Gimbals

Sunday 24th June
As we make our wa slowly to the finish line, some 130 miles away, I've been
reflecting on the last three weeks, spent at various angles, mostly greater
than 40°. Which brings me to gimbals. Where are they now? In case you're
not aware, the gimbal was a natty device, consisting of three concentric
circles with bearings between them, at right angles, such that whichever way
to tilted the outer ring, the inner ring stayed horizontal. They were used
extensively on old sailing ships, to keep chronometers, compasses and oil
lamps in an even state, even when nature was doing its best to instil chaos
in the innards of the boat. Today, you hardly ever see one, excelpt perhaps
in those boutiquey chandlers, where you might find one to hold the
"Skipper's cocoa" or a recipe book level.
The only device which might be considered gimbal-ish in a modern yacht is
the oven, which is usually longitudinally, to combat the greatest of the
three forces acting on the boat - roll. Pitch and yaw are a lesser threat
to one's dinner, so are ignored.
So why has the gimbal disappeared? Well, I;ve surmised that the main reason
is probably the pendelum effect. Odd motions ccan be coped with by the
gimbal, but a regular, even motion can turn the gimbal into a swingombeter,
which can ultimately create more violent motion than was originally
experienced. I seem to remember a contemporary of Brunel who designed and
built a ship whose entire innards consisted of a huge cylinder that pivoted
on the longitudinal axis of the ship. So confident was this hapless
indiviual that this would provide the ultimate solution to the tilting
world, that furniture was not fixed and they even had a billiard room. The
maiden voyage was poulated by eminent dignitaries and their spouses, with a
dinner-dance planned for the evening. The dance orchestra played and diners
ate as the ship set sail. All went well until the ship nosed its way out of
harbour. Then the pendelum effect took sway. Within minutes, the ship was
a complete shambles, with dignitaries, instruments and billiard balls
sloshing from side to side on the bucking floor. Thought also to provide a
solution to seasickness, the ship's motion had entirely the opposite effect,
with epidemic consequences. The ship gingerly turned around and was
promptly scrapped.
Some of you budding designers, in response to my earlier request for a novel
design of ship's toilet, might have strayed towards thoughts of the gimbal,
as a solution. Next time you are paying a visit, consider the pendelum
effect. Experiment a little, if you like - but do clean up afterwards.
Trev