The AI-generated cat pictures thread
02-01-2016, 02:20 PM
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,026
Total Cats: 6,592
Derspite the small efficiency gain from the improved aerodynamics (drafting effect), I can't see why ten locomotives ganged together, on flat ground, would have a higher top speed than one all by itself. Most modern diesel electrics are gear-limited, and can achieve top speed even while pulling a train. 6,200 HP is a lot.
Reply
0
0
02-01-2016, 02:21 PM
SADFab Destructive Testing Engineer
iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
depends on whether or not one locomotive can reach its max speed. Thats like saying a bugatti veyron has the same top speed whether you keep the v16 in it or swap in a B6 engine.
Reply
0
0
02-01-2016, 03:22 PM
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,026
Total Cats: 6,592
When we say that a vehicle is "gear limited," we are saying that the maximum speed of the vehicle is limited not by the amount of power that its engine can produce relative to its aerodynamic drag, but by the gearing of the drivetrain relative to redline RPM.
Assuming that they have the same transmission, differential and rear-end, a stock NB and an NB producing 250 HP both have the same top speed, because the stock NB is fully capable of reaching redline in 5th or 6th gear. It just takes longer to get there.
The loco shown in the pictures is a GE Evolution series, which is primarily used in freight service. I'm not sure which specific model (they range from a 4,400 HP V12 to a 6,200 HP V16), but they are all geared for 70-75 MPH. The higher HP models simply have more dead-weight (towing) capacity and are better suited for use on western routes where they deal with greater inclines.
The GE Genesis series passenger locomotives (which is what I used to ride every day when I lived upstate) use a related family of engines and drivetrains, but in that application, they're geared for 110 MPH at the expense of a lower towing capacity. Passenger trains tend to be much shorter and lighter than freight trains, and demand greater speeds.
Reply
0
0
02-01-2016, 04:21 PM
SADFab Destructive Testing Engineer
iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
No, it's not like that. It is, however, like saying that a stock NB has the same top speed as one making 250 HP. Because it does.
When we say that a vehicle is "gear limited," we are saying that the maximum speed of the vehicle is limited not by the amount of power that its engine can produce relative to its aerodynamic drag, but by the gearing of the drivetrain relative to redline RPM.
Assuming that they have the same transmission, differential and rear-end, a stock NB and an NB producing 250 HP both have the same top speed, because the stock NB is fully capable of reaching redline in 5th or 6th gear. It just takes longer to get there.
The loco shown in the pictures is a GE Evolution series, which is primarily used in freight service. I'm not sure which specific model (they range from a 4,400 HP V12 to a 6,200 HP V16), but they are all geared for 70-75 MPH. The higher HP models simply have more dead-weight (towing) capacity and are better suited for use on western routes where they deal with greater inclines.
The GE Genesis series passenger locomotives (which is what I used to ride every day when I lived upstate) use a related family of engines and drivetrains, but in that application, they're geared for 110 MPH at the expense of a lower towing capacity. Passenger trains tend to be much shorter and lighter than freight trains, and demand greater speeds.
When we say that a vehicle is "gear limited," we are saying that the maximum speed of the vehicle is limited not by the amount of power that its engine can produce relative to its aerodynamic drag, but by the gearing of the drivetrain relative to redline RPM.
Assuming that they have the same transmission, differential and rear-end, a stock NB and an NB producing 250 HP both have the same top speed, because the stock NB is fully capable of reaching redline in 5th or 6th gear. It just takes longer to get there.
The loco shown in the pictures is a GE Evolution series, which is primarily used in freight service. I'm not sure which specific model (they range from a 4,400 HP V12 to a 6,200 HP V16), but they are all geared for 70-75 MPH. The higher HP models simply have more dead-weight (towing) capacity and are better suited for use on western routes where they deal with greater inclines.
The GE Genesis series passenger locomotives (which is what I used to ride every day when I lived upstate) use a related family of engines and drivetrains, but in that application, they're geared for 110 MPH at the expense of a lower towing capacity. Passenger trains tend to be much shorter and lighter than freight trains, and demand greater speeds.
Reply
0
0
02-01-2016, 05:14 PM
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,026
Total Cats: 6,592
Fair enough.
It took a minute for my brain to say "wait a sec, no that's wrong. The drift effect will improve per-loco economy slightly, but unladen top speed isn't limited by HP on these things like it was back in Doc Brown's day."
It took a minute for my brain to say "wait a sec, no that's wrong. The drift effect will improve per-loco economy slightly, but unladen top speed isn't limited by HP on these things like it was back in Doc Brown's day."
Reply
0
0
02-01-2016, 05:19 PM
SADFab Destructive Testing Engineer
iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Time to go delete all the screenshots of proof recorded in case my genius was edited by a moderator.
Reply
0
0
02-01-2016, 06:25 PM
Elite Member
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
Reply
-1
-1
