A palisade is a wall of vertical logs set in a trench, and logs 15-20 cm across and 2.5-3 m long buried 60-80 cm leave only 1.7-2.4 m standing above ground. Its limits are geometry, rot and fire: a fighting platform 1 m below the top gives its occupant cover to about hip height only, the buried butts rot in years, and the wall burns. It works as an obstacle and a screen, not as cover.
A palisade is a fence of closely set vertical timbers, the standard frontier wall wherever trees are plentiful and masonry is not.
What Stands Above Ground Is Log Length Minus Trench Depth
The parent article specifies logs 15-20 cm in diameter and 2.5-3 m long, set in a trench 60-80 cm deep. The height left above ground is the log length minus the buried part:
- Shortest log, deepest trench: 2.5 − 0.8 = 1.7 m.
- Longest log, shallowest trench: 3.0 − 0.6 = 2.4 m.
The parent article puts a fighting platform 1 m below the top, “protected to chest height”. Standing on that platform, the defender has only the top 1 m of wall in front of them. On an adult that is roughly hip to waist height, since chest height is around 1.3 to 1.4 m (a recalled body proportion). To cover the chest the top must be about 1.35 m above the platform, which puts the platform at 1.7 − 1.35 = 0.35 m to 2.4 − 1.35 = 1.05 m above ground. The parent’s figure is therefore too generous: either lower the platform, raise the wall, or accept waist-height cover. Cover to the chest and a view over the top are also mutually exclusive, so observation is by gaps or loopholes at eye level, not by a lower wall.
Wall Mass: A Palisade Is Much Lighter Than An Earth Wall
Round logs standing in a row do not fill the wall: the cross-section per row is π d²/4 for each log of diameter d, so the equivalent solid thickness is π d / 4 = 0.785 d.
| Log diameter | Equivalent thickness | Softwood, 500 kg/m³ | Hardwood, 700 kg/m³ |
|---|---|---|---|
| 0.15 m | 0.118 m | 59 kg/m² | 82 kg/m² |
| 0.20 m | 0.157 m | 79 kg/m² | 110 kg/m² |
The densities are recalled air-dry values, not measured. A rammed earth wall 0.45 m thick at an assumed 1,800 kg/m³ is 810 kg/m², from about 7 to about 14 times the mass per square metre of the palisade values. This is why the palisade is a barrier and a screen. This corpus has no penetration tests: it cannot say what a log wall stops, and a claim of protection needs a cartridge and a range. The softwood log row in the ballistic table of Defensive Architecture is marked unproven for this reason.
Method: Set The Logs
Step 1: Choose the timber. Straight logs of the species available, bark stripped so insects and moisture have less to hold. The parent article puts pine and spruce at 3 to 5 years in the ground and cedar, locust and oak at decades. “Locust” there should mean black locust (Robinia pseudoacacia), the durable one; do not assume honey locust matches it (recalled).
Step 2: Dig the trench. 60 to 80 cm deep, slightly wider than the logs. On a slope, step the trench so every log stands vertical. A layer of gravel in the bottom lets water drain away from the log butts.
Step 3: Set the logs side by side. A log of 17.5 cm and 2.75 m weighs about 33 kg at 500 kg/m³ (π x 0.0875² x 2.75 = 0.066 m³). Slide the butt down a ramped end of the trench and raise the log with ropes and forked poles; do not lift and drop. Check each for plumb with a string and weight.
Step 4: Backfill and tamp. Pack earth tightly around each log, tamping every 10 cm (parent article). Loose backfill is where a palisade starts to lean.
Step 5: Close the gaps. Logs do not touch along their whole length. Fill the gaps with split poles or a second offset row if the wall is meant to screen.
Step 6: Tie the logs with rails. Lash horizontal rails inside at two heights, 60 cm and 150 cm from the ground (parent article), so a leaning log cannot work loose.
Step 7: Treat the gate as the weakest part. A gate opens the wall; keep it narrow, set the hinge posts deeper than the rest, and bar it from inside.
Worked Example: 30 m Of Wall
At 17.5 cm diameter, touching: 30 / 0.175 = 171 logs, roughly 190 allowing for crooked ones. Each is 0.066 m³, so 171 x 0.066 = 11.3 m³ of timber, about 5.7 tonnes at 500 kg/m³. The trench is 30 x 0.25 x 0.7 = 5.3 m³ of earth. Equivalent thickness 0.785 x 0.175 = 0.137 m, areal density 0.137 x 500 = 69 kg/m².
Rot And Fire
- Charring the butt. The parent article chars the bottom 80 cm until the surface is blackened 5 to 10 mm deep, and Fence Types chars to about 6 mm or soaks in pine tar. I could not source the benefit; whether charring prolongs life is disputed (recalled). The measures that clearly help are rot-resistant species, no bark, a gravel drain and keeping standing water away.
- Fire. A palisade burns. Keep brush and stacked wood back from it, keep water and buckets on the platform, and do not tar the above-ground face, since tar burns. A palisade plus a thatched roof beneath it is the worst fire case; see Timber Fortifications.
- Points. Sharpened tops make climbing harder and are a visible deterrent. They are not a concealed trap: do not hide stakes or points where a child, neighbour or animal could fall on them.
Heavy logs, falls from the platform, fire
Raising and setting logs of roughly 20 to 65 kg is a crush hazard: work as a team, keep feet clear of the trench and never stand under a log being raised. Platforms 0.35 to 1.4 m above ground are a fall risk and need a rail or a firm edge. Sharpened tops at head height injure the people the wall is meant to protect, so set them above reach. Plan at least one exit that does not pass through a wall on fire.
What’s Next
- Learn next: Log Crib Walls — adding earth mass behind timber
- Combine with: Log Construction — selecting and handling logs