The Bathtub
Encyclopedia
"The Bathtub" refers to the underground foundation area at the site of the World Trade Center
and accompanying buildings in New York City. Despite its title, it does not hold any water, rather it keeps water out and acts as a bathtub in reverse.
The Bathtub encompasses a large, roughly rectangular excavation
down to bedrock
surrounded by reinforced concrete walls, intended to serve as dam
s to prevent water
intrusion from the nearby Hudson River
(North River
). The World Trade Center
site was located on man-made water-clogged landfill that had accumulated over centuries, providing an extension of land out onto the Hudson River
from the original Manhattan
shoreline, with bedrock located 65 feet (20 m) below. Manually removing water from this area would have severely damaged the water levels surrounding the World Trade Center site and endanger the foundations of nearby buildings, causing them to sink. This is why the Bathtub method was used.
The Bathtub contains a 16 acre (~65,000 m²) site, including seven basement levels, the downtown terminal of the Port Authority Trans-Hudson
rapid transit
line, and the preexisting New York City Subway
's IND Eighth Avenue Line
. The South Tower of the World Trade Center was actually built around the PATH
tubes that passed through the foundation area, thus service was uninterrupted throughout the whole of the construction period. The waterproof walls are three feet (~1 meter) thick and 70 feet (~21 meters) high.
The excavated material that was dug up to build the bathtub was again used as landfill to construct Battery Park City, and
the same method was also used to construct the foundation area of the Willis Tower in Chicago
.
, endangering workers and possibly compromising other buildings and flooding a significant portion of the subway system. To prevent this, reinforcements were attached to bedrock to shore up the bathtub walls.
World Trade Center
The original World Trade Center was a complex with seven buildings featuring landmark twin towers in Lower Manhattan, New York City, United States. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is currently being rebuilt with five new...
and accompanying buildings in New York City. Despite its title, it does not hold any water, rather it keeps water out and acts as a bathtub in reverse.
The Bathtub encompasses a large, roughly rectangular excavation
Earthworks (engineering)
Earthworks are engineering works created through the moving or processing of quantities of soil or unformed rock.- Civil engineering use :Typical earthworks include roads, railway beds, causeways, dams, levees, canals, and berms...
down to bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
surrounded by reinforced concrete walls, intended to serve as dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s to prevent water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
intrusion from the nearby Hudson River
Hudson River
The Hudson is a river that flows from north to south through eastern New York. The highest official source is at Lake Tear of the Clouds, on the slopes of Mount Marcy in the Adirondack Mountains. The river itself officially begins in Henderson Lake in Newcomb, New York...
(North River
North River (New York-New Jersey)
North River is an alternate name for the southernmost portion of the Hudson River in the vicinity of New York City and northeastern New Jersey. The colonial name for the entire Hudson given to it by the Dutch in the early seventeenth century, the term fell out of general use for most of the river's...
). The World Trade Center
World Trade Center
The original World Trade Center was a complex with seven buildings featuring landmark twin towers in Lower Manhattan, New York City, United States. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is currently being rebuilt with five new...
site was located on man-made water-clogged landfill that had accumulated over centuries, providing an extension of land out onto the Hudson River
Hudson River
The Hudson is a river that flows from north to south through eastern New York. The highest official source is at Lake Tear of the Clouds, on the slopes of Mount Marcy in the Adirondack Mountains. The river itself officially begins in Henderson Lake in Newcomb, New York...
from the original Manhattan
Manhattan
Manhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...
shoreline, with bedrock located 65 feet (20 m) below. Manually removing water from this area would have severely damaged the water levels surrounding the World Trade Center site and endanger the foundations of nearby buildings, causing them to sink. This is why the Bathtub method was used.
The Bathtub contains a 16 acre (~65,000 m²) site, including seven basement levels, the downtown terminal of the Port Authority Trans-Hudson
Port Authority Trans-Hudson
PATH, derived from Port Authority Trans-Hudson, is a rapid transit railroad linking Manhattan, New York City with Newark, Harrison, Hoboken and Jersey City in metropolitan northern New Jersey...
rapid transit
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...
line, and the preexisting New York City Subway
New York City Subway
The New York City Subway is a rapid transit system owned by the City of New York and leased to the New York City Transit Authority, a subsidiary agency of the Metropolitan Transportation Authority and also known as MTA New York City Transit...
's IND Eighth Avenue Line
IND Eighth Avenue Line
The Eighth Avenue Line is a rapid transit line in New York City, United States, and is part of the B Division of the New York City Subway...
. The South Tower of the World Trade Center was actually built around the PATH
Port Authority Trans-Hudson
PATH, derived from Port Authority Trans-Hudson, is a rapid transit railroad linking Manhattan, New York City with Newark, Harrison, Hoboken and Jersey City in metropolitan northern New Jersey...
tubes that passed through the foundation area, thus service was uninterrupted throughout the whole of the construction period. The waterproof walls are three feet (~1 meter) thick and 70 feet (~21 meters) high.
The excavated material that was dug up to build the bathtub was again used as landfill to construct Battery Park City, and
the same method was also used to construct the foundation area of the Willis Tower in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
.
Problems
It was feared that the wall might collapse during the removal of debris from the September 11th attacksSeptember 11, 2001 attacks
The September 11 attacks The September 11 attacks The September 11 attacks (also referred to as September 11, September 11th or 9/119/11 is pronounced "nine eleven". The slash is not part of the pronunciation...
, endangering workers and possibly compromising other buildings and flooding a significant portion of the subway system. To prevent this, reinforcements were attached to bedrock to shore up the bathtub walls.