Joel Up Front Posted January 19, 2011 Share #1 Posted January 19, 2011 What makes a train fast or slow? Most R-contract cars (R22s being one exception, and the NTTs) have 115 HP/axle, but everyone says that the R62s or 68s are slow when they have the same output per axle. Am I interpreting something wrong? Link to comment Share on other sites More sharing options...
Roadcruiser1 Posted January 19, 2011 Share #2 Posted January 19, 2011 Go ahead, and look around. R62 R62A R68 R68A Link to comment Share on other sites More sharing options...
King Of RedBirds Posted January 19, 2011 Share #3 Posted January 19, 2011 I Took A R38 Train When I Was Younger I Swear He Was Going So Fast He Almost Hit An R46 Train I Saw The R/R SIGN TO SLOW DOWN I WAS SCARED(NYCT) Link to comment Share on other sites More sharing options...
IRT Bronx Express Posted January 19, 2011 Share #4 Posted January 19, 2011 Is it necesarry for you to capitalize the first letter for all words in one sentence? Link to comment Share on other sites More sharing options...
SubwayGuy Posted January 19, 2011 Share #5 Posted January 19, 2011 What makes a train fast or slow? Most R-contract cars (R22s being one exception, and the NTTs) have 115 HP/axle, but everyone says that the R62s or 68s are slow when they have the same output per axle. Am I interpreting something wrong? Many things. In terms of design, weight to HP ratio is one of the biggest. All cars today are designed with an initial acceleration rate of 2.5MPH per second, however that tapers off. Where it tapers off depends on the car class and weight to HP ratio. R62s are not slow. R68s and R68A's are slower when compared to other cars in the fleet. They have a higher weight to HP ratio. It's also why the BMT Standards were some of the slowest cars running when they were around. In terms of in practice, a number of things could cause it. Open resistance circuit in a car (dead car), dead motor(s), and so on. But they all get back to weight/HP ratio because if a motor dies you lose that HP. Link to comment Share on other sites More sharing options...
Fan Railer Posted January 21, 2011 Share #6 Posted January 21, 2011 Many things. In terms of design, weight to HP ratio is one of the biggest. All cars today are designed with an initial acceleration rate of 2.5MPH per second, however that tapers off. Where it tapers off depends on the car class and weight to HP ratio. R62s are not slow. R68s and R68A's are slower when compared to other cars in the fleet. They have a higher weight to HP ratio. It's also why the BMT Standards were some of the slowest cars running when they were around. In terms of in practice, a number of things could cause it. Open resistance circuit in a car (dead car), dead motor(s), and so on. But they all get back to weight/HP ratio because if a motor dies you lose that HP. I don't know if you guys can see this, as I may have to publish this, but I made this little spreadsheet on Mass to Power Ratios a while back. Hope you can make sense of it: https://spreadsheets.google.com/ccc?key=0AucfHj0GlYYPdC1nRmRsYzVOeHcyMmZvbTIydFdiZ0E&hl=en#gid=0 Link to comment Share on other sites More sharing options...
2 Train Master Posted January 21, 2011 Share #7 Posted January 21, 2011 R62s are not slow. R68s and R68A's are slower when compared to other cars in the fleet. Yea those cats on the move! And yea for some reason the R-68A's feel faster than the R-68's but then again I could be wrong. Link to comment Share on other sites More sharing options...
SubwayGuy Posted January 22, 2011 Share #8 Posted January 22, 2011 I don't know if you guys can see this, as I may have to publish this, but I made this little spreadsheet on Mass to Power Ratios a while back. Hope you can make sense of it:https://spreadsheets.google.com/ccc?key=0AucfHj0GlYYPdC1nRmRsYzVOeHcyMmZvbTIydFdiZ0E&hl=en#gid=0 Makes sense to me. I'd stay away from the "imaginary" car classes if I wanted it to be taken seriously though because you have put some thought into it. There are other issues that affect TOP SPEED and acceleration rate, but since all acceleration is designed to be the same nowadays weight/HP is the best predictor of acceleration for cars in general. Most prewar cars had acceleration rates of 1.75 MPH/s because that is what they were designed for. It was not until the first SMEE cars (the R10s) that the rate was upped to 2.5mphps. If you want to fill out the Lo-V section you'll also have to adjust for different types. Steinway cars had different gear ratios designed to increase torque and reduce top speed (to climb the Steinway tubes). Standard Lo-V's did not have this modification. For all intents and purposes, in a 10 car train of Standard Lo-V's, you would have had 3 trailers (or less). In a 10 car train of Steinways, all would have been motors. Link to comment Share on other sites More sharing options...
SubwayGuy Posted January 22, 2011 Share #9 Posted January 22, 2011 And yea for some reason the R-68A's feel faster than the R-68's but then again I could be wrong. Just your perception. They do not differ significantly in propulsion performance from each other. Link to comment Share on other sites More sharing options...
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