Tractive Effort - How to use it?

[Didz]

Has anyone come up with an easy way of comparing tractive effort to performance for freight trains?

I have no idea how to assess the optimum length/weight of a train based upon its tractive effort. I recall that in Railroad Tycoon it was relatively simple as the buying screen gave a visual indication of how a locomotive would perform with various numbers of trucks and carriages. But this game just has a number.

[Thork]

There actually is a power rating shown in the vehicle details window once you bought a train. You can check that and resell it for full price when paused.
It's really just a guideline value though and depends on usage. Even a "good" power rating might have trouble pulling full loads uphill.

However, same is true if you go further and apply math. It would be quite the task taking into account every incline etc. on the route.

There are some topics on it if you search the forum. Be aware that patches made crucial changes after initial release. Specifically cargo weight was added by patch, so early discussions might complain about missing it.

This spreadsheet might still be the best/easiest help besides the power rating:
https://docs.google.com/spreadsheets/d/1FW5R8aq3E88py-sTObi5s-w8U1z_li8Q9Mzp1ZQ9iPU/edit#gid=1891888107

It was posted early on in this thread:
http://steamcommunity.com/app/446800/discussions/0/215439774872043182/
Should still work fine if you add data for weight. The vanilla weight value for a cargo unit is 1200kg.

It really depends on how much work you want to put into it. I don't take it THAT serious ;)
I'm personally just estimating based on power rating and my experience, then follow the first fully loaded train to check the speed. Having slow-downs due to incline is usually a bad sign and you might then be better of with a faster setup or a change in track layout.

[ste]

I dont know either, wouldnt mind knowing, all Ive been doing as a simple rule I follow, is dividing the TE by weight of trucks, 100TE I would stick 10 10t trucks on it, It seems to work well enough for me, The more weight you pull the slower it will accel anyway,

[chrisasnyder]

My advice is don't overcomplicate the topic. Tractive effort is the ability of the locomotive to transfer power from the engine to the tracks. This will effect both acceleration and the ability to hill climb. As Thork said, the Power rating gives you the resulting calculation for a train based on the empty running weight. Hover over the power rating gives some more details, specifically how long it takes to get to full speed on flat and incline. That's all you really need.

Pretty much any poor rating for any train is going to be a problem. Medium for cargo is usually sufficient. Passengers will want Good.

Really it comes down to just watching the trains. If you built lines that have hill climbs, you are going to need more power, add more engines to the train. Apply same rule to accelleration issues where a train takes to long to get to full speed.

[Didz]

According to the wiki Power and Tractive Effort have different affects.

e.g. Power - has an impact on acceleration and is important for fast trains such passenger expresses. Whilst Tractive Effort - determines the ability of the locomotive to haul heavy loads, e.g. freight.

It also says that for really heavy freight one can double-head the train to provide more tractive effort. But it gives no indication of the relationship between the Tractive Effort and the amount of cargo it can haul effectively.

If every cargo units weights 1200Kg as suggested by Thork then there should be a relationship between the number of loaded wagons and the tractive effort of the engine, as was the case in Railroad Tycoon.

[uzurpatorex]

TPF follows a realistic acceleration model. In it tractive effort is the maximum amount of force a locomotive can exhert when starting from a standstill. TE is important at speeds below 5-10km/h (depending on a train). Moreover - what the game displays is maximum TE. In actuality TE is dependant on current speed, power and weight of a locomotive nad the result is almost entirely dependant on power above speed of ~10km/h.

In practice, worry about TE when your trains are:
- heavy
- ride up mountains
- often need to start/stop

Overall, in this game it is fairly minor thing to worry about. Power - or more specifically, power/ton of train weight is more important.

[Didz]

Well it certainly wasn't a minor thing in Railroad Tycoon, in that game you chose the locomotive suitable for the task. So, certain engines were best suited to fast passenger services, whilst others did not have the speed but had the ability to haul long heavy freight trains.
https://i.imgur.com/EDiv6JQ.png
The choice was made simple by the information provided in the purchasing dialog, and you could visually check how an engine would perform pulling varying numbers of carriages or wagons prior to purchase.

By comparison the approach used in Train Fever and Transport Fever seems unecessarily vague and complicated.

[chrisasnyder]

TpF does all the math for you and shows you the values in the Power Rating.
If you build a train and the empty weight says it will take 4 minutes to get to 65mph, then you need to add engines until the time is more reasonable for the length of the trip.

The numbers are really more useful when comparing one engine to another. Early pre-1900's they are all pretty week. Later, in the diesel years, there are more options, but the choice still isn't that big of a deal. Add engines till the train will move. As a general rule, every 10-15 wagons needs at least one more engine. Step grades, +1.

[Didz]

I think thats a matter of opinion. For me playing on hard mode buying the right engine, and knowing how much a train will cost is a very big deal.

Likewise putting an engine on a 10 car train only to find the thing struggling to move it, is a massive deal as it means I've not only wasted a fortune, but possibly compromised my entire cargo strategy by assuming I could deliver the goods.

I can't really understand why Urban games are determined to make the player do all the maths when game designers from 30 years ago already had the maths worked out and incorporated into their game.

Its the same with the finances. I have to run a seperate excel spreadsheet alongside this game to work out the P&L for my company, whereas Railroad Tycoon just gave you that as a standard financial report every year. It's what computers are good at.

[uzurpatorex]

Originally posted by Didz:

Well it certainly wasn't a minor thing in Railroad Tycoon, in that game you chose the locomotive suitable for the task. So, certain engines were best suited to fast passenger services, whilst others did not have the speed but had the ability to haul long heavy freight trains.
https://i.imgur.com/EDiv6JQ.png

RRT did not use simulate physics. The model used there was entirely arbitrary.

By comparison the approach used in Train Fever and Transport Fever seems unecessarily vague and complicated.

What is so hard in TPF?
Power - how much work a vehicle can perform in a period of time.
Tractive Effort - how much weight it can sensibly start

Consider two locomotives with the same TE, but different power:

Loco1: 1000hp
Loco2: 2000hp

Both weigh the same with their train. It is certain that loco1 will hit all of the speeds slower then loco2, arriving at the destination much later then loco2. Given sufficiently steep hill, loco1 will reach almost half of the speed of loco2.

Consider two locomtives with same power but different TE:

Loco1: 100kN
Loco2: 200kN

Above speed of ~10km/h they will perform _identically_, however below that speed the loco2 will have an advantage and in extreme case loco2 will not stall on a hill, while loco1 will.

EDIT:

Essentially, in this game you mostly need to worry about Power/Capacity ratio. Trains which have simular Power/Capacity rating, which carry the same commodity, will perform the same. 300kW train with 50 capacity will perform almost exactly the same as 900kW with 150 capacity.

[Didz]

Originally posted by uzurpatorex:

Originally posted by Didz:

Well it certainly wasn't a minor thing in Railroad Tycoon, in that game you chose the locomotive suitable for the task. So, certain engines were best suited to fast passenger services, whilst others did not have the speed but had the ability to haul long heavy freight trains.
https://i.imgur.com/EDiv6JQ.png

RRT did not use simulate physics. The model used there was entirely arbitrary.

I can't comment on how accurate Railroad Tycoons locomotive models were, and to be quite honest I don't really give a damn whether they were accurate physical models or not. The point i am making is that the Railroad Tycoon developers presented the player with the information they needed to make a decision on which locomotive to buy in a simple and understandable format. Whereas Urban Games just throw numbers at the player and leave them to work out the information value (if any) for themselves.

It's bascially bad design.

Originally posted by uzurpatorex:

By comparison the approach used in Train Fever and Transport Fever seems unecessarily vague and complicated.

What is so hard in TPF?

Well as I said above what we are provided with by Urban Games is basically raw data, or 'Noise' as we call it in the trade e.g. 'sounds impressive but means nothing'. In order to derive any information value from it the player has to process this data outside the game.

In Railroad Tycoon when you open the Locomotive purchase screen it gives you a simple little table which shows at a glance the potential performance of that locomotive with different manifests over different gradients. So, you can see at a glance which engine is going to be the most efficient for the role you are trying to fulfill.
https://i.imgur.com/1T2E80m.png
So, if you look at this image of the purchase screen for the 4-2-0 Prussian you can see clearly what that engine can haul and at what speed over various gradients of track.

[Thork]

The power rating combined with the info while hovering is almost the same as in RRT, but you have a valid point. It could be better presented and/or expanded to understand and work with. Same for the annual ledger and improved statistics.
I guess it is/was rather low priority compared to other issues and maybe noone on staff is a real statistics nerd.
There were some improvements and there is hope it gets further improved.

I don't mind as much as you do though.

[Didz]

Originally posted by Thork:

I don't mind as much as you do though.

Well I problably come across as more annoyed about it than I really am.

In reality having to work out your company profits on Excel when the game could have given you the information directly and wasting money buying trains that aren't fit for purpose just because the game designers were too lazy to present the facts in an understandable format is just a minor niggle.

I was just hoping someone would have come up with an easy way of converting the meanless data provided by the train depot into something useful.

The spreadsheet you linked earlier is more useful, but its still way too over-engineered for my needs. At least having played Railroad Tycoon I recognise some of the loco's and know what their intended to be used for.

[uzurpatorex]

Originally posted by Didz:

I can't comment on how accurate Railroad Tycoons locomotive models were, and to be quite honest I don't really give a damn whether they were accurate physical models or not.

It is relevant, because it being a physical model makes it pretty darn hard to make a pre-baked table of intended usage.

The point i am making is that the Railroad Tycoon developers presented the player with the information they needed to make a decision on which locomotive to buy in a simple and understandable format.

The thing is, you can't make such a table outside of a context of a train the locomotive is going to be pulling. The best you could possibly get in TPF is a plot showing you time to reach certain speed on level track from a standstill i with preset train weight. Such tables are actually compiled IRL, btw. But real life railroading is a tad more difficult then a game.

Whereas Urban Games just throw numbers at the player and leave them to work out the information value (if any) for themselves.

It's bascially bad design.

What UG did is merely expose your ignorance of what are you dealing with. Would you want a table of enemies slain per second or projectiles absorbed per hit instead of damage and armor respectively?

Well as I said above what we are provided with by Urban Games is basically raw data, or 'Noise' as we call it in the trade e.g. 'sounds impressive but means nothing'. In order to derive any information value from it the player has to process this data outside the game.

Also known as "playing the game". As I said - it is your ignorance of what those numbers mean that is the issue, not the format they are presented as.

So, if you look at this image of the purchase screen for the 4-2-0 Prussian you can see clearly what that engine can haul and at what speed over various gradients of track.

Except you can't make such table for TPF, or any other game that has a physical model of acceleration ( Mashinky and OTTD come to mind ). Even if only because inertia is a thing in TPF and a train approaching a hill at significant speed will power through it regardless of what such table would claim.

The "raw data" you are presented with is precisely what a train dispatch needs to deal with when composing trains. Sure, it would be cool if a train also showed us 'power_per_ton' ratio instead of a vague 'power rating' but that is a minor problem.

[Didz]

Originally posted by uzurpatorex:

Originally posted by Didz:

I can't comment on how accurate Railroad Tycoons locomotive models were, and to be quite honest I don't really give a damn whether they were accurate physical models or not.

It is relevant, because it being a physical model makes it pretty darn hard to make a pre-baked table of intended usage.

Nonsense! what do you think the game engine does when its computing the speed a train moves. Stop making excuses for bad game designers.

Originally posted by uzurpatorex:

The thing is, you can't make such a table outside of a context of a train the locomotive is going to be pulling.

Patently not true, as Railroad Tycoon did it. We aren't talking about some amazing new technical innovation in game design just copying something that has already been done before and was actually useful.

Originally posted by uzurpatorex:

What UG did is merely expose your ignorance of what are you dealing with.

I'll leave others to judge whose being ignorant here, the person who thinks a computer can't crunch complex numbers, or the one arguing that players should not be expected to do it in their heads.

Originally posted by uzurpatorex:

Also known as "playing the game". As I said - it is your ignorance of what those numbers mean that is the issue, not the format they are presented as.

Actually I think there is a bug in the physic's model anyway, based on these tests conducted by @NUB Sauce which shows that Tractive Effort is not affecting engine performance at all even on a gradient. That doesn't sound logical to me.
https://youtu.be/sXrKIzf4C8s

Originally posted by uzurpatorex:

Except you can't make such table for TPF, or any other game that has a physical model of acceleration ( Mashinky and OTTD come to mind ).
Even if only because inertia is a thing in TPF and a train approaching a hill at significant speed will power through it regardless of what such table would claim.

Of course you can. It's already been done by Railroad Tycoon's designers, the game itself does it in order to compute the speed of a train, and Thork linked a spreadsheet that does it offline. The only problem is that the Urban Games development team lack the experience of producing a useful user interface. It shows in both the lack of useful financial reports, the use noise in the line management data and the unhelpful train purchase screen.

[Thork]

Just a quick note. Would need to do some tests on my own, but the results of those he did are not really surprising to me. Once the acceleration kicks in there is indeed little difference. Pretty sure you will see more of a difference given some more weight and stops on incline.
I surely seen a bigger practical difference when using heavy loads.