Motor Vehicle Safety Regulations — 903
903 (1) Every C-dolly shall be equipped with (a) an automotive-type or a turntable-type self-steering mechanism; (b) a means to return the wheels to within one degree of the straight-ahead position whenever any steering force applied to the wheels is removed; (c) a device that automatically locks the steering mechanism in the straight-ahead position in the event of a failure of the means referred to in paragraph (b); and (d) a device (i) that includes a switch by means of which the driver can, while seated in the normal driving position in the cab of the truck towing the C-dolly, lock the steering mechanism in the straight-ahead position, or unlock it, (ii) that locks the steering mechanism in the straight-ahead position in the event that the control for the device fails or the power supply to the device terminates, and (iii) that includes, in both official languages, the information specified in subparagraphs (12)(b)(i) and (ii) on the switch referred in subparagraph (i) or on a label affixed near that switch. (2) Every C-dolly shall have a GAWR of 9 100 kg. (3) The longitudinal distance on a C-dolly, measured on the longitudinal centre-line from a point aligned with the centre of the coupling to a point aligned with the centre of the axle, shall be no greater than 2 m. (4) Where the coupling on a C-dolly consists of a single component, that coupling shall have (a) a static load rating of (i) 800 kN in the longitudinal direction, and (ii) 80 kN in the lateral direction; and (b) a static moment rating of 76.2 kN.m about the longitudinal axis of the C-dolly. (5) Where the coupling on a C-dolly consists of two metal eyes, the two eyes shall (a) be separated laterally by a distance of 762 mm ± 2 mm; (b) be equidistant from the longitudinal centre-line of the C-dolly; (c) have a mounting height of 900 mm ± 10 mm, when the C-dolly is not loaded; and (d) each have a static load rating of (i) 400 kN in the longitudinal direction, (ii) 100 kN in the vertical direction, and (iii) 40 kN in the lateral direction. (6) Where a C-dolly is tested in accordance with the Motor Vehicle Safety Test Methods, Section 903 - C-dolly (October 1, 1992), published by the Department of Transport, (a) the axis of rotation of a turntable-type steering mechanism shall not deviate from the vertical by more than 0.5 degree; (b) the kingpin axes of an automotive-type steering mechanism shall not deviate from the vertical by more than 0.5 degree; (c) the steering mechanism shall keep the wheels within one degree of the straight-ahead position when the steering mechanism is subjected to (i) a lateral force of 22 320 N that is applied to a point located 50 mm behind the centre of the tire contact patch, or (ii) a longitudinal force of 8 930 N that is applied through the centre of one of the tires in the case of a C-dolly that is equipped with one tire on each side, and through the centre of one of the dual tires and wheel assemblies in the case of a C-dolly that is equipped with two tires on each side; and (d) the steering mechanism shall not permit the wheels to move beyond one degree from the straight-ahead position unless the steering mechanism is subjected to a force exceeding the force referred to in subparagraph (c)(i) or (ii). (7) Where a C-dolly is equipped with a pressurized hydraulic or pneumatic system that provides the means referred to in paragraph (1)(b), the system shall (a) be independent of the brake system of the C-dolly; (b) be fitted with a pressure gauge that indicates (i) the minimum pressure required to meet the requirements of paragraphs (1)(b) and (6)(c) and (d), and (ii) the amount of pressure in the system; and (c) not permit any adjustment of the steering force. (8) Every C-dolly referred to in subsection (7) shall bear a label, in both official languages, that states the minimum pressure referred to in paragraph (7)(b). (9) Every pressure gauge referred to in subsection (7) and every manual valve and switch, if any, that forms part o