Gravity and MSTS2

Hi!One of the more annoying unrealities of MSTS1 is
the lack of gravity effects on individual cars.
For example, a real freight car should roll if
the brakes are released on a hill. Similarly,
each car on a train adds or subtracts individually
to the forces acting on a locomotive, not ganged
like in MSTS1. (For example, run a 100 car coal
train down a mountain and then stop the engine at
the bottom on flat ground section. If you let go
of the brakes, the train doesn't move. Each car's
forces are taken at the same incline as the engine,
which isn't right.) Until this is fixed, it's not
a sim but a video game.Tony Burzio
San Diego, CA

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RE: Gravity and MSTS2, lenglel, May-29-03, 04:52 PM, (1) RE: Gravity and MSTS2, heffed, May-29-03, 10:42 PM, (2) RE: Gravity and MSTS2, driver89, May-30-03, 05:49 AM, (3) RE: Gravity and MSTS2, heffed, May-30-03, 09:34 PM, (4) RE: Gravity and MSTS2, andrewpickell, May-30-03, 10:07 PM, (5) RE: Gravity and MSTS2, JonN, May-31-03, 00:36 AM, (6) RE: Gravity and MSTS2, plainsman, May-31-03, 06:34 AM, (7) RE: Gravity and MSTS2, Brando, Jun-05-03, 11:10 AM, (12) RE: Gravity and MSTS2, dispatcher618, Jun-01-03, 12:17 PM, (8) RE: Gravity and MSTS2, plainsman, Jun-07-03, 04:07 PM, (13) RE: Gravity and MSTS2, tburzio, Jun-03-03, 07:02 PM, (9) RE: Gravity and MSTS2, dispatcher618, Jun-03-03, 11:52 PM, (10) RE: Gravity and MSTS2, heffed, Jun-04-03, 03:36 AM, (11) RE: Gravity and MSTS2, Swissie, Jun-08-03, 11:16 AM, (14) RE: Gravity and MSTS2, heffed, Jun-09-03, 00:58 AM, (15) RE: Gravity and MSTS2, tonka, Jun-09-03, 04:05 AM, (16) RE: Gravity and MSTS2, Swissie, Jun-09-03, 04:30 AM, (17) RE: Gravity and MSTS2, tonka, Jun-09-03, 04:34 AM, (18) RE: Gravity and MSTS2, Swissie, Jun-09-03, 04:57 AM, (20) RE: Gravity and MSTS2, tonka, Jun-11-03, 00:46 AM, (21) RE: Gravity and MSTS2, Swissie, Jun-11-03, 06:08 AM, (22) RE: Gravity and MSTS2, tonka, Jun-11-03, 10:22 PM, (23) RE: Gravity and MSTS2, dispatcher618, Jun-11-03, 11:56 PM, (24) RE: Gravity and MSTS2, xlspecial261, Jun-12-03, 01:51 AM, (25) RE: Gravity and MSTS2, tonka, Jun-12-03, 02:55 AM, (26) RE: Gravity and MSTS2, Swissie, Jun-09-03, 04:44 AM, (19)

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I wholeheartedly agree with you. This is exactly
why trainmaster has trainsim beat on physics. *STAMP*
Oh, looky, it's my siggy!

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>(For example, run a 100 car coal
>train down a mountain and then stop the engine at
>the bottom on flat ground section. If you let go
>of the brakes, the train doesn't move. Each car's
>forces are taken at the same incline as the engine,
>which isn't right.) Until this is fixed, it's not
>a sim but a video game. Hmm.... I get pushed by the cars on the hill. Maybe you aren't waiting for the brakes to fully release?Similarly, if my loco is on flat ground and the rest of the train is hanging down a hill, I get pulled backwards.-Jeff

Union Pacific is my drug.

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I think the problem here is that people are expecting the cars to keep rolling when the un-couple them from the consist. Unfortunately when you un-couple something from a consist in MSTS the sim automatically applies the brakes so the car doesn't keep rolling.James.

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>Unfortunately when you un-couple something from a
>consist in MSTS the sim automatically applies the brakes so
>the car doesn't keep rolling. This is true, but this is not what the example described.-Jeff

Union Pacific is my drug.

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Unfortunately when you un-couple something from a
>consist in MSTS the sim automatically applies the brakes so
>the car doesn't keep rolling.
>
>James. No word of a lie I watched a knuckle snap off of a AC4400 last week right in front of my eyes. When the air hoses came apart the train dynamited and the cars came to a stop quite quickly. Luckily the train was slowly down for a meet.In this regard I think MSTS is doing a good job. Unless it had a feature to close the angle cocks to prevent the car from dynamiting when the air hoses were disconnected.- Andrew

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Destpite the areas in which MSTS did a fairly good job, one part of brake physics where MSTS really flubbed is in brake propagation (brakes engage/release on cars at front of train before end). In MSTS, all the cars release/engage their brakes simulatniously. Jonathan Nikiforovs.
Milepost 180, CP Belleville Sub.

Repainter for Yonder Locomotive Works.

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Hi Jonathan,
Although very tedious and time consumming, it is possible to fudge this effect into the sim, by setting up your .wag files with different brake properties, such that the cars toward the front release before the cars toward the rear. You will need 4 or 5 sets of settings for the cars, and they have to stay ordered by their brake properties, not the ideal solution, but it works.
Bob

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>Hi Jonathan,
>Although very tedious and time consumming, it is possible to
>fudge this effect into the sim, by setting up your .wag
>files with different brake properties, such that the cars
>toward the front release before the cars toward the rear.
>You will need 4 or 5 sets of settings for the cars, and they
>have to stay ordered by their brake properties, not the
>ideal solution, but it works.
>Bob
Cool workaround, but tedious is right. Neat idea, though.

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I am impressed with v1 of MSTS, but now it is time to raise the bar, and MSTS is going to need a lot of fixing in order to capture my attention again. Maybe a lot of it is the way the physics are set up. Maybe it's just a matter of doing the right research to get the right constants. In MSTS when I move two cars around in the yard at 6-10 MPH, I can stop almost instantly by making a 5 psi reduction on the train brake- depending on what locomotive and what cars are used. In real life, yesterday, I moved two passenger cars to a siding, and at 6 MPH a 5 psi reduction (bailed off the independent) took me at least 8 car lengths to bring me to a stop. I'm also still waiting for them to program in the air leaks. There's nothing like dealing with an annoying little air leak as you go down hill. There just isn't any subsitute for working on the real thing.

- DISPATCHER 618

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Just curious,
Have you tried the Version 4.5 physics update files? The default trains stop on a dime largely because KUJU thought that was needed to make the "game" playable. The version 4.5 files will enable you to get a much more realistic feel to your equipment (self serving ad for my own work..hehe).
Bob Boudoin

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Hi!> Similarly, if my loco is on flat ground and the rest
> of the train is hanging down a hill, I get pulled backwards. Since all the cars are calculated by the inclination
of the *engine*, then if your engine is on even
a slight down hill you will indeed go backward. The
difference is the *rate*, not the direction. A 100
car loaded coal train up a steep cliff should pop
you down the tracks at an alarming rate. I can see
why they did it of course, to save on processor power,
but I think it is an important part of a sim.Take for example the "hogback" profile where you
have ups and downs in a sine wave. These areas
are notoriously hard to run in real life, since
you have slack and stretched out couplers in regular
patterns throughout the train leading to broken
knuckles. MSTS can't model this since everything
is calculated from the engine's inclination.Tony Burzio
San Diego, CA

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I've always wondered about that because it seems in those areas that I am most likely to exceed "freight durability limits". I always wondered if it had something to do with the slack action. There is slack action, but if what you say is true then it is miscalculated- especially if the brakes aren't following the proper physics.

- DISPATCHER 618

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LAST EDITED ON Jun-04-03 AT 03:38 AM (EDT)

>Since all the cars are calculated by the inclination
>of the *engine*, then if your engine is on even
>a slight down hill you will indeed go backward. The
>difference is the *rate*, not the direction. A 100
>car loaded coal train up a steep cliff should pop
>you down the tracks at an alarming rate. I can see
>why they did it of course, to save on processor power,
>but I think it is an important part of a sim. Hmmm... Interesting "theory" you have here. So what you are telling me is that when my train crests a hill and the loco starts going downhill, the rest of my train still coming "up" the hill is in effect going "down" as well? Sorry, but no.Try this. Park your train on the crest of a hill with the loco on the downside, while the bulk of the train is hanging over the up side. Granted, you will not get pulled backward "at an alarming rate", but your loco will very definitely be pulled back over the top of the hill. This would be impossible by your reckoning.Now lets drive a long train from a flat area transitioning to a nice upward grade. You don't start loosing much speed until a good portion of your train is also on the hill right? If all the cars were making their gravity calculations based on the inclination of the loco, you would hit a wall instantly. As soon as your loco transistions, the entire weight of your train would instantly come down on you. But this isn't what happens is it? No. What actually happens is that you gradually loose speed as more weight makes it up the incline. The inverse is also true. You gain more speed as more of your train comes over the hill.The only way this effect could be attained if all the cars were going off the engine, would be an algorithm that basically "ramps up" the train weight as soon as the loco starts uphill. This calculation would have to be based on the number of cars and their respective weights. The longer the train, the longer it takes to reach full weight on the hill. However, this calculation would be blasted out of the water as soon as the loco reached the bottom, as the loco is now either on the flat, or going up again which would prematurly end the weight versus time curve. So now we see that the sim would also need to take into account the length of the hill and stuff that into the algorithm as well in order to get an approximation of how quick your train should loose speed. This is a much more complicated method than giving each individual car their own set of gravity calculations.Also look at your sine wave analogy. Obviously slack action across this would be difficult to calculate if everything is based on the loco. As the loco enters the downward swing of the wave, all the cars on the upward swing would also be seen as going down. Not a good perspective for slack action. So, by this token, slack action would have to be non-existant on hills. The sim is by no means sophisticated enough to decide which type of hills slack action should be "enabled" on. If slack action couldn't be calculated on a sine wave like hill pattern, it would also have to be canned on longer slopes because the sim doesn't know the difference between many smaller hills in a row as opposed to one large hill. This is easy to verify by watching how the automatic fireman behaves. If there is a medium to long length dip in the track, it will decide it needs to kick on the injectors because the boiler water level dropped. It's not smart enough to realize that it will traverse the dip in 20 seconds and that it really doesn't need to make any adjustments with the water.So, by the simple fact that slack action does exist on hills, and gravity does behave (mostly) like you would expect coming up or down hills, your theory can not be accurate.
-Jeff

Union Pacific is my drug.

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LAST EDITED ON Jun-08-03 AT 11:19 AM (EDT)

Hi Tony,> Each car's forces are taken at the same incline as the engine,
which isn't right.are you absolutely sure & with positive evidence at hand that this is true? I observe quite a different behaviour on my copy of MSTS.To test your statement, I drove a 30-car mixed freight train westbound onto the grade at Coyote Wells on the SDA 2. The first 15 or so cars of my train were light boxcars, then came some heavier 58ft tankers, a few (light) empty loggers and at the end of the train 4 loaded coal hoppers (about the heaviest cars to hook to the train).The route is good for testing physics because it has many grade changes and some very steep, yet short intermediate grades (i.e. next to the overpass over the interstate). I had no problems or noticeable effects with only the first half of the train on a grade, but as soon as the heavy tankers met the grade, my engines could no longer accelerate the train any more (despite the grade being constant!), and when the coal hoppers met the grade, my speed started to drop off. I barely made it to the first level stretch past the Interstate, and as soon as the tankers and hoppers got on that level piece of track, I picked up speed again - engines already on the next, mild grade - until tankers and hoppers met the grade again.So IMHO the position of the cars are taken into account. The other thing is that default car physics are rather crappy - if you put a coupled train into idle on level track, depending on which cars you put on your train, it slows down rather quickly, more or less like an automobile. A long freight train put into idle on level track should go for miles and miles due to the minimal rolling resistance of steel wheels on steel rails, inertia and the mass involved.I remember being on board an Intercity passenger train some years ago. It was made up of an electric engine and 14 coaches plus minus 1. While speeding at 140 kph (85mph or so) on level track, the engine developed a problem that lead to a force-shutdown of its electric gear, which the frequent traveller noticed by the sudden death of the air condition system and the lowering of the panto at full speed. Thing is: The engineer idled the train on for another 15-20 minutes over some 10-11 miles of track, loosing speed only very slowly. We came to a stop only 100 yards short of the crest of an intermediate uphill grade. Had we had just 10 mph more (or had the problem developed 500 yards later), we'd have made it past that grade and into the next scheduled stop, which apparently was what he tried to achieve...Lukas a.k.a Swissie

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>are you absolutely sure & with positive evidence at hand
>that this is true? I observe quite a different behaviour on
>my copy of MSTS. My experiences are the same as yours Swissie. I posted as much above.MSTS simply does not behave the way it would if all gravity/weight calculations were based on the inclination of the locomotive.As you may notice, he hasn't responded.-Jeff

Union Pacific is my drug.

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LAST EDITED ON Jun-09-03 AT 04:14 AM (EDT)

Okay..this is what I'VE found with MSTS...While driving the following consist:6 x SD40-2
50 x coal hoppers
6 x mid-section SD40-2
50 x coal hoppers, rear.Route: Tokyo - Hakone.Anway, I started at Shinjuku, with this consist and what I discovered with this (I hope I'm making sense here), is that, YES, she does start to slow down (usually in run 8) while coming up the grade and I don't bother to power brake, but what's even worse is when I'm half way through clearing crest where you get the equilibrium of forces in the consist, one trying to pull you FWD, the other REV. What I do after that, is when I'm 3/4 past the crest I ease the throttle, put dyn brakes in 'Setup', Automatic brakes in 5% application, before slowly applying the independent brakes. I do this so there's no violent smash when the slack increases in the couplings. After I've fully apllied the I. brakes, I release the Auto brakes and notch up the dynamic brakes. While cruising down the grade, (depending on my speed control) I might pump the auto brakes...deceleration rate is usually 1 mile/minute...that's 5 seconds after full braking conrtol has kicked in. What also have found on this route while in control of this conist, is that while I'm cruising downhill, the speed limit changes from 68mph to 53mph...and trust me, that is a real task...well, at least for me. I discovered the above braking method the hard way...by myself after deraling a few times...not by overspeed, but by the slamming of the couplings while passing the crest. I'm not sure if this method is used in real life. Just my 2 cents worth...hope this means something to some ppl.BTW, this consist takes about 2 miles to slow down to a grinding halt on flat ground while cruising @ around 66mph...minus the mid-section locos, around 1.5...dunno why????Attn Swissie:Always have the heavier wagons up front right behind the loco/s and the lighter ones at the rear...this'll help you cruise up hills. Particularly if you have a couple of 6 axled locos up front and 4 axled locos lashed-up right behind them...I always do that!!
Six axle locos equal high traction, while 4 equals speed...keeping in mind this is steel on steel and not rubber on tarmac. I think the axial loading is smaller on the 6s because of the smaller wheels, but it's more concentrated, because of the smaller contact area.Tonka.

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Hi Tonka,> Always have the heavier wagons up front right behind the loco/s and the lighter ones at the rear...Yep, I think I'd get quite a few nasty remarks from the engineers if I were a real life yard man putting consists together with the lightest cars in the middle of the consist! That's definitely not what the way our RR's rule books call for. Apart from the engine's performance, having light cars in the center of a long consist and a bunch of heavy ones in the rear does also put some unnecessary & unwanted forces on these cars in the center. In real life they'd be running a certain risk of derailing in case I'd have to apply brakes a little fast, especially on curved track...The above consist was done with the heavier cars at the rear on purpose, to test best when their gravity effects would actually "kick in".Lukas a.k.a Swissie

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Ahhh, gotcha!!..lol

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Hi again...> I discovered the above braking method the hard way...by myself after deraling a few times...not by overspeed, but by the slamming of the couplings while passing the crest. I'm not sure if this method is used in real life. Just my 2 cents worth...hope this means something to some ppl.Controlling such a heavy consist as the one you described is certainly requiring all the engineering skills of real engineers. I assume your method is very close to the prototype operation, where a combination of available braking methods is required. The RR's in my country run freight trains of max. 1500 metric tons "only", IIRC, and have just recently begun trials for 3000 metric tons trains (which - according to the press reports - translated into some 80 loaded hopper cars). So I cannot (yet) share first hand experiences from watching trains such as yours. On the other hand, these 1500 ton trains already require quite some skills on trans-alpine routes with their long 2.6% grades. I'd expect that a prototypical RR where trains such as the coal train of yours operate would signpost the lower speed limit at the beginning of the downhill grade already.One thing that many users repeatedly state is to remember the critical locations of a route and to think ahead when it comes to braking. Lukas a.k.a Swissie

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.
these 1500 ton trains already require quite some
>skills on trans-alpine routes with their long 2.6% grades. It's the sine-wave grades that add the extra challenge to keeping the train under control. Anway, isn't terrain like that the norm in Europe? I remembere seeing a photograph of 'The Flying Hamburger' which was a high-speed passenger DMU and the scenery looked perfect setting for a European dream time story..the mountains and hills, covered with snow like icing on a chocolate cake...now I can relate to some trainsets and diplays in the Maerklin catalogues!!
Anway, back to MY consist, I was inspired by the trains in the Pilbara, up north in Western Australia. The have mammoth consists, mainly due to the low down grades the trains do to their drop off. Some of the grades are kinda steep and sometimes they're okay for some1 in a wheel-chair to climb up, but none of the gradients can be compared with those on Marias Pass in MSTS. The consists are made up of this, I think:Up Front. 1 or two GE AC6000CW with a Dash8s or 9s lashed up behind.50 or 60x iron ore hoppers.1 AC600CW -OR- a couple Dash 8s, mid-section.50 or 60x iron ore hoppers, rear.These are only guesstimates, they change the order every now and then. They also split the consistin half after unloading.Like I said, they can afford consists like this is because the terrain is not mountainous like it is in Europe (picture this baby rolling up and down in Switzerland..lol). The tracks have about 1500 sleepers (or ties if you prefer) per kilometre and the infrastructure are built according to US loading gauge, not Australian...but I'm open to criticism. You could not place any one loco (from the mine) onto mainline tracks,simply because they're too heavy.
>I'd expect that a prototypical RR where trains such as the
>coal train of yours operate would signpost the lower speed
>limit at the beginning of the downhill grade already. The MAX speed limit on the track monitor changed. It was first 68mph, then 53, flickered to 68, then flickered back again to 53. Like as if the computer was doing something by itself. On the game I mean, but in real life, I'm not sure, but I wouldn't be at all surprised.
>One thing that many users repeatedly state is to remember
>the critical locations of a route and to think ahead when it
>comes to braking. I know what you mean. I find the worst (and most challenging) IS the Tokyo - Hakone. There are so many kinks in the track geometry, that the safe maximum speed is sometimes aroud 62-63 mph, even though the track monitor says 68. Sometimes I have become a lil over confident on some curves and flying past them at 75mph to see what happens..only to derail by fishtailing.I hope you find this interesting...*crosses fingers*Tonka.

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LAST EDITED ON Jun-11-03 AT 06:20 AM (EDT)

Hi Tonka,> I hope you find this interesting...*crosses fingers*Sure do! Interesting thing on this forum is that it literally has people from all over the world on it. All of them coming from very "different RR cultures" if I may say so, ranging from the heavy coal (or ore) haulers to New York City subway & traction fans, from TGV and ICE high speed buffs to NG steam affecionados.Yet everybody gets about as exited as the rest when it comes to the smell of warm tar on wooden ties (slippers, whatever), the clicking of wheels on a train going by, the feeling of this barely tamed power waiting to be unleashed in an idling loco...> It's the sine-wave grades that add the extra challenge to keeping the train under control. Anway, isn't terrain like that the norm in Europe? Depends on where you go. Lots of main line track are flat as flat can be (Northern Germany, Holland, some areas in the South.) The real grades are in the mountain ranges like the alps, and other ranges (Pyrrhenes, northern Norwegian coastline (the famous Narvik ore route!). Still, grades on mainlines are often very constant over longer stretches of track, no that much of a roller coaster as Tokyo Hakone or some free add-on routes. That made building the RR back in the 19th century quite expensive, but allows for some quite smooth running today. I just know some of the Swiss mainlines over the alps, simply by riding trains on them fairly regularily (once to twice a year, at the least). Signposted speed for the freight trains going over these passes tend to be ca. 50 mph (80 kph), but not all the trains are allowed to use that speed to the maximum (issue of weight and available power - see braking restrictions below). Furthermore, they can only go constantly downhill if there is enough dynamic braking available from the engines. This is now the case as remotely controlled helpers at the end have been introduced with the more recent engine types (Re 460s).Engineers on older freight engines were taught a different braking method on long downhill runs, as they had to rely on the train brakes to maintain controll of heavy trains. But these cannot remain applied constantly, or you'll really run into problems stemming from excess heat on brake shoes and wheels, such as hotboxes, sticking brakes, flying sparks causing wildfires etc. Therefore, the so-called "saw-blade" technique was used on heavy trains: When going downhill at sth near 80 kph, and dynamics engaged, the crew used the train brakes to slow down to sth. like 50 kph or even less, then released the train brakes & let them cool of a few minutes until the train approached the 80 kph limit again, to start all over with that cycle.I remember from reading in a novel that told the tale of an 1920's boy in rural Ticino state in Southern Switzerland. He had to fight hard to get a way from his traditional minded father when he wanted to become a RR engineer. The book tells a lot about his work in the 1920s, and such techniques were already used in the days when steam explorations over St.Gotthard pass ended and gave way to all (early) electric traction. Back then, IIRC, the speed limit was lower (55 to 65 kph for freight, 70 kph for passenger trains over the pass), and the weight of the trains over the pass were limited to 800 metric tons (if the novel is accurate on this, which I do not doubt). These trains required two or three heavy rod-driven electric engines of the "Crocodile" type (see below), which of course were not equipped with MU or remote control, but needed its own two man crew each. Communication via whistle signals ment anything but 100% accurate synchronisation, so both uphill runs - you don't want wheel slippage with 800 tons on the hook and barely enough power to crawl up the hill at 50 kph - and downhill braking really needed a lot of care and standing on guard! -> Here's one of the "Crocodiles" - 2 or 3 of them are preserved today in working condition.Hope you find that interesting, also Lukas a.k.a Swissie

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- and downhill
>braking really needed a lot of care and standing on guard! lol..I know what you mean!!I remember reading about a cetain class of electric locomotive in Sydney, Australia; made by Metropliton-Vickers about 40 yrs ago. Anyay, what the engineer/train-driver (depending on your preference..lol)would do was to put the throttle on a particular notch and the regenerative brake in a certain noth as well. I can't remember in great detail, but it was the 1st kind of cruise-control. When going up hill, it would slow down, therefore making the regen. brakes redundant and letting the throttle take charge. Once the loco had passed the hill, the loco would be going 'too fast' and the regen brakes would automatically take control. All the driver has to do is press the yellow button.This is a good website to visit if you want to know more about the iron ore trains I was talking about before.http://members.iinet.net.au/~rjtonkin/pilbaratrains.html
Enjoy!!!Tonka.

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>Engineers on older freight engines were taught a different
>braking method on long downhill runs, as they had to rely on
>the train brakes to maintain controll of heavy trains. But
>these cannot remain applied constantly, or you'll really run
>into problems stemming from excess heat on brake shoes and
>wheels, such as hotboxes, sticking brakes, flying sparks
>causing wildfires etc. Therefore, the so-called "saw-blade"
>technique was used on heavy trains: When going downhill at
>sth near 80 kph, and dynamics engaged, the crew used the
>train brakes to slow down to sth. like 50 kph or even less,
>then released the train brakes & let them cool of a few
>minutes until the train approached the 80 kph limit again,
>to start all over with that cycle. Not only do you run into problems with hot (brake) shoes, but you also have to factor in the time it takes for the air to charge on the train back to the operating brake pipe pressure. The brake pipe can charge pretty fast, but depleats the main reservoirs, which can only be recharged by the air compressors. That's another thing that the default MSTS physics (.ENG and .WAG files) don't accurately simulate- as a result, the brake pipe fills very quickly and the main reservoirs are always full or fill very quickly. The other thing that isn't quite right is that the auxilary reservoirs on each car need to recharge as well to be able to get a good set on the brakes the next time they're applied. I believe this is where retaining valves come into play for long trains, and I seem to remember the topic was discussed in another thread a few months ago.

- DISPATCHER 618

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Tonka,Don't use your independant brake if you want to run like the prototype. YOu only use that at very low speeds when stopping or stopped. Never at mainline speed, unless of course you are running light power (no train).
I have never tried out the Tokyo route, so I have no idea what the grades are like. However, you are running it like a lot of pros would. Minus the independant brake anyway.Myself, I bunch them up with the dynos before setting any train air. Or, if I am on an intermodal train for instance, I may stretch brake it instead, never using the dynos. Instead, you keep pulling the train in run 4 or so while applying the train brakes. This is a very smooth way to stop. One question I do have however; Are the grades so steep you need that much power? 12 units worth of dynos is a bit excessive. The six you have on the head end exceed the limit we have on CP by 16 axles. Todd
CP hogger

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>
>Don't use your independant brake if you want to run like the
>prototype. YOu only use that at very low speeds when
>stopping or stopped. Never at mainline speed, unless of
>course you are running light power (no train). Gotcha!!
>
>I have never tried out the Tokyo route, so I have no idea
>what the grades are like. However, you are running it like a
>lot of pros would. Minus the independant brake anyway. I think 1 station name is Ebina (I think) and it's nr the creast of the hill...very steep. I'm not a certified engineer, but what I'm in run 8, travelling at around 55mph with the help of my 12 babies. However, I have tried with 6 SD50s and they worked seamlessly...a total charm over the 12 SD40-2s. But, on Marias pass, I had about 6 or 8 AC6000CWs up front with about 110 coal hoppers and I couldn't even make the pass, I just slid down!!!>Myself, I bunch them up with the dynos before setting any
>train air. Or, if I am on an intermodal train for instance,
>I may stretch brake it instead, never using the dynos.
>Instead, you keep pulling the train in run 4 or so while
>applying the train brakes. This is a very smooth way to
>stop. Is that technique a left over from the caboose days??..pls excuse my ignorance...*sheepish smile*
>
>One question I do have however; Are the grades so steep you
>need that much power? 12 units worth of dynos is a bit
>excessive. The six you have on the head end exceed the
>limit we have on CP by 16 axles. When it comes to using SD40-2s, hauling at least 100 fully loaded hoppers over torturous grades at a desriable speed, yes!!..lol
And besides, I'm probably bit of a control freak!!
However, if I'm doing mixed freight with MSTS (excluding any hoppers in the consist), I have up front a couple of 6 axled locos and right beind them some 4 axled locos. What I have found is that my acceleration from rest is unbelieveable and I can go faster that usual than if hadn't had the 4 axled locos (like I stated in a previous post). Does any RR do this in real life for this PRECISE purpose?????
Tonka.

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Hi Jeff>> Each car's forces are taken at the same incline as the engine,
which isn't right.Another modern myth destroyed by evidence Just a little follow-up on my earlier posting regarding the coasting & rolling resistance. While attending the opening ceremonies of a new stretch of high speed track around town, I had a little chat saturday with the engineer of the shuttle train taking us through the new tunnel - which has a mild incline. The engineer said, as a rule of thumb, engineers are taught that when going down an incline of 4 promille (i.e. 0.4%, or 4 metres per kilometre, or roughly 20ft per mile) that incline is just enough to equalize the rolling resistance of a well maintained train, so that in idle it will coast constantly downhill.Lukas a.k.a Swissie

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