The basis for this sundial was a flat ring having an outside diameter of 190 cm, a width of 10 cm and a gauge of 8 mm.
This ring is cut in two, and the two parts are incorporated in an L-shaped frame of 10 x 5 cm stainless steel conduit.
This construction is sufficiently rigid.
A stainless steel wire on the L-frame serves as pole style. The angle between the wire and the short leg of the L is 65 degrees.
A turnbuckle keeps this wire taut.
An adjustable tilting mechanism in the base reclines the entire construction, giving the pole style the correct angle with respect to the horizon.
Because of its resemblance to a sailing vessel, the sundial was dubbed the Sun ship.
Hour lines could have been drawn on two surfaces, but only the horizontal surface was used.
Large holes in the ring indicate the hours, smaller ones the half-hours.
The hour points are adjusted for longitude so that, not counting the equation of time, the sundial indicates civil time.
There are no numerals, but the twelve o’clock hole has a stainless steel plug in it.
To read time, one counts from this point.
Two times each year, this stopper is moved for winter (standard) or summer time.
After the sundial was set up, measurements were performed to check it.
Taking into account the equation of time, the dial proves accurate over the entire day.
The photograph below shows 13:00 hour summer time.
Fer de Vries
Design and realization: Bert Leurink, early 2009
Calculation of the hour points: Fer de Vries
English translation: RH