This is what I have in my Locomotive Specifications Table that I created some time ago. I don't recall the source of information for this particular model, but it may be of help to you.
The specifications for the AC44C6M you have appear to apply to the ES44AC locomotive (as well). From information I have so far on the AC44C6M locomotive is that it has a starting tractive effort of 200,000 lbs, and a continuous tractive effort of 180,000 lbs. These specifications I have do not match your specifications.
I really think your figures apply (only) to the ES44AC locomotive. The AC44C6M locomotive has slightly higher values with respect to the ES44AC locomotive, I understand.
The rebuilds are just AC4400s on smaller non-gevo frames with 16 instead of 12 cyl engines of an ES44AC but have Gevo software/brains. They are replacing DC dash9s, old school AC4400s of various early designs, and CTE-brained AC4400s
The electronics in the ac drive was changed as well, which as I understand it made them better than ac4400's and es44 loco's.
I do not remember where that information came from and I cannot find it now.
I really can't remember where I got this data from. I remember spending days and days trying to find al the relevant data to make the table that I wanted to. AC44C6M was particularly elusive (as opposed to ES44AC, for example).
I still have a lot of documents in my archive, so if I do find the source or something else relevant to your question, I will let you know.
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Yes, I still can't find the maximum dynamic braking effort specification either (yet). I understand from reading some information elsewhere where it suggests/states the AC66C6M dynamic braking effort is improved with respect to previous locomotive models.
Did the changes in the retrofit improve effort or did they improve adhesion? Those are two completely different things. If they're the same motors, the available braking effort would not change. But the amount of force that can be applied at the wheels, either for traction or braking, is a function of adhesion. For example, individual axle control, if so retrofitted, improves adhesion and allows a greater proportion of the available force to be used at low speeds without risk of wheelslip. For clean, dry rail, this probably isn't much of an issue with dynamic braking, but in inclement weather, this would greatly improve dynamic braking capability.
But this wouldn't require changes to your dynamic braking force. It would require changes to your adhesion curves. If you changed your force values and left adhesion the same, OR would accurately model the increased force... and slip your wheels under the conditions where such a locomotive would benefit from these upgrades!
A popular retrofit to Dash-2 locomotives is a plug-in microprocessor control system that vastly improves traction characteristics. They yank the old WS10 module and drop in a microprocessor replacement, such as an EM2000 module, and there's your upgrade. The locomotive keeps its old D78 motors and the rest of its traction system. The power characteristics don't change. What does change is a massive increase in fine slip control over the heavy-handed WS10 system that detected a slip above a certain value and simply chopped field excitation to the motors. The locomotive gains a significant boost in adhesion characteristics, which allows it to precisely meter the amount of power delivered to the wheels at low speeds, meaning it can pull more with the same powertrain that was otherwise limited by the ability of WS10 to respond to slip.
Maximum adhesion is achieved with precise and fast detection of wheelslip amount coupled with precise and fast modulation of power input to maintain a precise amount of wheel creep. Simply retrofitting a better wheelslip control module gets the operator a significant boost in adhesion, which can be improved further with the addition of ground radar for faster and more precise speed detection which aids in the fast and precise detection of slip. These features became standard on large locomotives in the 1980s. The last major development on the production line, within the last decade or so, was the shift from slip detection and control at the truck level to detection and control at the axle level. Current production models detect slip and apply correction at each axle individually, which is significant because each axle encounters slightly different adhesion conditions than the axle that precedes it.
So, if these locomotives are upgrades of existing models, and they're primarily changing out electronics and traction control, then the maximum braking force is probably the same... but I'd see if there's any figures for adhesion improvements in the literature.
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The 6-motor AC GEs tend to be set at 98,000 pounds of dynamic braking force or 117,000 pounds, with a max braking horsepower of ~5,200 horsepower or ~6,000 horsepower. You can’t easily tell if it’s the 98k or 117k style, though the 117k setup appears to be much less common, probably restricted to only the heaviest or otherwise highest performing units. But for the power rating, you can tell if one’s capable of that 6,000 hp figure if it has 3 dynamic brake blowers. The 2 blower system is cooling-limited to 5,200 hp (even the DC units can do this) but with an extra blower the theoretical heat capacity becomes 7,800 hp. The actual limit becomes the motors, which are limited to slightly over 1000 horsepower each.
It seems that the C6Ms are generally built with the 3-blower setup, so it’s fairly safe to assume they can do 6,000 horsepower of dynamic braking. As for the force, I’d probably stick to 98,000 pounds unless you really know they do something different. Anything else is non standard and only shows up case-by-case.
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