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EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Thu Oct 02, 2014 6:09 am
by rlbomber
I've been trying to complete a scenario on the Horseshoe Curve addon and cannot keep the train from over speeding. It seems that the braking system is either on or off and I cannot get it set so that the train will descend at a constant speed. What is the trick to operating the braking system on this locomotive?

Someone said on another forum that there is a fix to the EMD F7 Pennsy so that the brakes are not as sensitive. If there is one, I can't find it.

thanks,

Rlbomber

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Thu Oct 02, 2014 9:51 am
by Chacal
I don't have this problem of brakes being either on or off. Maybe you should verify your local files to make sure your installation is OK.

The throttle, air brakes and dynamic brakes on most north american trains are notched, so you can't adjust them to the precise degree you need them for getting a constant speed. This means you have to continually change the throttle and braking effort as needed.

When descending long grades such as on the HSC, use your dynamic brakes to the notch where your train is just slightly accelerating, adding more brakes from time to time when the speed is aboutto go over the limit. Let it slow a few mph then release a notch.

WIth heavier trains or steeper grades, it is quite possible that dynamics won't be enough, in which case you add a little bit of air braking.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Thu Oct 02, 2014 5:49 pm
by Ericmopar
The dynamics on the HSC engines are way to powerful and cause issues.
What I'm thinking is that rlbomber may not know about non self lapping and brakes on older engines that need to have the pressure applied to the desired level and then the brake lever moved back to Holding or maybe Lapping. It takes some practice on the older engines and the terms are different on the various engines.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Fri Oct 03, 2014 5:43 am
by rlbomber
Chacal, that's what I've been trying to figure out. The manual does not help with this in anyway.

I've seen "self lapping", "hold" and "applied" As the train starts to pick up speed I increase the brake to about 49% applied. The train is still picking up speed so I increase the brake a little more to about 60%. Next thing you now the train is slowing way down and I have to reduce the brake to self lapping again, which in turn cause the train to increase again. I've been trying to find that sweet spot where the brakes are applied and held and the train maintains a constant speed descending the long grade.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Fri Oct 03, 2014 9:54 am
by Chacal
Watch the cylinder pressure gauge (or it's digital equivalent in the F5 hub).
That's the amount of actual braking you're applying.
You'll see the time it takes to apply the changes you command with the brake valve.

I don't remember what brakes are used in the HSC F7, I think it's self-lapped. Most DTG brakes are.
It's easy to determine by checking the cylinder pressure.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Fri Oct 03, 2014 3:49 pm
by Ericmopar
The HSC curve brakes have to have "Holding" applied when the desired pressure is reached. The farther passed "Holding" that the lever is moved to, the faster the pressure is dropped in the line and the faster the brakes will apply.
I had forgot until I ran "100" last night, that the couplers are fouled up too in that DLC. What that means is "Slinky Train Effect" do to the settings being wrong.
When that is combined with the fact that the speed is measured from the rear of the train in the HUD, there is a delayed reaction.
The brakes are to powerful at minimum reduction as well on those engines.
I can post a patch for that, but it will stop a person from being able to compete in the career scenarios as do all patches and fixes.
I've already got it ready, I just need to include the coupler fix.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Fri Oct 03, 2014 4:08 pm
by Ericmopar
I posted a fix for those brakes and couplers. So it should show up in the file library this weekend.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Tue Mar 10, 2015 2:29 pm
by Captainbob
I tried running this scenario a couple of times and found the stock brakes on the F7 to be terrible. Even the dynamic brake was grabby and caused wheel slip under the slightest applications. I installed the brake and coupler mod which was discussed, and the braking is much , much better. Thanks for the mod.

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Tue Mar 10, 2015 2:58 pm
by Chacal
What scenario?

Re: EMD F7 Pennsy and Horseshoe Curve Scenario

Unread postPosted: Tue Mar 10, 2015 3:15 pm
by Captainbob
Chacal wrote:What scenario?


Career Scenario " People Power",