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Reading Topic #1713
zekeMember since Aug-27-02 · 31 posts
Finally finished with 12 seconds to spare! I stopped at Summit to apply retainers (handbrakes) and again at Java West? to release them. I have reduced the MaxBrakeForce on all of my rolling stock because 50kN is just way too strong. I belive setting retainers is prototypical in this situation. I never had to go into emergency although it did take 122 saves to get through the whole 5.5 hour activity. Wow!Rob "Zeke" ZychOshawa,Ont. Trainsimming since July 26th, 2002
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> > Finally finished with 12 seconds to spare! I stopped at >Summit to apply retainers (handbrakes) and again at Java >West? to release them. I have reduced the MaxBrakeForce on >all of my rolling stock because 50kN is just way too strong. >I belive setting retainers is prototypical in this >situation. I never had to go into emergency although it did >take 122 saves to get through the whole 5.5 hour activity. >Wow! > >Rob "Zeke" Zych > >Oshawa,Ont. >Trainsimming since July 26th, 2002 Thats interesting. I never modified anything in the consist having to do with brakes. What you see is what you get. It would be interesting to see how this adjustment would make the heavy load behave. I should have asked plainsman what kind of force can be expected from a loaded car.I'm also curious about the philosophy behind the use of the hand brakes. From what my reading has revealed, the use of hand brakes for stopping or slowing a train in progress has not been common since airbrakes were adapted almost universally by 1890. Applying handbrakes on a train in progress (typical before 1882) was supposedly both time consuming and dangerous. In any event, that was a clever approach.Hope you enjoyed the activity.
Yardlimit
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csxchrisCharter Member · 25 posts
RE: Wow! Whitefish Widowmaker on Marias 3.1
Retainers are not handbrakes! Retainers are as the name implies. The purpose of the retainer valve is to hold the brakes of a car on when an application is made and released so the cars have enough time to recharge the service portion of the air reservoir before another brake application is made, thus maintaing braking effort for a delayed period of time and aiding the recharging of the air so safe levels can be maintained or otherwise face a runaway with no air. Most freight car brakes and locomotive brakes are not like tractor trailers with spring brakes. Yes, locomotive and freight car brake cylinders have springs in them, but it is to suck the piston back in, not force it out when there's a lack of air. A retainer valve usually has three positions, normal, delayed, and full on (won't release until the handle is returned. I am not sure how long the delayed period is , but I can check. But that's why back in the day they had to STOP to set the retainers, as you couldn't very well run with the feature the whole way. Similar to the Retaining valve, is the conductors valve, which normally would have been employed on cabooses. Almost like a little automatic valve, except it could only be applied gradually, to full emergency, but not graduated off. It was used primarily as an emergency type deal, but also I have read for teh backing up of trains too. Feel free to forward any air brake questions to my emailcrittner@nycap.rr.com If I can't answer it, I'll find the correct answer.Chris
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zekeMember since Aug-27-02 · 31 posts
RE: Wow! Whitefish Widowmaker on Marias 3.1
It had me on the edge of my seat getting up and then going down the big hill. Just when I thought it was safe let the train speed up, wham!, runaway and derailment. Good thing I don't work for a railroad! It did take a while to get everything installed with no errors in Route Riter or Conbuilder, but it was definitely worth it. I used the handbrake to simulate the use of a retainer on six cars closest to the engine. The rest of the cars MaxBrakeForce were set at 0.22*Mass. The .22 is probably a little too low. I'm still experimenting. I had a lot of fun cursing, swearing and finally relief at getting to Whitefish. Great activity, definitely 5 outa 5.Rob "Zeke" ZychOshawa,Ont. Trainsimming since July 26th, 2002
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yardlimitCharter Member · 149 posts
RE: Wow! Whitefish Widowmaker on Marias 3.1
So what do you guys think a realistic MaxBrakeForce would be with a 50t loaded coal car circa 1957?
Yardlimit
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zekeMember since Aug-27-02 · 31 posts
RE: Wow! Whitefish Widowmaker on Marias 3.1
Honestly, I don't know. I'm just going by what I've read here in other threads. Bob Boudoin sets his cars between 18 and 25 kN if I remember correctly. I followed a link to an AAR site that basically said that maximum braking for an empty car should be 65% of its mass and 13% for fully loaded. I tried that in the sim and couldn't get any fully loaded cars to stop! I may have misinterpreted the data on the web site. I increased the percentage for fully loaded cars to 22% but I think it should be a little higher still. It took a while to convert the Maxbrakeforce lines to ( 0.22*Mass )but now it's really easy to adjust them up or down by doing a find in files and replace with UltraEdit. I'd like to find out what the value *should* be as well. I like to try and get this sim as close as possible to the real world. Well, as close as Kuju's programming allows anyway. Rob "Zeke" ZychOshawa,Ont. Trainsimming since July 26th, 2002
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yardlimitCharter Member · 149 posts
RE: Wow! Whitefish Widowmaker on Marias 3.1
LAST EDITED ON Jun-15-03 AT 00:16 AM (EDT)
We'll, thats more than I knew. It might be interesting to experiment with "Widow" using reduced brakeforce. I'll try anything to make it a little more "interesting."