Use File Open to open the graphics file.
For this tutorial, use L21.tpg from your layouts\images directory, or click here to download the same image in jpg format:
Copy or save the file to a convenient directory, and open it from there.
The image opens, the grid appears in a
default position, and the Edit Tool 
becomes active.
If the grid is not visible, use View Grid to display it.
Point to an intersection point on the grid, press the Shift key, and drag until the red lines coincide with any two grid lines on the drawing. This anchors an origin point.
Without the Shift key, drag an intersection point to resize the grid, until the grid squares match the drawing as shown at right.
Shift-drag moves the grid, drag alone resizes it. Dragging by an intersection point keeps the grid square.
After adjusting, use View Grid to turn off the grid display.
Choose the Circle Tool. Point to the center
mark 
near Gills Landing,
press and drag. Adjust until the circle exactly overlays the
left-hand curve, as shown.
To move rather than resize the circle, press the shift key while you drag.
Draw a second circle overlaying the right-hand curve, with center near Oyster Bay.
This picture shows the result when you use View Background to turn off the image. Toggle this every now and then, to check your work.
Choose the Straight Track Tool. Point to the top of the left-hand circle (so it highlights), then press and drag to the right as shown.
Note that the straight section remains tangent to the circle as you drag.
Drag until the moving end touches the right-hand circle (so it highlights), then release.
The straight snaps to be tangent to both circles.
Repeat the above steps to add a segment completing the loop: press and drag from the bottom of one circle to the other (in either direction).
When you release, the circles disappear and become curved track sections.
If the result doesn't look like this picture, use Edit Undo to go back a step, then try again. Make sure a circle is highlighted when you start or end drawing each straight.
You might use File Save As to save a copy of the layout at this stage, and again every so often as you work.
Choose the Circle Tool. Drag from the center near Oyster Bay and overlay the curve leading to Gills Landing.
Toggle the shift key on and off while you drag, until you get both radius and position just right.
Choose the Straight Track Tool. Drag from the stub above Gills Landing to the circle (so it highlights), then release. This creates the first leg of the curve.
Create the second leg: drag from the bottom left of the circle, moving down and to the right, until the lower segment highlights as shown and the cursor is positioned at the switch, then release.
When you release this segment, the circle disappears and becomes a curve, and a switch is automatically created.
At this point you have a loop and a curved branch with an operating switch, as shown. Toggle View Background to check your work.
Test the switch by clicking the intersection point.
Drag a straight segment starting at the stub above left of Swampscott. Release at the point where the track bends, as shown by the cursor position in this picture.
Drag another segment starting where you released the last one. A green square highlight must be showing before you begin the drag, as shown above right.
Release at the point where the siding intersects the loop, shown at right.
When you release this segment, a second switch is created.
The track is complete. Operational possibilities: you can run around the loop, or divert to Gills Landing or Swampscott.
Test the switches. Save a copy of the file. Admire your work.
To have the train to hide as it goes through the tunnel under Telegraph Hill, you need to isolate that portion of track and mark it hidden. You can isolate a portion of track by chopping it where you want the ends, using temporary straight segments.
Drag a segment from an arbitrary point and release at the upper tunnel entrance. When you release, a switch is formed, as shown at right.
Repeat with another segment at the lower entrance, as shown in progress at right.
You now have two unwanted straights and two switches at the tunnel entrances. The next step is to get rid of them.
Point to the lower segment, so it highlights as shown at right, then press the Del key. The segment and switch disappear.
Repeat with the upper segment.
You have now created two junctions, such that the portion of the curve between tunnel entrances is an isolated section of track.
Position the cursor on the tunnel track (so it highlights) and press the right mouse button. You see the track context menu, as shown.
Choose Hidden. This marks the selected track section, and displays it as a dashed line. Any train passing over this section will appear hidden.
Congratulations! The track for the Rockport & Oyster Bay is complete.
Bring up the Inspector, Layout tab. Enter the layout name, add some comments, and save the completed layout.
Screen shot is not from Mac.
Use Train New Train to create a train on the layout. You're ready to begin operating.
