About 200,000 net tons of iron total were used just for building the railroad from Omaha to Sacramento [at 2000 lbs/net ton, the modern useage, also called the short ton; the metric ton = 1000 kg ].Details, at 60 lb/yard (per single rail) single track from Omaha to Sacramento: 1776 miles x 60 lb/yard x 5280 feet/mile x 1/3 yards/feet x 2 rails x 1/2000 ton/lb = (1776*60*5280*2)/(3*2000) = 187,546 tons of iron.If the rail is 56 lb/yard, then the total rail weight is about 175 thousand tons (about a hundred tons of rail per mile).
Other sources speak of "fifty-ton locomotives" and "two or three tons of spikes and fish plates" per mile.
For locomotive numbers and weights, also see the multi-page CPRR and UPRR locomotive lists.
(Not sure if the weights of locomotives listed are shipping weight or maximum track loading including water.) If you estimate from the available data that about 21,000 miles of track were put in place during the 1860's in the U. and that the amount of iron used is proportional to the track miles built, then the percent of iron used in building the transcontinental railroad (compared to all U. railroads' iron use during 1860's construction) is about: (1,776/21,000)*100 = 8.5% According to Galloway: "The number of ties varied from 2,260 to 2,640 per mile, depending upon alignment and grade. The total completed length of the sheds and galleries was about thirty-seven miles, the building of which consumed 65,000,000 feet board measure of lumber and 900 tons of bolts, spikes, and other iron." of rail was accounted for, as shown by a letter from Collis P.
See the discussion of "dollars per mile of track" including the question of exactly where do the Sierra Nevada mountains begin and end. Graves states that the 1887 Pacific RR Commission said the cost of construction from Sacramento City to Promontory, as of July, 1869 was $61,249,916.11; cash or cash equivalent was $32,397,135.58.
See comments regarding the role of the government in financing the transcontinental railroad. The bonds were sold at par in New York, then transferred to San Francisco where they were converted to cash/gold.
A ,000 bond in New York was valued at 0 to 0 in San Francisco."Railroad Reorganization: Union Pacific." By Stuart Daggett, Ph.D., Harvard Economic Studies, 1908, states on page 256 that: " ... both principal and interest were paid in full." Regarding the CPRR and Western Pacific RR, Tutorow, p.1004 reports that final payment to the government was organized by a commission appointed by an 1898 act of congress, determined to be ,812,715.48 on Feb.1, 1899, and that the complex transaction was completed on February 1, 1909 when the last of the government debt was duly paid.How much iron and lumber was used in the construction of the transcontinental railroad?