Why slow the boat Jim Flood. Why slow the boat. (when you could go faster)? By Jim Flood.

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1 Why slow the boat (when you could go faster)? By Jim Flood

2 Why slow the boat (when you can make it go faster)? As a rower, I was seldom given an explanation of what to do to make the boat go faster, other than, If you row harder you will go faster (which is not always the case!). As a learner, I was often frustrated by a teaching policy based on being told; Don t worry about an explanation of why we learn/do this, it will become clear later. I needed to know why in order to be able to learn how. I m pleased that modern learning methods now place an emphasis on why as well as how, although rowing coaching seems to me to be still behind the curve on this issue. In summary, successful learning sessions are now based on the learners knowing the answers to the following questions: What will I be learning? How will I learn it? Why am I learning this? How will I know if I have been successful? So, this is my attempt to explain to beginners, improvers and even experienced rowers, coaches and coxes, the what and how of some of the mechanics of boat speed. Hopefully it will provide a basis for rowers, coxes and coaches to have informed discussions about how to make the boat go faster.

3 Why slow the boat (when you can make it go faster)? This ebook is going to examine some of the factors that slow a boat down. Some of the ideas may seem heretical to you. If so, good; knowledge progresses by dealing with heresies, either by challenging them or by taking them on as a new form of conventional wisdom. You are invited to challenge them. There are six main areas of focus: Good balance The timing and angle of the blades at the catch and finish Extracting the blade at the finish Placing the blade at the catch Maintaining a constant boat speed Some American coaches divide rowers into boat movers and anchors. The following slides might help you to avoid being classified as an anchor. The slides can be used in a read through mode or as individual slides to discuss specific points.

4 One way of slowing the boat down is not to travel (where possible) in a straight line It should be obvious that a boat constantly changing direction will have to travel further to complete a race or time trial. But by how much? Let s assume a boat deviates by 1 metre from a straight course, every 25 metres over a 1000m and it needs to be corrected to get back on course. What is the additional distance it will travel? We can use a crude mathematical model based on Pythagoras. Actual course 1 metre deviation 25m Intended course The additional distance travelled every 25m is 0.02m, so over 1000m this is 0.8m further. In fact the slowing effect of the turns will make this around double the additional distance. Treating the deviation as a sinusoidal wave form and using the formula gives an increase of around 5%.

Poor balance is a main cause of the boat not running straight These views show the

boat runs straight These views show the boat from underneat h at the waterline When

turns This is a computer generated drawing of a boat using Google Sketchup.

it is tilted (unbalanced) Coxes and steerpersons can use this effect to steer around

5 Poor balance is a main cause of the boat not running straight These views show the boat from the front With the boat level the shape underwater is symmetrical and the boat runs straight These views show the boat from underneat h at the waterline When the boat is tilted to one side the shape underwater becomes asymmetrical and the boat turns This is a computer generated drawing of a boat using Google Sketchup. The aim is to compare the shape of the boat underwater when the boat is level and when it is tilted (unbalanced) Coxes and steerpersons can use this effect to steer around gentle turns without using the rudder by asking the crew on one side to draw slightly higher at the finish.

6 Without good balance it is impossible to row consistent strokes. To understand more about the mechanics of balancing a boat, and therefore to improve boat speed, download a free copy of Balance creating rowing and sculling boat balance at odbalance

Directional instability is also caused by differences in the angle of

the catch between stroke side and bow side.

Although an eight is shown, the same problem can be observed in single

7 Directional instability is also caused by differences in the angle of the catch You should be able to identify the difference in the angle of the catch between stroke side and bow side. What is the effect on the boat? Although an eight is shown, the same problem can be observed in single sculls. Reaching further with one hand (or less with the other) is a more effective way of steering a single scull than rowing harder on one side.

8 In this eight, only the rower in the bow position is out of time, having placed the blade late at the catch. When the other seven place their blades for the catch, there are, effectively four blades on stroke side and three on bow because bow is late placing the blade. This causes the boat to steer to bow side. As bow takes up the pressure at a different angle to the rest of the crew, the unequal sideways force moves the bow of the boat to stroke side. In each case the cox will probably apply rudder to correct the course, slowing the boat even more. Bow and 2 in a crew in sweep oar boats have a disproportionate effect on steering which is why they need to be technically good rowers.

Rowing too deep (also known as digging or looming ) slows the boat In this example the rower at 6 in the eight is rowing too deep causing the loom (shaft) of

The cause is likely to be a combination of attacking the catch which drives the blade deep, the trunk swinging to the upright position too early in the drive

9 Rowing too deep (also known as digging or looming ) slows the boat In this example the rower at 6 in the eight is rowing too deep causing the loom (shaft) of the blade to be dragged through the water. The cause is likely to be a combination of attacking the catch which drives the blade deep, the trunk swinging to the upright position too early in the drive and tension around the neck girdle which prevents the shoulder rotating (necessary to keep the hands moving parallel to the water). A useful exercise to correct this is to row with blades at half depth that is half out of the water. This exaggeration often achieves the desired result.

Know where the blades are effective at moving the boat Catch Area of effective work Extraction (roll out) The greater the angle of the blade relative to the boat the less effective the force is at

For a more detailed explanation go to http://www.physicsclassroom.

10 Know where the blades are effective at moving the boat Catch Area of effective work Extraction (roll out) The greater the angle of the blade relative to the boat the less effective the force is at moving the boat forwards. The blue arrows show the force exerted on the water. The red arrows show the relative size of the force moving the boat forward. For a more detailed explanation go to Forces The aim should be to build pressure when the blade is locked in the water in preparation for the maximum effort where it is most effective. At the finish, think more about speed than power, there are fewer muscles you can recruit at this point in the stroke. The effect should feel like the follow through of a tennis or golf stroke.

Exercises that will help to minimise directional instability due to different catch angles Keeping the wake of the boat straight.

of the water available. The whole crew need to focus on the wake and keeping it straight.

Use pause drills at different positions in the stroke to check the blade angles if necessary against drinking straws positioned with Blu

11 Exercises that will help to minimise directional instability due to different catch angles Keeping the wake of the boat straight. Row for set numbers of strokes, say 10 initially, without using the rudder build up to as many strokes as possible given the limitations of the water available. The whole crew need to focus on the wake and keeping it straight. This is a particularly important exercise for rowing in Pairs (2-). Use pause drills at different positions in the stroke to check the blade angles if necessary against drinking straws positioned with Blu Tack. Although an eight has been used to illustrate the effect of different catch angles, the effect is even greater on smaller boats (including single sculls) as they respond more quickly to turning forces. No wasted energy Energy wasted Reach to the straw!

Tapping the blade vertically out of the water at the finish slows the boat Imagine that you have reached the end of the drive phase, the blade is in the water and about to be extracted vertically (as

12 Tapping the blade vertically out of the water at the finish slows the boat Imagine that you have reached the end of the drive phase, the blade is in the water and about to be extracted vertically (as in square-blade rowing). Effectively the blade has stopped moving relative to the boat but the boat is still moving so what is the effect? Try this in the boat in slow motion. For example, in a boat travelling at 3m/s and the blade tapped out vertical in 1/20 th of a second, the blade will drag in the water for 150mm. The solution was thought to be that the spoon part of the blade pushes a wall of water in front of it, creating a trough behind from which the spoon can be extracted. This requires an incredibly powerful (and ineffective *) finish that few rowers are capable of and even in this case the blade surface has to be pulled away from the suction of the wall of water. Blade Wall of water Extraction Trough Square blade rowing is a great exercise for the catch and drive but a terrible exercise for the finish because it encourages washing out. Direction of the boat In reality most rowers roll the blade out of the water. If the hands are relaxed, a slight downward movement begins to extract the blade, and the force of the water rotates it on to the feather. Force on the blade as it is extracted from the water Note the greater area of blade below the axis which causes rotation at the extraction unless the handle is gripped too tightly! * See page 9

13 Coaching beginners and improvers to tap down slows the boat badly - and also slows down their progress in learning good technique Not only extracting the blade square slows the boat but it also slows the process of learning to row. The reasons are: Unless all of the blades are tapped down at the same instant, the boat will be very unstable causing tension and even panic during the recovery phase Tapping down sharply tends to destabilise the shoulders with a consequent loss of good posture The feeling of the square blade dragging in the water at the finish tends to cause the blade to be gripped more tightly and the arms to tense When learning to scull, most rowers row with their blades on the water in the recovery phase for obvious reasons. In my opinion it is much better for rowers in crew boats to be coached to roll the blades on to the surface of the water and to maintain very light contact with the water during the recovery phase. This teaches the correct trajectory of the hands in order to keep the boat balanced. As speed picks up the blades come off the water naturally.

This fails to lock the blade in the water and results in moving several kilogrammes of water backwards and a consequent loss of drive in moving the boat forwards.

14 Lack of control at the catch slows the boat The main problem is late squaring and snatching at the catch with tensed arms. As soon as the blade begins to enter the water, it has to be allowed to move, otherwise it acts as a brake. The other problem is attacking the water. This fails to lock the blade in the water and results in moving several kilogrammes of water backwards and a consequent loss of drive in moving the boat forwards. The recovery phase should really be known as preparation for the catch. To have good control of the blade it is vital to slow the forward movement of the spoon as squaring begins then with the blade square slow it down still further before hooking it into the water at the point of full reach. Squaring begins Fully squared Blade feathered Think about keeping your belly button in contact with your thighs until the blade is locked in the water.

Don t slow the boat by attacking the water and chopping the blade in hard at the catch Watch the video at: http://youtu.

15 Don t slow the boat by attacking the water and chopping the blade in hard at the catch Watch the video at: Spinning a bike wheel with the edge of your had is similar to the action of placing a blade in the water and moving the boat. If the edge of the hand is slammed down hard on the tyre, the effect is to stop the wheel. This is very similar to the effect of slamming the blade in at the catch it stops the boat. The aim is to hook the water quickly and effectively and then roll the blade out quickly and cleanly at the finish. Aim for A V shaped splash at the catch. Watch the puddles that blades make after they have left the water. Frothy puddles indicate a poor catch and finish dark puddles indicate an efficient catch and finish.

Don t tire the leg muscles unnecessarily with sudden changes of direction To slow the blade down, the speed on the slide has to slow. The mass of the body moving forward does contribute to boat speed.

If in doubt, try the experiment shown in the photograph. This is a squash ball rolling down a slightly inclined track inside a floating container.

16 Don t tire the leg muscles unnecessarily with sudden changes of direction To slow the blade down, the speed on the slide has to slow. The mass of the body moving forward does contribute to boat speed. In terms of Newton s Third Law of Motion the mass of the body is greater than the mass of the boat so the boat moves forward faster than the rower. If in doubt, try the experiment shown in the photograph. This is a squash ball rolling down a slightly inclined track inside a floating container. The speed up the slide does not affect boat speed but swinging the body over at backstops, and moving away quickly achieves three things: It sets the trunk in the catch position and requires no further movement (good for posture and balance) It lowers the overall centre of gravity of the crew making it easier to balance the boat It shifts the mass of the crew away from the bows allowing the boat to run more easily If at this point on the slide the speed approaching front stops has not reduced, there will be a sudden change of direction at the catch that will not only tire the leg muscles but will also lead to a loss of control at the catch. Listen to the sound of the seat wheels slowing down as the blade is squared.

A loss of reach can slow the boat by shortening the stroke length (arc) Poor posture at the

In this case a loss of 25cm 25cm loss of reach equates to this amount of loss of reach at the

Adjustments then need to be made to the height of the heels, and possibly the span in order to

17 A loss of reach can slow the boat by shortening the stroke length (arc) Poor posture at the catch is one of the main causes of a short stroke. In this case a loss of 25cm 25cm loss of reach equates to this amount of loss of reach at the catch Poor posture can be improved by exercise but sometimes there are physiological limits. Adjustments then need to be made to the height of the heels, and possibly the span in order to achieve a good reach. Check out books on rigging, including the free one shown to the right.

18 A word to the cox/steersperson on how avoid to slowing the boat Any experienced rower will have felt the effect of too much rudder being used - the braking effect is considerable. Every touch of the rudder slows the boat. Any turn of the rudder produces drag due to turbulence, the greater the angle of turn the greater the drag. Beyond 45 degrees the rudder is completely ineffective and more than 35 degrees the braking effect can easily be felt so consider limiting the rudder movement to 35 degrees each way. Use of the rudder tips the boat over to the wrong side, for example right rudder tips the boat to the left. The change of shape in the waterline (see Slide 3) counteracts the effect of the rudder. Therefore try only to steer when the blades are in the water and the boat is resistant to tipping. If a sharp turn is necessary, ask the crew to lean in to the turn and to draw the finishes higher on the outside of the turn. There is considerable scope for re-designing rudders to make them more efficient for example by adding a trailing edge flap similar to those on the wing of an aircraft. Contact me if you are interested in such a project. For a more detailed explanation, go to:

19 Changing speed takes more energy loss of energy slows the boat First of all it is important to understand that speed is costly in terms of energy. The equation for this is Energy= Mass x Velocity 2 If we take a single boat and rower with a mass of 125 kg, a velocity of 4 metres per second requires a constant energy input of around 125 x 4 2 that is 2000Watts. If the speed goes up to 5 metres per second the energy requirement is 125 x 5 2 which is 3125W. So that is around a 56% increase in energy to obtain a 25% increase in speed.* Variation in boat speed is also costly on energy expenditure The amount of energy expended over a period of time is measured in Joules ( 1 joule = 1W over 1 second). So lets look at identical twin rowers, Anne and Alice. with the same body and boat weight of 125kg. They race over 500 metres and should finish in a dead heat in a time of 111 seconds, an average boat speed of 4.5 m/s. However Alice rows at a constant speed but Anne rows the first 250 metres at 4m/s, realises she is behind and rows the next 250 metres at 5m/s and should finish at the same time as Alice. However Alice has a little energy to spare for a sprint finish, and wins the race. Alice 125 x x 111 = Joules Anne (125 x 4 2 x 55.5) + (125 x 5 2 x 55.5) = Joules Although there can be considerable psychological advantages in sprinting at different points in a race, a near constant boat speed maximises the use of energy available. Work at maintaining your maximum boat speed over increasing distances until you can achieve it over the target race distance. *All calculations ignore friction and air resistance

20 Don t slow the boat by dropping the rating Rowing longer distances at a low rate is a good form of training to build up aerobic fitness, however in a race there are some plus points for keeping the rating high (say above 34 strokes per minute). Most international events are won by the crew rowing the greatest number of strokes unless the winners have a considerable lead. At a higher rate, the boat slows down less between strokes which reduces the costly variation in velocity. However the penalty is that there will be more body movements up and down the slide, and blade movements, that require an additional energy input. Also it requires a greater level of fitness to maintain stroke length at a higher rate. Work at maintaining blade control, stroke length and effective technique at higher rates. For more detailed information on the mechanics and physics of rowing, visit

21 Know how fast (or slow) you are moving the boat There is a lot of modern technology, such as Apps that will provide data on boat speed. However GPS-based technology does not allow for variations in the flow rate of the water or wind speed. Assuming that you have a set distance to time yourself over, and that you can line up two points on the bank for the start and finish, check the flow rate/wind speed using a drift test. This will provide an approximate guide to the true boat speed. Select a fixed point around 10 metres beyond the start point by taking the time for the boat to drift over this part of the course. Assuming a drift time of 20 seconds in the direction you will be rowing, this is a flow rate of 0.5 m/s to be deducted from your average boat speed over the course. You can also use a plastic bottle on a long string to check the flow rate (which might be negative, in which case add it to your timed boat speed Set yourself a target (say a boat speed of 4m/s) and practice achieving it over short distances. When you can achieve this regularly over say 250 metres, extend it by units of 250 metres until you can achieve it over the target distance. Rowing a race is an art, not a frantic scramble. It must be rowed with head power as well as muscle power - George Yeoman Pocock

22 The role of the coach in making the boat go faster is, in my opinion, to: Avoid the search for the winning training plan or winning technique. Experiment with ways to make an individual or crew go faster. Recording and analysing data is essential to this process. Spend at least 50% of communication on listening to athletes and encouraging them to talk. Agree on personal objectives both long and short term. Watch the way that the blades and the boat move - as much as the athletes. Always explain the reason for all aspects of training and skills development; that is to provide answers to four questions: What is it that we are aiming to achieve in this session? How are we going to achieve this (what drills and exercises)? Why are we doing this (an explanation of the reasons and the benefits) How will we measure/judge if we have made progress? And to remember: There is no such thing as the perfect rowing technique, there is no such thing as the perfect body size for rowing. There is, however, the perfect feeling of how to make your boat fly. Aram Lemmerer, founder of Biorower (

23 Jim Flood Coach at Reading Rowing Club and a British Rowing and FISA Coach Educator Publications: Know the Game: Rowing, A C Black, 2007 The Complete Guide to Indoor Rowing (with Charlie Simpson), Bloomsbury 2012 Coaching balance, Rowperfect, 2010 The Ergonomics of Rowing, Rowperfect, 2011 A Manifesto for Teaching Beginners, Rowperfect 2015 If you are interested in the development of rowing in African countries, have a look at the following websites: UavB_G08CzaUs1YlpiWEdwaVE/edit Most of the drawings in these slides are screen grabs from accurate computer generated models using Google Sketchup. This set of slides are provided free, however, if you have found it useful, please consider making a 5 donation to Oxfam To challenge some of the ideas in these slides, contact me at jimflood42@gmail.com

Basic Rowing Technique

COMPETITIVE ROWING BALANCE ROWING STROKE TIMING & SPEED CATCH DRIVE FINISH RECOVERY 1 BASIC ROWING TECHNIQUE The rower s aim is to: a> produce the highest physiological performance and b> transform this