The Northern Avenue Bridge was constructed in 1908 spanning the active Fort Point Channel, then a major industrial transportation route. As constructed, it was an operable steel three-span, triple-barreled, Pratt-type through-truss bridge with a rim-bearing center span that swung open to allow for water traffic. The bridge was designed to carry horse-drawn and motorized truck use through the outside barrels, freight locomotive passage through the central barrel, and pedestrians on sidewalks cantilevered beyond the outside barrels. At the time, the bridge was constructed as an integral part of the development of South Boston as a maritime and industrial center for Boston and the region and continues to serve as a reminder of that part of the city's evolution. Currently in a state of severe disrepair, the bridge is closed to all traffic and is threatened with total loss. The Walsh administration is considering options for its reuse or replacement.
More information about the Northern Avenue Bridge project can be found here.
The Alliance has been advocating for the preservation of the Northern Avenue Bridge for decades. More recently, the Alliance has actively engaged in the City's efforts to evaluate the condition of the bridge, explore options for reuse, assess transportation needs, and encourage dialogue and a thoughtful, thorough process. We've been a strong proponent for community desires to preserve an iconic element of Fort Point, a supporter of walking and biking advocates' voices for the historic bridge, and a watchdog making sure the City follows various historic preservation regulations that establish a clear process that dictate how any changes to the bridge need to be reviewed. We will continue to emphasize the need for an open, public process that integrates the voices of the community.
We feel that the bridge is valuable in many ways: it embodies the changing technologies in bridge construction and functionality, illustrates the history of maritime Boston, and contributes character and sense of place to the waterfront. Unlike much of the new construction in the area, the bridge represents something uniquely Boston, and when a pedestrian is on the bridge it provides an engaging relationship with harbor, history, and the city unlike any place else in Boston. There are opportunities to creatively reuse the bridge, updating structural elements that are failing while restoring the truss system and creating a unique destination for visitors and a pleasant experience for commuters. The bridge is a rare survivors of a once common form of infrastructure, with only about 120 swing bridges left in the nation, and this one of the largest and perhaps the only one surviving that was once powered by compressed air.
Highlights from our activity log:
August 23, 2018
Alliance ED, Greg Galer attends fourth Task Force Meeting.
Chief Osgood notes that the city heard clear feedback from last meeting that the Task Force wants more analysis and data and will be providing it. The timeline has been adjusted to be sure there is time to do it right and that the city is fully engaged with and responsive to the Task Force.
AECOM summarized ongoing additional traffic data gathering to be presented at next meeting. This was in response to feedback from the previous meeting. The Task Force requested a funding summary at the next meeting – What money is available? Where is the city looking? What demands are being made by potential sources? Chair was very clear to state that the Task Force will lead the design and partnerships and money outreach will follow. Money sources are not driving design.
AECOM team circulated a decision matrix to try and move some items from discussion to decision. They went through several items and asked each member of the Task Force for a response. The Task Force members will have the opportunity to respond electronically after discussion with their board/group if needed. Examples include:
Raise each end and center? (Galer reluctantly supports, noting clearly our long desire was not to raise, but given resiliency issues it’s hard to not.) All around table were questions re how it meets the edges, grade, etc. Galer also noted concern about how angled approaches are done without negatively impacting trusses and the look of the historic bridge.
The AECOM team updated structural reports. Now it is looking like most of the verticals (assuming a lower splice can be developed-- which they are working on) could be saved. Diagonals to be replaced (Galer notes their replacement is easier without visual impact than riveted lattice-girder verticals). They also re-examined load capacity and the swing span looks good if the condition can be brought up. Approach spans not in as good condition; with some additional structure we might be able to save more, but at some point it may make less sense (if a vertical requires additional structure to take load plus bottom splice, does that make sense to save?).
The Task Force was asked to comment on spectrum from Preserve – Replicate (all new material) – Reinterpret – New Bridge. Galer took the lead by commenting first, given Alliance's obvious strong interest here. He notes Alliance Board discussion. Our desire/preference remains repair and we are awaiting more data (splice joints etc.) to see if that is feasible. We have concern about the realities of a replicate situation - how authentic/real would it be? We don’t want beams with fake rivet heads stuck on. Don’t want Disney. We may get to a point where repair/replication doesn’t make sense and we see this as an opportunity for something new and unique that captures the essence of the bridge (outdoor room, scale, proportions, shape). BUT VERY CLEARLY states that we aren’t at that point yet. More information is needed on splice joints, how repairs and/or replication of elements would occur.
There was much agreement around the room for this position.
July 26, 2018
Alliance ED, Greg Galer attends third Task Force Meeting. There is much discussion of traffic implications and impacts of the bridge and what benefits would or would not be of various modes of transport on the bridge. The Task Force pushes for more data to better understand the suggestion that HOV+ traffic on the bridge provides the best traffic benefits.
The AECOM team presented some preliminary structural engineering reports plus a loading analysis that suggest 86% of the truss members would need replacement. Galer pushed on analysis of the viability of splice joints in existing members to allow more to be saved. The AECOM team provides clarification on loading - that the bridge needs to carry "assembly" loading of 100 lbs/sf so bikes and pedestrians only doesn't mean a less strong structure than cars. City Engineer notes it we should design with loading for future flexibility in use.
Galer notes his hope that there is no preconceived notion of the outcome and that the expertise of the Task Force is taken seriously and we are provide the data we request to be able to provide real input and guidance. In particular he notes the Section 106 historic review process which this project will need to clear and provide data to support.
Team to report back with more data next meeting
July 17, 2017
June 28, 2018
Alliance ED, Greg Galer attends second Task Force Meeting. These are public meetings and all materials (agenda, minutes, and various reference documents) will posted on a new city web site to go live soon. There will also be an online opportunity to provide feedback. After Labor Day the city team expects to have an open house/public meeting with a more formal design hearing about a month later. In the meantime they want to meet with various constituent groups.
The consulting team has looked at all “ideas competition” entries for spirit and aspiration and note that almost all have the existing bridge remain and even those that proposed taking it out still create a destination.
Rich McGinnis from BPDA presented Climate preparedness planning and suggests that elevation changes surrounding Fort Point will be the likely path forward. He suggest looking at Climate Ready South Boston documents. Already this winter water was hitting the bottom of the bridge during storms. The recommendation is to raise the bridge and fix it in place, with the bottom matching the bottom clearance of the Moakley Bridge.
Bridge Engineer from AECOM, Joe Allwarden, presents report on their analysis of condition of bridge, starting with a primer on bridge terminology. The floor system is in very rough shape – 66% of 900+ members are in poor or critical condition. Reusing elements that are in ok condition not impossible but has challenges due to need to disassemble pin connected joints and inability to know their internal conditions in advance. Many elements just have one end (deck end) in poor condition but challenging to splice onto those, particularly with desire for 75 year lifespan going forward. Perhaps possible for some diagonals. Top cords mostly likely viable for reuse and cross bracing. They will be talking to MassDOT for lessons learned on projects like the Longfellow Bridge. Substructure (piers, abutments) under analysis now. For context the center, round, drum pier has 870 wooden piles under it.
A variety of preliminary conceptual designs were presented (best to look on web site once up). All focus on main goals: honor past, resiliency, destination/placemaking. 6 sketches shown, each with pedestrian, biking, some limited vehicular (type/amount tbd – minimum emergency vehicle), and programmable space (particularly on “the island” which is the space over which the swung-open bridge sits). Three schemes had a stronger preservation bent with fewer interventions to the original design, although some altered the spacing between the barrels. Three focused more on the placemaking with extensions, ramps, etc.
There was a fair amount of discussion about putting traffic on the bridge - desires of various constituencies, perceived traffic demands, and what traffic studies show a reopened bridge can provide, balanced against desires for pedestrians, bikes, and making the bridge a programmed destination. This will be discussed in more detail at next meeting and traffic studies provided in advance. Rick Dimino notes that the study they completed showed that benefit of putting traffic on the bridge is limited by the intersections and narrowness on either side which reduces throughput. Although Councilor Flaherty was adamant that traffic should be primary most around the table didn’t seem to agree. Will be discussed in detail at next meeting.
Upcoming task force Meetings:
July 26 will focus on mobility and traffic; a structural analysis update; programmable space
August – conclude programmable space; financing; permitting requirements
September – public workshops and public design hearing
A Mayoral Advisory Task Force is formed and notified that the engineering firm AECOM has been selected to design the project with support from Urban Idea Lab of Boston and BEaM from London, England. The design philosophy for the replacement bridge continues to focus on mobility, climate resiliency, honoring history, and creating a destination. City officials promise this will be an open process, with extensive public engagement which will begin soon.
Alliance ED Greg Galer attends first meeting as a member of the Task Force.
The City of Boston's Public Works Department issues a Request for Qualifications for architecture and engineering design services relative to the new Northern Avenue Bridge. The Alliance urges the City to refrain from describing the project as designing a "new" bridge since the process has not been completed to determine if the bridge will be restored or replaced. Also, the RFQ fails to note experience in historic structures which should be a priority for this project. The RFQ is followed by a Request for Proposals which addresses several of the Alliance concerns including requiring relevant historic bridge experience.
The Army Corps of Engineers sends a letter claiming adverse effect to this historic bridge and invites to Alliance to join the consultation process.
Boston City Council authorizes $15M from the City's Capital Grant Fund to support engineering and design services related to the bridge. This funding likely needs to be held in reserve in case the bridge deteriorates to the point where it impedes water navigation and emergency removal is required.
May 25, 2016
Alliance ED Greg Galer serves on a jury for an Ideas Competition launched by Mayor Walsh to collect ideas for the Northern Avenue Bridge. There were over 100 submissions and eight were selected as winners, most of which were largely concepts that preserved key elements of the historic bridge.
February 18, 2016
Alliance sends an AllianceAlert asking for supporters to submit comments to the Army Corps of Engineers in support of saving the bridge. About 175 comments are received and nearly all support a preservation solution.
Alliance staff discusses possibility of emergency relocation of bridge with City Engineer due to dangerous conditions. Alliance communicates with Massachusetts Historic Commission and others. After a discussion with the Board of Directors, the Alliance sends a letter to the City's Chief of Streets.
April 24, 2015
The Alliance sends a letter to Mayor Walsh reinforcing the recommendation that was made after many meetings with stakeholders that the City pursue a strategy of rehabilitating the existing bridge.
The Alliance hosts a meeting of engineers, advocates, and other related professionals to discuss viable options for reusing the bridge. Several additional meetings are held with various stakeholders to discuss priorities for the bridge and analyzing cost estimates.
January 16, 2015
Executive Director, Greg Galer, meets with Mayor Walsh, the City Engineer, the Chief of Civic Engagement, and the Interim Commissioner of Public Works to discuss a reconstruction plan with an eye toward preservation.
The Northern Avenue Bridge is closed to all traffic, including pedestrian, due to safety concerns. An article in the Boston Globe notes that the City is working with the Alliance to balance preservation issues with the need for public safety. The Globe also publishes an Editorial by Alliance Executive Director. Alliance staff maintains close dialogue with stakeholders.
November 18, 2014
Alliance staff joins City of Boston staff for a tour of the bridge and assess current condition.
The Alliance joins other advocacy groups in efforts to reengage with the City regarding the Northern Avenue Bridge. Alliance staff attends meetings and participates in conversations with City officials, local advocates, and others to encourage dialogue.
In the News
Boston's urban planners and placemakers have an opportunity to make the Northern Avenue Bridge, now a rusting relic in Fort Point Channel, a postcard-worthy destination that draws in tourists and r
It has been nearly four years since anyone could walk across the old Northern Avenue Bridge, and two decades since you could drive across it.