You need to look closely at the switches and see where the momentary short is coming from. It's not uncommon for certain locomotives to have issues with a specific switch type or size, the trick is finding the contact point and addressing it.
With the O22 switches it's quite possible that it's the power surge from the O22 solenoid that is creating a spike and tripping the PH180 breaker. Try a 1uf 50V capacitor across each outside post to the center post of the switch motor and see if that resolves it.