ON THE
COST OF TRANSPORTATION, &c.
I have never yet seen any formula, derived from the experience ofactive lines, by which the cost of transportation on railroads may bedetermined with an approach to accuracy. The expenses of main-taining a line of railroad are not all proportional to the distance trav-eled by the locomotive engine, nor to the tonnage conveyed; neitherare they all independent of either of these considerations. But theaggregate annual cost is made up of certain items, which are, in fact,nearly proportional to the distance run by all the engines; of otherswhich are strictly proportional to the tonnage conveyed; and of somewhich are nearly, or quite, independent, both of the trade and of thedistance traveled.
I offer the following rule for the determination of this aggregate, inthe belief that every well managed railroad, of ordinary construction,carrying engines of ordinary power, where the transportation is ef-fected at the usual speed, and which accommodates a respectableamount of business, will exhibit results in close agreement with itsindications. This formula is derived from the considerations whichfollow, and the constant quantities are supplied from the best experi-ence I have been able to obtain from the past management of thepublic works of this country. In course of time, when the velocityof burthen trains is reduced to three or four miles per hour, and com-panies learn to know where and how to economize, it is probablethat some of the items may be reduced; but time and experience haveyet to decide how much.
I . Repairs of Road .—The repairs of a railroad consists of two dis-tinct divisions; the first of which is nearly independent of the amountof the trade, and may be estimated, on the average, at about $500per mile. The second division is dependent on the amount of thetonnage, and represents the injury done to the road by the passage ofone ton of freight. I estimate this wear and tear at T 3 ^ of a cent perton per mile.
II. Expense of Cars .—The expense of repairing and renewing theburthen cars is proportional to the distance which they run, or to thetonnage of the line; and may be estimated at T y„ o{ a cent per tonPer mile.