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BNSF tests EMD SD70ACE-P4s again
Possibly changed the gear ratio? That’s my guess.
Other than cost what is the advantage of four traction motors instead of six?
CJ of MO.
Say that you’ve got ten locomotives of each powered axle count.
You have 10 engs without the material which is the equipment, traction motors and circuitry, hardware and software to be controlled and be maintained by the skilled inspectors techs mechanics and electricians. Maybe you don’t need to employ them.
You have 10 engines which required you to obtain 20 more traction motors, than the other 10, which, their inspections, repair, removal and installation by those skilled tech’s to do it, were included in the package.
Lower initial cost? Less locomotive weight? Likely higher train speed…'cause the 4 AC axles=6 DC axles=better efficiency…same horsepower?
CJ of MO.
Say that you’ve got ten locomotives of each powered axle count.
You have 10 engs without the material which is the equipment, traction motors and circuitry, hardware and software to be controlled and be maintained by the skilled inspectors techs mechanics and electricians. Maybe you don’t need to employ them.
You have 10 engines which required you to obtain 20 more traction motors, than the other 10, which, their inspections, repair, removal and installation by those skilled tech’s to do it, were included in the package.
Lower initial cost? Less locomotive weight? Likely higher train speed…'cause the 4 AC axles=6 DC axles=better efficiency…same horsepower?
The ‘P4’ locomotive has no truck change - the inboard axle is not powered. The HTC truck transfers the load to the two end traction motors. The locomotive has 4 inverters & 4 traction motors. The software handles the power sent to each inverter/motor. The GE version has no center axle traction motor, and needs an air piston ‘lift’ to unload the idler axle when high TE is needed. It does not lift the wheels off the rail(that would exceed the axle loading). The builders are offering this option so they can stop DC traction motor sales and this offers DC 6 motor price/performance with AC motors.
Well thats good news so far. But I wonder what type of modification did they make on the P4s?
Well thats good news so far. But I wonder what type of modification did they make on the P4s?
With all the new technology and lighter materials, time to bring back the DDA40X.
Also, AC motors are cheaper than DC motors. no brushes, less maintenance. In the end, it is to make an AC-powered locomotive price-competitive with a DC locomotive.