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By Donald Maurice Kreis
For the Valley News
Three years ago, the new Ledyard Bridge turned nearly
everybody in the Upper Valley into an architecture critic. The debut
of that crossing’s fabled, steroid-sized concrete spheres ignited
a regionwide debate about the aesthetics of spanning nature’s
waterways with busy highways. Now this legion of design aficionados
has reason, if not to dance in the streets, at least to walk cheerfully
across a new bridge that brings grace and delight to the process
of entering one of the area’s historic villages.
The new Chelsea Street Bridge, which crosses the White
River and thereby connects South Royalton to the rest of the world,
is not a historic engineering feat like Roebling’s Brooklyn
Bridge, nor a work of sculpture like the birdlike bridges of Spanish
architect Santiago Calatrava, nor even a grand contemporary gesture
like the new Bunker Hill cable-stay bridge that is part of Boston’s
Big Dig project. Rather, the Chelsea Street Bridge is simply a modest
but enduring monument to public participation.
When the Vermont Agency of Transportation (AOT) decided
a decade ago that the beautiful but dilapidated steel truss cantilever
bridge that crossed the White River at South Royalton needed replacement,
the department did what it usually does: It instructed its engineers
to come up with an off-the-shelf design for a standard steel-girder
highway bridge. But the people of the region -- speaking through
the town’s board of selectmen and the Two Rivers Ottauqueechee
Regional Commission, made plain their view that a generic and undistinguished
bridge would be inadequate to the task.
To this point, the story is similar to the one that
led to the new Ledyard Bridge. There, the New Hampshire Department
of Transportation turned to Concord architect Christopher Carley
to add some unique design to the mix. Here, at the urging the Royalton
selectmen, the Vermont AOT called on Burlington’s Truex Cullins
and Partners -- well known in South Royalton as the firm that has
recently designed two major buildings, with a third in the planning
stages, for the village’s biggest presence -- the Vermont Law
School.
As everyone in the area now knows, Carley’s famous
solution was a series of Newell posts on steroids; the resulting
bridge balls are distinctive, inspiring revulsion in some, but offering
a whimsical sense of welcome and transition. Truex Cullins’
solution to essentially the same design problem is more subtle and
ultimately more satisfying.
The charge, recalls architect Tom Hengelsberg of Truex
Cullins, was to take the AOT’s standard bridge and "humanize
it, get the scale down and celebrate the act of crossing the White
River.
As the project designer, Hengelsberg wanted to make
the bridge look "hydrodynamic" to its users, by which
he means that his design reflects the reality of rushing water,
just as an automobile or locomotive is shaped aerodynamically to
minimize wind resistance. In other words, the gentle curves one
sees at the level of the bridge deck are meant to remind users there
is a river beneath.
Clad in Vermont granite, the abutments at either shore
and a pier at the center of the 400-foot span reach up and above
the roadway. In cross-section, the bridge is asymmetrical because
only the west side of the structure contains a pedestrian walkway.
The three granite-covered structures celebrate rather than hide
this fact. The walkway cuts a decisive gap through the three supports,
whose modest heights above the roadway trace a gentle curve.
What can you do with limited resources to create an
image of passing through something? Hengelsberg recalls wondering
this as he sat at his drafting table. His solution was an "imaginary
gateway. "Because the open spaces of the road and walkway vastly
exceed the width of the pilings, the curve traced by the pilings
is mostly imaginary, but quite obvious to the eye.
This profile does more than announce a gateway. It
makes the walkway obvious, in a manner that proclaims that pedestrian
access is a vital aspect of this river crossing -- a welcome innovation.
As it approaches each piling, the walkway widens slightly, an invitation
for pedestrians to pause and enjoy the scenery. "It was a key
point,"recalls Executive Director Peter Gregory of the regional
commission, suggesting that the point "is not just to get across
the river but to stop and converse."
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The curve also recalls the profile of the 67-year-old
classic bridge it will replace and whose landmark status helped
provide the impetus for creating a significant work of design here
in the first place. Finally, the curved profile of the pilings takes
a cue from the form of the big girders of Cor-Ten Steel that carry
the load of the bridge across the river. The stress on these girders
is at their maximum not at the center of the span but at its ends.
In consequence, the girders need additional reinforcement at these
points; they are thus slightly curved to an additional width there.
(This gesture proves that engineers also appreciate beauty, as they
could have simply added additional steel plates to the ends.) Hengelsberg
loves the girders, with their rich, brown rust-induced coloring,
describing them as "a pure expression of the latest structural
technology."Those who pause long enough to savor the color
palette will also appreciate the resonance among the rust-colored
girders, the mottled gray of the granite, the paler gray of the
cement, the shinier gray of the galvanized steel railings and, for
punctuation, the decisive black of the ultra- contemporary lamps
and lampposts.
Perfectionists will discern a few discordant notes.
There were concerns that the span would be too massive if an additional
girder were added to carry the pedestrian walkway; the designers
opted instead to use a series of diagonal struts to support the
load. This achieves the desired effect in a manner Hengelsberg likes,
but they are almost rickety in appearance -- a bit of 19th-century
engineering on what is otherwise a cleanly contemporary set of lines
and gestures. Some of the details are sloppily executed where concrete
intersects with granite. And, while the architects planned an arched
opening in the center of the mid-river pier, the engineers decided
to fill in this space with concrete in order to protect the structure
from the effects of rushing water.
Hengelsberg professes approval for the way the engineers
expressed this element by leaving the opening uncovered by the granite
facing -- but, still, a view across the entire river from beneath
the bridge would have been satisfying.
It would be satisfying, too, if the Chelsea Street
Bridge marked the strengthening of a regional trend that began,
haltingly, with the Ledyard Bridge. Alas, there is still ingrained
resistance to building bridges (and other important structures in
the public realm) for the ages, as opposed to designing as cheaply
as possible.
"I’d rather build two 'Plain Jane' bridges
than one fancy gateway," confesses an ambivalent Christopher
Williams, the AOT engineer who served as project manager.
Williams has mixed feelings. On the one hand, he is
deeply proud of the design engineer on his staff, Wayne Symonds,
who worked so persistently to make the Truex Cullins design a physical
reality. On the other hand, Williams reports that every town in
Vermont seems to be proclaiming its new bridge project a "gateway"
that merits special "enhancements," the bureaucratic term
for design elements beyond the structurally necessary.
"In these times," says Williams, meaning
times of fiscal austerity, "I’m not a big fan of this
sort of thing going on -- building more bridge than necessary."
To be fair to Williams, engineers have pragmatism
drilled into them in engineering school. His earnest desire to use
public funds prudently is sensible and, in the design context, often
manifests itself as the kind of limit-setting that can make a work
of architecture better by introducing a kind of creative tension
missing from a project with an infinite budget. And, no doubt, the
AOT’s official spokesperson would focus, justifiably, on the
excellent working relationship the agency has with the state’s
12 regional commissions.
But, still, one can only hope that creating a river
crossing of beauty and wonder, particularly in a prominent location
and as a replacement for a historic structure, will never be defined
as "building more bridge than necessary."
It is worth noting that, according to Williams, AOT
has an informal policy of allowing roughly 10 percent of a bridge
project’s budget to be devoted to enhancements, and that the
cost of enhancements at the $5.7 million Chelsea Street Bridge only
modestly exceeded this guideline.
On behalf of the regional commission, Gregory pronounces
the bridge a "wonderful example of architecture." It his
agency’s charge to provide expertise and momentum in the service
of its member municipalities, and if that means persuading AOT to
postpone a paving project or two, in order to dignify a bridge that
will stand for a century, so be it, Gregory believes.
This is the view, presumably, that enjoys popular
support in Royalton, where voters have approved $600,000 in bond
financing as the town’s share of the construction cost.
Appropriately, the townspeople who will service this
debt through their property taxes will be the most likely to wander
the pedestrian walkway that will eventually pass under the Chelsea
Street Bridge on the southern bank of the White River, where they
will receive an uncommon glimpse of what makes this structure special.
Like any bridge, this one looks great from beneath,
fully revealing the mighty structures that support the roadway.
This perspective also reveals something pleasing about
the Truex Cullins design -- an open space on the east side, of perhaps
a foot, between the roadway with its horizontal steel girders and
the mid-river abutment that reaches up vertically from the earth.
The concrete of the roadway curves outward to meet the abutment
-- and the resulting open space, a sliver of light when viewed from
below is just the slightest delightful reminder that this bridge,
like all such structures, is a bit of a gravity-defying engineering
wonder.
"It looks great -- they built it exactly the
way we designed it," Tom Hengelsberg says with satisfaction
of a project that left his drafting table nearly eight years ago.
He exaggerates, but only slightly.
Most of what the architects envisioned is there. One
enters South Royalton now with a dash of glory, rather than just
with highway department blandless -- or with bridge balls.
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