CP Spike from Sacramento
[Here] are photos of a CP spike (or the mortal remains of it) found in Old Sacramento during the 1970s excavation of the CP Passenger Station site. It appears to be wrought iron. Does anyone have an idea when they switched to bar iron for making spikes?
—Kyle
5 Comments:
Also see the related exhibits of Railroad "Iron" and Hardware.
From: CoolGuy127@aol.com
... Unfortunately, to me, the picture looks like a picture of any old rusted railroad spike. I can't tell the difference between wrought iron and bar iron, so I'm afraid that I can't help you out.
—Daniel
From: KyleWyatt@aol.com
The striations and grain are characteristic of wought iron. But the question was really more of a historical technological question of when the railroad industry suppliers shifted from wrought spikes to spikes made from bar iron.
—Kyle
Wrought iron is called a metal fiber composite as it is a mixture of pure iron and particles of slag. (See American Iron 1607-1900, by Robert B. Gordon, Johns Hopkins, 1996, page 8.)
I have been told by those that would be in a position to know that wrought iron spikes went the way of the dodo in about 1871, about the time that steel rail replaced the wrought iron rail. Bar iron spikes are visually the same as a wrought iron spike except for the 'throat' that is exibited on the newer spike. The CPRR/SPRR used 5 1/2 inch x 9/16ths spikes from 1863 to about 1925, then converting to a larger spike, this to accomodate the larger rail then in use.
Sorry I can't be more explicit as to the date of change, however my slender railroad library just doesn't have a specific date mentioned.
P.S. ... Now ... realization that "bar iron" is "wrought iron"
From: "Lynn Farrar" littlechoochoo81@netzero.net
My records from SP show that the larger spike was in use as early as the early 1900's, probably after Harriman got control of SP and his staff initiated close standards for both UP and SP. Thus our common Form 30 for work to be done was the same as the UP's Form 30. Same for GMO, General Manager's Order, CS for Common Standard drawings and probably others that I have forgotten. As to the old smaller spike the reports on original construction to Promontory say it weighed 1/2 pound while the first weight book I have shows the same 9/16 x 5 1/2 size but the weight is shown as 0.58 pounds, probably due to the added throat on the later spike.
—Lynn
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