Document ID: chunk:federal_register_of_legislation:F2024C01065:body:0:p42
Version: federal_register_of_legislation:F2024C01065
Segment Type: other
Provision Reference: 
Character Range: 104822–107589

of a critical item or component of the system.

   VISUAL INDICATOR - that part of an instrument or device intended to display information for the driver and includes any specified label.

   V-VALUE - the theoretical vertical reference force between towing vehicle and trailer.

   WHEEL - means a complete wheel consisting of a 'Rim' and a wheel disc.

   WHEEL GUARD - a fitting or device which is so constructed and affixed that it will so far as practicable catch or deflect downwards any stone, mud, water or other substance thrown up by the rotation of the wheel for which such fitting or device is provided.

   WHEELBASE – The dimension measured horizontally and parallel to the longitudinal axis of the vehicle between the front and rear wheel centrelines at 'Unladen Mass'. In the case of the rear 'Axle Group' the dimension must be to the 'Centre of an Axle Group'. For a steerable front 'Axle' or 'Axle Group' the dimension shall be to the centreline of the foremost 'Axle' (See illustration over page).

   WIDE SINGLE TYRE - a single truck tyre having a 'Specified Design Section Width' of 375 mm or more which is intended to perform the function of a pair of dual truck tyres. There are 2 ranges of 'Specified Design Section Width', viz 375 mm to 450 mm and over 450 mm.

   WINTER TREAD (includes tyres known as "Mud and Snow", "M&S" or "Snow") - a tyre whose 'Tread' pattern and whose structure are primarily designed to ensure in mud and fresh or melting snow a performance better than that of an ordinary (road-type) tyre.  The 'Tread' pattern of a 'Winter Tread' generally consists of 'Groove' (rib) and/or solid block elements more widely spaced than on an ordinary (road-type) tyre.

   ZERO HOURS – means the point at which testing and controlled service accumulation commence.  This shall be a point after normal engine assembly line operations and adjustments and before one additional engine operating hour has been accumulated (ADR 36).

   ZERO KM – means that point at which controlled 'Stabilisation Distance' commences, subject to the requirements of clause 37.3.2.4 of ADR 37/00 or clause 6.2.4 of ADR 37/01, after initial engine starting (not to exceed 150 km of vehicle operation, or 10 hours of engine operation) and at which point normal assembly line operations and adjustments are completed, including pre-delivery procedures.

   ZERO-GRADE AIR OR ZERO-GRADE NITROGEN - means air and nitrogen gases having allowable impurity concentrations not exceeding:
   (A) For measurement of HC concentration in 'Fuel Evaporative Emissions' test
     - 1 ppm equivalent carbon response;
   (B) For measurement of HC, CO, CO2 , 'NOx' concentrations in 'Exhaust Emissions 37/00' test:
     - 1 ppm equivalent carbon response
     - 1 ppm CO