panel. Stora Enso took this waste panel optimisation further during the manufacturing process, and the panels were carefully split to ensure the most efficient nesting - meaning that elements have been designed to fit neatly into the mother panels in order to minimise offcut waste.
Working with the tides allowed only a very short window of 2-3 hours at the pier for assembling the highest parts, so it was necessary to limit the number of crane lifts and incorporate connection detailing that could be undertaken quickly and easily on site.
The sculpture is designed in four sections, each measuring approximately 3 – 5 m in width, and weighing between 1.5 – 3.4 Tons. The total weight of the sculpture is 9.52 Tons including the 16 equal angle steels which, instead of the usual screw connections, were used as bolted connections between main sections to aid ease of dis-assembly. A total of 23.054 m3 of CLT was used for the sculpture equating to 197 m2 of area with panel thicknesses ranging from 100–180 mm of non-visual CLT.
Head Above Water was rebuilt and a planting design incorporated as a symbol of positivity and regeneration at the Northfleet transhipment facility, which is the land side logistic function for FLO (Ferrovial Agroman and Laing O’Rourke joint venture) on the central section of the Tideway project. The facility is the main Hub of the ‘More by River Scheme’ which aims to take thousands of vehicle movements off the streets of London, redirecting their movements into the site and then loading the materials onto barges utilising the river to deliver to site.
More than 100 individuals and organisations joined forces and worked pro-bono to deliver Head Above Water. “The great legacy from this project is the incredible camaraderie of professional people coming together wanting to do something amazing for the benefit of others.” Comments Steuart Padwick. “It’s in all areas where people are at the top of their game and I hope that one of the long-lasting things is the connection between all of us. For me it has been an absolute privilege.”
Images: Luke Walker / Getty Images