WILLIAMSTOWN, Mass. — With most of the major concrete pours completed and many of the work areas soon to be enclosed, construction at Williams College's new library is set to continue out of sight and, more than ever, out of earshot in the months ahead.

Progress continues to be made on the new Sawyer Library and renovated Stetson Hall, Williams College Librarian David Pilachowski said recently.

Onlookers may not be able to get a good look at the progress during the winter months. The plan is enclose much of the site in plastic to allow construction crews to keep the $128 million project on track for its planned July 2014 completion date.

When it is finished, the new Sawyer will feature 130,000 square feet in four stories, but because much of the building's mass will be below grade, it will be less prominent than 1923's Stetson Hall, which will be joined to the newer building by an atrium.

"Contractors are working in all parts of [Sawyer] and making great progress," Pilachowski said. "They're also making progress on Stetson. They're starting to do finish work on the fourth floor.

"Enough is enlcosed or soon will be enclosed to allow work to continue."

But that work will not include the kind of major concrete installations that had as many as 40 trucks arriving on the job site in a single day at the height of construction, Pilachowski said.

Williams Senior Project Manager Bruce Decoteau said such large-scale deliveries are not part of the plan from here on out.

"I think it is fair to say that the intensity of truck traffic has and will certainly diminish," Decoteau said. "Delivery of some very large quantities of material still remain.

"These deliveries, unlike the placement of concrete decks, will be spread out over a longer duration of time, so, again, I think the overall intensity will diminish."

Historic Stetson Hall has been closed since 2008 when the college originally conceived construction of a new library. Those plans were put on hold that same year when the worldwide financial crisis dented the college's endowment and prompted a moratorium on construction.

The moratorium was lifted in 2010, and ground was broken on the Stetson-Sawyer project the next year.

If all goes according to plan, the current Sawyer Library, built in 1975, will be razed and replaced with green space.