Which way up On Jangada Too?

As we make our way 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 instill chaos in the innards of the boat.  Today, you hardly ever see one, except 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 pendulum effect.  Odd motions can be coped with by the gimbal, but a regular, even motion can turn the gimbal into a swingometer, 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 individual 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 populated 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 pendulum 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 pendulum effect.  Experiment a little, if you like – but do clean up afterwards.

Trev