Brake Lapping

I've notived that the older diesels (and steam) don't have self lap air brakes. Some eng files have brake lap in percent or just "lap" settings. Now the question becomes which is correct for older diesels (such as the F7s)? Would you really be able to set the brakes by a percentage?GH

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Brake Lapping [View All], GaryH2, 09:23 AM, Nov-30-02, (0) RE: Brake Lapping, IcyFire, Nov-30-02, 10:15 AM, (1) RE: Brake Lapping, jm1941, Nov-30-02, 06:26 PM, (2) RE: Brake Lapping on steamers, Captain Bazza, Dec-01-02, 04:30 PM, (3) RE: Brake Lapping on steamers, derekmorton, Dec-01-02, 08:40 PM, (4) RE: Brake Lapping on steamers, GaryH2, Dec-01-02, 08:53 PM, (5) RE: Brake Lapping on steamers, xlspecial261, Dec-01-02, 08:56 PM, (6) RE: Brake Lapping, jm1941, Dec-01-02, 11:04 PM, (7) RE: Brake Lapping, xlspecial261, Dec-01-02, 11:17 PM, (8) RE: Brake Lapping, jm1941, Dec-01-02, 11:52 PM, (9) RE: Brake Lapping, SHEPLEY1935, Dec-02-02, 04:49 AM, (10) RE: Brake Lapping, dispatcher618, Dec-02-02, 03:42 PM, (11) RE: Brake Lapping, jm1941, Dec-02-02, 06:33 PM, (12) RE: Brake Lapping, Captain Bazza, Dec-03-02, 00:00 AM, (13) RE: Brake Lapping, jm1941, Dec-03-02, 01:43 AM, (14) RE: Brake Lapping, Coonskin, Dec-03-02, 02:07 AM, (15) RE: Brake Lapping, Captain Bazza, Dec-03-02, 04:20 PM, (16) RE: Brake Lapping, dispatcher618, Dec-03-02, 09:48 PM, (18) RE: Brake Lapping, jm1941, Dec-03-02, 07:48 PM, (17) RE: Brake Lapping, jm1941, Dec-04-02, 01:19 AM, (19) RE: Brake Lapping, Coonskin, Dec-04-02, 02:05 AM, (20) RE: Brake Lapping, tchouftchouf, Dec-04-02, 11:38 AM, (21)

Conferences | Topics | Previous Topic | Next Topic

the non-self lapping brakes are correct, later on when other brake valves were introduced, it featured self lapping, but most steam and early car body diesels shold have non-self lapping brakes

Sincerely,
Shawn Kenselaar
ShawnSSK@Yahoo.com

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi GH,Goto to here http://www.railpage.org.au/steam4me/trainsim/ and download the Victorian "S" class by "Christine Sweetman" in this cab of this engine you use the brakes like in real old engine, no percentage crap. From "release", one quick tap of key and your in "Lap", another tap of key and your in "Apply". WATCH the air gauge as to the amount of of air you require for reduction and tap key back to "Lap" to hold it. Another tap of key you "release", and 3 quick taps of key and your into "Emergency", quick, LIKE real. This percentage working nonesense is terrible. Your not in proper control, the Sim is. Frustrating, but great now. Hope all future older engines pick up on this.In process of figuring how to do this to my old steamers, my GP38 has it now, no more perecentage. I'm in control as it should be.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

This discussion on brake lapping is timely, because I'm interested to know how locomotives were controlled on steep downhill grades. I know that only brakes were used to control the downward momentum and prevent runaway, every engine driver's nightmare, but surely they were not continuously applied, as this would have led to horrendous brakewear. The lap process seems to supply light but steady applications of brake pressure, more suitable for speed control on long grades, rather than the on - off - on pressure used for stopping?A while back, I remember Fozzy saying, you couldn't use cylinder steam pressure as a braking force under those cirumstances, because it damaged the steam cylinder gland packing seals.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi Bazza,Without dynamics you only have one brake, and if a constant application is no good then you have to get them on and off,
BUT when you release them you have to allow time to charge up the WHOLE train before you apply the brakes again, so you have to slow down to well under the speed limit before release.
I have a 8km grade thats 1 on 40 on the line I drive and it takes 3 cycles on/off to keep the speed to anything like what it should be.Lap only hold the application you have made (with the simple brakes we have). You still have to get them on and off.Derek

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Good question. THat was one of the next ones along with the steam pressure as a rudimentary "dynamic brake." I would imagine hotboxes were a lot more common before good dynamic brakes were developed. This explains all those pictures you see of the freights bathed in brake shoe smoke.GH

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

>Good question. THat was one of the next ones along with the
>steam pressure as a rudimentary "dynamic brake."
>
>I would imagine hotboxes were a lot more common before good
>dynamic brakes were developed.
>
>This explains all those pictures you see of the freights
>bathed in brake shoe smoke.
>
>GH Hot boxes are actually overheated axle bearings. They are not caused by excessive brake heat.TR Jones
CPR

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi Captain Bazza,Here study this from an great era gone by, just may answer your question a little.Here on the old South Australia Railways we use to use Grade Control Valves which were fitted to most bogie wagons, we also had a lot of 4 wheeled wagons (not fitted with these Grade control valves) The amount of 4 wheeled vehicles on a train heading down a steep grade was governed by how many bogie wagons were fitted with these grade control valves. (fairly obvious why that was)When a train arrived at on top of say Mt Lofty (Broad Gauge) or Belalie North (narrow gauge) The Guard (Conductor) would walk along his train and set these grade control valves to the HP position on all these bogie wagons. When the train descended the steep grade and the first application was made the train brakes would apply, but as soon as the brakes were released all but 7lb psi would be retained, so all the brakes were slightly on all the time, this worked very well.
(see 1. EX---- explanation in picture 2 below)Before these the reason for brake vans (cabooses) and train were limited in tonnage and how many handbrakes could be appied before decending.Now on the Narrow Gauge from Belalie North to Jamestown (my stamping ground on Peterborough Division from 1963 to 1970) these grade valves were placed into the HP or up position for the steep descent. When the train arrived at Jamestown the train would stop and the Guard and station staff would put these grade valves into the horizontal or IP position. They would stay like this all the way to Port Pirie.
see 2. IP---- explanation in picture 2 below)Here is several pictures about our grade valves.
Sorry for so many pics, but had to keep to the under the 100kb per pic.

I scanned them out of my old copy of the:-
S.A.R General Appendix to the Rule Book and Working Time Tables and Other Instructions book.
Hope this maybe answers your question, or found it at least interesting.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

"grade control valves" are the same thing that we call "retainers" in the States. All cars in interchange service are required to have them.They are rarely used today, but there are instances where they are necessary for safe operations.TR Jones
CPR

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Thanks TR,I often wonder if these Grade Control Valves were used in the US, as this is first I ever heard of them outside Oz. Probably did see it, but I would not have twigged the name "retainer" for a GCV.An early South Australian Railways Commissioner (I think) came from the US and when one looks around the old South Austrlaian Railways your see a lots of things that are very similar to the U.S. I would dare to say the S.A.R took a lot after the U.S. in many ways, we just have or had different name for them.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Good Morning All,This is one of the most informational threads that I've read in a long time...Thank you all for your input!

Don Shepley-Chicago

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Getting back to the original discussion of self-lapping and brake percentage-On the engines I've driven (in MSTS) I don't mind so much when a non-self-lapping locomotive still shows an application percentage. (Case in point, TA's ESE or the USRA Mountain.) It's not so much that I'm applying the brakes a certain percent, but it's more of a measure of how fast I'm making a brake pipe reduction (just like every brake stand I've used in real life on vintage equipment) The only argument I have is that it's hard to make a quicker application with keyboard controls, except for pressing "delete" to dump the air and go into emergency application. Those of you who design locomotives without self-lapping brake stands might consider carefully how you set up the .ENG file. It's frustrating to have to wait for the computer to move the brake handle to 50% APPLY (as I begin careening down the grade) and then when I get to my target reduction, have to wait for the handle to move back to LAP (by which time the brake pipe is down to 40 psi and my train is stopping). Okay, I exaggerate just a bit, but you get the idea.

Either way (self-lapping or not) I always watch the brake pipe pressure either on the brake gauge or the status display, and completely ignore the percentage value shown by the computer. - dispatcher618

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi Despatcher,Well maybe things will be correct very shortly, no more stupid brake percentage instead like real non-self-lapping brake handles, I know exactly what you mean and have put up with the frustration since MSTS hit the shelves. At one stage nearly deleting MSTS altogether.
This is probably more annoying for anyone with some engine experieces than those who have not experienced this. It was taken as must be normal, far from it. But when I saw Christine Sweetman's Aussie Victorian "S" class cab namely the train brake handle this gave me the answer. (thanks here for whoever figured that out) I'm an old era steam person myself and I like very much the K36, (reminds me of our "T" class) but the braking was terrible, (did not help with that percentage slider thing'o) as it seemed either all on or off, and very little or no control like as in real. Look sorry to say that, but a spade is a spade. I might add here the K36 is one very beautifully done and great sounding engine, gets top marks in my book, but the train brakes sorely needed attention. (well to me anyway) Trying to get down the MP3 smoothly and properly was near hopeless as with most steamers, but also the lag to apply and releasing brakes while holding the train brake key down, then trying to quick reverse the key back. Oh what a BIG PAIN. Not talking here about actual train braking etc, just the stupid time it takes for that brake handle to move and the way MSTS goes about applying it. Totally unrealSo I have been fiddling for awhile (eng files not my cup of tea) was just not quite getting this K36 brake handle thing'o correct, so I asked a dear friend of mine in Japan who is quite clever at this and he sent me back a revised K36 eng file with proper train braking like in the Aussie "S" class. In real life I have had drives of Garratts and "T" class steamers many times. And at LONG last the K36 now is like real. I'm rapt. Now to have a go at the engine brake as well.The train brake handle now is instant like real, one tap of key is like moving the handle by your actual hand, instant and immeadiately you see the air gauge react, watch amount of air reduction, another quick tap back to "Lap" and perfect. So far I can even make roughly small 3 to 5lb reductions if I'm quick enough to tap the key back to lap. NO PERCENTAGES, just one tap "Release", one tap "Lap" one tap "Apply" and another tap "Emergency", OR if in "release mode" and need for an "emergency" hold key down and you into emergency instantly like you had your hand on the brake handle yourself, all at a tap of the key.To me this has made MSTS really come to life. And for shunting is perfect. I can head down the track, one tap, wait a fraction of a second till 10lb reduction, then another quick tap to "lap". While engine is coming to a standstill wind the reverser back, one quick tap to "release", open throttle into reverse just like my shunting days. If I'm really on the ball I can even slip the wheels (a no no normally) but fun as now the loco forman cannot see me doing it, so no dockets to answer.This morning I did a test run with this revised eng file from Ballooon (loop) North on the MP3 down to Essex. Twin K36's (I like double headers reminds of my old trainworking days) with a full load of cattle and containers and set 25mph as max speed and YES a steady 20 to 25 mph, working the brake handle like I remember it, all the way down in absolute total control. It was like I remember coming down the Belalie Bank in a "T" class, in the 1960's, but we had Grade Control Valves on ore wagons, but the trip this morning down MP3 was absolutely a steam drivers dream.Now I have to un-learn keeping finger off the key instead of tapping it once at a time for the correct positions. I found I would tend to forget leave finger on key and go into emergency. Drat. Now to unlearn.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi, and thanks for the information folks.Hi John, would it be possible to post the relevant brake info from the ENG?
Thanks.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi Captain Bazza,Will post it in this thread, WHEN I get the engine brake figured out properly as well. I'm well pleased with the train brake as is. I'm not an .eng file whizz kid, just an oldy doing like most I suppose, a crash course in .eng & cvf files purely out of utter desperation and frustration. The .eng and .cvf file have to be altered together.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

It's exciting to think that we may be getting ready to improve the brakes tremendously on our older model MSTS locomotives.At this point, I only have one .eng file with train brakes that feel "good". It's TA's RS11. I've hacked the brakes into my other Alco powered stuff, but have yet to attempt hacking it into an EMD powered product, mainly because of air sound issues. Though the TA RS11 brake codes still have an application percentile once applying... it's a far cry better from the other default-based brake codes I've been using. It's a tap, tap, tap situation instead of the "mash and hold the ' key forever then mash and hold the ; key for the same eternity" system.Like you, I've also noted the engine brakes are waaay too wimpy when running light. The engines I've been around will shut down quickly when running light (under average conditions). In MSTS, I was amazed at how I could be running light at about 15-20 MPH, and have to sroll up to around 100% engine brake to EVENTUALLY get the thing whoa'd up!! Of course, if that was done with the prototype locomotives I've run, you'd could be sliding the wheels.I too, am looking forward to seeing/using the brake codes you are talking about John.Andre Ming

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

About three or four months ago I had an authorised cab ride in a diesel, doubled headed - no wagons. (WOW) Unfortunately, the ride was only about fortyfive minutes duration and it was too noisey to talk the driver (engineer). The locos were backed into an industrial to pick up a single tanker wagon. As the locos were reversing into the siding the driver suddenly applied the brakes; from about a speed 3 or 4 mph the 2 locos stopped dead* in their tracks (pun??). The locos then proceeded, the driver guided by his shunting assistant, who readout the decreasing distance over the radio. The stop was smooth and spot on for coupling. At the start of the trip, it was exciting to be in the cab during the engine startup sequence. The whole loco really shivered and shook as the starter turn over the main engine. An amazing experience. (Thanks to Matt and his Dad.)(*3 mph to 0 mph, instantly.)

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Oh... yeah... that was my other peeve about brakes. A side note on the engine brake... I downloaded the add-on SD40-2... is it not supposed to have a bail off feature? I noticed in the freight pull to whitefish those cement cars kept running into the back of me when I set the brakes. I realized the bail off switch wasn't working. Was it wrong for me to modify the .ENG file so it would work? (I've never driven a real SD40-2 before, so that's why I'm asking.) I just like keeping my train stretched, that's all. I also have to agree with Coonskin about TA's RS11 "brake stand". I'm tempted to copy the brake lever definitions for that EMD NW2 I reskinned. - dispatcher618

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

Hi Captain Bazza, and Andre,Bazza, my point about braking and stopping, MSTS has a bit to go in that area. Now you may see how it frustrates one who has been in the hot seat before. Did you take note how quick the air brake reacted, certainly in MSTS leaves a bit to be desired from a real environment.Well I fiddled some more with the Engine brake till late last night, but I think is a bit beyond me as I think there is something in MSTS itself, or just maybe my lack of proper knowledge of what settings do what.I did get the engine brake to move quick and more realistically, for what good it is, as I noted something Andre mentioned about when one applies engine brake on a light engine and the engine seems to go on forever, you need to use the train brake. Cannot seen to change that Hmmmmm.. needs someone with more know how to perhaps cure this, or is one of those querks of MSTS, but the train brake is more important at present.Anyway here are my K36-483 .eng and .cvf files in a zip, best I can do so far with time I got.
http://www.train-sim.com/dcforum/User_files/3ded44336079436d.zip
Oh nearly forgot, first backup the K36 originals first, before using these.Maybe you guys can improve on them, or figure it out properly but for me this K36 steam engine is now TOPS in the TRAIN brake area, well far, far, far better than before in my view. Would like to hear your input and feelings on this once you have tried it out. Remember tap the key do not press brake key like usual, you will have to relearn to do it properly. I still get caught not thinking. Darn learnt wrong habits die hard.If you want to do the other K36-487 is not hard to fiddle so same as K36-483. I will later experiment with a couple of my other near favourites steamers when time permits. But at moment I use the K36's double headed, with 483 leading.
Ah yes, well here's to those good ol days of steam. If anyone can get this braking better, please let me, or us know in this thread.
Hope I did not upset anyone doing this (namely using certain .eng files) and hope I added something to MSTS, though very trivial, but to me now this is great move forward at last.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

APOLOGIES..........I was just using the K36 and I noted I have accidently uploaded in my last post the not quite the latest .eng file I did last night. They may be the same as previous, but this one was my last dated effort and the one I'm using. Sorry about this. http://www.train-sim.com/dcforum/User_files/3ded9d0f4f12861a.zipOld timer's disease.

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

I think we're stuck with the engine brake weirdness. It may be asking too much of the sim to compute the complicated physics of running light and using engine air only, compared to running with a heavy train. In otherwords, my experiments indicated I could get tweak to get stronger engine brakes when running light... but then they were too strong when switching and handling cuts of cars.There may be limitations. Oh well...Andre

Alert | IP

Printer-friendly page | Edit | Reply | Reply With Quote | Top

I speak of this problem:
http://www.train-sim.com/dcforum/DCForumID5/5337.html
JLC

Alert | IP

[ Home | MSTS Forum | MSTS FAQ | File Library ] Copyright © 2002 by Nels Anderson. All Rights Reserved.