Date nails

[NW Mailing List]

I have some questions about date nails.
1 What year did the N&W stop using date nails?
2 Where did the N&W get there date nails from, manufacturer, made in house?
3 When date nails were put down into the ties, how many ties were there between date nails?
4 With the use of date nails, are there any tie replacement documents on this subject.
Thank you for any help.

Jeff Wood