A case study in technical design and constructability of floating structures: Northeastern University boathouse ramp and crew dock
The most fascinating part about this small rowing pontoon and gangway built for Northeastern University in Boston, MA, are the challenges associated with the constructability of the design and how they were overcome.
At 100 feet wide by 17 feet long the gangway at Henderson Boathouse is truly one of a kind. To a layman, these dimensions might not seem extreme. But to a marina builder, to build an oversized gangway like the one envisioned for Henderson and have it land on an 8-foot-wide by 120-foot-long floating dock that has a six-inch freeboard is no small feat.
Northeastern’s vision for their new boathouse and rowing dock was perfect on paper. The poster child for functional luxury – elegant in design and calculated in its function.
The challenge was in the constructability of it. The University hired renowned marina builder Bellingham Marine to help design and build a system that would meet the rowing team’s technical, aesthetic and budget requirements.
Below is a brief summary of the project’s technical requirements.
TECHNICAL REQUIREMENT #1:
A floating dock with 6” of freeboard. At this height, the riggers on a rowing shells are able to extend over the deck allowing the skull to sit flush against the dock.
CHALLENGE #1:
A uniform freeboard of 6” can be extremely difficult to achieve and requires consideration of the types of materials that will come in contact with the water.
SOLUTION #1:
100% flotation coverage, use of low profile tubs and an aluminum dock frame helped designers meet the 6” freeboard requirement while providing the desired longevity.
TECHNICAL REQUIREMENT #2:
A high live load capacity. Given the dock’s intended use, public profile, and number of individuals and equipment that could be on the dock at a given time, the dock needed to have a high live load capacity as well as be a show piece.
CHALLENGE #2:
To maintain a high live load capacity on a floating dock with 6” freeboard can be a challenge.
SOLUTION #2:
To maintain a high live load capacity on a floating dock with 6” freeboard can be a challenge. A lightweight aluminum dock frame with 100% flotation coverage with an IPE deck was selected; this combination best met the performance and aesthetic requirements.
TECHNICAL REQUIREMENT #3:
A gangway structure whose width extended the length of the boathouse and would allow the skulls to be carried down to the dock parallel to the shore.
CHALLENGE #3:
The gangway envisioned for the site would weigh nearly 10 tons, with 6 tons resting on the edge of the dock. The challenge would be getting the lightweight dock to float level.
SOLUTION #3:
The gangway was fastened to the dock with a double hinge connection; flotation was placed on the underside of the gangway to elevate the amount of weight placed on the floating dock.
The shores of the Charles River, where the Henderson Boathouse is located, are dotted with boathouses both ancient and elegant that reflect the popularity of the sport. Northeastern wanted a boathouse that would rival all others and be a long-term source of pride for the University. With the help of a design and construction team well acquainted with the possibilities and limitation in floating dock design NE University received a beautiful facility that is as functional as timeless and will serve their rowing teams well for years to come.
