B&O M55 - Adding Weight
I have noticed that the car is a bit light, which occasionally derails the car. The other thing I have noticed about coupling is that a very light car can cause the coupler to not fully close. So putting those two things together, I took this opportunity to add weight to the car. I added 1oz (two 1/4oz lead weights on each side) to the car. Subsequent testing of the car proved that both issues were resolved. The car has not derailed since then, and coupling has been working flawlessly.
Adding Weight