on the trailer vs in the trailer

Both "on the trailer" and "in the trailer" can be correct depending on the context. "On the trailer" is used when something is physically on top of the trailer, while "in the trailer" is used when something is inside the trailer. They are not interchangeable and should be used based on the specific location relationship.

Last updated: March 29, 2024 • 775 views

on the trailer

This phrase is correct when referring to something that is physically on top of the trailer.

Use "on the trailer" when describing something that is placed on top of the trailer, such as luggage or equipment.

Examples:

The bicycles are on the trailer.
The tarpaulin is on the trailer to protect the cargo from rain.

Show examples from the web [+]

Location of components on the trailer: ...
Reduction ratio and efficiency of the mechanical-transmission device on the trailer
If a tractor is equipped to draw a trailer the hazard-warning signal control must be also capable of bringing the direction-indicator lamps on the trailer into action.
Annex 12 - Appendix 4 - Test report on the compatibility of the inertia brake control device, the transmission and the brakes on the trailer
The plug together with the cable shall be situated on the trailer.
Drawbars for centre axle trailers shall have a support device which is adjustable in height if vertical bearing mass at the drawbar eye on the trailer exceeds 50 kg, when the trailer is uniformly loaded to its technically permissible maximum mass.
The test wheel position on the trailer or the tyre test vehicle shall be equipped with a rotational wheel velocity measuring system and with transducers to measure the braking force and vertical load at the test wheel.
The relay for actuating the braking current in accordance with paragraph 5.2.1.19.2 of this Regulation, which is connected to the actuating line, shall be situated on the trailer.
The power-driven vehicle is fitted with a control device for the endurance braking system on the trailer:
Except as provided in paragraph 6.23.9.2. below, if a motor vehicle is equipped to tow a trailer, the control of the emergency stop signal on the motor vehicle shall also be capable of operating the emergency stop signal on the trailer.
In addition, the actuation of the parking brake system may also actuate a braking system on the trailer via the electric control line.
If the operation of the parking braking system on the power-driven vehicle also operates a braking system on the trailer, as permitted by paragraph 5.1.2.3, then the following additional requirements shall be met:
When the power-driven vehicle is equipped according to paragraph 5.1.3.1.2, the actuation of the parking brake system on the power-driven vehicle shall actuate a braking system on the trailer as prescribed in paragraph 5.1.3.7.1.
A failure warning device is not permitted on the trailer for the purposes of providing a warning in the event of a failure within the trailer braking system when the braking system is powered from the additional supply.
Transmission devices on the trailer
All right, she had surveillance on the trailer park.
Both those guys on the trailer are in it.
All units... move on the trailer property.
Traditionally, amateur racers go off for a weekend of motor sport, with a motorhome to sleep in and the car on the trailer behind.
I don't know, I... I mean, I think I left it on the trailer.

Alternatives:

on top of the trailer
attached to the trailer

in the trailer

This phrase is correct when referring to something that is inside the trailer.

Use "in the trailer" when describing something that is located inside the trailer, such as furniture or boxes.