A fence marks and slows, a palisade of upright logs is a real obstacle, and both fail in the same few ways: they rot at the ground line, they are climbed or dug under, and they trap the people they protect. A 50 m palisade of 20 cm logs set edge to edge needs about 250 logs and roughly 20 m³ of timber, so decide first whether the length is worth it.
Part of Perimeter Defense Design
Fences and palisades are the timber and wire barriers of the middle delay zone: post-and-rail and wire fences that mark and slow, and palisades of vertical logs set in a trench that form a wall.
Fences Delay Casually, Palisades Delay Seriously
The parent article distinguishes three tiers. A post-and-rail fence 1.2-1.5 m high slows foot traffic, stops most livestock and defines the boundary. A wire fence, with barbed wire if available, is a stronger obstacle, and even smooth wire strung at several heights is a nuisance in the dark. A palisade of sharpened logs 2-3 m long, buried 60 cm in a trench, with tops at 1.5-2 m, is a serious wall but needs a lot of timber.
For the post-and-rail details (species, spacing, rails by animal) see Fence Types; for how thick a wall must be to resist different threats see Fortification Materials. This page is about failure.
What You Need
- Rot-resistant timber for anything in the ground, charred or treated at the base (methods in the fence article).
- A trench or post holes of 60 cm or more for a palisade.
- Lashings or pegs that can be cut or knocked out from inside.
- A planned emergency opening on the defended side.
Method: Build It So It Fails Late And Opens From Inside
Step 1: Put rails on the inside. Horizontal rails on the outside face give an intruder steps. Fix them to the face towards you, so the outside is flat.
Step 2: Close the bottom. An intruder digs under rather than climbs. Set a bottom rail, a stone sill or a buried board so the lowest gap is closed.
Step 3: Set palisade logs edge to edge in a trench, tamp the backfill in layers, and lash a horizontal rail across the inside so the logs lean on each other.
Step 4: Decide the tops. The parent article sharpens them. Sharpened tops make climbing slightly harder and are an injury hazard to anyone who falls or reaches over, including your own children; at head height or below, leave them square or sloped.
Step 5: Build in a breakaway panel. One bay of the wall secured with lashings that a person inside can cut, or pegs that knock out, opens to the outside and is marked by feel. A closed compound with a single gate is a trap in a fire.
Worked Example: A 50 m Palisade
Inputs (assumptions for the example): log diameter 20 cm, logs 2.5 m long, buried 0.6 m, laid edge to edge, 50 m run.
- Logs per metre: 1 m ÷ 0.20 m = 5. For 50 m: 50 × 5 = 250 logs.
- Height above ground: 2.5 m - 0.6 m = 1.9 m, within the parent article’s 1.5-2 m range for tops.
- Timber per log: π × (0.10 m)² × 2.5 m = 3.14 × 0.01 × 2.5 = 0.0785 m³. For 250 logs: 250 × 0.0785 = 19.6 m³, about 20 m³.
- Trench: 0.6 m deep × 0.25 m wide × 50 m = 7.5 m³. At the parent article’s 1 m³ per person-hour, 7.5 person-hours.
Felling and trimming 250 logs is the heavy part, not the trench. The felling method is in Felling Technique. If a settlement’s woods can supply poles at that rate, see Timber and Building Materials.
Failure Modes And How To Diagnose Them
- Rot at the ground line. The wood is wet and aired at once. A palisade fails first at the base. Probe the log at ground level with a knife each season; soft wood means that log is due for replacement.
- Leaning. Backfill that was not tamped, or frost heave, tilts logs. Tilt more than a few degrees at the top is a sign to re-set that bay.
- Climbing aids. Cross-bracing on the outside, a stacked woodpile, or a tree beside the wall. Clear them.
- Digging under. Look for disturbed soil along the base after rain.
- Fire. A timber wall beside a building carries fire to it. Keep a cleared strip between them and do not stack firewood against either.
Common Mistakes
- Wire at neck or ankle height across a path the household uses. Smooth wire strung at several heights in darkness is, as the parent article notes, a significant obstacle, and to your own people running at night too.
- A single gate. Add the breakaway panel.
- Building the wall before the watch. A wall with nobody looking at it only buys time for the person cutting it.
Safety
Felling, wire and fire
Felling trees for palisade logs kills careless workers; use the three-cut method and clear the fall zone. Wire under tension whips when cut. Barbed wire injures people and livestock and should not be used where children play. Do not place a timber palisade where a fire in it could cut off your only exit.
What’s Next
- Learn next: Gate Placement — where the openings go, and how many
- Combine with: Thorny Hedgerows — the living barrier that replaces the fence as it rots