Understanding Mast Stiffness

[Last year] was a first-up effort [with the University of Miami Composites Lab to measure mast bend more precisely] and now that UM are signing-on for a much more expansive relationship with us, I think we’ll see much more progress in shorter time.

The process  i.e., turnaround time - was way too long last time.  And the sample size was way too small to derive much meaning - the importance of the archiv[ing] and continuously adding to the database with ACCURATE data [is crucial]. We’ll [be] ask[ing] for the data to be turned around overnight or let’s say, at worst, within a week of the testing being done.  That commitment alone should inspire more confidence in the sailors.

Francisco, [our UM contact] wants to  utilize some digital image correlation tools to look at rig strains on the water and then match back to the static tests to determine better deflection loads/conditions etc.  There is an element of investigation here for which we should perhaps use some of [the ODP] young guns.

In October or November, we could do some on-water trials and work back into the December testing for [USST members] if that is their preferred window with UM?  In this way, we are doing some tech work involving the feeder group but ultimately benefitting the top group in the process…

- Dr. Peter Logan, US Sailing Innovation, Research and Development Director

While one-design equipment is all supposed to be the same in theory, and manufacturing tolerances have improved a lot in recent years, the reality is that every mast is slightly different. Whether due to the amount of resin used in the construction, the cure time, the atmospheric conditions of the construction environment, or human error, slight differences in rigs can cause deviation in bend characteristics. When evaluating equipment, we know for sure that we want symmetrical equipment (spreaders square, bend characteristics the same from side to side, mast track straight, etc.), but to understand exactly what combination of stiffness and softness we’re looking for in the three mast sections, and overall in the rig as a whole, we need to establish a baseline for comparison.

The US Sailing IR&D team worked with the University of Miami last winter to establish measurement protocols, reporting formats, and workflow procedures, and this year we’re in a position to really tackle some equipment comparisons, and get a good snapshot of what the range in equipment looks like.

With the testing process in place, the last ingredient is… masts! Last year we measured a few rigs in each class, but to get a good sample size for comparison, and to really see what’s working, we need to measure as many rigs as possible this year. The target time for the measurement will be early November, to ensure that during our winter training, you’ll know exactly what you’re dealing with, and be able to make comparisons between sails, rigs, etc. in a more meaningful way.

If you have rigs that we can include in the project, please shoot me a quick e mail with subject line: rig measurement 2018 and in the e mail body, just the # of rigs you’d like to get measured so that I can work on getting a head count for the IR&D team.