The brake book we're reading, The Principals and Design of Foundation Brake Gear, reports that the standard approach on passenger cars is to design for no-load and disregard the weight of passengers. The only exception they give are subway cars in NYC.
(While a great resource, the book is horribly colored toward superfluous gauge railroads utilizing the braking system of a certain competitor of our good old buddy Fred Eames, so anything they say might be taking as a colored grain of salt.)
We also can't slide wheels with the brake system when the cars are empty- and varying the capacity of the braking system for empty vs load is not a simple matter.
There are acceptable ranges of braking ratios- so I'll run the numbers for both empty and loaded to ensure we land in the range at both ends.
see ya
Jason
