by Deb Whitehorse | Sep 6, 2025 | 2026, Home Page
Here is an excellent photo from Poland that I’ve been waiting to use for a while, proving how far the obsession can go: a commercial ice cream freezer repurposed to keep runners cold during sharpening sessions. Brilliant!
It is no secret that DN sailors are obsessive about runners and keeping them sharp. For nearly 200 years, the explanation for why runners slip on ice was simple: pressure and friction melt the surface. But new research from Saarland University in Germany shows the real story. It is molecular dipoles, tiny electrical charges in the runner metal interacting with the ice, that disrupt the crystal structure and create a thin liquid film. If you want a deep scientific dive into why things like runners glide on ice, check out the full article on phys.org.
To get a better understanding of what is going on, it helps to know how ice is structured. Below zero degrees Celsius, water molecules (H₂O) arrange themselves into a highly ordered crystal lattice in which the molecules are all aligned neatly with one another, creating a solid, crystalline structure.
When someone steps onto this orderly structure, it’s not the resulting pressure or friction of the shoe that disrupts the top layer of molecules, but the orientation of the dipoles in the shoe sole interacting with those in the ice. The previously well-ordered structure suddenly becomes disordered.
by Deb Whitehorse | Dec 19, 2023 | 2024, Home Page
Dust collection tech Robin Schmidt readying his Ice Optimist for some clear coat.
Western Region DNer Matt Schmidt US5536 shares some family Ice Optimist news
My youngest Robin (4 1/2) is helping get his Ice Optimist ready for the first freeze! We were given an unfinished hull a few weeks ago and scrambled to build a plank and sort out steering gear. The second clear coat is on tonight. Hoping that he, his brother Caleb (7), and sister Sarah (7) will put it to good use!
Hoping for ice in Pewaukee,
Matt
In case you didn’t know, Ice Optimists were created specifically as a youth trainer, designed to be easy to build using commonly available materials and to keep costs minimal. It uses a standard Optimist dinghy sail plan (hence the name), so youth sailors can use much of the same equipment in summer and winter if they sail/race in both seasons. Learn more about Ice Optimists and the DN Youth program from our North American Junior Sailing Program Director, Sam Bartel.srbartel4@gmail.com
by Deb Whitehorse | Oct 25, 2023 | 2024, Home Page
As we approach Minnesota’s Western Challenge in 37 days, here’s a practical article on DN iceboat plank deflection recently forwarded to a new DN builder and sailor by Warren Nethercote KC3786.
John Jambock’s article was published in the 1991 DN Newsletter. Deflection is a critical factor in improving the performance of an iceboat, and it determines how well the boat handles on the frozen surface. John Jombock’s article provides valuable insights into the optimal thickness and materials for planks that can achieve the required stiffness.
DESIGNING DN RUNNER PLANKS FOR STIFFNESS by John Jombock US1513
If you’re interested in exploring more articles with technical and sailing tips, check out our archive from the original DN class website originally created by Paul Goodwin. There’s a wealth of knowledge waiting for you there. IDNIYRA Website Articles Archive
by Deb Whitehorse | Aug 7, 2021 | 2022, Home Page
DN class members have been doing a lot of ice thinking this summer. Brian and brother Bruce Jones are making dust, mixing glue, and giving their clamps a work-out while building 2 DN hulls in steamy Florida. The IDNIYRA Facebook community has been following along, asking questions, and giving suggestions.
DNer Mike Miller has been dreaming of Minnesota’s Lake Christina, site of many Western Challenges, the first unofficial DN gathering of the season. Mike posted a short video from Lake Christina on the IDNIYRA Facebook page, reminding us what’s “coming soon.” I can’t embed it, so here’s one from Jim McDonagh US5213.
This website has a new page, the Runner Tracks Library, where you can see all the covers of our class newsletter since it went electronic in 2013.
Runner Tracks Library
The season approaches.
Jones Brother’s Florida DN build.
by Deb Whitehorse | Nov 13, 2020 | 2021, Home Page
How To Build a DN Composite Mast
For all you DN home-builders out there, Bob Rast of RKR Composites has uploaded an instructional manual “How to Build a DN Composite Mast” in a Google Doc. Click here to access the document. Bob and Mark Isabell show you how it’s done in a YouTube video posted a few years back.
