Reduce the entry points to a settlement to 2-3 well-defined, watched paths and gate them with barriers that close quickly, such as heavy timber gates, vehicle barriers or stacked sandbags. A single 3 m timber leaf of about 288 kg pulls its top hinge with 2.6 kN, four times the pull on each hinge of a 1.5 m leaf in a two-leaf gate, and every gate must also be the way out in a fire, so it opens outward from inside by pushing, with nothing to unlock.
Part of Defensive Architecture
Controlled access points are the few designated gates and paths through a settlement’s barriers, positioned and watched so that people and carts enter in a way that can be seen, greeted and, if needed, closed.
The Gate Is Where The Whole Barrier Is Decided
The defensive-architecture guide reduces entry points to 2-3 well-defined paths and gates them with barriers that can be closed quickly. The household gate guide adds the layout: the main gate covered from two observation positions, approached by a winding path, with a greeting area 20-30 m outside it where visitors are seen and spoken to, and the gate as the strongest point in the barrier (Gate Placement). The access-control guide supplies the routine (Perimeter Access Control). This article adds the settlement-scale mechanics and the fire side.
Worked Example: Gate Loads And Gate Flow
Inputs: a timber leaf 3 m wide and 2 m high of planks 8 cm thick at 600 kg/m³ (assumed); hinges 1.6 m apart; the horizontal pull on the top hinge of a leaf of weight W and width w is W × (w ÷ 2) ÷ h, as worked in the hardware article (Door & Window Hardware). Crowd flow 1.3 persons per second per metre of clear width (a figure recalled from fire-engineering references, not read from this corpus); 150 people.
- Leaf mass: 3 × 2 × 0.08 × 600 = 288 kg; weight 288 × 9.81 = 2,825 N.
- Top hinge pull: 2,825 × 1.5 ÷ 1.6 = 2,648 N, 2.6 kN, equal to the weight of about 270 kg hanging sideways from the post.
- Two leaves of 1.5 m, each 144 kg and 1,412 N: pull 1,412 × 0.75 ÷ 1.6 = 662 N per leaf, one quarter of the single leaf’s pull, so the single leaf pulls four times as hard. The gate posts take it, so they are set deep and braced.
- Evacuating 150 people through one 3 m opening: 3 × 1.3 = 3.9 persons/s; 150 ÷ 3.9 = 38 s. Through a 0.9 m wicket: 0.9 × 1.3 = 1.17 persons/s; 150 ÷ 1.17 = 128 s.
- The visitor approach: 20-30 m from the waiting point to the gate at 1.4 m/s is 14-21 s, which is the time the watchers have to see and judge.
A two-leaf gate is lighter on its hinges and, with a wicket, serves both carts and people. Three gates give the evacuation redundancy: if one is blocked by fire, the others still pass the settlement.
What You Need
- 2-3 gate sites on the main routes, each covered from two posts
- Heavy timber leaves, deep set posts and diagonal braces; a vehicle barrier or stacked sandbags for a quick closure
- A waiting point 20-30 m outside, and a lamp that shows faces without blinding the watchers
- A wicket or emergency panel that opens outward by pushing
- A named warden for each gate and a visitor routine
Method: Open And Close
Step 1: Choose the gates on the existing paths, not new ones.
Step 2: Make the approach wind, so a vehicle cannot run at the gate, and mark the waiting point.
Step 3: Hang two-leaf gates on deep posts, with braces.
Step 4: Build the emergency panel so that someone inside can open it with one hand and no key.
Step 5: Close by the day’s rule: shut at night or when a threat is signalled; open and watched by day.
Step 6: Rehearse closing and opening in the dark, and a fire evacuation through every gate.
Common Mistakes
- A single wide leaf on light hinges. It drops and jams.
- One gate. In a fire or flood it is the only exit.
- A gate that cannot be opened from inside. It traps the settlement.
- A bright lamp that blinds the watchers. Shade it so it lights the waiting point.
Safety
The gate is the settlement's fire exit
Whatever makes the gate strong, a person inside must be able to open an exit in a few seconds in the dark, and a crowd must be able to push it open. A bar or key that must be worked first fails under a crowd, and in a fire that is the press you get. Bar the main leaf if you must; never bar the escape panel. Heavy gate leaves crush: keep fingers and children clear of the closing edge.
What’s Next
- Learn next: Dual-Purpose Design — making each feature work for peacetime too
- Combine with: Visitor Protocols — what the warden does at the waiting point