So it’s been a while since I’ve been around here — but I’m back! Refocusing a little bit, rather than the ages I’ve done in the past, I want to focus on particular architectural aspects … like spiral staircases, for instance.
The earliest spiral staircase still standing resides in Rome: Trajan’s Column, built in 113 CE. The exterior frieze, the typically notable element, tells the story of the military campaign the column was built to commemorate; but inside, a 185-step spiral staircase leads to a viewing platform near the top of the column. Spiral staircases are typically built with 16 or 12 steps to a full rotation, however this one is done at a more complex geometry of 14 steps per rotation — and yet built so soundly that all these years (and several earthquakes) later, the column has barely tilted half a degree.
The origin of spiral staircases could be traced back to around 1000 BCE, as there are Biblical references to spiral staircases in the Temple of Solomon. However, the earliest archeological evidence dates to 480 BCE … and we’re back to Italy, at the acropolis in Selinunte, Sicily. Temple A, thought to be dedicated to either Apollo or the Dioscuri (Castor and Pollux), bears evidence of two spiral staircases leading to a gallery level of the temple.
The Romans popularized the spiral staircase, especially after Trajan’s Column, as both a space-saving engineering feat and a grand presentation associated with gods and their mortal upholders, the emperors. But once the Middle Ages and the times of defensive castles were entered, they gained a whole new level of use.
The spiral staircases in castles are often be found to be a) winding upwards clockwise and b) to have vastly uneven steps. One theory suggests a military benefit for this: a soldier trying to climb the stairs would have limited space on his likely sword arm (right side) while not knowing the steps, vs a defender who would know the steps and have more room for the sword arm. However, it’s also true that counterclockwise staircases exist and realistically, more medieval spiral staircases exist in ecclesiastic settings than secular.
One way or another, the defense theory works quite well. Hundreds of years later, no sword-swinging soldier in sight, and a lack of roofing so some sunlight filtered through — I still managed scraping up my ankles climbing spiral staircases in Welsh castles. Of course, the insane steepness could factor in too.
Once the Industrial Era hit, spiral staircases got revolutionized. Far fewer stone or marble cases, now it was relatively easy to cast metal into balusters, treads, and a central post for the elaborate Victorian style of wrought iron staircases or the industrial steampunk-associated style. Alternatively, while the most straight-forward spiral staircases are post-centered, the other option (rare prior to the Industrial Era) exist sans central post, either built into the exterior walls or self-supporting. Since they haven’t exactly changed form much since, besides getting more and more streamlined into kit builds, there is a lack of design innovation to note in the last century.
Spiral staircases really are a fascinating architectural fixture though — on one hand a handy practicality from castle tower to lighthouses and fire escapes to space-saving in ships, submarines, and industrial areas, and on the other, the possibility of a breathtaking grand entrance or ornate accessory to design. For an excellent collection of spiral staircases, check out Spiraling Out of Control.