As we soaked in a swimming pool in rural Jamaica this spring, another couple told us of their recent visit to Boston, where they saw "that big hole where we're throwing all our tax dollars." We immediately jumped to the defense of the Big Dig, singing paeans of praise for our new cable-stay bridge and boring them silly with the mechanics of cofferdam tunnel construction. After more than a decade of watching construction vehicles snuffle along the waterfront like giant skunks grubbing for worms, we have become civil engineering junkies. We hate to admit it, but we will almost be sad if the Big Dig is finally completed in 2005. The legacy of the Big Dig is still up for grabs -- we'll know it when we see it. But Massachusetts has been here before. Four equally ambitious projects of times past transformed the economy and way of life in the Commonwealth. Three of the four still play quiet roles in everyday life, and all four have visitors centers that fill you in on construction that didn't affect your commute.
Blackstone Canal We don't mean to rub it in, but the Blackstone Canal, which paralleled the Blackstone River between Worcester and Providence, came in on time and at budget. Of course, it was private enterprise.
The river's 438-foot drop over its 45-mile course provided power to the mills of the Industrial Revolution, but the falls and rapids also made it impossible to take finished goods to the wharves of Providence for shipping. Inspired by New York's Erie Canal, Providence and Worcester merchants formed the Blackstone Canal Co. in 1822, selling 7,500 shares at $100 each. Six years later, the canal system opened and horses drew freight and passenger vessels up and down the river. Once the Massachusetts heartland was open to the sea, the mills and factories of the Blackstone Valley flourished. But the canal never took in more than $15,000 in a single year, and in 1847, the Providence & Worcester Railroad made it obsolete. Two years later, Blackstone Canal went bankrupt.
The visitors center of the Blackstone River and Canal Heritage State Park at River Bend Farm in Uxbridge relates the tale of the lost canal with straightforward photo-and-text exhibits. Irish laborers, working with picks, shovels, and iron pry-bars, dug the canals and laid giant granite blocks -- moved into place with horses and oxen -- to create 48 stone locks, 10 feet wide and 82 feet long. With an average lift of 9 1/2 feet, the locks enabled vessels to bypass the falls and rapids in ascending and descending the river. There's a lovely picnic spot by the pool below the dam outside the center, but to grasp the challenges the laborers faced, stroll along the four-mile interpretive trail on the old towpath.
Most of the locks were destroyed when stone was salvaged for building material (many a Blackstone Valley barn has a canal block or two in its foundation), but Goat Hill Lock, about a mile north of the visitors center, remains intact. You can reach an even more evocative lock from a walking trail in Millville Center, south of Uxbridge on Route 122. Park at the lot at the corner of Hope and Central streets and hike through the woods along the abandoned railroad bed for about three-quarters of a mile. Moss creeps over the stones of the lock, and the oak gates have long since rotted away. The chamber squats in the forest, mysterious and Druidic, relic of a vanished world.
Hoosac Tunnel The 4.8-mile railroad tunnel through Hoosac Mountain between North Adams and Florida was almost a canal. In the early 19th century, the Legislature planned to link Boston to the Hudson River by water, using locks to cross the Berkshires. But the cost of building 220 locks over the mountains seemed prohibitive and the project languished. By the time the Legislature got around to appropriating money (sound familiar?), technology had advanced, and the mountain-climbing locks were set aside in favor of a mountain-penetrating railroad tunnel.
If you visit the Western Gateway Heritage State Park in North Adams, guide James Del Ratez Sr. can give you the lowdown on every great engineer whose dreams were broken by a combination of the technical challenges and the Legislature's parsimony. Nearly 200 men died over the 22-year project, and the 1.9 million tons of rock blasted from the mountain ended up paving a goodly portion of Western Massachusetts. Black powder was originally the explosive of choice, but the tunnelers ultimately made the first commercial use of highly purified nitroglycerine.
When crews working from each side met on Thanksgiving Day, Nov. 28, 1873, their alignment was off by a mere 916 of an inch in digging a 25,081-foot tunnel. More than 125 years later, that is still the record for tunneling accuracy. Moreover, the Hoosac remains the fourth longest tunnel in the United States. It took more than a year to finish work, including setting the 20 million bricks of the western portal, but on Feb. 9, 1875, the first train passed through. Construction of the project, counting interest, cost $17 million and came in on budget. But historical controversy still lingers over money never paid to the engineers and construction companies.
For the first three-quarters of a century, an average of 100 trains a day sped through the Hoosac Tunnel. Tracks were centered in 1958 to accommodate wide-body trains and a few low spots were heightened to 19 1/2 feet in 1996 to accommodate double-deck freight cars and triple-deck auto carriers.
Displays and a half-hour video at the visitors center vividly re-create the claustrophobia and weariness of working on the tunnel, right down to the sound of water dripping from the ceilings and the roar of blasting rock. For a taste of the immensity of the project, follow a footpath from the visitors center down to the eastern mouth of the 321-foot "starter tunnel" through an edge of Mount Greylock that was built in 1851 as the first part of the overall project. To get the full effect, you will have to drive Route 2 to Charlemont, turn off on Zoar Road, and follow it along the Deerfield River (it changes name to River Road) for eight miles. There's a turnout just below the eastern portal of the Hoosac Tunnel. With luck, you'll catch one of the 15 to 30 freight trains that come rolling through each day, alas, not on a fixed schedule.
Cape Cod Canal The nine-year pause between planning the Big Dig (1982) and starting it (1991) was nothing compared with delays in digging the Cape Cod Canal, which Myles Standish first proposed in 1621 and the Massachusetts Bay Colony considered again in the 1690s. During the Revolution, George Washington even had the route surveyed with an eye to cutting a canal so American ships could evade the British fleet. There was never any doubt how useful the waterway could be. When the Cape Cod Canal did finally open in 1914, it trimmed 135 miles off the sea route between New York and Boston.
While cyclists glide down the bike paths and fishermen cast from the banks, some 20,000 vessels carrying 24 million tons of cargo pass through the canal each year. The Cape Cod Canal visitors center next to the Sandwich Marina on the south side of the canal provides a nice summary of the project. The first serious attempts at digging a canal began in the 1880s, using the newfangled steam shovel, but those efforts never got more than a few hundred yards from Cape Cod Bay before the developers ran out of steam (or money). Finally, New York financier August Perry Belmont had both the will and the cash to make it happen. With William Barclay Parsons, fresh from constructing the New York subway system, as his chief engineer, Belmont started digging, cutting, blasting, and scooping in 1909. In 1914, the Cape Cod Canal opened to traffic.
But Belmont and Parsons' canal was just 100 feet wide and 15 feet deep. Stiff current and narrow openings on the drawbridges led most ships' captains to take their chances on the Cape Cod shoals. The canal was a money-loser, and Belmont gladly sold his franchise to the Army Corps of Engineers in 1928. The Corps remedied the problems by removing another 30 million cubic yards of earth between 1935 and 1940 to broaden the canal to 480 feet and deepen it to 32 feet (minimum) at low tide. During the same period, the Corps built the Sagamore and Bourne highway bridges (wider would have been nicer) and the Bourne Railroad Bridge.
At the visitors center, you can see the same array of sensors that the marine traffic controllers watch as they control the passage of vessels through the canal. The readouts include five radar screens, a dozen closed-circuit video cameras, and wind and tide sensors. The controller is ensconced at the other end of the canal, in the Buzzards Bay administration building, where access is often limited for security reasons.
The same controller who calls the shots on how and when vessels pass through the canal also operates the New Bedford Hurricane Barrier, which stretches between New Bedford and Fairhaven harbors about 24 miles west of the Cape Cod Canal via Route 6. Built between 1962 and 1966, the hurricane barrier protects the harbor from devastating large storms, such as the 1938 hurricane. The 9,100-foot line of rocks, the largest manmade stone structure on the East Coast, has a 150-foot opening in the middle to allow ships to pass. When the weather whips up and waves begin to rise, the Buzzards Bay controller closes the two 440-ton gates, walling out the sea. The top of the barrier is open from both sides for walking or in-line skating. On the Fairhaven side, there's a small sandy swimming beach and the ruins of a Revolutionary War fort -- a scenic picnic spot from which to watch the fishing trawlers come and go.
Quabbin Reservoir An elegiac gloom hangs over the Quabbin because the creation of the reservoir and its protected watershed forced about 2,500 people from their homes and wiped four villages off the state map. That human dimension tends to overshadow the heroic scale of the engineering project in which humankind and nature collaborated on the state's largest lake and surrounding near-wilderness.
Creating the Quabbin Reservoir sounds reasonably simple: Put a dam and a dike across the Swift River and wait for the valley to fill up with water. But the video slideshow at the Quabbin Park visitors center in Belchertown dispels any illusion of simplicity. It took the decade between 1926 and 1936 just to build the 24-plus-mile aqueduct -- a rectangular tunnel -- between the Wachusett Reservoir and what would become the Quabbin. During that period, the people of Dana, Prescott, Enfield, and Greenwich abandoned their homes, the buildings were torn down, and the land was cleared. By the time construction began in 1935 on the most complex aspect of the project, the Winsor Dam, the valley looked like a scarred, smoking battlefield.
Workers labored on day shifts for the first two years, but as the dam progressed, they worked around the clock, going into late November and starting again in March. A cofferdam kept the Swift River flowing around the construction as giant caissons were set into place and cemented to the bedrock. The middle of the dam was created by pouring a slurry of powdered rock and water over the caissons -- a then-novel process that required the engineers and workers to invent techniques as they went along. Long sloping banks of rock and earth were laid in place on each side, and finally, in August 1939, water began to back up behind the dam.
The Quabbin Park visitors center has some modest, rather homemade-looking exhibits that help tell this tale -- notably giant aerial photos of the towns shortly before they were destroyed. On the first and third Tuesdays of the month, a handful of construction workers who helped build the Quabbin hold forth at the visitors center from 1 to 3 p.m. But many of the center's exhibits focus less on the human past than on the "accidental wilderness" of the 56,000-acre watershed reservation around the 412-billion-gallon reservoir.
The visitors center sits at the west end of Winsor Dam, and you can walk across the 2,640-foot structure on a 35-foot-wide road. The base of the dam tapers outward to a maximum width, deep below the waters, of 1,100 feet. One side brims with the water of Quabbin Reservoir, the other is a deep green valley. Security concerns have closed the road over the dam for automobiles, so you have to drive to the east side of the dam on Route 9 to access the rest of the Quabbin Park road system.
It's worth parking near the eastern entrance to walk down and see the long chute of the overflow relief channel. These channels (there's another on the west side) protect the dam from bursting at times of high water -- a catastrophe that would send a tidal wave crashing down the valley all the way to Hartford. On the rare occasion every few years when water does fill the 400-foot-long channel, it creates a spectacular 80-foot cascade beneath the spillway bridge. Continue along the road to the Enfield Lookout for the best vista across the nearly 39-square-mile lake dotted with islands that used to be hilltops. The lake and its surrounding forest constitute an engineering marvel that is so well crafted and so much of the place that the disruption it wrought seems inconceivable.
Maybe that's how the Big Dig will feel by 2160.
Patricia Harris and David Lyon are freelance writers who live in Cambridge.