Puzzle

I believe there is only one 072 curve involved, and it is the one that the arrow points to. The pieces of track immediately above and below the 072 curve are 45 degree arc pieces that are each cut down to create arc pieces of 33.75 degrees. The two pieces of 33.75 degrees and the one at 22.5 degrees all add up to 90 degrees and thus complete the loop. Rich

I agree that the diagram is wrong. I'll take a shot at this, saying that there two 072 curves and two 031 half curves in addition to the 4 normal 031 full curves. That adds up to 270 degrees and might just close that loop.

You guys are too used to software, and Fastrack "perfection.

Bet its a bit of a force, & you might need to file/trim the center & outer rails a little, but after playing on software, I see it as "close enough" for tubular. 

Build all but the 0-72. Now align the 0-72 radial center line to horizontal & move it close, but don't "lock it" to either end just look at it.

 If you lock it, that gap you see now, will really be split among a few joints (like 2 or more pairs).

Gargraves has 072 curves at 30deg.  Could it be that they based this on an old Lionel size? they've been around as long.  Thus the three Lionel 072 would be 45deg and fill the gap.

Cant find a reference to old 072 track.

Joe, that came from Page 28 of Lionel Trains and Accessories 1954 posted here on the Forum.  It's titled No. 020 and No. 1021 Crossings.

Thanks for the full manual.  Did anyone see the paragraph on high voltage DC current in NY city on page one?

Anyway, just did the track plan in question in Scarm. The plan works, you just fudge the angle of many connections.  Something we have all done when playing with track.

Problem solved.