MIT to unveil the Sean Collier Memorial, designed by Professor and Head of the Department of Architecture, J. Meejin Yoon. The unprecedented, solid stone five-way arch structure to translate ‘Collier Strong’ into a permanent memorial for Officer Sean Collier.

Via Höweler + Yoon Architecture, LLP

Marking the second anniversary of the Boston Marathon bombings, the permanent memorial to Officer Sean Collier opens at MIT next week. The memorial is built at the intersection of Vassar Street and Main Street on the edge of the MIT campus to mark the site of the shooting. Designed to create an intimate space of reflection, the memorial is a five-point figure with a void carved from its center to create a shallow vaulted structure made of solid stone. As architect J. Meejin Yoon described the memorial: “It needed to convey the feeling of absence and loss, so I designed the memorial as a five-walled figure with a void for reflection at its center.” The memorial has been described as both a five-pointed star and an open hand. The five-way vault renders the idea of «Collier Strong» and «MIT Strong» into solid stone. As a compression structure, the arch is dependent upon the stability and the interaction of its individual parts. “Each stone is necessary to transfer loads and create equilibrium. The memorial represents the community coming together where strength comes from unity,” says Yoon.

The memorial combines ancient techniques of masonry stone structures with contemporary design and fabrication technologies of robotic stone milling. The asymmetrical and shallow masonry vault was challenging to calculate with conventional means. To resolve structural challenges, Yoon enlisted the help of colleague Professor John Ochsendorf, a structural engineer and expert of masonry vaulting structures, as well as Knippers Helbig Advanced Engineering from Stuttgart, Germany. The design and construction team utilized sophisticated custom software applications to develop and engineer the shape of the memorial. “The structure is completely unique and required an array of engineering approaches, ranging from hand calculations, physical models, and computational software,” says Yoon. “The collaboration of architects and engineers resulted in a process that was very collaborative.”
The design team worked closely with the Collier Memorial Committee at MIT throughout the design process. The stone fabricator, Jim Durham from Quarra Stone, stone installer Phoenix Bay State, and contractor Suffolk Construction were also all involved very early in the design process. “The process for design and construction of the stone arches of the memorial were so unprecedented that we had to rethink all of our assumptions about fabrication, tolerances, and construction sequencing,” said Jim Durham.

Stone blocks were individually selected at the Virginia Mist granite quarry near Culpepper, Virginia. The fabrication involved sophisticated stone carving by computer-controlled saws and a robotic arm to create the complex curved geometry of the blocks. The installation team worked through the winter (which suffered the highest recorded snowfall) to erect thirty-two solid blocks of granite and complete the construction of the memorial in time for the 2-year anniversary.

Rob Rogers, Sean Collier’s brother and project manager from Suffolk Construction, oversaw the construction of the memorial and was on site every day for the past several months. “Working on the memorial has been a kind of healing process,” said Rogers, “In a way, it has helped bring people together.” The construction team has been on site since October, working through challenging weather conditions, exacting material tolerances, and highly complex logistics.

Under the supervision of Professor John Ochsendorf, a group of MIT structural engineering students also closely monitored the construction process. The students predicted movements and deflections, as well as monitored the process of the load transfer from the temporary scaffolding to the permanent arches. Lowering the scaffold involved a carefully choreographed sequence of incremental lowering of the supports. As the load shifted from the temporary supports to the adjacent stones, strain gauges at the joints and scales below the scaffold were monitored until the load was fully transferred into the legs. Over eight hours, thirty people watched as the scaffold was lowered and the arching action in the stone took place. Ochsendorf and Yoon commented that watching 100,000 pounds of stone not move was extremely exciting. Yoon says, “the process of designing the memorial has been very special: it brought together the MIT community, experts in engineering and fabrication, pushed the boundaries of construction and fabrication technologies, and achieved something unique. Drawing upon MIT’s motto, “Mens et Manus,” or “Mind and Hand,” the process and project is especially “MIT.” The memorial captures Sean’s adventurous and generous spirit, and his love for MIT and the outdoors. Carved into the memorial is a quote from Officer Sean Collier’s eulogy delivered by Rob Rogers: “Live long like he would. Big hearts, big smiles, big service, all love.”

Yoon says, “In these trying times, we choose to represent and honor Sean and his service with an open hand over a closed fist by creating a space of remembrance that is open yet intimate; heavy yet light; respectful yet adventurous; singular yet collective; and most of all, truly special and unique.”

The official dedication of the memorial will be on Wednesday April 29th at 12 PM. MIT and community leaders will gather to introduce the MIT community to the new structure, and to reflect on the events of April 2013. Professors J. Meejin Yoon and John Ochsendorf will present a public, Institute-wide lecture, “The Making of the Collier Memorial,” on Monday, April 27th at 6 PM in 10-250.

Related MIT News articles:
http://newsoffice.mit.edu/2014/mit-unveils-plans-for-permanent-memorial-to-officer-sean-collier
http://newsoffice.mit.edu/2015/sean-collier-memorial-dedication-and-community-picnic-honor-fallen-mit-officer-0414
http://newsoffice.mit.edu/2014/work-begins-collier-memorial-1010