Something just occurred to me the other night

[dtrainBNSF1]

I was doing some diesel power testing on Stevens Pass the other night when something occurred to me: BNSF has rules regarding the amount of dynamic braking on the head-end of a train, but some of the tonnage limitations for places like Stevens Pass for example seemingly break that rule. General Service couplings (grade C equipment) according to the November 2003 timetable (latest I personally could find) are limited to use on trains that are either 4800 tons or 7,000 feet long (including power) without helpers. Doublestacks and Boeing cars (Grade E equipment) are allowed up to 6000 tons or 7,000 feet without helpers. Trains made of mixed C and E equipment (intermodal trains that have both stacks and trailers for example) can also have 6000 tons or 7,000 feet with no helpers. I emphasise the point of "no helpers" because that means all power would be restricted to the head end of the train. For a 6000 ton intermodal train that typically can climb up a grade at 20 mph you would need at least 5 ES44DCs on the head end which as far as dynamic brake requirements go would be a blatant infraction of the rule of no more than 32 axles of dynamic braking on the head end of intermodal trains, bulk loaded commodity trains, and trains with conventional equipment in which the first 25 cars are loaded weighing at least 100 tons each.

Obviously BNSF doesn't break their own rules. So why would they put such a rule in and list it under "no helpers" i.e. no dpu? Then it hit me: they cut out the dynamic brake power on the 5th loco so that the train satisfies the HpT requirement without breaking the dynamic brake rule. Now in order to pull this off the weight of the 5th loco (unbraked) must be included with the total listed tonnage to ensure that the train even with a total of 32 axles of dynamic braking on the head end of intermodal trains will still have enough dynamic braking power to keep the train under control on the descending grade. But that's it. They really do this.

That's when I got to thinking: why hasn't anybody made a mod of a loco with its dynamic brakes cut out? It'd be easy: just make a copy of the "No Driver" loco, adjust the dynamic brake figures so that everything is 0, rename it to something like "BNSF ES44DC ND - non-braked", remove all the .GEOPCDX files and submit it for publication. We could really start to make flexible consists in scenarios with such a mod that granted the physical limitations of TS2015's platform would at least look and act more like real trains that we see all around us all the time whether it be on special railfanning trips, driving to school or work, or what we see on youtube.

Just a thought. What do you guys think?

[Kali]

Or just remove all the dbrake entries entirely, that would work too :)

[BNSFdude]

As we say, with every rule, there comes exceptions. I'll paint an example of how rules work.
FRA CFR
GCOR-ABTH (gonna leave out the others)
SSI (system special instructions)
Timetable
General Notices-General Orders
GTB or Verbal instruction from Immediate Supervisor like a dispatcher.

Each of those going down may make modifications, additions, remove entirely a rule or regulation.

As for the total rated DB Axles that you are talking about. There's a few exceptions listed in the Air Brake and Train Handling book. Normally you would be limited to a total DB axle (figures for such which are listed in Item 2 of the SSI) of 28 axles. Except when operating a train consisting entirely of loaded double stack container cars. Then the limit of DBA would now be 32. And even further than that, there are exceptions such as the limitation only applies to a single locomotive consist on a train, and a consist doesn't include any Helpers or DPUs, as they are not married up to other engines in the lead, controlling position.
Further than that, the timetable for the Scenic Sub may modify this, or even a General Order/Notice, or it could be listed as a form C on their GTB.

[dtrainBNSF1]

As we say, with every rule, there comes exceptions. I'll paint an example of how rules work.
FRA CFR
GCOR-ABTH (gonna leave out the others)
SSI (system special instructions)
Timetable
General Notices-General Orders
GTB or Verbal instruction from Immediate Supervisor like a dispatcher.

Each of those going down may make modifications, additions, remove entirely a rule or regulation.

As for the total rated DB Axles that you are talking about. There's a few exceptions listed in the Air Brake and Train Handling book. Normally you would be limited to a total DB axle (figures for such which are listed in Item 2 of the SSI) of 28 axles. Except when operating a train consisting entirely of loaded double stack container cars. Then the limit of DBA would now be 32. And even further than that, there are exceptions such as the limitation only applies to a single locomotive consist on a train, and a consist doesn't include any Helpers or DPUs, as they are not married up to other engines in the lead, controlling position.
Further than that, the timetable for the Scenic Sub may modify this, or even a General Order/Notice, or it could be listed as a form C on their GTB.

True enough. Every BNSF timetable I've got does make a point of saying that loaded double stacks can have 32 axles of dynamic braking power in the lead. And yes I am aware that the limitation is per locomotive consist and not just in general for the whole train.

What I'm saying is that I have seen on more than one occasion that there will be 5 8-axle-rated locomotives on the head-end of a stack train on Cajon Pass or the Scenic Sub. In a situation like that, according to the ABTH rules I have, the dynamic brakes on the 5th unit in such a consist would have it's dynamic brakes cut out to keep the train in compliance with the dynamic brake limit of 32 for loaded double stacks or trains in which the first 25 cars are fully loaded and weight at least 100t. (or something like that) Every other train on the system to my understanding has the general limit of 28 dynamic brake axles per consist.

What I propose is that someone develop a modified Dash-9 or ES44DC which has no dynamic brakes so that such a thing can be simulated.