IEEE
You are not logged in, please sign in to edit > Log in / create account  

Electronics in the sport of Rowing

From GHN

Revision as of 19:18, 8 October 2009 by Administrator4 (Talk | contribs)
Jump to: navigation, search

Electronics in the sport of Rowing

Eight-oared crewshell used in the sport of rowing.  Photo copyright Robert Colburn; please credit source if reusing
Eight-oared crewshell used in the sport of rowing. Photo copyright Robert Colburn; please credit source if reusing


The sport of rowing uses many electronic devices, especially for timing the races (the margin of victory may be in thousands of a second) and for measuring the numbers of strokes per minute, and -- on land -- to measure the effort expended by rowers using an excercise machine called an ergonmeter ("erg" for short).  Aboard the boat (called a "shell") a device called a CoxBox controls the shell's loudspeaker system, as well as measures the number of strokes per minute (the rating), total strokes taken, and also provides a timer to assist the coxswain (who steers the boat) in conducting the drills or timing a race.

The CoxBox was invented by Richard Kellerman and Paul Nielsen who later formed their own company, NK, to manufacture them.  To read the oral history interview with Richard Kellerman and Alix Kocher on the history of the CoxBox, click here:

A CoxBox, electronics used aboard a rowing shell.  Photograph copyright Robert Colburn.  Please credit the source if reusing.
A CoxBox, electronics used aboard a rowing shell. Photograph copyright Robert Colburn. Please credit the source if reusing.
The timing of rowing races is done in a number of ways depending on the electronics available at the race venue.  The simplest way is for a race official who follows the boats in the race in a launch, to start a stopwatch when the starter says go, and to click a button to take the splits from watching a flag on shore at the finish line.  The flagger signals when the bow of each boat crosses the finish line by alternatively lowering and raising the flag.

A more precise method is to use radio, where someone at the finish line listens by radio for the starter's command to start the stopwatch, and then take the splits by clicking the split button as each bow crosses the finish line.  This rules out the reaction time.  Sometimes the finishes are so close that the flagger cannot raise and lower the flag quickly enough to be perfectly accurate.

When timing head races, which are long (typically between three and five-plus kilometers) races where a series of boats start in a moving start fifteen seconds apart and the places are determined by elapsed time, the clock is allowed to run continuously and the exact time each boat crosses the starting line is subtracted from the exact time that boat crosses the finish line to give the total time over the course.  This way, as many as 1800 boats can be timed with the same clock in the course of a full day of racing.

Because finishes can be extremely close, video cameras are used at the finish line so that judges can consult them to determine the order of finish.