History

The Alden Triangle was designed in 1925 by prolific yacht designer John G. Alden, who was best known for his Malabar designs in offshore racing. The Triangle was a one-design answer to the Universal Rule designs being sailed in Marblehead, MA in the early 1920’s. The “Triangle” represents the three prominent yacht clubs in Marblehead: the Eastern, Corinthian, and Boston Yacht Clubs. Around 60 Triangles were originally built. After significant research, I was able to connect with the owners of 5 Triangles (4 in “ready to sail” shape, 1 under restoration). Therefore, I estimate that between 8 and 12 Triangles remain today.

MIT Museum

The plans for the Alden Triangle are currently kept by the Hart Nautical Collection within the MIT Museum. I visited the original plans, and was stunned by the breathtaking clarity and detail in the construction and sail plans. The plans are controlled by MIT and I am not allowed to publish them, but I was able to learn and verify a number of important details about the design. The specifications are listed below.

Some interesting findings:

• The designs are conflicting about the overall length and waterline length. The September 8th 1925 sail plan clearly lists it as an 18’ 5” waterline knockabout and states its overall length as 28’ 5”. However, the Lines diagram dated October 1925 clearly states its overall length at 28’ 6”. Since the Lines diagram is a later revision, I personally accept this as the overall length. Multiple online sources list the overall length as 28’ 6”

• The rig was revised on January 20th, 1958, notably to reduce the length of the boom to allow for a backstay. The updated rig can be seen in the color image on the left. Some photos of the original rig can be seen here: Link 1, Link 2, Link 3. The double forestays were replaced with a single forestay and an upper set of forward spreaders to control mast bend. The mainsail area was reduced from 335 square feet to 271 square feet, and the jib area increased from 72.5 square feet to 96 square feet.

• As can be seen in the photos linked above, the spinnaker halyard comes out slightly below the forestay. This is a curious arrangement, since it means that when gybing, the spinnaker would have to pass “under” the forestay, that is, through the triangle formed by the forestay, mast, and deck. This seems to be alleviated in the 1958 sail plan revision.