Post 387 – by Gautam Shah




Water wells are deep terrain entities. The wells are used to draw water or go down and reach the water for ritual procedures. To draw water one needs a rope and bucket, but wells have stepped access. The stepped access have taken many different architectural forms. One or multiple straight directional access systems have been used. Wells with spiral stairs have equally varied forms.

Central Murray Road footbridge Clockwise spiral stairs HongKong

Spiral stairs are of FOUR basic types: 1. Winding around a central supporting pole, 2. Winding as projection from surrounding square or circular peripheral structure, with or without a central open space, 3. Steps supported on both the edges within a double walled drum, and 4. A free spiral supported only at top and bottom ends.

Wells with spiral stairs are ancient structures, and fairly deep one, so the spiral stairs of type 4 (as above) are not found. Deep wells with several helical winds make the central support (as in item 1 above) very heavy, and its failure can collapse the stair structure entirely. Wells with spiral steps winding as projection from the surrounding square or circular peripheral structure are possible with steel or concrete constructions. But with stone as the material for constructing projected steps, chances shear failure are high. Spiral step-wells, as a result are structures where steps supported on both the edges within a double walled drum.

Sidi Bashir Mosque Ahmedabad India Minarets with spiral stair

Spiral stairs can be clock-wise and anticlockwise in terms of ascent (or descent). For ascent clockwise movement is favoured for two reasons. Ascent is more strenuous then descent, and clockwise movements are easier for right handed persons (larger populace who by nature or forced habit are right handed). Spiral stair steps are narrower on the inner end, and wider on the outer edge. This forces the user to select a position where the steps are of just right size (the tread width). This however, must be achieved by taking support of the outer wall (or its railing -if there is one). These two conditions make a spiral stair passage comparatively of narrow width. The narrow width makes the use of stair difficult for concurrent ascent and descent.

Double Helix Spiral stair with open core at Vatican Museum

Double Helix Spiral stair with open core at Vatican Museum

Circular stairs with large diameter and with open central core have the advantage of a more consistent tread width. Such stairs have sufficient step width to for concurrent ascent and descent. Alternatively to separate the ascent and descent traffic, either two sets of stairs are required or entwined spirals of double helical forms are used. Double helix spiral stairs are also used to meet a legal requirement to have two separate fire escapes.


The Pozzo di San Patrizio or St. Patrick’s Well is a historic well in Orvieto, Umbria, central Italy. It was built by architect-engineer Antonio da Sangallo, between 1527 and 1537, at the behest of Pope Clement VII, who had taken refuge at Orvieto during the sack of Rome in 1527 by the Holy Roman Emperor Charles V, and feared that the city’s water supply would be insufficient in the event of a siege. The well was completed in 1537 during the papacy of Pope Paul III. A central well shaft with two spiral ramps in a double helix, accessed by two doors, allowed mules to carry empty and full water vessels separately in downward and upward directions. The cylindrical well is 53.15 metres (174.4 ft) deep with a base diameter of 13 metres (43 ft). There are 248 steps and 70 windows provide illumination.

Pozzo san patrizio orvieto > Double helix spiral stairs for mules to move up and down to fetch water

Pozzo di San Patrizio Oriveto

Top of the well

Taff’s Well thermal spring is located in Taff’s Well, north of Cardiff, South Wales, UK. The spring emerges on the eastern bank of the River Taff. The spring is enclosed inside a well and stone building constructed in the 19th C. A brick built spiral staircase is incorporated in the inside of the well.

Taffs Well Thermal Spring Helix stair

Château de Maulnes in Cruzy-le-Châtel, Burgundy, France: the central helical stairs around the well, also used as a skylight.

The Well of Initiation located in Quinta da Regaleira, Sintra, Portugal was built 1904 – 1910. At the bottom of the well is seen the Rose of the Winds placed upon the Rosy Cross.

Sintra Quinta da Regaleira