"Stacked Ties" are available in a 9 pack from Fine N-Scale Products. Knowing the quality of their freight car kits, I wouldn't hesitate to get some of these for my layout, which I plan on doing if they're still in business if/when I get around to it! Here's where to look on their website under "lumber":
https://www.finenscale.com/loads.htmlCheerio!
Bob Gilmore
