SAN FRANCISCO -- Bridges speak but they can require translators.
To that end, internationally renowned architect Donald MacDonald has set out to explain why the eastern Bay Bridge replacement span looks the way it looks.
Few know the subject better.
MacDonald was the lead architect on the team that submitted the winning Bay Bridge design in 1998 and he has remained an architectural consultant on the project through its 15 politically tortured years.
Now, finally, the bridge is months away from completion and despite construction setbacks that cloud the precise opening date, MacDonald is ready to tell the $6.4 billion span's story from an architect's perspective.
"The idea was to get into the layperson's mind and explain the bridge in a way that wasn't a technical engineering thing," MacDonald said. "Why bridges look the way they look, how they came about and how they work with the natural and man-made environment are often not explained in a digestible form."
The architect feeds that void with his latest book,"Bay Bridge: History and Design of a New Icon." At half the size of a sheet of letter paper and packed with MacDonald's colorful illustrations, the little aqua book co-written with author Ira Nadel fits snugly in the hand and offers readers a gentle introduction to bridge architecture vocabulary.
The book is the third in a trilogy about the history and design of three prominent features in San Francisco Bay. MacDonald and Nadel released "Golden Gate Bridge: History and Design of an Icon" in 2008. Last year, they followed with a look at Alcatraz.
Now in his 70s, the Canadian-born architect worked on the Golden Gate Bridge's toll plaza and suicide barrier. He helped craft a master plan for the historic Alcatraz.
But none of those jobs were as fundamental as his role on the new Bay Bridge.
MacDonald was the architect on the team that submitted the 1998 winning design for the new 2-mile bridge, an all-white, asymmetrical, single-tower self-anchored suspension span and accompanying viaduct. It is the largest bridge of its kind in the world.
In the diffused light from MacDonald's second-story window in a gritty industrial block south of Market Street, the angular architect with intense blue eyes thumbed through his Bay Bridge drawings during a recent interview.
He described how over the years he perfected his illustration method -- ink, colored pencils, tracing paper -- as a quick means of showing his clients what he had in mind.
The artwork isn't a big stretch for him. In the early days before his architectural business took off, MacDonald sold his own oil paintings to pay the rent.
Accompanying the explanatory text, MacDonald's drawings take readers from historic Ohlone Indian housing on Yerba Buena Island, to design types considered for the original 1936 bridge, to the new span's architectural details.
The first bridge had an architect but engineers rejected most of the nonstructural aesthetic proposals as too costly. This included an Egyptian-like figure on the western span's monolithic concrete center pier, according to MacDonald's book.
In stark contrast, both architects and engineers sat at the design table for the new Bay Bridge and overcame the critics who argued a "plain vanilla skyway" would be cheaper and faster.
"I have to give the public a lot of credit," MacDonald said. "They really wanted a signature span and they stuck with it. What you see today is the winning design that we did with the public."
MacDonald's architectural contributions to what he calls the "White Span" have their roots in the "golden ratio," a specific mathematical proportion long considered pleasing to the human eye. Painters, building architects and furniture designers all use it.
Photography, for example, has a similar principle called the "rule of thirds," a concept in which an image is more pleasing if the horizon runs along the upper or lower third of the frame rather than at dead center.
On the new bridge, the "gold" is prominent in its pentagon-shaped tower legs, light poles and pier corners. The deck's placement is two-thirds of the distance from the top of the 525-foot tower, MacDonald said.
Readers of the book will also learn of MacDonald's largely undiscussed inspiration for the tower, the Saturn V launch rocket.
He didn't mention the spacecraft in the late 1990s when he pitched the ultimately successful design in public hearings, fearing it "wouldn't come across in the right way," MacDonald said.
But the rocket's aesthetic influence on the four-legged tower is undeniable as shown in MacDonald's side-by-side illustrations -- round facades affixed at the top mimic the rocket, and intentional spaces called voids between the tower legs are similar to the spacecraft's blacked-out areas.
"I want the public to understand what they've got," he said. "That's why I wrote the book."
MacDonald said he isn't worried the latest political firestorm set off by construction glitches -- chiefly, broken anchor rods in crucial seismic stabilizers -- will permanently stain the public's appreciation for the span.
"There has always been so much politics around this project," MacDonald said. "But the bridge will get done."
Contact Lisa Vorderbrueggen at 925-945-4773. Follow her at Twitter.com/lvorderbrueggen.
San Francisco architect Donald MacDonald and co-author Ira Nadel have released the final book in their trilogy about three of the San Francisco Bay's most prominent features: