Palisade

[edit] Introduction

A palisade (derr. Latin ‘palus’ meaning stake) is a wall or fence typically comprising individual vertical elements bound together to form a sturdy barrier, usually for the purposes of creating a secure enclosure. Palisades are typically made from timber or metal stakes. The visual effect may be of a wall or fence, depending on whether there are gaps between the uprights.

[edit] Historical use

Historically, palisades were made from tree trunks arranged without gaps and rising up to 4m in height. The tops would usually be pointed like a pencil to create a more effective deterrent. They were quickly and easily built from materials that were often readily available. Because of this, a palisade might have been built as a temporary wall around a castle until a more permanent stone wall could be constructed.

Ancient Greek and Roman military camps would often be encircled by palisades, and such constructions were also common in medieval Germany and colonial America.

[edit] Modern variants

Wooden palisade fencing can resemble a traditional picket fence. However, contemporary palisades (pictured above) are just as likely to be made from steel, comprising slender uprights with gaps of less than 100mm between. They are very difficult to climb, provide high levels of security and damage resistance, and have proven popular for schools and on industrial sites.

A typical construction for galvanised steel palisade fences up to 3m high is to have two horizontal rails – an upper and lower – although for taller fences additional rails can be included at higher levels. The uprights (or ‘pales’) are typically fixed to the horizontal rails using galvanised bolts. Special uprights are set into shallow concrete pad foundations at intervals determined by the manufacturer’s specification.