Friday, 29 November 2019
Friday, 15 November 2019
Can RANDALLfoils improve head-racing results?
I finally had the chance to test the performance of the foils in my single during the 2019 Head of the Hooch. Between 2015 and 2019, I have competed in the Men's Lightweight 1x (55+) event every year, although the event was shortened in 2018 due to conditions. In all other years, this event is a 5000 m downstream course with variable current and wind conditions. While raw times vary with current and wind, I have had the benefit of competing against 3 of the same competitors every year.
In 2019, I had the second-fastest raw time in this event, which is by far my best finish place in this event since I first rowed the event in 2015 (see Table of results). But did the foils make me faster? To answer this question, I compared my raw times against the three other rowers mentioned above (see chart). Rower A always gets the best raw time; he is one of the best >60 lightweight male scullers in North America. Rower B generally gets the second-best raw time, although this dropped to third (behind me) in 2019; he is an experienced rower and very consistent. In contrast, Rower C improved significantly from 2015 to 2017. Between 2015 and 2017, I was generally 36.8 to 58.0 seconds behind Rower A and 15.0 to 25.1 seconds behind Rower B. In 2017, I was 6.1 seconds behind Rower C. But between 2017 and 2019, I gained between 27.8 and 35.5 seconds on these three rowers. I attribute this 2.4% to 3.0% speed increase almost entirely to the foils. It is certainly not due to an increase in my fitness as my best 5K erg times have remained relatively constant since 2016 (19:12.7 in 2019, 19:17.3 in 2018, 19:19.6 in 2017, 19:19.5 in 2016). Your mileage with foils might vary, but they clearly help me a lot.
Bob Symonds
You can contact Bob to inquire further about his experiences with foils and can purchase directly from him. [email... powerpre321@gmail.com
Tuesday, 5 November 2019
Fire, Ice, and Physics : The Science of Game of Thrones by Dr. Rebecca C. Thompson
[on oars]
"For his war galleys, Stannis chose a different method of propulsion, one no less dependent on shape: rowing. The physics of rowing is pretty straightforward, so the speak. It's a simple lever action. When the rower pulls back on the handle, the oar blade is pushed against the water. Because every action has an equal and opposite reaction, the ship is pushed forward a little bit. When 100 people are doing this simultaneously in choreographed synchrony, the ship can get going quite quickly.
The shape and size of the oar blade is important in getting the most out of each stroke. The larger the blade, the more power it can generate, and that power combined with the force the rower provides to the lever of the oar is what moves the ship forward. This is a tricky balance to maintain, however - you need someone strong enough to generate that kind of power, and you want the largest oar your rowers can handle efficiently. If there's too much surface area, the ship might move quickly for a short time, but the rowers will tire sooner. It's a marathon, not a sprint.
The shape of the oar is also important in getting the maximal speed out of each stroke. Traditional oars, the type that Stannis’s ships would have used, are symmetrical. The blade looks the same on each side of the shaft. In 1991, former Olympic rower Dick Dreissigacker and his brother Pete designed the cleaver oar. A main drawback to the symmetrical, or tulip, oar was the drag caused by the shaft. With a tulip oar it is impossible to get the entire blade in the water without also dunking in a lot of the shaft. The shaft then drags through the water without proving any real forward motion to the ship. With the cleaver oar, the shaft is attached to the top with the entire blade hanging down. This way the blade can go in the water without much of the shaft having to drag though the water. It seemed like an obvious solution after someone else thought of it.
More recently, an Australian rower named Ian Randall developed yet another oar design: the Randall Foil. This oar adds a small lip to the top of a cleaver oar in the direction of oar movement, allowing the oar to make full contact with the water without having to dip the shaft in. In addition, it catches the water that normally flows over the top of the oar causing turbulence. Independent studies found that these oars can increase a boat’s speed by around 5%. I bet Gendry’s wishing he had a pair of those." (P.221)
The shape and size of the oar blade is important in getting the most out of each stroke. The larger the blade, the more power it can generate, and that power combined with the force the rower provides to the lever of the oar is what moves the ship forward. This is a tricky balance to maintain, however - you need someone strong enough to generate that kind of power, and you want the largest oar your rowers can handle efficiently. If there's too much surface area, the ship might move quickly for a short time, but the rowers will tire sooner. It's a marathon, not a sprint.
The shape of the oar is also important in getting the maximal speed out of each stroke. Traditional oars, the type that Stannis’s ships would have used, are symmetrical. The blade looks the same on each side of the shaft. In 1991, former Olympic rower Dick Dreissigacker and his brother Pete designed the cleaver oar. A main drawback to the symmetrical, or tulip, oar was the drag caused by the shaft. With a tulip oar it is impossible to get the entire blade in the water without also dunking in a lot of the shaft. The shaft then drags through the water without proving any real forward motion to the ship. With the cleaver oar, the shaft is attached to the top with the entire blade hanging down. This way the blade can go in the water without much of the shaft having to drag though the water. It seemed like an obvious solution after someone else thought of it.
More recently, an Australian rower named Ian Randall developed yet another oar design: the Randall Foil. This oar adds a small lip to the top of a cleaver oar in the direction of oar movement, allowing the oar to make full contact with the water without having to dip the shaft in. In addition, it catches the water that normally flows over the top of the oar causing turbulence. Independent studies found that these oars can increase a boat’s speed by around 5%. I bet Gendry’s wishing he had a pair of those." (P.221)
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