Western Australian Current Regulations Western Australian Current Regulations (1) In this
regulation —
least favoured chamber means the brake chamber
with the longest line to the treadle valve in the prime mover.
(2) The pressure in
the least favoured chamber of the braking system of a B‑double or road
train with brakes that operate using compressed air must comply with
subregulations (3) and (4) when the air pressure before the brakes
are applied is not under —
(a) the
average of the maximum and minimum pressures in the operating pressure range
specified by the vehicle’s manufacturer; or
(b) if
there is no manufacturer’s specification — 650 kPa.
(3) The pressure must
reach at least 420 kPa within —
(a) for
a B‑double — one second after the rapid and complete
application of the foot‑operated brake control; or
(b) for
a road train — 1.5 seconds after the rapid and complete
application of the foot‑operated brake control.
(4) After the brakes
have been fully applied, the pressure must fall to 35 kPa, or the
pressure at which the friction surfaces cease to contact each other,
within —
(a) for
a B‑double — one second after the release of the
foot‑operated brake control; or
(b) for
a road train — 1.5 seconds after the release of the
foot‑operated brake control.