Is there any utility out there that calculates a consist to determine the amount of horsepower/engines required to run the Train? If not, we need a tool that would add up the gross tonnage of a consist. MSTS must do that automatically as far as running the program. I have received some very good info from engineer Al Krug which should help all of us to devise better activities.
1. Locos will be pulled or pushed down a grade if the force of gravity acting on the train weight exceeds the weight-on-drivers times adhesion. The pull or push force of gravity is 20 pounds per ton of train. Thus a 6,000 ton train on a 1% grade has 120,000 lbs of gravity froce, and on a 3% grade that would equal 360,000 lbs of gravity force. Locos would have to generate power equal to or grater than the gravity force either by brakes and/or applied power to control the train.
2. Adhesion of a steel wheel on a steel rail is about 20% of the weight on the drivers. A C44-9 weighting 400,000 pounds would give 80,000 pounds of "holding force." Modern wheelslip controls can raise the adhesion up to 33% or better--more holding power using the power than just the brakes. The 33% figure would also equate to the minimum pulling force needed to start a train with a modern engine/s.
3. Concerning power required to maintain track speed, Al says, if a train weights 6700 tons and the grade is 3% then a train would go up the hill at 12.5 mph not considering curves with engines totalling 19,600 hp, and on a 1.5 % grade it would be 25 mph.
4. In rain, tractive effort (TE) of engines drops from max of about 33% adhesion down to 20%, by applying sand the TE can be raised back up in the 28-30% range. He says there is very little difference in the tractive effort produced bwetween snow and rain. The MSTS default.wag setting makes a considerable differenct. He says at higher speeds the snow is not melted by the friction as fast and that can make a difference.
5. Concerning the tunnel setting. He says that grease and oil accumulates and is not a problem until moisture is added--snow or light rain, and tunnels are more slippery than outside dry rail. He did not feel that winter cold snow made any worse condition in a tunnel than would a fall rain.
6. Can a train go skating down an incline--you bet! If connected with engines insuffient with weight and/or power and under bad track conditions. I hope these figures may be useful.Bob Edwards
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RE: Calculator to Determine Engines Needed, CPR_Malice_96th, Jun-23-04, 08:49 AM, (1) RE: Calculator to Determine Engines Needed, oakpalms, Jun-23-04, 09:53 AM, (4) RE: Calculator to Determine Engines Needed, goonybird, Jun-23-04, 09:21 AM, (2) RE: Calculator to Determine Engines Needed, oakpalms, Jun-23-04, 09:52 AM, (3) RE: Calculator to Determine Engines Needed, goonybird, Jun-23-04, 11:03 AM, (5) RE: Calculator to Determine Engines Needed, oakpalms, Jun-23-04, 04:06 PM, (6) RE: Calculator to Determine Engines Needed, Brad 110, Jul-17-04, 03:42 AM, (10) RE: Calculator to Determine Engines Needed, harryadkins, Jun-24-04, 10:26 AM, (7) RE: Calculator to Determine Engines Needed, oakpalms, Jul-11-04, 08:36 AM, (8) RE: Calculator to Determine Engines Needed, robertreedy, Jul-11-04, 06:56 PM, (9) RE: Calculator to Determine Engines Needed, oakpalms, Jul-20-04, 02:17 PM, (11)
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