Changing Safety Valve Volume Level

[2995Valliant]

I've kept quiet on this thread so far but here's my thoughts:

I fear the day that N3V "dumb down" the physics as Trainz then loses any claim to be a serious simulator. The current steam physics aren't perfect and need a few functions adding, but the real issue is that as the physics become cleverer (as they did with TC3/TS2009) then the quantity and quality of the data required goes up, as does the skill required to drive one (which is a good thing in a simulator, surely?)

You can't use a generic set of values in the steam container as other things (such as wheel diameter & mass) are picked up from elsewhere up by the code and used in the calculations so you're back to GIGO

The spreadsheet originated by Billegulla seems to me to be an effort to take us back to TRS2004 style steam physics (which were awful IMHO), are over powered - and STILL suffer the the blowing off problem.

Using real world values specific to each loco does seem to work - the only fudged value in my specs is for the clearance volume which is consistently set to twice the real world value in all my specs. After that it's just a case of fine tuning the fire temperatures and draughting to match known performance which all takes time and research. I've written enough now that I've got a feel for it and they'll work pretty well "out of the box" Unfortunately outside of my testers I've had zero feedback on my specs and I have to admit that AI has not been our main focus but as far as I know they don't suffer the blowing off problem in DCC. They certainly behave very realistic in cab mode so long as they are driven properly - ie don't keep stuffing coal and water in regardless of whether or not it's needed. On occasion where specs have been applied to loco's for which they weren't intended unless they are dimensionally very similar they don't work well.

What needs fixing then? We need dampers to control the fire more easily in CAB mode, and we need the AI to use them and learn how to fire (it's the biggest culprit for stuffing coal in). It's currently difficult to write a spec that will perform well in cab mode without excessive use of the blower.

I can see American loco's being difficult to drive simply because they are so big. The size of the grate and the boiler are such that considerable forward planning must be required but again functioning dampers would help enormously as one could then turn the fire down much more quickly in this case as well as restricting the draught through the fire during fast downhill running. There were two classes (Merchant Navy and West Country) of pacific in the UK without dampers and guess what, they were notoriously difficult to stop blowing off.

In my dream world where N3V are implementing dampers then they would also look at the way valve events are treated in reverse - performance in reverse is very much poorer than it should be.

Just my two pennyworth

hth,

Anthony

 

[clam1952]

I've kept quiet on this thread so far but here's my thoughts:


In my dream world where N3V are implementing dampers then they would also look at the way valve events are treated in reverse - performance in reverse is very much poorer than it should be.

This is my one major grumble, as I can't get line speed in reverse on my NG route, 25mph forwards is fine but the current physics can only seem to manage 15mph in reverse under load, unless you start "exaggerating" the engine spec.

 

[Azervich]

That's the interesting thing with reversing, in real life the locos are slipperier due to no sanding 'sand is only on the lead wheels, only Tanks have rear wheel sanding' yet in trainz you can do a full thrust take off with a heavy load without even slipping, lol.

 

[clam1952]

Tanks maybe but I'm talking locos that were designed to run in both directions. On the Welsh Highland their NGG16's have no problem going backwards or forwards and on the Ffestiniog the Double Fairlies have no sanders anyway. Both types have two sets of lead wheels and on the Ffestiniog reverse is a continual average 1.3% ish gradient so even the single ended loco's with sanders don't need them as running backwards downhill. The WHR is prone to occasional wheelslip when wet anyway due to small problems like stretches of 1 in 40 in several places some quite long one with a station and and a Halt. The FR just stick another loco on the front of the Fairlies that has Sanders if it's wet, usually in the Autumn.

 

[2995Valliant]

@ Azervich Not necessarily the case in my (UK) experience. I wouldn't expect to need sand on dry rails: Tank engines have a quite high adhesion factor anyway, and sanders on most of the classes I'm familiar with work equally well both ways. With the specs I've done, so long as the rest of the loco physics are correct ( especially mass, water and coal capacity) then you can't just open the reg and take off with a heavy train. Then try the T3P wet physics rule if you really want a challenge

One of the problems here is that content creators often use the working weight of the loco as the mass in the loco config (I believe it should be the dry weight) and it makes a much bigger difference than you'd think.

@ Malc - I'm glad I'm not the only one, but perhaps there are not many of us modelling end to end operations? They can turn loco's at both ends of the West Somerset now so I can avoid the problem!!

Anthony

 

[Azervich]

Hi Anthony,

Most of the Tank locos we have on the Victorian Railways such as the E class was actually built in England by Kitson & Co 1887 and exhibited in Melbourne 1888 as a propose suburban locomotive with a 2-4-2T arrangement, this was then adopted into a Shunting loco by making it a 0-6-2T and both still have rear axle sanders, only tender locomotive don't have rear sanding and are given less than 10% schedule load while running tender first on a grade 1in100 or steeper "noted in the 1926 loads of goods trains book".

I have also noticed that allot of people put the total weight into the loco when I've found the e-spec also adds boiler and coal weight, take Billegulla's X, S and R Class for example, they are so over weight that the wheels feel like there glued to the rails and the hud won't even flash just once, lol

what I mean about being able to go 'Full Thrust' in reverse... is that I've found the loco is way under powered, say you pull 305tons of a 2% '1in50' in forward and climb at about 13mph with little slipping going on, then do the same trip and grade in reverse you completely stall and can't get up and you also have no power for the wheels to actually slip and get a piston lock up, most of my locos I've built and in Beta are low powered types, Bore x Strokes 15x22, 16x24, 17x24, 17x26, 18x26 at 100PSI to 140 PSI Boilers ranges and starting tractive from 7,000lbs to 17,470lbs as I model 1870-1905 2 Tone Green Era and it's those locos which are impossible to slip in reverse or even pull much in reverse that trainz has them so weak.

Cheers.

 

[wva-usa]

I fear the day that N3V "dumb down" the physics as Trainz then loses any claim to be a serious simulator.

Frankly, I think your fears are unfounded, largely because I have yet to see anyone advocating "dumbing down" the physics.

The current steam physics aren't perfect and need a few functions adding, but the real issue is that as the physics become cleverer (as they did with TC3/TS2009) then the quantity and quality of the data required goes up, as does the skill required to drive one (which is a good thing in a simulator, surely?)

Personally, I don't think the physics are flawed, but I do think most/all the e-specs for large American steam need to be reviewed for accurate values.

You can't use a generic set of values in the steam container as other things (such as wheel diameter & mass) are picked up from elsewhere up by the code and used in the calculations so you're back to GIGO

No actually, you can come up with a "generic set of values" for the USRA steam locomotives. Why? Because the USRA used common designs. For example, the light Pacific boiler and the light Mikado are practically the same boiler. But don't take my word for it. Review the data in the first column of these two data sheets that provide the dimensional data for the USRA locomotives -- USRA Data - Part I and USRA Data - Part II.

Elevation drawings with data for both locos are also available for comparision here -- USRA light Pacific and USRA light Mikado.

Using real world values specific to each loco does seem to work...

Well, let's test that theory out. Here's a drawing with the dimensional data for a USRA light Mikado. (Click it to access a view larger version). In theory we should collectively be able to come up with a method of determining its boiler-volume based on the dimensions shown in the drawing. From left to right, if I use the 2nd, 3rd, and 4th boiler sections I get 23.126 m³, but that's including a small section of the firebox (as well as including areas occurred by tubes and flues, etc.)



Can we please use this thread to put our minds together, and walk through all the values for all the steam containers and (collectively) come up with e-spec for the USRA light 2-8-2 that we can put "to the test"?

What needs fixing then? We need dampers to control the fire more easily in CAB mode, and we need the AI to use them and learn how to fire (it's the biggest culprit for stuffing coal in). It's currently difficult to write a spec that will perform well in cab mode without excessive use of the blower.

Personally, I think the most American steam had to be operated with the blowers running much of the time. I was pretty young in the late-1950s, but I can remember visiting the N&W's Bluefield yard with my dad and seeing evidence (judging from the large plumes of smoke rising from their stacks) of use of blowers on the steam locos idle in the yard and on 2-8-8-2 Mallets preparing for departure. All of the large American steam I've been around in the 1980s to date have made great use of blowers to get steam up.

I've read several old books that mention how inefficient the smokeboxes of American locos were compared to their European counterparts. The American designers never seem to be willing to go to the trouble of making the smokebox do the (draft) work -- they seemed inclined to blowers as a work around.

I can see American loco's being difficult to drive simply because they are so big. The size of the grate and the boiler are such that considerable forward planning must be required but again functioning dampers would help enormously as one could then turn the fire down much more quickly in this case as well as restricting the draught through the fire during fast downhill running. There were two classes (Merchant Navy and West Country) of pacific in the UK without dampers and guess what, they were notoriously difficult to stop blowing off.

It'd be nice to be able to bank the fire as well and to have the ability to build different sorts of fire in the firebox. And have a stoker control, rather than hand firing. The thought of hand-firing a large Mallet with an occasional shovel of coal is absurd.

All that would be the gravy, but one of my primary reasons for not using cab control is that most/many of the large steamer can't come anywhere close to being able to pull the same number of cars as the prototypes did. The N&W Y6b is a good example of a loco that horribly underpowered. Oddly enough, running light the locomotive has totally unrealistic acceleration. But on level track it can barely lug 20 cars of coal (at ~2 MPH), while in real-world the Virginian was able to move 75 car coal trains using somewhat smaller 2-8-8-2 Mallets.

 

[2995Valliant]

Right, USA locomotive practice is definitely not my area of expertise, nor something I have the time to study, but the links you kindly included in you post above gives me almost all the information I need at my fingertips to create an e-spec along the line of my UK ones. If there's a couple of people here willing to test, perhaps learn to adapt their driving style*, and provide some detailed feedback - ie logged runs over route with some known real world performance data then it will be interesting to see how easily my method translates.

To answer your points in order:

1) Not in this thread, but there have been enough complaints over the years that you can imagine N3V decided that it's too difficult for their target market as it stands.

2) No argument at all there

3) No - different loco's will have different draughting arrangements according to design speed, which will vary with wheel diameter and intended use. As far as I can see, Trainz uses the rotational speed of the wheels to calculate the flow of steam from the boiler to the pistons, but the linear speed of the loco to calculate at least some, if not all of the draughting, so this will soon start to go wrong in a generic spec. Your point is noted about smokebox design - see below.

4) I'd expect any loco to need the blower on when standing to raise steam, but if American practice was to use the blower when moving then it gets much easier to provide a controllable spec. There's quite possibly more to this than meets the eye - boilers were much longer and grates much bigger on American loco's, so it may be that the design of blastpipe needed to get a decent draw on the fire caused such a back pressure inthe cylinders when exhausting that it was not viable?

5) No - fire temp is dependent on the calorific value of the coal used and the amount of air for combustion (American loco's always seem to be making lots of black smoke in the photo's I've seen..) The key is how much of that energy is transferred to the boiler, and if wer're working in the real world that is a very complicated area which fortunately has been taken care of for us by the original designer of the loco when they worked out the heating surfaces.

6) Banking a fire to calm it down does work on the size of loco I'm used to in Trainz - as the grate gets bigger it takes longer to run down, and also more to build back up, but we'll see.**

7) The key thing missing in all the data you linked to is cylinder clearance volume. This is crucial in real life, but even more crucial in Trainz as it causes some unprototypical behaviour: too small and the loco will slip at speed, too high and it will be monumentally overpowered. One of the key things that tok a while to fall into place for the UK stuff was the power output - it suddenly fell into place when stovepipe worked out that the default engine spec used for the rolling stock has way too much drag for UK prototypes. This may also need looking at for American prototypes - anyone?

So: decide which one you want, and if you can let me know

Typical service speed,

Calorific value of the fuel used,

Clearance volume

"Dry" weight

A test route and train to pull

and I'll have a crack - but as anyone I've previously done an e-spec for will testify, it will be when I have time, which depending on work might to tomorrow, or it might be next month. To those who are still waiting - I apologise now!

* Historically, people used to cab driving in TRS2004 do not get on with the new physics

** This, and the fact that the tester was doggedly in the above group, was the biggest problem I had when experimenting with an Aussie engine a few years ago. I've learnt a lot more since then though!

Regards,

Anthony

 

[Robert2d6]

Since many of the posts on this thread are now exhibiting a great deal of knowledge on this issue from the people in these discussions, which I am trying to understand, it appears that a simplified summary would be as follows for us less technical folks. The mechanism creating the steam pressure, in many of the Large US locos, has too high a generating capacity, with almost no way to control the pressure by the operator of the engine. The fire can't be reduced, because there is no damper, so about all one can do is let the coal burn down which would create a smaller fire, or add water, but the addition of water doesn't seem to have any effect when the pressure is just about at the maximum. Never turn the blower on unless the pressure starts dropping at too high a rate would be another rule to follow. Dropping pressure doesn't seem to be an issue with many of the large engines unless the loco is very heavily loaded with a heavy consist , or has to go at high speed or up a steep grade. So with many of the engine specs set up the way they are now, about all the driver can do is to put up with the safety blowing off, creating a horrendous noise, until the pressure finally drops which may not be for many miles if ever, especially when the loco is under light load ( low speed and flat terrain).

So that leaves only 3 solutions to the problem:

1 Re-do the loco specifications of the commonly used engines, one at a time, so that they operate realistically, which many of them do not do at this point in time.
2. Have Auran add a damper into the steam loco physics so that the fire is not always running full blast wide open, but can be controlled by the driver
3. Have a shut off for the safety valve audio, so even though the pressure is too high, and the safety valve is controlling the over pressure , the driver can drive in peace.

I don't think there is a 4th possible solution, but I am open to any suggestions. I wonder if any of the above 3 suggested work around's will ever be implemented?

 

[2995Valliant]

@Azervich - I'm with you now, I'd mis-understood your post!

Most of my specs will perform well enough that if driven with care they can perform the duties asked of them reasonably well up to about 30mph in reverse, but I'm modelling more modern loco's in the 160 - 200psi range. Traffic managers in the UK generally wouldn't load trains that heavily either. The load limit on the WSR (25mph line speed, ruling gradient 1 in 100, max 1 in 65, but twisty) for a 17000lb TE loco is 5 bogie coaches (which would be not much over 200 tons loaded) to prevent trains slipping to stand.

Regards,

Anthony

 

[ZecMurphy]

Hi Smash
I'm pretty sure I mentioned it's something that could be looked into for DCC mode. However, as has been pointed out (By azervich I think?), a correctly made enginespec can definitely fix this in both CAB and DCC modes...

For Anthony, WVA, and Azza, RE blowers.

All loco crews, and workshop people, I've spoken too have told me that the blower should be open to some degree at all times, for good reason. Namely, this is to prevent any back-draft of the fire through the firedoors. If you do not have the blower cracked, and go to throw some coal in, you can have the fire coming out through the doors. Now, you don't need it open much (approx 10% I would guess?). This is at all times, with it being opened up a little more as needed. Same as if you enter a tunnel, always open the blower, otherwise you can get severed blowback (enough to open some fire doors apparently).

Regards

 

[clam1952]

This is turning into a very useful thread, keep it coming guys, I'm learning a lot here.

 

[wva-usa]

Right, USA locomotive practice is definitely not my area of expertise, nor something I have the time to study, but the links you kindly included in you post above gives me almost all the information I need at my fingertips to create an e-spec along the line of my UK ones. If there's a couple of people here willing to test, perhaps learn to adapt their driving style*, and provide some detailed feedback - ie logged runs over route with some known real world performance data then it will be interesting to see how easily my method translates.

The links I gave go to one of my websites. The two charts, boiler diagram, and elevation drawings I put online this morning. I'm willing to see what I can dig up as far as specs and drawings, etc., and put them online, etc.

To answer your points in order:

3) No - different loco's will have different draughting arrangements according to design speed, which will vary with wheel diameter and intended use. As far as I can see, Trainz uses the rotational speed of the wheels to calculate the flow of steam from the boiler to the pistons, but the linear speed of the loco to calculate at least some, if not all of the draughting, so this will soon start to go wrong in a generic spec. Your point is noted about smokebox design - see below.

I was actually referring to the nearly identical boilers (and fireboxes) being used on, for example, on the USRA the light 4-6-2 and light 2-8-2. Yes, the cylinders specs varied; stoke was obviously longer, etc. Other values varied -- I was simply pointing out boilers were practically the same between 4-6-2 and 2-8-2 and between 2-10-2 and 4-8-2, etc.

4) I'd expect any loco to need the blower on when standing to raise steam, but if American practice was to use the blower when moving then it gets much easier to provide a controllable spec. There's quite possibly more to this than meets the eye - boilers were much longer and grates much bigger on American loco's, so it may be that the design of blastpipe needed to get a decent draw on the fire caused such a back pressure inthe cylinders when exhausting that it was not viable?

I'm pretty sure the blowers were often used while the locomotives were in motion. I'm basing that much of that opinion on conversations I've had my dad (who was a locomotive fireman) on the subject (his mention of blower use usually came up in regards to "black smoke", see below)

Many photos of locos running at fairly good speed taken during the steam era seem to support this idea -- if the photo is enlarged to say 8x10 size or larger, you can see often see a jet stream from the blower affecting the smoke plume. It's usually more apparent if the photo was taken during cold weather.

Re: American smokeboxes: I think it was Livio Dante Porta, noted Argentine steam locomotive engineer, who once commented something to the effect that "American steam locomotive exhaust designs couldn't have been designed more badly". Porta briefly worked with Ross Roland's enterprise in the 1980s, that was attempting to build a modern steam locomotive (ACE 2000).

From what I've seen (in diagrams), the smokeboxes of most British locos were less cluttered than their American counterparts. The American locos seemed to favor the use of a low mounted, short nozzle while the British locos' nozzle was mounted higher. And the American smokebox typically used one, or several, petticoat pipes. I've read some sources that claimed the British practice was to clean firetubes from the smokebox end, but the American shops usually clean out the firetubes from the firebox end simply because access through the smokebox was a pain due to the clutter of pipes.

The N&W did some testing on smokebox/exhaust design in an attempt to improve efficiency beginning in the early 1900s, as did the Pennsylvania Railroad. Apparently the N&W ended up implementing some of their findings -- if you look at the smokestack of the N&W Y6b in Trainz, it doesn't go straight up, it's angled towards the front of the loco. I think this is due to the configuration used in the smokebox. In real life, you could always tell a Y6b, even at a distance, by it's exhaust smoke pattern. The smoke would fire out of the smokestack at an angle, while the older N&W Mallets had smoke plumes going straight up.

5) No - fire temp is dependent on the calorific value of the coal used and the amount of air for combustion (American loco's always seem to be making lots of black smoke in the photo's I've seen..) The key is how much of that energy is transferred to the boiler, and if wer're working in the real world that is a very complicated area which fortunately has been taken care of for us by the original designer of the loco when they worked out the heating surfaces.

My dad was adamant in his opinion that a good fireman could (and should) always avoid black smoke. Although he admitted that under all operating conditions it wasn't always possible to run with a "clean stack", he claimed a skilled fireman should produce little to no visable smoke what-so-ever once the loco got underway (according to Dad, skillful use of the blower made this sort of "smokeless" running possible). Many American cities had black smoke ordinances and would fine locomotive crews that were caught producing black smoke within city limits.

In my area of the country (Central Appalachia), the railroads made extensive use of the so-called "smokeless coal" once common in the region, which was coal from the Pocahontas and New River coal fields which had a BTU value of ~15,000 (Per pound? I'll have to check.) or the so-called "gas" coals which had an slightly higher BTU rating. The "smokeless coals" was the coals of choice for the U.S. Navy due to its high BTU output and other favorable characteristics (low ash, etc.) The "smokeless coal" producers marketed their coal was "the only American coal equal to the famed Welsh Cardiff coals".

6) Banking a fire to calm it down does work on the size of loco I'm used to in Trainz - as the grate gets bigger it takes longer to run down, and also more to build back up, but we'll see.**

I can't recall seeing much of an effect at all on the big American Trainz steam I've run, but I probably should make a run with some of them cab mode to say for sure.

7) The key thing missing in all the data you linked to is cylinder clearance volume. This is crucial in real life, but even more crucial in Trainz as it causes some unprototypical behaviour: too small and the loco will slip at speed, too high and it will be monumentally overpowered. One of the key things that tok a while to fall into place for the UK stuff was the power output - it suddenly fell into place when stovepipe worked out that the default engine spec used for the rolling stock has way too much drag for UK prototypes. This may also need looking at for American prototypes - anyone?

Well, cylinder volume data for most American locos is difficult to find. Taking a guess I'd say ~10% (percentage of stroke) simply because that's what was the Pennsylvania Railroad managed to achieve on their "state of the art" steam locomotives, the PRR's Pacific and Atlantic type locos, just prior to the USRA era...

I'll see if I can dig anything up...

So: decide which one you want, and if you can let me know

Typical service speed,

Calorific value of the fuel used,

Clearance volume

"Dry" weight

A test route and train to pull

and I'll have a crack - but as anyone I've previously done an e-spec for will testify, it will be when I have time, which depending on work might to tomorrow, or it might be next month. To those who are still waiting - I apologise now!

Thank you! Let me see what I can find...

 

[Azervich]

Hi all,

I made this thread in Suggestions Boxcar to ask N3V if they could make the physics more accurate to steam locos and diesels, it didn't really show any interest to other people though, but these where ideas I thought would make physics better and it had to be said in a way to make it simple for people to understand though so my wording my might messy, lol

http://forums.auran.com/trainz/showthread.php?78029-Some-Tag-Idea-s

Cheers.

 

[stovepipe]

One thing that shouldn't be lost sight of is that the vast majority of rolling stock in Trainz uses the same "default_wagon" physics. As Anthony mentioned earlier in the thread this was simply not accurate enough for UK standard gauge rolling stock, which meant the locomotive engine spec had to be bent out of shape to account for the vastly greater drag created than in reality.

I imagine the some overestimate of drag applies to the US rolling stock, and therefore this probably needs to be fixed in conjunction with the loco enginespec. My approach was to develop new friction values based on known performance of a diesel loco on a real life gradient with a known load. The gradient I used (1 in 200) fortunately had been built accurately in the epic ECML route for Trainz. You could approach the problem from the other end, if you have details of the drag characteristics for the rolling stock. Generally though this is fairly specialised information held by railway companies.

 

[2995Valliant]

Hi Zec,

Thanks for your comments about Australian practice - that's different to the UK where the blower would be only be put on when moving when entering a tunnel or some similar event that could create back pressure. It's kept shut during normal driving.

I've spoken to a couple of friends involved with real steam loco's this morning and two comments leapt back - "Anything looks inefficient compared to Porta's work" (Mr Chapelon excluded!) and a comment that the thin steam trail observable from many American loco chimneys could well be something else - a turbine generator exhaust for example?

Regards,

Anthony

 

[wva-usa]

One thing that shouldn't be lost sight of is that the vast majority of rolling stock in Trainz uses the same "default_wagon" physics. As Anthony mentioned earlier in the thread this was simply not accurate enough for UK standard gauge rolling stock, which meant the locomotive engine spec had to be bent out of shape to account for the vastly greater drag created than in reality.

I imagine the some overestimate of drag applies to the US rolling stock, and therefore this probably needs to be fixed in conjunction with the loco enginespec. My approach was to develop new friction values based on known performance of a diesel loco on a real life gradient with a known load. The gradient I used (1 in 200) fortunately had been built accurately in the epic ECML route for Trainz. You could approach the problem from the other end, if you have details of the drag characteristics for the rolling stock. Generally though this is fairly specialised information held by railway companies.

I rarely run Trainz diesels (ever) but from what I remember when I dinked around them some time ago they seem to come close to matching real world tractive power. I may have to (shudder!) try running a few diesels to see what they can do. Many of the medium to largest steam seems to be terrible pullers. The Big Boy is the only one that seems to have reasonable amount of pulling power, but since I'm more a fan of Eastern U.S. steam I've only run the Big Boy a couple of times. But I do remember the Big Boy being able to out pull the Y6b by an absurd amount -- probably >4 to 1 -- even tho' the real Y6b had a higher tractive effort rating than the Big Boy.

Re: Drag

There's also the real-world reality about how a car equipped with the older "flat" bearings (typical during the steam era) should have a higher drag coefficient than a car with roller bearings (typical in the post steam era)...

I've spoken to a couple of friends involved with real steam loco's this morning and two comments leapt back - "Anything looks inefficient compared to Porta's work" (Mr Chapelon excluded!) and a comment that the thin steam trail observable from many American loco chimneys could well be something else - a turbine generator exhaust for example?

I'm fully aware of what a generator looks like. Photos I recall seeing were of locos that would have had their generators mounted in the area of the boiler between the steam dome and the cab.


Here's what the book Practical Locomotive Running and Management had to say about blowers and safety valves.

Always try to keep down smoke as much as possible When steam is about to be shut off open door a little just before throttle is closed and put on the blower a little.

When using steam smoke can be prevented by keeping a white heat firing a little at a time and holding door open about an inch for a few seconds after firing. Do not allow steam to blow off if it can possibly be avoided.

Steam blowing off means a waste of coal water and labor. It can always be prevented while using steam by watching the gauge closely and opening door on the latch before pop valve raises. Try to keep the fire so that the steam pressure will vary as little as possible. By doing so the engine will use less coal and there will be less strain on the boiler and firebox owing to the temperature being even.

Always carry as light a fire as possible as by doing so much heat can be obtained from the coal than with a heavy fire It takes a certain amount of air to get out of a quantity of coal all the heat If you carry a heavier fire than is necessary it will be a much harder matter to get sufficient air through the fire to enable it to mix thoroughly with the fuel and the gases.

 

[Robert2d6]

I rarely run Trainz diesels (ever) but from what I remember when I dinked around them some time ago they seem to come close to matching real world tractive power. I may have to (shudder!) try running a few diesels to see what they can do. Many of the medium to largest steam seems to be terrible pullers. The Big Boy is the only one that seems to have reasonable amount of pulling power, but since I'm more a fan of Eastern U.S. steam I've only run the Big Boy a couple of times. But I do remember the Big Boy being able to out pull the Y6b by an absurd amount -- probably >4 to 1 -- even tho' the real Y6b had a higher tractive effort rating than the Big Boy.

Re: Drag

There's also the real-world reality about how a car equipped with the older "flat" bearings (typical during the steam era) should have a higher drag coefficient than a car with roller bearings (typical in the post steam era)...




I'm fully aware of what a generator looks like. Photos I recall seeing were of locos that would have had their generators mounted in the area of the boiler between the steam dome and the cab.


Here's what the book Practical Locomotive Running and Management had to say about blowers and safety valves.

.Disregard post

 

[wva-usa]

I just tried operating the N&W Y6b that comes with TS12 in cab mode and it' far worse than I remembered. What the...?

Has anyone here actually tried driving this thing lately? The one I have seems demon processed. It's head isn't spinning around (yet) but based on how it's acting I wouldn't be surprised if started saying its "choo choos" backwards.

Seriously. Does anyone here that has driven the Y6b find that it drives "normal"?

 

[Robert2d6]

I just tried operating the N&W Y6b that comes with TS12 in cab mode and it' far worse than I remembered. What the...?

Has anyone here actually tried driving this thing lately? The one I have seems demon processed. It's head isn't spinning around (yet) but based on how it's acting I wouldn't be surprised if started saying its "choo choos" backwards.

Seriously. Does anyone here that has driven the Y6b find that it drives "normal"?

I scrapped that loco the first time I tried running the N and W Appalachian Coal run. Didn't have enough power to get out of it's own way. Just replaced it with my USRA 2-8-8-2 TS12 with the modified engine spec, and it runs great on that route with no safety valve screeching . Now if I can just fix the bugs in the route, it would be nice.