I
n the history of yachting the impact of hollow masts
and spars is rarely mentioned, which is peculiar
because they are central to the story. Reducing the
rig weight of any yacht increases her stability, so
making it safer and usually easier to sail; this is especially
true in smaller boats, and the arrival of reliable hollow
masts and spars from about 1890 onwards was in no
small part responsible for the popularisation and spread
of the sport in the late 19th and early 20th centuries.
It is impossible to fix when hollow spars were first
used, because it is certain to have been in antiquity.
Bamboo was recognised as a good material for spars
wherever it was available, and continues to be employed
to good effect even now. But bamboo has limitations; it
is fairly readily available up to about 20ft long and six
inches in diameter, but larger sizes are rare. As yachting
developed away from bamboo’s natural habitats, it
seems to have only ever been used in relatively small
craft. It seems, too, that in the 19th century there were
no imports of bamboo to the USA, which prompted the
boatbuilders there to develop hollow spars somewhat in
advance of their counterparts in Europe.
Hollow iron masts (for ships) had been tried from
c1820 but even by the 1850s they were still rare; Great
Eastern (1859) had three huge iron masts (3ft 6in
diameter at deck, and over 100ft long) that were, like
many aspects of that ship, much remarked upon. Dixon
Kemp mentioned that hollow steel yacht spars were tried
c1863, which is about the same time they started to
appear on ships, but that after “two or three masts were
carried away rather suddenly” the experiment was
abandoned, for yachts anyway. Towards the end of the
19th century a few yachts had steel (lower) masts(Columbia’s snapped in 1899 during the America’s Cup
defender races) and booms (Rainbow, GL Watson’s fine
schooner of 1898, had a 91ft long main boom “of
special steel”), but in general steel spars were seen only
on the largest yachts. From the very start of yachting
until after the Second World War nearly all yacht masts
and spars were made from wood, and from the outset
they were usually solid.
The benefits of hollow spars were clearly understood
long before their construction was practical. The science
of struts and columns bending and buckling was
convincingly defined in mathematical terms by Euler in
the 1750s, but an instinctive grasp of the benefits is clear
from the example of hollow timber lances written about
as early as the 9th century. The advantage of a hollow
mast over a solid one was clearly demonstrated by Skene
in his Elements of Yacht Design where he produced a
diagram illustrating the point nicely; a 10ft long hollow
round mast 4in diameter with a ½in wall would have
equal strength to a solid one that was 3ft^5 / 8 in diameter
(i.e. only 9 per cent less), and the hollow one would
weigh about 53 per cent of the solid one. Alternatively, if
the weight were equal, the solid mast would have to be
only 2^5 / 8 in diameter and would be 74 per cent weaker (in
buckling). If the outside diameter of both were 4in, the
solid spar would actually be 50 per cent stronger than
the hollow one, but at the cost of being 128 per cent
heavier. Masts in particular are designed to be stiff
enough to resist bending and buckling, but also as small
and light as possible. On the basis of weight or stiffness
the hollow spar wins (nearly) every time.
Hollow spars could also offer other possibilities.
According to the Aberdeen Journal of 15 January 1840,From bamboo to the early America’s Cup,
Theo Rye tells a story central to yachting’s
development, but one curiously overlooked
THE HISTORY OF
HOLLOW SPARS
FACING PAGE: BRASKER MASTEN