The following comes from “Greenberg Guide to Lionel 1901-1942, 0 & 00 Gauges, Vol. II, page 18:
Lionel’s initial 0 Gauge track sections in 1915, consisted of 3 tubular rails, fastened by three metal ties, with the center rail insulated by fiber from the metal ties. Eight curves formed 28 1/2” circle, with straight sections at 10 1/2” long.
In 1919 Lionel increased the circle diameter to 31 1/2”, and increased the.length of the curved sections. This stayed the same until 1942.
In the 1930’s Lionel introduced FIVE new types of track, an inexpensive 0 Gauge track made in both 2 & 3 rail versions, which became what is known as 027; a premium 0 Gauge track, which it called 072; and both two & three rail 00 Gauge track.
The 027 track was first made by Lionel in 1930-31 for it’s Winner Line, it’s new line of very inexpensive electric trains. As a cost reduction process, a new less expensive trackwas made for these trains. The track was an adaptation of the existing IVES track, retaining the 1 1/4” spacing between the outside rails, that defined 0 Gauge. The track was made with thinner gauge steel and was lower in height. A circle of Winner track made a 27 1/2” diameter circle, compared to 31 1/2” of 0 Gauge track.
Lionel (& American Flyer) took over IVES, after bankruptcy in 1929, and Lionel eventually bought out AF. We were coming out of the Depression of 1929, and in order for Lionel to stay competitive, it needed to produce less expensive sets, compared to its earlier 0 Gauge Sets, which were quite expensive. Thus Lionel produced very low expensive trains, early Lionel-Ives, such the Winner Line; Lionel Jr. Sets, that all included the lower profile, lower costing 027 track.
Lionel first offered its premium 0 Gauge track, 072, in 1934 with its new 752 Streamliner Set. 072 track had the same height, metal gauge, and width between the rails as Lionel’s traditional 0 Gauge track, but consisted of 16 pieces forming a 72” diameter circle, while traditional Lionel 0 Gauge Track only required 8 pieces to form a 31 1/2” circle.
This should explain why & how both 0 & 027 came about.:smilie_daumenpos::smilie_daumenpos: