Formulas to calculate running and purchase cost of vehicles

[Purno]

I'm interested in the formulas you people use to calculate running and purchase costs of vehicles, mainly trains, for graphic sets.

For the 2ccset I made these formulas;

PurchaseCost = ( MaxSpeed*15 + TractiveEffort*1 + HorsePower*1,5 + Weight*2 ) ^ 1,3
RunningCost = ( MaxSpeed*1 + TractiveEffort*0,2 + HorsePower*0,2 + Capacity*0,25) ^ 1,3

Resulting in reasonable high costs for good powerfull engines, and payable costs for cheap MUs and engines, so passenger traffic is still profitable.

[Rendall]

I miss the life cycle of a vehicle. A train last much longer than a tram and a tram longer than a bus or a lorry.

1) Lifetime

Speed is important and power as well. But most speedy engines are more expensive than a slow but powerful engine.

2) Speed
3) Power

Don't forget freight type. Passangers and mail, which is prefered to travel quickly cashes more money than slow freight like coal, ore and wood. Also freight like grain or livestock is more valuable than ore but less than passengers. Or what if you have mixed freight

4) Freight type. (slow, medium, fast or mixed)

Ans I think I will miss some details now. There should be 2 more of this kind of arguments.

[PikkaBird]

I'm interested in the formulas you people use to calculate running and purchase costs of vehicles, mainly trains, for graphic sets.

I make the first few engines, and playtest them, and adjust the prices if the game is too easy/hard/whatever. Then I cost the rest of the set comparatively by eye. It can take a few iterations to get everything right. But it makes more sense to me than using a formula, because I often want to take so many things into consideration (fuel type, ease of maintanance, level of manufacturer support) that a formula would be unwieldy, and I'd be fudging it to fit practically every vehicle.

Occasionally I'll have a rule-of-thumb - for example, in av8, my plan was that modern planes on an average route should pay for themselves in 5-10 years (eg, make a profit of 1/10 to 1/5 of the purchase price per year). But by no means do I try to make sets perfectly "balanced", where every vehicle's costs perfectly reflect its capacities. Real life isn't like that - most historical designs were average, but some were outstanding, and some were dogs, and that should be reflected in their TTD representations.

[Purno]

So, you're suggesting;

- To include a vehicle's life in the formula (I agree with that, didn't come so far with the 2ccset yet)
- Let MaxSpeed play a greater role in the price (and HorsePower less)? (Both Running and Purchase costs? I could understand if a fast train was more expensive to purchase, but a powerfull engine more expensive to run (gameplay wise I see HorsePower as fuel usage, and MaxSpeed as technology. )).

And I wanted a formula for all trains, so not seperate formulas for freight trains and passenger trains (AFAICT, freight trains have more HP and passenger trains more speed).

At least one new post has been made to this topic. You may wish to review your post in light of this.

@ Pikka, so you're using the real life to make some vehicles better than others? E.g. a vehicle which sucks IRL will suck in your game too? Do you make it cheaper than or do you define the price by real life too? E.g., a vehicle which was quite expensive but seemed useless IRL, would also be expensive and useless in your set? (Which means you could as well exclude it, I guess)? How do you make sure every vehicle in your set will be used / is useful?

[Rendall]

[quote] powerfull engine more expensive to run [/quote]

That's true. But in real life heavy load trains are very long and that pays off. Passenger trains mostly do not have that length. What also is important is the time era. In the beginning of 1900 transport was for the happy few (rich) and goods were far more important to transport by train cause there were simply no or less roads. Everything has to be done by train or boat. After 1950 road vehicles became important. I think there are to much arguments to make a good formula allthough it can be done.

[Purno]

IMO, a formula ensures the vehicles are well balanced, gameplay wise. If there's a crappy engine in the set, it'll also be cheaper to buy/run.

But, reading your post, I guess MaxSpeed should have more influence on PurchaseCost?

[Rendall]

In a later timespan yes. But in the beginning speed was no issue cause there were no fast trains. Also in a later era there have to be more cargo so you will have more heavy loads.

[Purno]

What is "the beginning" in your opinion? TTD starts in 1920 as earliest. Weren't there any relatively fast trains at that time? E.g. for express passengers?

[Rendall]

In 1920 there were a few fast trains. But you only draw trams from 1919? Or do you start earlier?
I would say: you will start in 1921 with at least 2 trains (or trams) from 1900 / 1921

[Purno]

Of course, a few will be before 1920, but not far before. And apart from wether or not there are fast steamers; If there are fast steamers, they should be more expensive than slow steamers right? :> (assuming HP is equal on both)

For trams (and RV), I assume HorsePower is quite useless, as it's usually enough to reach top speed, isn't it?

[Rendall]

About the RV's you are right but the value can be a fixed one at that moment still using such a formula.
Trains... how are you planning compount and non compount engines? If there is a difference between engines that is maybe an argument cause compounts were more expensive. But let me just figure out a formula. At least let me try.

[Purno]

True, a formula wouldn't be very realistic, but it'd optimize gameplay, I think.

If you can choose between a compount vehicle, and a non-compount vehicle, with the same stats, but the compount vehicle being more expensive, why would you ever choose the compount vehicle?

[Rendall]

..... no way. I give up http://en.wikipedia.org/wiki/Expected_value

[PikkaBird]

E.g., a vehicle which was quite expensive but seemed useless IRL, would also be expensive and useless in your set? (Which means you could as well exclude it, I guess)? How do you make sure every vehicle in your set will be used / is useful?

By (mostly) not including those that weren't.

Occasionally I'll include a vehicle that wasn't particularly good, but has aesthetic or historical appeal. It doesn't bother me that people won't use them much because, in reality, they probably weren't used much either.