Question - how does the train pull the 80 cars up the first hill with no “previous hill”. If the train is to be able to make the run in both directions, wouldn’t that imply that the first slope in either direction would have to be down hill?
It depends on the grade of the first hill, it could be the first hill had a very slight grade and the train had no problem pulling the load up, but on a steeper grade it couldn’t do it.
I just want Tom or Ray to document that such a run actually exists. The answer I submitted for the puzzler would work on any run that starts off on a downhill grade and ends on an uphill grade, which I’m sure is much more common than the imaginary one from Rochester to wherever. Sounds like a Journey song. I’m glad other CarTalk listeners call these guys out on some of thier bogus stuff. They are funny though.
It seems that part of the attraction of a segment like the ‘puzzler’ is being able to think oneself more intelligent than the creator of the scenario. Did any run ever exist on the B&O where the last 20 cars would still be coming down the previous hill just when the engine needed the extra push? Check all the old maps.
Right. I’ll rush out and check all the old maps.
Aw, you take all the fun out of being fastidious.
Love your show, but you blew it on a comment about the locomotive wheels. You said the first two don’t do anything, but if that were correct why would they exist? They are there to help guide the driving wheels through curves. Think about the engineering difficulties of having those big powerful parallel driving wheels having to fit into curved track at speed. Also the forces they put on the track with the guidance of those leading wheels as opposed to not having them. Note that smaller engines that travel at lower speeds often don’t need them.
This is a simple mental exercise, not meant to be over thought. BTW. I saw this “puzzler” in a book or magazine when I was a kid and it was old then. It has been a long time since I was a kid too.
I agree that the front wheels are there as “leaders”, but they primarily support weight. A steam locomotive is a long heavy machine, and the weight is mostly concentrated on the drive wheels. Because the drive wheels are close together due to the design of the drive system, and with so much machinery beyond the front drive wheels, the front carriage is needed to support the overhanging weight. Yard engines need no front carriage because they have little overhang.
I should add that their function as “leaders” is also due to the weight overhanging the front drive axle. Without something to pull the weight in the direction of a curved track, locomotives would probably be inclined to roll over off the tracks on curves.
NOTE: the drive wheels’ axles are “locked” to prevent them from stopping in a position where both pistons (one on each side) were fully extended (at either end) at the same time. It would be impossible get the train rolling again on its own power with the pistons in that position. Just an FYI.