Chapter 12: The Yellow Book and the Final Roof Geometry
When he arrived at Hellebk and saw the spherical solution for himself, Arup was deeply impressed by Utzon's expression of a simple and uncompromising shape to the complex form of the roof.
He was also surprised that Utzon would so readily accept the substantial change to the profile of the shells. Ove Arup and Partners had consistently treated the shape as sacrosanct and as a result had not seriously pursued other geometries outside the parabolic over the last three years.
Beside his admiration for Utzon's approach further confirmation of the architect's brilliance and his relief that deep and incumbent problems within the scheme had now been solved Arup was, on a personal level, genuinely dismayed that Utzon was capable of changing the shape and profile of the roof.
Arup also noticed immediately that the new shape altered considerably the clearances in areas that were already congested and reduced the internal volume of the halls at ground level.
However, a rationalisation of the structure was just what he and Zunz had been asking for, and they assumed their architect would also solve these new problems that the spherical solution was presenting.
Late in 1961, a letter to Harry Ashworth in Sydney reflects Utzon's optimism for the new design:
"We were riding two horses for a long time. The last six months the real solution for everything technically and aesthetically was developed and it was even the cheapest way of making it you could dream of... Of course, all the work during the past three years has been the background for arriving at this magnificent solution."
Ove Arup wrote similar sentiments, reminding Ashworth that Pier Luigi Nervi's structures are based on repetitive concrete elements.
But by the end of the year, Ove Arup had become very ill, suffering fainting attacks brought on by low blood pressure and compounded by stress. The difficult process of designing the roofs, the tight schedule being applied to the project by the client, and the fact that Ove Arup and Partners was close to failing financially in large part due to the effort invested into realising the Sydney Opera House all took a toll and Arup retreated to Austria, cancelling a trip to Sydney with Utzon and Zunz, both of who presented the shell designs in The Yellow Book in March.
The Australian Broadcasting Commission produced a half hour studio presentation of the new design principle in which Harry Ashworth interviewed both Jørn Utzon and Jack Zunz and the two explained the spherical solution.
Despite the charm and excitement with which the new form was presented, it was not taken lightly by Australians. The new design was used to sensational effect by Sydney Morning Herald journalists, and by August the government had decided that a second opinion should be sought.
Jack Zunz organised for the great French engineer Yves Guyon to report to the government his report asserted that he found the scheme and approach to be sound.
"The structural scheme is basically sound and attainable provided the members are of the correct dimensions and reinforced adequately... The erection procedure which has been devised is in my opinion sound."
While more than another year of design and preparation ensued to finalise the geometry and prepare the construction schedule, the scene was now set for the move to Sydney to oversee Stages 2 and 3: the roof and the interiors.
When in December 1962 Utzon closed the Hellebk office, it was the end of an extraordinary and collaborative period between architects and engineers.
But Utzon was also ending the collaboration with key staff members of the period. Yuzo Mikami had left in 1961 and by the beginning of 1962 was working for Ove Arup. While his work on Sydney Opera House continued, there was some antipathy regarding his move to Arups.
Paul Schooboe, Knud Lautrup-Larsen, and Aage Hartvig Petersen all ended their work with Utzon.
Only four of the inner group of nine architects went to Sydney - Jakob Kielland Brandt, Mogens Prip Buus, Jon Lundberg, and Oktay Nayman.
Many had suggested to Utzon that he was underestimating the work load and would benefit from contracting a firm to work as job architects, especially when he arrived in Sydney. When Osmond Jarvis had suggested this in 1960, Utzon had raised his voice at him, exclaiming "I am the job architect!".
Arup, Ashworth and others would continue to be concerned that Utzon's preference, for a small group of architects, was not the right match for the volume of work required.
With the loss of senior close confidants and the move to a radically different part of the world, a new chapter of the story had begun - one which would bring with it both tragedy and hope.