Aquarium station (MBTA)

Aquarium station

Company type	Rapid transit station
Industry	Public transportation
Founded	April 5, 1906 (1906-04-05)
Headquarters	Boston , United States
Products	Rapid transit services (Blue Line)

Aquarium station is a subterranean rapid transit stop on Boston's MBTA Blue Line, positioned beneath State Street at Atlantic Avenue. It lies on the eastern boundary of Boston's Financial District, close to Boston Harbor. The station derives its name from the nearby New England Aquarium and is located adjacent to Long Wharf, which serves as a terminal for four MBTA Boat lines. The facility includes two side platforms alongside the Blue Line’s dual tracks and features an arched ceiling over the platform area. Situated roughly below ground level, it ranks as the MBTA network’s second-deepest station after Porter station.

The Boston Elevated Railway (BERy) inaugurated the Atlantic Avenue Elevated on August 22, 1901, which included a station at State Street. Subsequently, on December 30, 1904, BERy commenced service through the East Boston Tunnel beneath State Street and Long Wharf for streetcar operations. Construction of the Atlantic Avenue station beneath the Elevated was postponed and eventually opened on April 5, 1906. Unlike other early Boston transit stations constructed using cut-and-cover methods, Atlantic Avenue was primarily built with a large barrel vault. Its eastern access shaft featured a three-story headhouse connected by a footbridge to the elevated station and incorporated four distinctive angled elevators linking the headhouse to the platforms.

In 1924, the Boston Transit Department converted this tunnel from streetcar use to accommodate high-floor metro trains by installing raised platforms at Atlantic Avenue. Although the Atlantic Avenue Elevated ceased operations in 1938, the subway station continued functioning. Beginning in 1948, the original headhouse and elevators were replaced with a more compact structure equipped with escalators. On January 28, 1949, a grease fire caused by welding activities resulted in an explosion down an elevator shaft, causing three fatalities and multiple injuries; this incident delayed reopening until January 1950. The station was renamed Aquarium in 1967 amid Massachusetts Bay Transportation Authority (MBTA) branding efforts.

Starting in 1996, the MBTA initiated extensive renovations including lengthening platforms to support six-car trains, adding new entrances west of Atlantic Avenue, and implementing full accessibility features. The station was closed from October 14, 2000, until October 29, 2001, with major construction completed by 2003. Post-renovation issues have included water infiltration and occasional flooding during high tides and storm surges. Plans for the proposed North-South Rail Link include a potential Central Station for MBTA Commuter Rail located beneath Aquarium station.

Station layout

Located beneath State Street at Atlantic Avenue near Boston Harbor, Aquarium station consists of two side platforms capable of handling six-car trains on both Blue Line tracks. At approximately below street level, it is second only to Porter station in depth within the MBTA system. The station's roof supports the overhead Tip O'Neill Tunnel, which carries Interstate 93. The platform area merges an older eastern section with an arched ceiling and a newer western section featuring triple vaults.

Faregate mezzanines are positioned at both ends of the station: the eastern mezzanine near Long Wharf adjacent to the New England Aquarium includes two glass headhouses—one equipped with escalators and stairs and another containing an elevator. On the west side under State Street near the Custom House Tower, access is provided via a headhouse with an elevator on its southern side and a smaller entrance inside a building on the northern side.

Aquarium station connects with MBTA bus route , which runs along Atlantic Avenue during peak periods. It functions as a crucial interchange between the Blue Line subway and Boston Harbor ferry services: four MBTA Boat routes—F2H, F3, F4, and F5—terminate at Long Wharf alongside several ferry lines serving Boston Harbor Islands.

State Street station

The construction of the Atlantic Avenue Elevated commenced on January 21, 1901. The Boston Elevated Railway (BERy) inaugurated the line, including State Street station, on August 22, 1901. Similar to other stops along the route, State Street was designed with a single elevated island platform accompanied by a mezzanine level beneath. Access points included stairways on both sides of Atlantic Avenue north of State Street, with additional exits leading to two staircases situated south of the street. Initially accommodating trains of three cars (approximately ), the platform was extended by June 13, 1902, to support four-car trains.

Atlantic Avenue station

On May 5, 1900, the Boston Transit Commission (BTC) initiated the building of the East Boston Tunnel, a streetcar tunnel connecting East Boston to downtown Boston beneath Boston Harbor. Construction began near Maverick Square at the eastern end, with the downtown alignment finalized on July 25, 1901. The route was planned to pass under State Street, featuring a station at Atlantic Avenue adjacent to the bustling Long Wharf. The station's construction was divided into two parts under separate contracts. The "Atlantic Chambers," located at the western end of the submerged tunnel segment, contained elevators, stairways, and ticket areas within an open cut just west of Atlantic Avenue. The primary arched station west of Atlantic Chambers was built using drift mining techniques. The two side platforms measured long and wide and were positioned below ground level.

Atlantic Chambers consisted of a rectangular shaft , segmented into four chambers by three reinforced concrete floors with walls thick. The lowest chamber housed elevator shafts and stairwells. Excavation began on December 5, 1901, and was completed by May 29, 1903. On June 19, 1903, a compressed air accident resulted in two fatalities and caused minor settlement of Atlantic Avenue above. Additional structural support was required to prevent sagging of the elevated railway overhead, disrupting operations between June and October 1903.

Distinct from other early Boston stations constructed using cut-and-cover methods, Atlantic Avenue station featured an expansive barrel vault. Vertical walls and the arch crown were formed by drifts; transverse sections and the invert followed this structure. The arch measured wide and tall, with walls thick and an arch thickness of . Work commenced on March 17, 1902, with arch completion achieved by June 26, 1903. Tile installation was finished on January 19, 1904, followed by granolithic platform completion on February 10. In response to the August 1903 Paris Métro fire, BTC and BERy incorporated emergency exits consisting of curved staircases at platform ends that connected to a straight staircase above the tunnel arch. These exit stairs were completed by September 6, 1904; a small building on State Street was finished by October 10.

A three-story headhouse () was erected above Atlantic Chambers housing the primary entrance on its ground floor, a footbridge connecting to State Street station’s fare mezzanine on the second floor, and elevator machinery on the third floor. Designed by Charles Brigham—also responsible for Scollay Square and Adams Square headhouses—the shafts within this headhouse served as the main ventilation source for the tunnel. Each platform featured two elevators that rose to ground level plus additional vertical travel to reach the footbridge. Due to platform separation and spatial constraints within the narrow headhouse, these elevators included an angled segment involving approximately vertical movement. As late as the 1940s, these elevators remained unique among subway stations.

In November 1903, BTC and BERy agreed to include the footbridge but disagreed over who should bear elevator costs: BERy considered them part of infrastructure expenses (BTC’s responsibility), while BTC viewed them as operational costs (BERy’s responsibility). In March 1904 they permitted elevator and headhouse construction to proceed while postponing cost resolution; this dispute was ultimately decided by a Massachusetts Supreme Judicial Court ruling in 1913. The contract for constructing the headhouse was awarded on August 15, 1904; however, steel fabrication delays postponed completion beyond December.

The East Boston Tunnel officially opened on December 30, 1904, providing streetcar service between downtown Court Street and Maverick portal; however, Atlantic Avenue station was not yet finished at that time. Most work on the headhouse concluded by July 1905; elevator testing occurred in January 1906. Atlantic Avenue station formally opened on April 5, 1906. Both Atlantic Avenue and State Street stations operated with separate fare gates necessitating paper transfers for passengers switching lines.

Alterations

In August 1908, the elevated platform was extended southward to accommodate eight-car trains, roughly equaling the platform lengths in the nearly finished Washington Street Tunnel. On October 26, 1908, a larger elevated mezzanine along with a second exit staircase were inaugurated. Major restoration work was carried out on the Atlantic Chamber, which serves as the headhouse of Atlantic Avenue station, in 1926.

Platform elevation

Originally, the East Boston Tunnel was designed to serve high-floor metro cars connected to the Cambridge Elevated line. However, after the 1903 revision of plans, stations were constructed with low-level platforms. The introduction of large bi-loading streetcars in 1905 and center-entrance cars from 1917 proved insufficient to manage passenger demand effectively.

Starting in 1921, the Boston Transit Department (BTD) initiated efforts to convert the East Boston Tunnel for use with high-floor metro trains. By 1922, BTD had authorized the installation of high-level platforms at Atlantic Avenue and other principal stations. Construction of concrete platforms raised approximately above the rails at Atlantic Avenue began late in 1923. A portion of the original low platform was retained during this period.

From April 18 to 21, 1924, operations transitioned to high-floor metro rolling stock. Temporary wooden platform segments allowed service continuation starting April 21, with permanent concrete platforms finalized by July 12. Elevators at Atlantic Avenue were adjusted to align with the new platform height. Remnants of the initial low platform edges remain visible beneath the elevated platforms.

Fire incident and new headhouse

The advent of the East Boston Tunnel significantly diminished ferry ridership from East Boston, weakening connections on the Atlantic Avenue Elevated line. The Elevated ceased operation on September 30, 1938, and was dismantled during World War II for scrap metal. Given the outdated headhouse and redundant Elevated link, city authorities planned station upgrades. On October 17, 1946, a contract worth $242,000 was approved for installing four escalators. Subsequently, in 1948, the Boston Transit Department awarded a $350,000 contract to replace elevators with escalators and construct a new headhouse on State Street’s north side.

During morning rush hour on January 28, 1949, a grease fire sparked by a welder’s acetylene torch spread down an elevator shaft onto the platforms amid approximately 300 passengers. Most evacuees escaped through an emergency exit opened by a rider; others used stairways in the main headhouse. The fire resulted in three fatalities: two passengers trapped on the second floor and one construction laborer. The blaze's severity was likened to that of the 1942 Cocoanut Grove tragedy.

Following this event, the station closed for rebuilding. The disaster prompted political scrutiny regarding MTA safety protocols—the MTA operated transit services owned by the city. The newly constructed headhouse showcased limestone and granite materials in a Stripped Classical architectural style and featured four escalators replacing previous elevators. The station reopened on January 12, 1950.

MBTA period

The construction of the Central Artery during the 1950s created a physical barrier isolating the station from Downtown Boston to its west. On February 13, 1967, as part of an MBTA-wide rebranding initiative, Atlantic Avenue station was renamed Aquarium. The nearby New England Aquarium, which opened in 1969, lies only away. Subway lines adopted color-coded designations; notably, the East Boston Tunnel became known as the Blue Line, and multiple downtown stations received new names.

Aquarium station underwent modernization as part of a $9 million systemwide enhancement program and was rededicated on August 26, 1968. Improvements included installing a steel-and-fiberglass ceiling liner aimed at minimizing water infiltration and noise levels. Porcelain wall panels adorned with fish illustrations sourced from a nineteenth-century publication were also added. The headhouse remained mostly unchanged pending redevelopment connected to a New England Telephone building project.

In the following decade, Atlantic Avenue was realigned one block west beneath the Central Artery for urban redevelopment purposes, leaving Aquarium station positioned on the street’s east side. With platforms located approximately below street level, Aquarium held the distinction of being MBTA’s deepest station until Porter station opened in 1984. Its aging escalators caused multiple injuries over time, including a severe leg injury sustained by a child in 1995.

Reconstruction

In 1988, the MBTA initiated an extensive upgrade to extend Blue Line platforms for accommodating six-car trains. On February 14, 1990, the MBTA board authorized advancing the renovation of Aquarium station—including the addition of a new entrance on State Street—into the final design phase. However, due to modifications related to the Big Dig project, the contract for final design was postponed until June 20, 1992. The updated design incorporated a reinforced box structure to support the new Central Artery tunnel situated above the station arch. By October 1995, bids were solicited for a $268 million project that combined station improvements with the construction of the Central Artery tunnel segment stretching from State Street to High Street.

Construction commenced in 1996 during the ongoing Big Dig, which involved relocating the Central Artery underground and creating the Rose Fitzgerald Kennedy Greenway park above it. Aquarium station was completely closed from October 14, 2000, until October 29, 2001; during this closure, State station was renamed "State/Aquarium," and shuttle bus service linked the two stations. Two new entrances were introduced on State Street west of Atlantic Avenue: first, a south-side headhouse with an elevator opened on October 29, 2001 (initially serving as the sole access point), followed shortly by a north-side entrance located within Marketplace Center. The refurbished Long Wharf entrance reopened on September 22, 2003. The total cost of this reconstruction reached $110 million.

The expanded station was designed by Harry Ellenzweig, known for his work on Alewife station. The extension moved westward and included broader platforms featuring a distinctive "triple vaulted aluminum ceiling," with the central vault mirroring the curve of the original arch. Fare mezzanines at both ends showcase red slate flooring paired with aluminum-paneled walls and ceilings. The western headhouse incorporates granite elements that harmonize with the architectural style of nearby State Street Block buildings, while eastern headhouses utilize brickwork consistent with Marriott Long Wharf’s appearance. Platform walls are adorned with Currents (initially titled Untitled Wall), two expansive black-and-white tile mosaics measuring 350 feet in length by artist Jun Kaneko, installed as part of the Arts on the Line initiative.

Water issues

Following the extensive reconstruction between 1996 and 2003, Aquarium station has continually experienced water infiltration problems, likely stemming from renovation activities or adjacent Big Dig construction efforts. Water seepage had been documented even prior to the station’s original opening in 1906, albeit on a smaller scale. Its proximity to Boston Harbor also makes it vulnerable to flooding during king tides and storm surges. On January 4, 2018, ocean water inundated the station amid the January 2018 North American blizzard, resulting in an indefinite closure that lasted until the following day. Additional flooding caused by a nor’easter in March led to another temporary shutdown. These flooding incidents damaged elevators and escalators, rendering them out of service for several months.

In response, the MBTA introduced temporary flood barriers at Aquarium station during storm events in 2019. Implementing a permanent fix to address ongoing leaks and flooding is estimated to require an investment ranging from $20 million to $40 million. During a planned Blue Line shutdown lasting 14 days in May 2020, drainage enhancements were carried out at Aquarium station. Subsequently, from August 2020 through March 2021, a $1.7 million project installed support structures designed to hold aluminum planks intended for use during periods of elevated water levels.

Central Station concept

The North–South Rail Link (NSRL) envisions an underground tunnel that would unite the two segments of the MBTA Commuter Rail network, running between North Station and South Station beneath Boston’s downtown area. The original design proposed a deep tunnel beneath the Central Artery, passing underneath Aquarium station at a depth of . In 2003, the MBTA's Major Investment Study and Draft Environmental Impact Report analyzed both two-track and four-track NSRL configurations, considering options with or without an intermediate Central Station. This proposed station would include platforms situated between State Street and Broad Street, four access points near Milk Street and India Street/East India Row, along with a direct link to Aquarium station. The study estimated that introducing Central Station could boost daily commuter rail boardings by 3,500 to 12,800 trips; however, it would increase construction expenses by approximately $540 million to $817 million—roughly one-sixth of the total project cost. To accommodate potential NSRL and Central Station development, slurry walls reaching a depth of were installed during Aquarium station’s renovation.

A reassessment conducted in 2018 revisited both two-track and four-track proposals beneath the Central Artery and explored two-track alternatives along Congress Street, an option previously dismissed. Only the more expensive four-track plan incorporated Central Station. The Congress Street scenarios suggested placing the northern station under Haymarket Square rather than North Station, which would facilitate a Blue Line connection at State station instead of Aquarium.