Revision as of 02:07, 28 October 2009

This page outlines some basic cost calculations I use in my vehicle sets, both pre-calculated spreadsheet numbers, and the code used for variable running costs in the game. When designing a set in a spreadsheet, it's probably best to use standard numbers first, then fudge values for vehicles which you think need to be more or less expensive.

Trains

Locomotives

Purchase Cost

Steam Locomotives

Weight in Tons * ProdCost

• ProdCost is usually 0.25, but can be fudged between 0.2 and 0.3.

Example: 4-6-0 Jubilee, 126 * 0.25 = 32

Diesel and Electric Locomotives

Weight in Tons * Prodcost * (Horsepower / BaseHP )

• ProdCost starts at 0.4 for early experimental diesels, 0.3 for 1960s production units, down to 0.22 for 21st century designs. Again, these numbers are fudgable if you think a particular vehicle should be more or less expensive. For electric locomotives, early vehicles are 0.5, and is down to 0.4 by the end of the century.
• BaseHP is a "typical" power output for engines of that type/era. For diesels, I use 2000 for models designed before 1975, 2500 from 1975 to 1990, and 3000 after 1990. For large electrics, I use 4000.

Example: EE Type 3, 107 * 0.3 * (1750 / 2000) = 28

Running Cost

(Horsepower * EffCost) / (SuspCost - MaxSpeed)

• EffCost is the efficency of the design, where a higher number is worse; 5 for most steam locomotives, with a slight bonus (down to 4.5) for later very large locomotives in NARS. 3.75 for most diesels, down to 3.5 for modern designs. 3 for most electrics. Very powerful locomotives may need lower numbers and very underpowered vehicles (eg railbusses) may need higher numbers.
• SuspCost represents the wear and tear on the traction system and track, and is a number roughly imagined as the speed at which the vehicle will fall apart. I use 200 for steam locomotives and 300 for modern electric locomotives, 225 for first generation diesels and 250 for modern diesels.

Example: 4-6-0 Jubilee, (1550 * 5) / (200 - 90) = 70
Example: EE Type 3, (1750 * 3.75) / (225 - 80) = 45

Variable Running Cost