Moments in a four
or eight…
Professor John D. Barrow
or how a cosmologist from Cambridge
University, with a passion for bringing
mathematics to the general public, proved (in his spare time) that the standard rigging
set up for a rowing four or eight really isn’t the right way to set up a boat if you want
maximum efficiency.
© MaxAlexander 2009
Rigging a four or an eight the standard way makes
no sense when it comes to making the boat go
in a straight line. This is the finding of University
of Cambridge professor, John Barrow.
rigging, that is, no sideways wiggle in the boat as
it moves forward through the water.
In basic terms, boat wiggle occurs because the
two parts of the stroke, the drive and the recovery,
the net force, are not the same so Barrow looked
at a line-up where these transverse forces would
cancel each other out.
used in Italy in 1956 by a crew that went on to win
gold at the 1956 Melbourne Olympics.
In his paper entitled, Rowing and the Same-Sum
Problem Have Their Moments (Nov 2009), Barrow uses
mathematical calculations to work out the best
positioning for rowers in a coxless four and then
extrapolates this out into an eight (and bigger boats).
Figure 1
(a)
First Barrow shows that the traditional, alternating
of stroke (port) and bow (starboard) side rowers,
rig produces a wiggle if all athletes in the boat are
rowing identically with identical power.
“The traditional rig appears symmetrical
and simple in ways that might tempt you
into thinking it is in every sense optimal.
However, this is not the case.” (p 2)
“During the first (catch and drive) part of
the rower’s stroke the transverse force at
the oarlock is directed towards the boat but
during the second (extraction and recovery)
phase of the stroke it reverses and is directed
away from the boat.” (p 3) “As a result, the
boat will wiggle steadily from side to side
as it moves forward under the influence
of this alternating transverse force.” (p 4)
(b)
(c)
Then Barrow looks at alternative line-ups to see
what combinations would produce ‘zero-moment’
Barrow has come up with three possible rigging
line-ups for a four (Figure 1) with only one having
no wiggle. This rig is currently used and is known
widely as the ‘Italian’ rig (Fig. 1 (c)) as it was first
Then Barrow took his calculations into an eights
situation. Barrow found four rigging solutions
where wiggle would not occur – surprisingly >
