I have been watching virtual railfan a little lately, and a few times now in the afternoon I have seen an Amtrak train turn at Santa Fe Junction in Kansas City. The train has a single locomotive, 3 coaches (one might be a cafe), and 3 baggage cars. I doubt that a small train like that needs that much baggage support. I thought I read about a year ago that BNSF requires 24 axles for breaking, so maybe that is the reason. I think this is the Amtrak St Louis to KC train. Does anyone know why it has all the baggae cars on it?
If its the St Louis-KC train, that operates over the UP.
Dave H. Painted side goes up. My website : wnbranch.com
Not familiar with BNSF or Amtrak, but most requirements involving braking revolve around dynamics or, tons per operative brake in the consist and are also railroad specific. Most railroads limit dynamic braking to 24 axles. This means, if the power consist is say five six axle units on the head end. The dynamics on the lead unit must be cut out, leaving the four remaining units to supply dynamic braking. When counting dynamic braking axles, start at the first dynamic braked axle closest to the train and count forward from there. There are other considerations that railroads apply to using DB. The best souce of this sort of information was the railroad's employee's timetable for the division of interest.
Tons per operative brake is exactly what it says. It is possible to have cars in the consist with defective brakes cut out. This places an additional burden on the brakes of the rest of the consist. Railroads, especially those with significant grades, limit tonnage that may be safely air braked over that route. For instance, the railroad has determined 80 tons per operative brake is the limit for a certain route. This is determined by dividing train weight by the number of cars with an operating brake. Example: train weight, 7400 tons, divided by the number of cars with operative brake, say 85. The result is a little over 87 tons per brake which, either additional operative brake cars must be added or, cars cut off to reduce the train weight. Compliance with this restriction is the responsibility of the yard that built and dispatched the train and, the conductor to insure the train is within the set limit for the route to be traversed. Again, this restriction is usually found and addressed in the ETT or special instructions for that territory.