Engineered by Arup as the prime design consultant, New York’s newest transport hub, the Fulton Center is ready to serve up to 300,000 passengers a day in post-9/11 Lower Manhattan.
Above ground it is a new iconic glass and steel structure, sitting easily alongside the federally listed historic Corbin Building: a restored 19th century ‘proto skyscraper’ that is now an integral part of the station. Beneath the surface are platforms for nine subway lines that were originally built by separate and competing commercial entities, some more than a century ago. They are now reached via a simply stunning bank of escalators within the center and some two dozen access points from surrounding streets.
Not surprisingly, a guiding principle for the design, from the master planning stage onwards, was to simplify access to these platforms and ease the transfers between lines for passengers.
How Oasys proved invaluable
The design team needed to understand how people would move through the station and resolve any potential conflicts before finalising plans for the US$1.4bn project. “With any transit project, there is a lot of competition for a limited amount of space,” says Eric Rivers, a pedestrian planner with Arup. Subway platforms, for instance, are used as corridors as well as for boarding, alighting, and waiting for trains. “The only way to understand it was with a micro-simulation model,” he says.
Of course the best way to simulate a multi-level structure with complex interactions between areas was in 3D, and at the outset of this project in 2003, the Arup engineers had the benefit of early access to the intricate 3D CAD Model. Arup very quickly recognized that the problem that had to be solved was to not impede train services; maintain a minimum level of service at key locations including platforms and key staircases, as well as safeguard the required fire and life safety egress levels, and that it could not be solved in 3D using currently (then) available tools. Arup set about writing the computer code to help analyse and solve the complicated 7 year staged construction sequence. Oasys MassMotion was born on the Fulton Center project, it is a 3D crowd analysis and pedestrian simulation tool that helps to inform design decisions. MassMotion that is now widely and commercially available and still the only truly 3D modelling tool available, and supports modelling of both everyday movements as well as supports modelling of both emergency and rare event scenarios.
MassMotion is infinitely scalable, so it allowed the design team to populate the project’s digital model with realistic numbers of “agents,” or virtual people, to evaluate how many passengers the facility could handle and predict what route they might take through the remodelled station or around obstructions. Arup subsidiary Oasys has also further developed MassMotion so that it can be used to understand how occupants will behave when faced with, for instance, a choice between a crowded escalator and a relatively empty set of steps. It will even taking into account cultural differences such as giving way to the left or right, the difference in pace length of a man and a woman; or doing value assessment of retail spaces or advertising potential of certain surfaces within the 3D Model.
Due to its sheer power and the speed with which queries can be run on a model, a 3D MassMotion model also creates an important BIM legacy, helping project teams to study the effect of operational changes during construction staging and throughout the operational life of a building or transit facility. Architects, engineers and designers have all become aware of the quantum leap they can make by switching from 2D to 3D crowd analysis in communicating complex ideas to stakeholders, and to explain and win the case for changes in designs or operations. The ease with which they can develop pedestrian environments in MassMotion using either imported CAD/BIM geometry or MassMotion’s new polygon modelling tools, coupled with new licensing options, is making MassMotion the pedestrian modelling tool of choice.
Craig Covil, Arup’s Project Director for the Fulton Center says that, “One of the most significant successes of the Fulton Center project, was the much increased subway network efficiencies as a result of reducing the dwell time of the trains at the platforms for loading and unloading passengers. Oasys MassMotion helped us analyse the problem and provide a more streamlined and better solution with less ‘friction’ that markedly improved the train movements through the center and in turn on the whole subway network”.
Craig goes on to say “We assessed the various stations that were built between 1904 and 1935 as separate privately financed and competing subway lines, reducing the ‘friction’ that was inherent in these independent legacy lines, to produce a much needed streamlined more seamless integrated transfers from one line to another, mitigating platform-end crowd loading, radically reducing train dwell times at the stations, and thus providing whole of subway network efficiencies to the MTA and NYCT and their passengers. The 4/5/6 Lines carry about 1.3 million people daily….more people per day than the combined Chicago, San Francisco and Boston subway systems, so 30 seconds saved with this many commuters per day – per year is a very significant value add to the community.”
“One of the most significant successes of the Fulton Center project, was the much increased subway network efficiencies as a result of reducing the dwell time of the trains at the platforms for loading and unloading passengers. Oasys MassMotion helped us analyse the problem and provide a more streamlined and better solution with less ‘friction’ that markedly improved the train movements through the center and in turn on the whole subway network”.