What is this?

[davesnow]

 

[Dinorius_Redundicus]

It's an arrester hook for when it lands on an aircraft carrier.

 

[OddRails]

If it's the underside of a caboose, they had a generator and belt running off an axle. But I would have expected it to be mounted on the sideframes of a truck or bogie.
That's my guess, but it doesn't look like a generator. Maybe some sort of odometer? Sorry.

 

[pdkoester]

It may be the PRV. Maybe show it from the side, too. I don't think it is a screw mount or a post.

I asked what that is using copilot, but I don't know if it is right:

the part circled in red is likely the magnet for the Easy-Peasy lighting system or a mounting post for the lighting control reed switch. Rapido often includes magnetic reed switches in their cabooses to allow users to turn interior lighting on or off by waving a magnet over a specific spot on the roof or underframe.

Here’s how to tell:

• If the caboose has interior lighting and no visible switch, this is probably the reed switch location, and the circled part is either the switch itself or a marker for where to activate it.
• If you wave a small magnet over that spot and the lights toggle, that confirms it.
• If there’s no lighting installed, it could simply be a mounting post or alignment peg used during assembly.

 

[pdkoester]

Asked Grok, and this is the response:
The part in the red circle is a reed switch for the model's interior lighting system. Rapido Trains cabooses often include track-powered lighting that can be toggled on/off using a magnetic wand (called the Rapido Lighter) waved near the switch. This non-prototype component is positioned on the underbody for accessibility without disassembling the car. It's a small glass-encased magnetic sensor that closes the circuit when activated by the wand's magnet.

 

[davesnow]

This is not a caboose, it's a Coil Car, specifically the Greenbrier Transverse Coil Car.

 

[norfolksouthern37]

It looks like it is the opposing brake rod lever for the truck on that end. It passes through the center beam at that location.

 

[TSwenson]

I'd also agree with norfolksouthern37, looks like brake rigging. A technical diagram (or the like) for that car will tell you exactly.

 

[289v8]

 

[JCitron]

It's one of those things that gets broken off easily after the kiddies and cats get ahold of the caboose.

 

[norfolksouthern37]

it is still not a caboose, though most cars would have a similar brake setup

 

[289v8]

It looks like the Die Maker that made the Mold for the chassis added that extra pipe brace(on Dave Snow's picture) so the pipe would be less likely to get broken off during handling, packing and etc. The brace in DS pic is probably not prototypical size but easy to make in the Mold process. Just my opinion.