RALPH MCMANUS: Alberta engineer, builder of Dunvegan Peace Bridge
Many have left their mark on Alberta, but few left it in such an obvious way as bridge builder and engineer Ralph Mcmanus, who died last month at age 93.
Every weekday, 100,000 people pass over his James Macdonald and Groat bridges in Edmonton.
Others rumble their bikes across the traditional wooden slats of his four walking bridges in Gold Bar and elsewhere.
And his most famous bridge appears on numerous postcards from northwestern Alberta.
The Dunvegan Peace Bridge, still the only vehicle suspension bridge in Alberta, spans 743 metres across the Peace River.
“Bridges were the love of his life,” said his wife, Beryl Mcmanus, who, after 68 years of marriage, surely also ranks among those top loves.
They had three children together — Maureen, Tricia and Bob — and three grandchildren.
Mcmanus died March 14 of cancer.
Mcmanus was born in southern Alberta on a homestead near Brooks, an area without irrigation where even hard work couldn’t guarantee a good harvest.
As a baby, his mother, Emma, kept him warm wrapped in blankets in a butter box near the wood stove.
He skated on a frozen river to and from school, said son-in-law Paul Marck, who wrote a short history for a celebration of his life.
Mcmanus dropped out of school, but after one year working in the coal mines, his older brother, Leslie, convinced him university offered a better life.
He followed Leslie to Edmonton, then a one-stoplight town, to finish high school, and enrolled in engineering at the University of Alberta.
At that time, the Americans were expanding the use of concrete in bridge construction, while Edmonton had only steel structures, such as the High Level and Walterdale bridges.
In 1949, Mcmanus headed to the University of Illinois on a full scholarship to study reinforcedconcrete pillars and learn from the best.
He later taught at the U of A for several years and co-founded T. Lamb, Mcmanus & Associates.
His Groat Bridge, completed in 1955, was the first in Edmonton to use reinforced concrete.
In 1971, Mcmanus’s team used new techniques in pre-stressed concrete to build the James Macdonald Bridge.
Pre-stressed concrete has reinforcements embedded into the wet concrete and pulled tight before it cures, adding tension and making a stronger concrete.
“You can build things lighter and stronger,” said Alan Mckay, a nephew who followed McManus’s footsteps in engineering.
But despite those innovations, Mcmanus’s favourite bridge was clearly the Dunvegan Peace Bridge, Mckay said.
“Suspension bridges were his love,” Mckay said. “It’s just an efficient use of material. From an engineering standpoint, you’re just using materials in a very thin and graceful way.”
The Dunvegan bridge opened Aug. 31, 1960, replacing the old river crossing, which unpredictable floes often made impassible.
A suspension bridge was needed because of the high cost of placing strong pillars in the river bottom.
In that era, engineers used slide rules, logarithmic tables and pen and paper to design the complicated structure.
Mcmanus was proud of the difference that bridge made to the region, Mckay said.
At its 50th anniversary in 2010, many people shared stories of that change.
“You could just see the bright glow in his face.”
Mcmanus was a quiet, steady, rational man.
“A real gentleman who treated everyone fairly,” said Bob Morison, one of several employees who bought Mcmanus’s company from him and his partner in 1972.