What type of air brakes can be used on heavy trucks?

Answer: C — Both straight air brakes and spring-loaded brakes

The use of both straight air brakes and spring-loaded brakes on heavy trucks is essential for their performance and safety. Straight air brakes employ compressed air to operate the brake system, providing excellent stopping power which is critical for heavy vehicles that require more force to halt due to their size and mass. They enable effective modulation and control, especially during demanding driving situations. Spring-loaded brakes, commonly referred to as parking brakes or emergency brakes, utilize a spring mechanism that is engaged when the air pressure is released. This design ensures that even in the event of an air system failure, the brakes remain operational, enhancing safety. This combination of straight air brakes and spring-loaded brakes is vital, as it ensures that heavy trucks can not only stop effectively while in motion but also remain safely stationary when parked or in an emergency. Other types of brakes, such as hydraulic or electronic, are not prominent in heavy truck applications due to their limitations in handling the demands of larger vehicles. Hydraulic systems may not provide the necessary force for heavy loads, and electronic brakes are typically more complex and less reliable for heavy-duty applications. Hence, the utilization of both straight air brakes and spring-loaded brakes is the norm in heavy truck configurations.