The following is pulled from the Narrow Gauge Railroad Discussion Forum
30′ rail: 16 ties, 22.5″ center to center
33′ rail: 18 ties, 22″ center to center
39′ rail: 22 ties, c. 21.25″ center to center
EBT notice to tie shippers; May 20, 1943 indicates they purchased 7 ft ties, tolerance between 7ft 1 in. and 6 ft. 11 in. They also purchased 6 ft ties, tolerance, no shorter than 6 ft.
Tie spacing has changed over the years. According to an 1876 engineering guide from the Hartford Providence and Fishkill (std ga) tie spacing was 30″ (roughly 2000 per mile), and at that only 1 tie in 4 was spiked on straightaways, 1 in 3 on broad curves, and 1 in 2 on sharp curves. ties were untreated.
Take a look at the November/December ’89 Gazette. There’s an article in there that covers rail and ties of many narrow gauge railroads. (Neither the EBT nor ET&WNC are part of the listing, unfortunately.) One thing that is clear from looking at that list–there was no such thing as a “standard” tie. They ranged from 5′ 11″ to over 7′ long, widths anywhere from 6″ to 10″ wide, depths from 6″ to 8″, and then some. Spacing was similarly all over the board. Most were in the 20″ to 24″ center range, but even the photo on the first page of the article (the EBT’s trackage at Mt. Union) shows a stretch where the spacing was, well, let’s call it “economized.”