Victorian Railways Wagon Physic before air brakes and light friction on the axels.
Used on AA and BB Passcars (3 axel bogies).
Also best on 25-30ton cars,
anything lighter or heavier makes it handle different.
Updated.
Notes:
Should only be used on a Wagon/Passcar/Van that has flyshunt script.
Should not be used in between cars/locomotives if other wagons are not fitted to 404079 e-specs as it causes weird results.