What is a column drum?

A column drum is a cylindrical block of stone that, stacked with other drums, forms the shaft of a column. A column carved from a single piece (a monolith) is heavy, hard to transport and liable to break. Building the shaft from drums made the work manageable. In Dutch it is called a trommel or zuiltrommel.

Construction and joints

• Tapering: the drums get slightly narrower towards the top. The taper is often not straight but has a slight swelling, the entasis.
• No mortar: on Greek temples the joint faces were dressed so that only a narrow outer band was perfectly flat and the centre was slightly recessed (anathyrosis). That let the drums seat tightly without mortar.
• Centring: a wooden block with a pin at the centre (Greek empolion and polos) guided the next drum into place as it was lowered. This system is known from the Parthenon, among others. Iron dowels only appeared later.
• Fluting afterwards: the flutes were often carved after the drums were stacked, so they run true across the joints.

At collapsed temples, such as the Temple of Zeus at Nemea, you can still see the drums lying on the ground like slices.

Other meanings

“Drum” also refers to the cylindrical or polygonal wall that carries a dome: the dome drum or tambour. The rotating reel of a winch is also called a drum.

Uses

• Classical and neoclassical stone columns
• Restoration and reconstruction of ancient buildings
• Modern natural stone columns, often made in sections for the same practical reasons

Practical tips

• Horizontal joints in a stone column are not damage; they show drum construction.
• Loose or displaced drums on listed buildings should be assessed by a conservation specialist. Filling or pointing the joints yourself can disturb the original connection.

Related terms

• Column
• Entasis
• Monolith
• Dome drum
• Flutes
• Doric

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