Old iron rail and drain grates, however, are not what Mancl, project field director for John Milner Associates, is on the lookout for beneath the cracked concrete and weeds of an old Hertz parking lot near Vine Street.
At the behest of the Delaware River Waterfront Corp., Mancl and his crew are seeking something older, more fragile, and more tenuous: evidence of Philadelphia's original waterfront — bulkheads, wharves, hewed timber dating from times before the arrival of William Penn in 1682.
"The potential for this lot is so high, we all are pretty excited to be out here," he said.
Sarah Thorp, DRWC director of planning, said the area is slated for development at some point in the future, although no construction is imminent. Nevertheless, the DRWC decided to explore the historic site now in case something major turns up. If that happens, Thorp said, "we start raising more money" to fund a much larger excavation.
An exploratory, two-week dig got under way Monday, and by Wednesday afternoon, three test trenches reaching down about seven feet had been carved out by earthmoving machines. The excavation is open to the public Wednesday from 1 to 3 p.m., Thursday from 10 a.m. to noon, and Friday from 1 to 3 p.m. Next week, it will be open by appointment (contact the DRWC, 215-629-3200, for information).
The first trench, about 20 feet long and partially filled with water, thanks to the proximity of the river, uncovered — water, disappointing archaeologists who expected, from maps, to hit old bulkheads.
A second trench, cut a bit to the west and south of the first, reached a layer of brick rubble and what are probably 19th-century stone foundations by Tuesday afternoon. The third trench, opened Tuesday, yielded the iron grate and rail. By Wednesday, that trench had hit 19th-century foundations as well; Mancl remained optimistic that the trench might eventually expose ancient bulkheads, part of the West Shipyard. Careful excavation by hand is the next step.
Why the optimism? James West owned a shipyard on the spot from the mid-1670s into the 18th century. About 25 years ago, archaeologists digging a bit farther north in the Hertz lot uncovered some of West's slipways — wooden tracks used to haul ships in for dry-dock work.
The Hertz lot and everything east to the current riverfront is built on fill piled into the river as the city flexed and expanded over the centuries. Directly to the west is a short stretch of historic Water Street, which used to be right on the bank of the river and was, in part, a disheveled and rowdy slum area in the 18th century, starting point of many a brawl and yellow fever epidemic. Leading down from Front Street to Water Street and the West yard are 18th-century stone steps, the last remaining steps to the waterfront that William Penn directed to be built.
Archaeologist Rebecca Yamin, a senior staff member at John Milner and director of interpretation on the current project, said the Hertz lot might well yield up a view of the city's 18th- and even 17th-century seafaring past. The area has suffered little deep construction over the centuries as the waterfront moved east. Prior to becoming a Hertz lot, it served as a rail yard. Before that, a market stood at its center.
"We're going down layer by layer," Yamin said. "The West shipyard dates to 1676. It predates William Penn, a notable fact which makes this part of Hertz potentially significant. We're digging deeper and deeper into the past hoping to uncover the 17th century."
One elusive possibility — although it's a remote one, the archaeologists say — is that excavation might uncover remains of the Penny Pot Tavern, a well-known alehouse owned by West and frequented for decades by waterfront denizens with great thirst but meager funds.
The tavern is known in the neighborhood to this day — one Water Street resident built a small replica on top of his rowhouse — and there is much debate regarding its precise location.
"It could be just outside our study area," Mancl said. "That's where it is on the maps."
James Quilligan, a neighbor and member of the Rivers Edge Civic Association, stopped by the dig Tuesday.
"I'm really, really interested in what's here," he said. "There were no deep basements dug in the area. We thought there would be several more wharves exposed. But nobody knows."
That uncertainty might well end in a matter of days.
"Everyone hopes we find the Penny Pot Tavern," Yamin said. "So far we haven't found anything. But we're certain we're in the right location."
Contact Stephan Salisbury at 215-854-5594 or e-mail at email@example.com, or on Twitter @SPSalisbury.