Dynamic Brake Weight

[Prole]

Anyone know off hand what the weight difference is between a dynamic brake'd engine and one without the system? Geep Seven's in particular.

Dave

[GaryG]

Hi

Dynamic braking wouldn't add a lot of weight; it mainly consists of the resistor grid(s), fan(s) on the roof and some control hardware. Around one ton might be a reasonable guess.

GaryG

[Prole]

That makes sense. Most of the MSTS physics codes seems to deal with the dynamic brake engines and I was just wondering if there is a difference.

Thanks for the reply-
David

[CRQ5508]

If you're on the train-sim forums you might ask Bob Boudoin (aka: Plainsman) He's known as the physics extraordinaire in the train-sim world and may know off hand how much dead weight dynamic braking adds to a locomotive. Like you said though, it probably does not add much weight, I'd venture a guess to even less than one ton. The resistor grids are nothing more than over-sized coils found in hair-dryers, toasters and space heaters. I remember reading once that EMDs new Q-type radiator fan (found on late model GP/SD38-2s and GP/SD40-2s along with all models from the GP/SD50 to the GP60 and SD90MAC. [Easily distinguished by it's lower profile and top mounted motor ((compared to earlier fans))]) weigh about 105 pounds a piece. That's including the motor, fan blades and housing. I imagine the resistor plates don't weigh any more than 500 pounds all together then there's maybe 50 pounds total of wiring from the traction motors to the resistor grids (remember this is high-voltage wiring.) There's nothing different about the traction motors on the locomotive with dynamic braking compared to ones with dynamic braking. Most of my information is based on EMD locomotives so I hope you weren't asking about a GE or ALCO locomotive (or any other builder!)