The NNE Scenic V3 is okanned as a three-deck around the walls layout with a G-shaped peninsula. Below is the current design of the three levels.
Minimum radius is 19", with the exception of a wye on the upper level. Planning is done in XTrackCad with easements set to normal except for connections to turnouts. Crossovers and turnout connections to parallel track use easements set to sharp. Minimum siding length as well as minimum distance between towns is slightly in excess of 10' to support a maximum train length of 30 cars plus caboose pulled by three diesel 4-axle locomotives.
The lower level models the New Hampshire portions of the Eastern Route of the former B&M railroad route between Boston, MA and Portland, ME. Both Boston and Portland are considered off-layout, with the track plan beginning with Salem, MA as on-layout staging extending in NH through Seabrook, Hampton Falls, Hampton, North Hampton, and Portsmouth. Portsmouth provides the main yard on the lower level. Provision has been made for the potential for the mainline from Portsmouth to be able to proceed through the wall into the unfisinished area in the future for off-layout staging representing Portland, ME.
On-layout staging in Salem, MA consists of the two separate ladders in Salem. One is the ladder on the Eastern Route seen towards the front of the bench work. The back ladder was on the Lawrence branch which I proto-freelance to have still been operating in my version of 1959. The Lawrence branch is represented as taking the helix up to the second level where Haverhill, MA will be represented.
Trains leaving Salem headed north on the Eastern route pass in front of the backdrop masking the helix headed to Seabrook, NH.
The middle level starts in Haverhill, MA and models the New Hampshire portions of the Western Route up as far as Dover, NH. But rather than continuing to Portland from Dover, the trackplan models the route that continues north through Rochester and Ossipee and then splits to model Wolfeboro on Lake Winnepesaukee on the middle level and heading up the second helix to the upper level headed towards North Conway, NH. Note that in the diagram below, I have not yet designed the Haverhill yard, so it is just fairly generic staging in the design at the moment. Haverhill design will precede starting work on the middle level sometime in 2021.
Trains leaving Haverhil northbound on the Western route pass behind the helix to emerge in Exeter on their way north.
By virtue of the turntables at both Dover and Wolfeboro, power could be turned for locals from Dover to work much of the second level, whereas through trains could continue to Rochester and points north.
The upper level starts from the second helix entering North Conway. The track them proceeds north to an interchange at Intervale to switch to Maine Central (MEC) power.
MEC heads west to Bartlett, across Frankenstein trestle to Crawford Notch, and then past Fabyan headed to the paper mill at Gilman VT.
Trains have the option after Fabyan of heading back down the helix instead of heading to Gilman. That route is primarily for continuous running options using the middle and upper levels through the two helices.