Canal Lock Chamber

What is modelled

A chamber of 80 m² plan area is connected by two sluice gates (5 m² each at full opening, rate-limited) to an upper and a lower canal pound. The module integrates level changes from orifice flows, a side pump, rain and a leak; the boat is a box hull whose draft follows Archimedes' principle. The module is the same file as on the 3D page.

Equations

• Orifice: Q = Cd A sign(Δh) √(2 g |Δh|), C_d = 0.62.
• Chamber: dh/dt = (Qin + Qout + Qpump + Qrain - Qleak) / Alock.
• Levelling time: t = 2 Alock √Δh / (Cd A √(2g)); draft m / (ρ Awp).

Checks run in the page

• Draining follows the Torricelli closed form.
• Filling follows it too, and the levelling time agrees.
• Pump-only filling matches h₀ + Q t / A.

Idealised: constant plan area, no wave or friction losses, gates opening at a fixed rate.

• Fill from the upper pound and read the head falling slowly near equalisation.
• Switch to the storm preset: rain and a bigger leak push the level up even with the gates closed.
• Reduce the waterplane area and raise the boat mass: the draft approaches the hull depth.