I have some questions about vacuum brakes:
1. Are the couplings between cars somewhat similar to those used with air brakes?
2. Assuming that you arrive at TOM and want to do a run-around, does one close angle cocks on the engine and nearest car, disconnect the hoses, uncouple the cars, run-around, couple the cars, reconnect the hoses, open the angle cocks, and "pump down the air?"
3. How long do the steps in #2 above take?
4. Would all cars in the train have to be equipped with at least a pass-through pipe?
5. Would all motive power (such as #52) have to be equipped?
6. Will supplemental hand-operated mechanical brakes remain?
-John