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INEOS Team UK's B&G Wind Sensor

A new level of performance in wind accuracy

Onboard Britannia, firmly visible at the front of the bowsprit, is a B&G wind sensor. It provides the most accurate wind speed and angle data, vital information for any America's Cup race, where every shift of wind angle or drop in speed could decide who crosses the line first.

For further information the main INEOS TEAM UK support boat has a full B&G weather /sailing station for monitoring off-boat conditions and data, which includes WS730, WTP3, Halo Radar and Zeus 3S Chartplotter.

With the speeds at which Britannia and the other AC75’s are travelling, there is no longer such an opportunity to judge wind direction based on the intuition, shadows on the water, or from the feel of the wind on your face. It's all down to the data on the displays in front of the sailors: so it is imperative that it is highly accurate, reliable and fast.

The wind sensor onboard Britannia is the same sensor available in the new B&G WS300 series (wired and wireless) and WS700 Vertical wind sensors, which have ushered in a new level of performance and accuracy in wind sensor technology. The WS300 series is designed for cruising and club racing sailors, whilst the WS700 series is designed for performance racing.

After rigourous testing of every sensor on the market, we chose the cup and vane sensor design from our tried and tested 213 sensor and iteratively improved the performance of each component. We made the best even better, and it's the perfect choice for Britannia and INEOS TEAM UK’s challenge for the America’s Cup.

In our design process for these new sensors we spent over 200,000 hours of testing to provide the best possible wind solution for sailing.

“B&G have really helped our team massively in terms of having the best instruments we can possibly have”
Sir Ben Ainslie, INEOS TEAM UK

How we tested them

We bought one of each wind sensor on the market, including our previous generation sensors, and subjected them to Wind Speed, Wind Angle and Heel tests in the Wind Tunnel at the University of Southampton. 

• Accuracy tests referenced to wind tunnel data, including:
– Wind Speed output accuracy -profile through wind speed range
–Wind Angle output accuracy
– Wind Speed output accuracy at all Wind Angles
– Wind Speed output at various Heel Angles
– Wind Angle output at various Heel Angles 

• A series of observational tests, including:
– Vane oscillation at all speeds (where relevant)
– Structural vibration or resonance at all speeds
– Mounting sturdiness

• A maximum tunnel speed test to test the robustness of each sensor in extreme conditions.

Wind Speed Test

This compares Wind Tunnel speed with the error in sensor speed output. A perfect result is a straight line along 0%, however it is normal to see a larger % error at low wind speeds because (e.g.) a 0.1 knot error is a 5% error at 2 knots, but only 1% at 10 knots.

Several competitor products showed significant errors, with two in particular standing out as very poor [Golf and Romeo]. Charlie is an ultrasonic sensor and - as expected - performed very well in this upright, controlled test. WS300/700 shows a very consistent and accurate speed reading.

Wind Angle Test

This test compares the sensor wind angle output with a known wind tunnel air-flow angle, using a fixture to mount the sensors in a repeatable manner. A good result is a small error at each angle, shown as a smaller area on the chart (closer to the centre), with a consistent error being preferred to an erratic one.

WS300/700 exhibits a significantly more accurate wind angle output than all other sensors, up to 10x more accurate than some sensors.

Heel Tests

A great test of a “sailing” wind sensor, this test compares the sensor wind angle output with a known wind tunnel air-flow angle while heeled - used to simulate normal sailing conditions. Errors here are caused by physically changing the angle when rotating the sensor in the air flow, so a good result is a small and consistent error across the wind speed range (at the same tunnel angle and heel angle), shown by a reasonably horizontal line on the chart. A bad result is a line with a steep gradient on the chart.

This test highlights general weaknesses in mechanical design. The unusual design of one sensor [Golf] provided very poor performance in this test with high errors. WS300/700 shows good response to heel, with a consistent offset that may be corrected in calibration. 

Find out more:

A wireless wind sensor from B&G, designed for cruising and club racing sailors. The WS320 wireless wind sensor pack offers a high performance solution, with exceptional data accuracy and improved aerodynamics, which is easy to install and includes all the parts you need.

A high precision wired wind sensor, designed for cruising and club racing sailors. The B&G WS310 wind sensor pack offers high performance data accuracy, with improved aerodynamics suitable for all yachts. Includes all you need for installation and connection to NMEA 2000®.

America's Cup

Find out more about the America's Cup and how B&G is helping teams to reach their potential in sport's oldest trophy.