36" long straight - I believe these are standard gauge (not sure on this)
40" long straight is O gauge (6-65523) (normal O is 10" x 4 = 40")
35" long straight is O27 (6-65024) (normal O27 is 8 3/4" x 4 = 35")
Seeing the 6-xxxxx, I dont know if it applies.(?)
I think he might have some early post war or prewar track. I can recall more ties being on some early track, but it was only 8 or 10" and evenly spaced. The double tie spacing seems familar too. Last modern tubular I looked at, 10" had the 3 ties (I did not see an L on it though. Bootleg? Williams? Post Kline, Pre Menard's)
....oh, duh...the double tie then wide space is to replicate the the pattern of short pieces when ASSEMBLED... I also forgot, I think I have modern 0-27 with that pattern...but I don't recall how long or for sure (shelf layout, I dont get up there to see it often.) I'll check & measure soon, someone is still sleeping in there.
Another reason might be fast identification and easier dealer sorting after Mr. Mess-ups weekly friday evenig visit and emptting of the bin, in search for that one perfect piece.... to return on Thursday so he could eat lunch on Friday ,before picking up his pay, and going to the train store to empty the bin, looking for that one perfect....ahh you get it....