61.3. What is the minimum number of wheel chocks that must be provided for a trolleybus with a permitted maximum mass of over 3.5 t?
UAЯкою мінімальною кількістю противідкатних упорів має бути укомплектовано тролейбус із дозволеною максимальною масою понад 3,5 т?
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This exam question from the Traffic Rules of Ukraine concerns the safety of stopping and parking heavy passenger vehicles and tests knowledge of mandatory equipment that helps prevent unintentional rolling on slopes. Wheel chocks are a simple yet critically important safety device: for a trolleybus, the large mass means higher risks even with minor movement, so the requirements for equipment in this case are particularly strict.
In essence, this question checks understanding of Section 31 of the Traffic Rules, specifically the requirements of clause 31.4.7 regarding the technical condition and presence of mandatory equipment. It is also linked to the definitions in clause 1.10, which explains what "permissible maximum mass" is and which vehicles are considered trolleybuses. The criterion "over 3.5 t" specifically determines the category of vehicles for which chocks are mandatory in the minimum required quantity.
The correct answer is two chocks, as the Traffic Rules set this as the minimum for trolleybuses and other vehicles of the corresponding mass: two chocks allow for more reliable blocking of the wheels, taking into account the possible direction of rolling. Options with four or six are not incorrect in terms of increasing safety, but in the context of the theoretical exam, this is no longer the "minimum quantity," but rather excessive equipment, which the traffic rules do not require as a mandatory standard.
Clause 31.4.7 (Section 31 "Technical condition of vehicles and their equipment" — absence of mandatory equipment)
The operation of a vehicle is prohibited if it lacks (in the designated places) mandatory means/items of equipment, in particular: a first aid kit, an emergency stop sign (or a flashing red lantern), a functioning fire extinguisher, as well as wheel chocks — in cases where they are mandatory (for vehicles of the relevant categories/purposes, including buses/trolleybuses and trucks with a permitted maximum mass of over 3.5 t).
Application to the question: this particular clause of the Traffic Rules establishes the requirement for equipping heavy passenger vehicles (including trolleybuses) with wheel chocks and determines the minimum quantity — two.
Clause 1.10 (term "Permitted maximum mass")
Permitted maximum mass — the mass of an equipped vehicle with cargo, driver, and passengers, established by the manufacturer as the maximum allowable.
Application to the question: the criterion "over 3.5 t" in the question is directly linked to this definition.
Clause 1.10 (term "Trolleybus")
Trolleybus — a non-rail mechanical vehicle driven by an electric motor and receiving electricity from an overhead contact system.
Application to the question: clarifies the type of vehicle for which the requirement for mandatory equipment is being checked.
Thus, the correct answer is "Two.", given that according to the Traffic Rules, trolleybuses (as passenger vehicles) with a permitted maximum mass of over 3.5 t must be equipped with at least two wheel chocks.
When preparing a trolleybus for departure and operation, it is important that it is equipped with the necessary devices for safe stopping and parking. One of these mandatory devices is wheel chocks, which prevent the vehicle from rolling unintentionally, especially on slopes or when parked with passengers on board.
The requirements for vehicle equipment directly take into account their mass. If a trolleybus has a permitted maximum mass of over 3.5 tons, it is classified as a heavy vehicle, for which enhanced safety measures are provided. One chock in this case does not provide a sufficient level of fixation, as a heavy vehicle can move under the influence of a slope, inertia, or uneven road surface. That is why a minimum is set, which guarantees more reliable wheel blocking.
In practice, two wheel chocks allow the vehicle to be secured more effectively: for example, when parking on an ascent or descent, the chocks can be placed according to the possible direction of movement so that the wheel cannot roll. For a heavy trolleybus, this is critical, since even a small unintentional movement creates significant danger for passengers and other road users.
Therefore, the correct answer is "Two.", since a trolleybus with a permitted maximum mass of over 3.5 tons, according to safety requirements, must be equipped with at least two wheel chocks to reliably prevent rolling while parked.