The most dramatic element is the arch: three curved steel beams that will rise 120 feet above the Providence River.

10:12 AM EST on Tuesday, January 18, 2005

BY BRUCE LANDIS
Journal Staff Writer

PLAINVILLE, Conn. -- In an unassuming cluster of industrial buildings, a few dozen skilled craftsmen are slicing slabs of steel into the parts of a giant's Erector set, one big enough to assemble a new bridge to carry Route 195 across the Providence River.

Journal photo / Bob Breidenbach

Ed Gale, of National Eastern Corp., Plainville, Conn., welds a section of the arch component that will eventually span the Providence River as part of Route 195.

Right now, armed with computer-controlled cutting torches and welders, cranes, and a remarkable number of bolts, craftsmen at the National Eastern Corp. are starting to cut and assemble sections of the new Providence River Bridge's most dramatic element: the arch, three curved beams spanning 400 feet, and rising to 120 feet above the water.

That section of the interstate highway will hang from the arch beams: one over each edge of the roadway, and one above the middle. A network of cables will drop down from each beam to hold up the steel-and-concrete bridge deck, and the traffic on it.

Crossing the river, just south of the Fox Point Hurricane Barrier, the bridge will be the most eye-catching part of a bigger state Department of Transportation project now well under way -- the relocation, southward, of a section of Route 195 and its intersection with Route 95.

The new bridge will be 1,240 feet long, with the arch making up the eastern 400 feet, near the Fox Point shore, where the tugboats dock.

The arch will leave an unobstructed space under the bridge, allowing watercraft, including the Newport ferry, clear access to the gates through the Hurricane Barrier. The rest of the bridge will be built on horizontal steel beams supported by piles going down into the river bottom.

The state Department of Transportation hopes to open the bridge in 2007.

A woodworker building a cabinet might throw a sheet of plywood onto a pair of saw horses, cut out the pieces, and assemble them with glue and screws.

National Eastern does something similar, but it starts with steel plates as big as the steel mills can make them -- up to 110 feet long, 10 feet wide, and more than 2 inches thick.

A cubic foot of steel -- a cube 12 inches on a side -- weighs 495 pounds.

The plates arriving at National Eastern can weigh 50,000 pounds. Their size helps to explain the company's location: on a railroad siding straddled by a traveling crane 65 feet tall that can pick up 90,000 pounds.

The three arch beams look slender in illustrations, but they will be long, curved steel boxes about 4 feet high by 3 feet thick.

Last week, a gracefully curved piece of steel plate, 3 feet wide and about 50 feet long, with its edges beveled, lay in National Eastern's steel receiving bay, a space big enough to play soccer. It will be part of the side of one of the arch beams, the bevels accommodating a weld down each edge.

It was cut out of a rectangular steel plate on a computerized 170-foot-long "table torch," where several cutting torches are mounted on a car that rides above the table, from one end to the other. Jacob Herman, a burning technician, programs the machine and then keeps watch as it rides along over a plate, slicing it into strips at just under 9 inches per minute.

National Eastern's craftsmen had set a 3-foot-wide plate that will become the top of this section of the arch, and another 4-foot-wide section of the arch's side, on edge next to it, with its ends curving up.

In the middle, they had started to "tack-weld," or weld the edges together in scattered spots, to hold the pieces until they could be welded permanently.

Even steel this massive can wiggle if unsupported. One of the remarkable sights inside the plant is a steel plate weighing thousands of pounds, hanging on edge from a crane, rippling along its length.

Artist rendering courtesy of The Maguire Group

The arch of the Providence River bridge, which is expected to open in 2007.

Bob Battaglino, National Eastern's senior project engineer, said the top of the arch beam will bend enough to follow the curve of the sides. Welded together, the "box" will be much stiffer than its pieces.

Further stiffening will come from rectangular "diaphragm plates" sitting crosswise inside each arch beam, welded to all four sides.

Part of each diaphragm plate's center is cut away, leaving the plates U-shaped. That's to allow inspection from the inside.

The arch span, the 400-foot section with the arch, will by itself contain almost 5 million pounds of steel, Battaglino said.

National Eastern is a collection of buildings sized to fit its products. The largest space, the main girder bay, stretches longer than two football fields. From one end, work at the other fades into the haze.

These huge spaces range from moderately noisy to occasionally thunderous, punctuated by an occasional shower of sparks when a workman grinds a rough edge. But much of the work is surprisingly undramatic, especially considering the size of the steel and what the workers are doing to it.

When President Rudy K. Walz describes his facility, he says it has 260,000 square feet, about six acres, "under crane," referring to the gantry cranes that ride overhead on rails running the length of the most of the buildings. His products are so big and heavy that floor space not "under crane" is less useful.

There are surprisingly few workers. Less than four dozen work at the facility now, officials said, a number that may grow a bit as the Providence bridge job picks up speed.

Automation increases their leverage. National Eastern workers do some handwork, but computer-controlled gas torches and arc-welding machines do most of the cutting and make welds that are more consistent than those done by hand. The devices are called "CNC" machines, for "computer numerically controlled."

One machine, for example, can hold a wide steel plate vertically, and a narrower one horizontally, making a T shape, and then haul the whole business past a stationary pair of welders.

They weld both sides of the seam at once, avoiding unbalanced heat that could warp the steel. The T assembly, in turn, becomes the side of a wide tub beam, like the ones that will hold up the non-arch portion of the Providence bridge.

Where the upper, arch sections will be welded together, the box beams holding up the bridge deck are fussier. The heat from welding could damage the steel, so the lower beams will be bolted together.

That means drilling thousands of holes -- holes every 6 inches along both edges of all four strips of plate making up the top, bottom and sides of the beam. Pieces of angle iron, shaped like the letter L but with sides of equal width, will run the length of the beams, holding each corner together. That means eight bolts every six inches.

How many bolts? National Eastern had to count, if only to bid for the job, and Battaglino looked it up: 65,000 bolts for the arch section of the bridge alone.

The bolts are mostly an inch in diameter -- and several inches long, to reach through the thick steel plates. They have to be tightened the right amount, measured in foot-pounds, like the bolts holding a car engine head block to the cylinder block.

National Eastern will put the parts together into sections from about 50 feet to about 100 feet long, to fit on trucks, officials said, and then temporarily bolt each pair of those pieces together, to make sure everything fits.

Even that takes care, Walz said.

Some of the assembly is done outside, sometimes with the end of a long section sticking out from under the roof into the sun. On a hot day, the steel may expand, making the beam inches longer, something that has to be accounted for, in making sure it's the right length.

James R. Caroselli, the Rhode Island DOT's chief civil engineer, said the steel parts National Eastern is making will be trucked to Quonset Point, North Kingstown, in early 2006, and assembled into the bridge, probably on a pair of barges linked together.

Then, with the bridge on top, the barges will be towed up Narragansett Bay to Providence for the installation.

It should be quite a show. "You'll look out your window and see a bridge floating past your house," Caroselli said.