I regularly see screenshots of TGV locomotives and eurostars hauling long coal trains.... And i think that is just stupid!
Such things are indeed horrible. Even for a "game".
To fix this i recommend setting commodity prizes steady for commodities that does not perish over time ex. for coal, wood, oil, goods, and so on.
In real life a power plant needs a steady supply of coal, the coal will burn just as well if it's been transported over 6 months as in 2 days.
AFAIK, this is already the case in original TTD. At least to a certain degree. Delivery prices for cargoes like coal or iron ore are decreasing only by a small degree over time, in comparison to prices for food or goods.
IMO, a small decrease for raw material prices makes sense, because even the most patient consignee wants to receive his order one day or the other.
Moreover, the game needs variable delivery prices to enable some sort of "competition" or "assessment".
Besides a TGV locomotive would not be properly geared to haul a lot of tonnage anyway so it would not be able to pull that much.
My coal trains husles along at 112 kph. even that is a bit high realisticly speaking but certainly better than 300+kph. Which is just stupid.
Also maybe limit more freight cars' speed.
Maybe a better realistic acceleration will take the gearing and drawbar pull to limit acceleration.
All this can be achieved by using a custom train set implementing proper tractive effort for locomotives and speed limits for freight wagons. I´ve set up such a set (the DB set) already 4 years ago for TTDPatch which, already at that time, included a realistic kinematic model for train movement, speedlimits for wagons, and weight multipliers to simulate long freight trains even on a limited network. Today, most of this should be also achievable in OTTD, but o/c not with the original train vehicles.
Many new locomotives are specified as having a huge amount of pulling power from the start. but from experience in my job as a train engineer 4 axle electrics starts slipping at around 200KN even on dry rails. even if they specify a maximum of 350KN. That's just an example but you get the idea.
Well, in locomotive design for train sets, I usually take the max starting tractive effort and the hourly max power into calculation (data from manufacturers or railway companies). However, the calculation cannot be as exact as the real life behaviour, mostly due to the actual state of the rails, or other small parameters of train kinematics which have been omitted from the kinematic model.
I agree about the coal thing - the price should not decrease with time as this material doesn't get any worse with time. Same with iron, oil? Don't know about the wood?Prices of cargo
don´t decrease with time. It´s the delivery prices
which go down if the time for delivery takes too long. This isn´t only "realistic" (in that way that in so-called "reality" delivery prices would also drop if delivery takes too long), but it´s a quite natural game feature.