They are called "tail nut locks" see on p95 at link:

https://books.google.com/books?id=6-I0AQAAMAAJ


On 7/19/2017 9:38 AM, Joseph Howell wrote:
> Hello HISTARCH folks,
>
> I am trying identify these metal objects found along an abandoned portion of the Southern Pacific RR. A fairly extensive search has turned up nothing, other than other people who don't know what they are either. We found quite a few of them, usually in association with crosstie plates, rail anchors, and spikes. I'm thinking they are some kind of lock washer. Anyone?
>
> https://drive.google.com/open?id=0B4GzvIWsfmnCUUZGblE1ZUNMb1E
> https://drive.google.com/open?id=0B4GzvIWsfmnCb1BndTJ5RkNXYlE
>
> Thanks!
>
>
> Joseph Howell
> Archaeologist
> Statistical Research, Inc.
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> Tucson, AZ  85712
> Phone: (520) 721-4309
>
>
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