Here is a Lionel 6-17203 O Gauge Cotton Belt Double Door Boxcar #17203

The Trainz SKU for this item is P11541251

The other is to spread out the engine's weight

Model Number: 20-67099

SoundTraxx 884002 TSU-2200 2 amp Steam Digital Sound Decoder LastUpdated_20262807063133 Here is a Lionel 6-17203This is a SoundTraxx 884002 TSU 2200 2 amp Steam Digital Sound Decoder. Features: 16 bit Digital Sound for Steam Prototypes, 35mm x 18mm x 6mm Universal Format, 2A Motor Stall Current, Over 50 Sound Effects with Selectible Reverb, Functioning Engine and Train Brakes, Reactive Dynamic Digital Exhaust with Adjustable Cut off, 6 Function Outputs with over 20 Hyperlight Effects, Hyperdrive2 Advanced Motor Control. Condition: Factory New (C 9) Operational