Martin’s Park Serves as Tribute to Boston Marathon Bombing Victims
New Park Honors Youngest Boston Marathon Bombing Victim: Recently Completed by MacKay Construction Services on the South Boston Waterfront, Martin’s Park is the City’s First-of-Its Kind Play Space
A $15 million park honoring the youngest victim of the 2013 Boston Marathon bombing recently opened on the South Boston waterfront, with Mayor Martin J. Walsh and Governor Charlie Baker, and the family of eight-year-old Martin Richard, joined by hundreds of residents to commemorate the event.
Located next to Boston Harbor’s Fort Point Channel across from the Children’s Museum, Martin’s Park was designed in collaboration with landscape architect Michael Van Valkenburgh and built by contractor MacKay Construction Services of Wilmington, Massachusetts.
Boston’s Parks Department oversaw the project that is said to be the city’s first-of-its- kind play space. Among its features are a reflection and water play garden, a wooden amphitheater, a 40-foot by 12-foot wooden play ship, a timber maze climber, cosmo climber, and a 35-foot-long pedestrian bridge.
Five cherry trees are planted in memory of bombing victims Sean Collier, Dennis Simmonds, Krystle Campbell, Lingzi Lu, and Martin Richard.
Stakeholders Agree to Memorial Park
At one time the Martin’s Park site was a large unused grassy field. For years the Children’s Museum had wanted to expand some of its activities to the field but there were four other stakeholders of the property including the Massachusetts Bay Transit Authority (MBTA), whose Silver Line underlies the site, so reaching a mutually agreeable land-use solution was stalled for years.
But an agreement was reached by the stakeholders when a memorial park dedicated to the marathon bombing victim was proposed for the property.
According to information provided by City of Boston Spokesperson Lauren Bryant, during the early period of park construction the Climate Ready Boston Report was released, indicating that a higher flood elevation for the design of the park should be used. In line with this, design and engineering work was adjusted to make sure that the park would meet the climate resiliency strategy desired by the City. This is in keeping with Mayor Walsh's plan, Resilient Boston Harbor, which lays out strategies along Boston's 47-mile shoreline to boost access and open space along the waterfront while better protecting the city during a major flood.
Park designers took preventive measures against future inundation by elevating certain areas of the park to prevent flood pathways, and by installing mini piles and vegetated beds reinforced with stone to prevent erosion at higher tides. The piles were drilled at neighboring portions of Harborwalk, a near-continuous, 43-mile linear park along Boston’s shoreline that connects Boston’s waterfront neighborhoods to Boston Harbor and each other. Another essential structural feature of the park was a concrete wall that was built along sections of the Harborwalk, which facilitated earthmoving within the one-acre park site.
Buoyant Foam and Mud Slab Anchor
The park is not a typical, level, play space, but instead has areas marked by wavelike contours and varying elevations – features that present a challenge to earthmoving equipment operators. Its undulating terrain could have required the import of large amounts of soil fill to fashion the elevated areas, but these factors were offset by the use of geofoam blocks instead of soil over much of the park to produce the desired shape and MacKay Construction’s utilization of heavy earthmovers equipped with machine controls and associated satellite navigation systems.
Expanded polystyrene(EPS) geofoam as used in Martin’s Park is manufactured in large lightweight blocks. Their primary function is usually to provide a lightweight fill below a highway, bridge approach, embankmentor parking lot that minimizes settlement on underground utilities. Geofoam is also used in much broader applications, including lightweight fill, green rooffill, compressible inclusions, and thermal insulation.
While geofoam is extremely lightweight and hence useful as fill, it is also very buoyant, and that could be a problem if the sea rises to unprecedented levels due to catastrophic storms or significant climate change. To counterbalance this tendency to float, park designers specified the construction of a mud slab consisting of 24 inches of 3,000 psi concrete to serve as a site anchor as well as a firm base for the geofoam. Furthermore, as workers placed geofoam to build up the topography, they wrapped the blocks in filter fabric.
Satellite Navigation and Machine Controls
The contractor graded the earthen subbase of the site and placed hundreds of geofoam blocks to match specific site contours using Topcon Positioning satellite navigation and machine controls.
“We have Topcon equipment in two Caterpillar 325 Excavators, two Caterpillar 335 Excavators, and one of our Caterpillar D4 Dozers,” said Kyle Annutto, Project Manager for MacKay Construction.
The machine controls included 3DMC2 dozer system, X531 3D excavator systems, and several GR-5 GNSS Rover Receivers with FC-5000 data collector and Pocket 3D software. The GR-5 receivers are capable of tracking GPS and GLONASS, among other satellite constellations (see accompanying sidebar).
Annutto added that they also employed the positioning systems and machine controls to help dig utility trenches and foundation walls, pour the mud slab, and accurately place about 350 trees and plants. He also pointed out that positioning activities were supported by the use of 3D landscape scale model software as a reference tool provided by Ray Antaya of ECI Technologies.
“We’ve been using these Topcon positioning systems for about five years, and they have saved us time and money,” Annutto said.
Hundreds of Donors Make Park Possible
Martin's Park was a $15 million project, made possible by private funding through hundreds of donors and $2 million from the City of Boston, including capital funds and Community Preservation funds. The Smith Family Foundation and Barr Foundation each provided $3 million. The park site includes a parcel that was conveyed by the MBTA to the City of Boston. Boston’s new commemorative park will be maintained through an endowment of the Friends of Martin's Park and will feature ongoing, no-cost programming.