Sven Yrvindvideo
Aft mast head fitting, the idea.
18 January 2026 · 6 min · 3K views
What this video covers
Sven Yrvind fabricates a custom masthead fitting for his small, shallow-draft boat intended for a 14,000-mile non-stop Southern Ocean voyage.▶ 0:15 The design utilizes Tufnol inserts within a 35mm diameter pipe to manage halyards for the sail, topping lift, and an AIS antenna.▶ 3:17 To ensure structural integrity and weatherproofing, Yrvind seals the antenna cable entry point with self-amalgamating tape and reinforces the masthead assembly with fiberglass.▶ 3:03 The mast construction allows the AIS antenna to sit atop the fiberglass structure, which prevents electromagnetic interference.▶ 2:07 Yrvind addresses concerns regarding component wear by citing the high durability of Tufnol, noting its historical use in industrial cogwheels and his own previous experience with 4-5mm halyards during a 150-day voyage near Iceland and the Bay of Biscay.▶ 5:10 The boat is currently positioned on its side to facilitate easier access for these mast modifications.▶ 0:49
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