Discussion relating to the operations of MTA MetroNorth Railroad including west of Hudson operations and discussion of CtDOT sponsored rail operations such as Shore Line East and the Springfield to New Haven Hartford Line

Moderators: GirlOnTheTrain, nomis, FL9AC, Jeff Smith

  by NJRail4129
 
I'm trying to find some basic info on the FL9AC's, googled it and came up with about 500 pics but no specifications.
- What did they use as prime mover, 710 12-cyln?
- was HEP off a inverter or a seperate plant?
- How much traction horsepower did the units have?
Basically the only stuff I could come up with was that the units were basically F59's stuffed in a FL9 body with AC traction... Any comments?

TIA, Matt

  by DutchRailnut
 
yup it had 12 /7210G3 in them
lenght 58 feet 8"
width 10 feet 4 3/4 "
height 14 ft 6"
weight 275.000 lbs
wheel diameter 40"
truck centers 34 ft
diesel power 2800 hp
main alternator output 1400 V DC
aux alternator 200 volt AC
HEP rating 480V AC 870 kVA
Fuel cap 1507 gallons
Lub oil 200 gallon
Cooling water 230 gallon
Gear ratio 74/21 90 mph
sand capacity 8 cuboic feet 650-800 lbs

  by NJRail4129
 
thanks Dutch

  by Penn Central
 
Don't forget that the FL9-AC was a true dual mode locomotive and could develop maximum horsepower in third rail mode. Propulsion worked differently with power from the invertors routed to a main bus that fed AC traction, HEP and aux. power. Without HEP, the engine would not run and the compressor would be shut down. This was a problem when the diesel engine was left on idle. The compressor would be shut down and there would be no air on the engine. Thinking that the compressor ran directly off the engine, like a regular FL-9, some engineers would knock off the hand brake in the engine room and get a big surprise when they started to roll.

Engine RPMs were constant when up in HEP mode like an F-40. As the engineer pulled out the throttle, it made a "request" to the MICAS-S computer that would control the amount of traction power based on a number of conditions.

Although it was never perfected, the FL9-AC had regenerative dynamic braking. Although it could have fed power back to the third rail in dynamic braking mode, that feature was disable for safety reasons. The power department did not want to risk a locomotive energizing a third rail that had power removed by the power supervisor. The dynamic brake was used to power the main AC bus. The engine was designed to switch from power to dynamic braking when going through third rail gaps to keep the bus energized. Great idea, but a bad feature. When running in GCT, the engine would hit a gap and switch to dynamic braking and slow the train enough to get it stuck in the gap. That feature was modified to work only at higher speeds.

The DC mode on Genesis engines develops reduced power because of the five invertor system. Another difference is that the FL9-AC had dynamic braking when running in DC mode. The Genesis engines use the dynamic brake resistors as part of the DC operation, so dynamic braking is disabled when running in DC mode. DC operation is only for short distances and slower speeds, so that's not a big deal.

  by DutchRailnut
 
correct the EMD/Siemens system for FL9ac and DE/DM units use one inverter for each truck plus a HEP inverter, and a stepup inverter to jump 700 volt third rail to 1400 volt DC bus. disatvantage one t/m failure or inverter failure reduces the locomotive to a less than 50% power condition. same if HEP inverter failed the engine needed a traction inverter to supply HEP reducing loco to 50% power.

This is how the ARR SD70's run with HEP, one traction inverter from 6 axle locomotive is used as HEP inverter running the Big SD70 as a A1A-A1A unit.
A bad thing about the one inverter per truck design is wheels need to be within 1/3 of " in diameter since they are on same inverter and only tolerate a limited amout of electrical slip.


A Genesis has one inverter per traction motor, one HEP inverter and Dynamic brake inverter used as stepup inverter to step up the 700 volt DC to 1400 volt DC bus while in third rail mode.
Plus point one traction motor or one inverter failure keeps locomotive near 100% due to extra capacity of t/m and inverters.
If HEP fails locomotive can reconfigure to 3 traction motors plus HEP by just recycling the computer.
again on 3 traction motors the GE will run at or about full traction power.

  by oddball
 
when was the last run of an FL9AC?
  by fordhamroad
 
-with all these useful features, the FL9-AC's never seemed to be a success on LIRR or Metro North. What problems led to abandoning the engines? With a large FL-9 fleet available for possible rebuilding, why did Metro North and LIRR prefer other alternatives?

Roger

  by DutchRailnut
 
The FL9ac's were experimental locomotives and cost a fortune to manufacture, nearly double what a genesis cost.
By the time the verdict was in on AC traction, GE came with a much better alternative, the Genesis.
the last few years the FL9ac's were very un reliable and ran in pairs most of time.
The wheel mismatch being main issue since the shop kept running them with more than maximum.
This caused inverter faults and had locomotives run at 50% power.

  by Penn Central
 
DutchRailnut wrote: A Genesis has one inverter per traction motor, one HEP inverter and Dynamic brake inverter used as stepup inverter to step up the 700 volt DC to 1400 volt DC bus while in third rail mode.
Plus point one traction motor or one inverter failure keeps locomotive near 100% due to extra capacity of t/m and inverters.
On one run to Poughkeepsie 10 years ago, I had an HEP invertor fault on a Genesis at 125 St.. The engine shut down and reconfigured the #1 tm invertor to provide HEP to the train. This was done automatically and took about two minutes. The remaining three traction motors ran at full power and I arrived at Poughkeepsie three minutes early. With an FL9-AC, that could never happen.

  by Alcochaser
 
DutchRailnut wrote: This is how the ARR SD70's run with HEP, one traction inverter from 6 axle locomotive is used as HEP inverter running the Big SD70 as a A1A-A1A unit.
A bad thing about the one inverter per truck design is wheels need to be within 1/3 of " in diameter since they are on same inverter and only tolerate a limited amout of electrical slip.
This is blatantly wrong. The ARR locomotives have three invertors on them. two for traction and one for HEP. If something should disable the HEP invertor one of the two traction invertors can be used for HEP. Leaving the locomotive with one powered truck. This was done because not having HEP in the great white north is a life threating situation. It does get mighty cold up there.

The info on all the Metro North equipment is correct however.

  by DutchRailnut
 
I am not wrong the SD70's when not providing HEP are 6 axle powewred, in HEP mode the one traction inverter out of the 3 available is used for HEP. making the SD a 4 motor unit.

  by Alcochaser
 
Here is the thing you are missing. And this will be my last post on the SD70MAC since it has no MN relavance.

A normal SD70MAC has a total of two inverters. One per truck. All of EMDs current AC frieght locomotive production have been this way since the first SD60MACs right up until the current SD70ACe. For the Alaska units EMD added a third inverter specifialy for HEP. They are 6 motor locomotives in HEP mode. Now they do not have near as much traction horsepower in HEP mode do to the HEP load, which on ARR can run upwards of 800KW to 900KW cars for the cruse trains.