CDL Combination Vehicles TestCombination Vehicle Air BrakesHard
A technician is connecting a 'converter dolly' to a second trailer. What is the primary purpose of the converter dolly in a combination vehicle configuration?
- ATo provide additional storage space for cargo.
- BTo electronically assist in steering the rear trailer during turns.
- CTo convert air pressure to hydraulic pressure for improved braking.
- DTo allow a conventional trailer to be coupled as a second, or 'pintle hook' trailer.
Show answer & explanationAnswer & explanation
Correct answer: D. To allow a conventional trailer to be coupled as a second, or 'pintle hook' trailer.
A converter dolly is a specialized piece of equipment with a fifth wheel that is used to convert a semi-trailer into a full trailer. This allows a standard semi-trailer (which normally requires a tractor) to be coupled behind another trailer, forming a 'double' or 'triple' combination.
Why the other options are wrong
- A. The dolly itself does not provide cargo space; it's a connecting mechanism.
- B. While it allows for articulation, it does not electronically assist in steering; it's a mechanical connection.
- C. Air brake systems use air pressure directly; conversion to hydraulic is not its function.
Converter Dolly
A short trailer with a fifth wheel, designed to convert a semi-trailer into a full trailer. It allows a semi-trailer to be coupled behind another trailer, enabling double or triple trailer configurations.
- Has its own axle(s) and brakes.
- Equipped with a fifth wheel.
- Connects to the lead trailer with a pintle hook.
- Essential for double/triple trailer operations.
Memory trick: Dolly Doubles Drivers' Deliveries.