Train Station Ventilation System Design
Background
The South Station Transportation Center (SSTC), located in Boston, Massachusetts, consists of a train terminal, regional bus terminal, and a public parking garage. Currently the bus terminal and parking garage are located above the south portion of the train platforms. The section of the tracks and platforms between the north end of the SSTC and the head house, which ranges in length from about 365 to 525 feet, is currently uncovered and open to the atmosphere.
The Boston South Station Project proposed to build high rise structures and to expand the bus terminal over the existing platform areas of South Station. In effect, the development will fully enclose the station tracks and platforms with the exception of the south “portal” area and the east edge of the development along Track 13.
Work Performed
Three locomotive/track arrangements were modeled to provide a representation of the “worst case” conditions with respect to the collection of the main and HEP engine diesel exhausts and cooling fan flows.
The efficacy of multiple exhaust hoods were evaluated to meet target health and safety standards while trains were parked at idle at the head end of the tracks. Specifically, the analyses were performed to ensure that the proposed track exhaust and general ventilation systems were able to maintain safe levels of train engine emissions concentrations and ambient air temperature while the trains were parked and idling in the station.
Project Evolution
- 1990 Alden initially provided the design for track exhaust hoods to remove diesel products from the ventilation systems to achieve safe levels. Design work was proved out through the use of physical scale modeling, chosen for its cost effectiveness
- 2005-2008 Alden provided the initial ventilation design for the high rise overbuild construction project
- 2017-2018 Following the reboot of the projct, Alden evaluated multiple scenarios to develop and finalize a robust ventilation system that could handle a variety of station situations.
Visualization of the Computational Model [below] shows the transient locomotive through station to show thermal and pollutant capture.
Capability
Civil InfrastructureServices
Gas Flow Modeling & DesignRelated Projects
Between 1932 and 2010 the state of Louisiana has lost about 2006 square miles of land due to a combination of subsidence, sea level rise, and management of the Mississippi River. Computer models predict a further loss of 1800 to 4200 square miles in the next 50 years, amounting to 55% of the land in Plaquemines Parish and resulting in $300 million in annual economic damage. Following hurricanes Katrina and Rita, the Coastal Protection and Restoration Authority (CPRA) was formed as a single state entity with the authority to protect and restore the lands of coastal Louisiana.
The $50 billion coastal master plan includes restoration and risk reduction projects. The restoration projects include barrier island restoration, hydrologic restoration, marsh creation, ridge restoration, sediment diversion, and shoreline protection. The Barataria and Breton Basins have experienced some of the largest land loss—almost 700 square miles. Two sediment diversions are being designed, one for each basin. The sediment diversions connect the Mississippi River to the basins, allowing for the controlled diversion of up to 75,000 cfs of water and sediment to the Barataria basin and 30,000 cfs to the Breton basin.
The design and construction of sediment diversions on the scale proposed for Barataria and Breton is unprecedented, the results of which will rely heavily on the numeric and physical modeling required to design the major diversion features, including the inlet, conveyance, and outlet structures. Alden is constructing two 1:65-scale, live-bed physical models to test performance and effectiveness of the diversions.
Discover more:
- Making Mississippi Mud In Massachusetts To Restore Wetlands | Here & Now [wbur.org]
- A Mini Mississippi In Mass. May Help Save New Orleans From Rising Seas [90.9 Boston NPR]
- Rerouting the Mississippi River could build new land—and save a retreating coast [Science Magazine]
- Find the Mississippi River in Massachusetts [Chronicle 5 WCVB]
- To Save Louisiana’s Vanishing Coast, Build a Mini Mississippi Near Boston [The New York Times nytimes.com]
- Louisiana researchers tackle a changing Mississippi Delta [PBS News Hour Weekend pbs.org]
- Mid-Barataria Sediment Diversion could create, save 47 square miles of land over 50 years [nola.com]
- CPRA Using Giant Model to Test Mid-Barataria Diversion
- Mississippi River Diversions Could Save Louisiana's Drowning Coast [enr.com]
- Louisiana Coastal Protection and Restoration Authority [Official Website]
- A Mini-Diversion in Boston is Paving the Way for Louisiana’s Boldest Coastal Project [mississippiriverdelta.org]

Civil Infrastructure
Mid-Barataria Sediment Diversion
Alden constructed two 1:65-scale, live-bed physical models to test performance and effectiveness of the proposed land rebuilding diversions on the Mississippi River.
The Cedar Cliff dam and hydropower project is located approximately six miles from Cullowhee, in Jackson Country, North Carolina. The dam and hydroelectric facility is owned by Duke Energy and is located downstream of three other hydroelectric projects that are operated as a system.
The primary spillway includes a Tainter gate and the existing auxiliary spillway system includes two fuse plug sections (with different crest/activation elevations). It was determined that the combination of the primary and auxiliary spillway systems were not adequate to safely pass the regulatory-increased Inflow Design Flood (IDF). The construction of a Hydroplus Fusegate system with six semi-labyrinth Fusegates in an enlarged auxiliary spillway channel was selected to increase spillway capacity to safely pass the new IDF which is now the full Probable Maximum Flood (PMF).
Two reduced scale physical models were constructed to determine the required size of a ventilation system for the proposed Cedar Cliff Fusegates and headpond and tailwater levels at each Fusegate for flows up to the sixth Fusegate activating. The tailwater levels were required for design of the Fusegate ballast system.
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Civil Infrastructure
Cedar Cliff Spillway
Physical model study to determine hydraulic performance of a proposed auxiliary spillway system during flooding events