The Boston Tea Party Ships & Museum: PART 2 – ANCHORS AWAY!

The Boston Tea Party Ships & Museum: PART 2 – ANCHORS AWAY!

The Boston Tea Party Ships & Museum: PART 2 – ANCHORS AWAY!

By Dan Perruzzi and Cyndy Gibson Murphy.

Now that you have the background on the history and future of the site, as well as how this project came to be and how MPA became involved (from Part 1 – All Aboard!), we can discuss how the project will be built.

Updating the Construction Documents
Boston Properties (BP) asked us to review the drawings and update them based on the new code requirements (the code changed following the initial issue of the drawings in 2007). After capturing these changes, we analyzed the envelope assembly for optimum performance, scrutinized material and product selections appropriate for a high-traffic environment, and redesigned the lighting systems and controls to capture efficiency and longevity through the use of various LED products. In the years since the drawings were first completed, building technology continued to evolve. We wanted the building to take advantage of the latest technology in order to save energy and help the building survive the elements.

Since a high performing envelope is a critical element, especially for a museum home to historic artifacts and high-tech audio-visual displays, we had to take the waterfront location into consideration when analyzing the envelope assembly. Our review included the selection of materials, thermal performance, and constructability. Simultaneously, we had to work inside the confines of a building design that had undergone intense scrutiny by various city agencies prior to obtaining approval to build.

This project had two unique issues that we had to address:

  • With one structure moving continuously up and down (due to the tides) while the other is fixed in place, we had to ensure accessibility requirements were met. Our solution was to provide two pairs of long sloped gangways with access to both levels, so that one of the two will be always meet the maximum allowable slope. Once at the barge, building visitors and staff can use the elevator to access the other levels.
  • The barge is essentially a large floating metal box. It remains afloat by keeping water from filling the hold. Let’s say, in a worst case scenario, that the new project catches on fire (since it had already suffered two in 2001 and 2007.). When attempting to extinguish the fire, the Boston Fire Department would have to spray the barge building with fire hoses, making it difficult to control where that water goes. Most of a fire hose’s spray would run over the building and off the side of the barge, however once the walls are compromised, the water would collect in the lowest point (in this case, the elevator pit) until it reaches the point of overflowing. To minimize the amount of water that could possibly collect, we subdivided the barge hold by constructing watertight compartments around the three access points (two sets of stairs and the elevator). We also added submarine-type doors that will allow water to collect in only a small area surrounding the elevator shaft.

We realized in this initial process that picking up the design from another firm was going to be extremely difficult, since we did not have the ability to speak with the original designer, nor were we provided the research and background every architect develops over the course of a project. We worked diligently to understand the site’s was intended function in order to allow us to think like the original architect. Drawings were completed in November 2010 and issued to the owner (BP and Historic Tours of America [HTA]) so that bidding could begin.

Construction Begins
Following the bidding process, Suffolk Construction was selected to build the project. Witnessing the construction of any project on which you worked is fun, but with the Tea Party right outside our door, this feeling was enhanced since we could constantly view the progress. Due to its unique nature, the Tea Party construction is full of very interesting operations. For example, one of the first construction activities was the removal of existing wooden pilings to make way for the installation of new pilings that would support the pier building. After a large construction barge (complete with crane) was floated into place, the marine contractor began removing piles by grabbing them with a huge, crane-hung jaw that pulled and vibrated the old pilings out of the mud and muck at the bottom of Fort Point Channel – it was amazing to watch.

We had all wondered how the pilings for the pier building would be placed accurately, given the constant motion of the ocean surface, which moves the floating barges. The marine contractor’s solution involved installing temporary pilings supporting a network of temporary steel beams. From the beams, the contractor could accurately lay out the pile locations and then use that platform to assist with the actual driving of piles. Once all the permanent piles were driven, the temporary piles and network of temporary beams were removed.

The Barge is Constructed
While work on the pier building moved ahead on the site, the barge was under construction far from the site. The Tea Party barge is an unusual shape and size for a barge. As a result, it had to be custom constructed. On a drydock at the Quincy shipyard, Suffolk’s marine subcontractor built the barge out of steel plate and other shapes. HTA, BP and MPA, as well as Suffolk, regularly visited the Shipyard to assess progress. All of us felt totally at sea (pun intended) doing this. Each of us can walk a construction site and immediately assess how far along the project is, even if we had no familiarity with the project. A barge is something else all together. In November 2011, the barge was completed and launched into the ocean.

Suffolk decided to construct at least part of the first floor of the barge building in Quincy, before the barge was moved to Boston. In early December 2011, much of the first floor of the barge building had been framed and the barge was ready to be floated into position. Two small tugs pushed the barge slowly out of the Quincy shipyard and up the coastline to Boston Harbor. As the barge approached the Federal Courthouse on Fan Pier, the old Northern Avenue Bridge began to open. Many of us from MPA, along with others from Suffolk, HTA and BP, had gathered on the shoreline and on the Moakley Bridge to watch the barge float in. Ominously, Suffolk had warned all of us that there would be only 6 inches of clear space on each side between the bridge abutments and the barge. We all held our breath as the barge approached that narrow opening. The day was windy, and the barge bobbed in the wind from side to side, but finally made its way through the opening, and into position where it was temporarily pinned in place. Over the following weekend, final pilings were driven through the yokes welded to the sides of the barge. While the yokes and their rollers allow the barge to float up and down with the tide, the pilings keep the barge from moving side to side. The barge was finally moored in place.

Stay tuned for Part 3 where we discuss building the individual elements of this project.