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Reduce beam of Mill Creek 16.5
I have my Mill Creek build wired together and getting ready to start with the epoxy. Just curious as to what the effect of reducing the beam by two inches would have on the handling of the boat. With the spreader stick in place the max beam is 33". If you remove the spreader stick the beam drops to 31" and the gunnel rises by slightly less than an half inch. Would there be any real difference in speed or handling vs stability? Any other unforseen consequences? Mostly idle curiouslty on my part. Thanks.
8 replies:
RE: Reduce beam of Mill Creek 16.5
Thanks for the reply! I should have been clearer. I am curious as to what the effect would be to intentionally reduce the beam by leaving off the spreader stick before filleting. This will be the beamiest boat I've paddled and since I will mostly paddle it solo from midships I wonder if it would be beneficial to be narrower. The question is mostly moot since after wiring in the aft bulkhead leaving off the spreader only reduces the beam by an half inch. I imagine altering a design if not done carefully could lead to some problems and this was mostly a thought exercise.
RE: Reduce beam of Mill Creek 16.5
I have to wonder if any effect at the waterline would be a more relevant aspect of leaving the spreader out? Higher gunwales likely increase windage of hull above waterline while hull shape at waterline might be little changed.
Everything about hull design is a balancing act....
RE: Reduce beam of Mill Creek 16.5
I don't have a Mill Creek but, with those designs where 2 side panels are joined to the bottom and at the stem and stern, reducing the beam reduces the secondary stability, changes the shape of the sheer so that it's a wetter ride and reduces the rocker so that the boat is lower and less maneuverable.
These are very general, I have no idea how much these effects will actually happen on a Mill Creek and how much other factors (such as total weight, balance, etc.) will keep them from being noticed.
Advice worth double what you paid for it,
Laszlo
RE: Reduce beam of Mill Creek 16.5
Well, tumblehome was prevelant during old ship days when there were banks of rowers but I'm thinking it isn't stable in small kayak like boats.
The question would be what is the beam measurement of the chines compaired to the beam measurement at the gunwales. If it is more than the boat may have less stability heeling, edging, secondary, etc. Would you notice it? I doubt it. Thirty inches, thrity-three inches, either one is a wide kayak. Paddling a tandem solo will likely be work out in any configuration. Messing with the basic design will give you something else, but open you up for unintended consequences as Laslo mentioned. Build as designed.
I'd be more concerned with weight distribution fore and aft. Too much trim aft and following seas, wind, etc will have dramatic effect when you solo. My canoe friends use a water jug in the bow for ballast to level trim. They also paddle 33" and 36" beam boats. They just use a double canoe paddle. Which different than a kayak paddle resembles one but has a 9' (274cm +/-) length and flat blades rather than spoons. Most "normal" kayak paddles range inthe 205 to 230cm range.
RE: Reduce beam of Mill Creek 16.5
Lemur,
I just came up another reason to not reduce your beam. I'm fitting the seats and foot pedals into my Mill Creek 16.5 and it is a tight fit where the front seat back and the rear foot braces mount. I'm 5'11" 200lbs,and the front seatback, foot braces and my shoe size 12 feet all are ending up in the same space. I'm finding I need every bit of that 33" beam!
RE: Reduce beam of Mill Creek 16.5
I'm at about the same point building a Mill Creek Hybrid and I would also observe that spreading the hull out to 33" is what gives the hull its rocker (the fore/aft curve of the bottom). Diminishing the width may lessen the rocker and affect the boat's handling. Kendall Jones
RE: Reduce beam of Mill Creek 16.5
Thanks for all the thoughtful replies. I never really intended to modify the hull. I guess it was just meant to be, I've started glassing the inside and don't even need a spreader stick. The beam is exactly 33" without the stick.
RE: Reduce beam of Mill Creek 16.5
» Submitted by shalpern - Fri, 11/25/16 » 10:44 AM
���Once the knee braces in the proper position and once the fillets cure, the gunnels will hold their position better. Once you fiberglass the outside, it will hold the 33" beam. Most important is the keep the spreader stick in for the fillets and fiberglassing the outside