This trace supposes the creation of a line of successive redans; great redans with faces 160 yards long alternate with small redans with faces that, according to described method, are no more than 40 yards long. This throws the small redans into deep re-enterings between the great redans while giving the great redans the character of advanced works offered to the enemy as so many exposed points of attack. If the faces of the small redans do flank the faces of the large redans and contribute some little fire to cover their salients' sectors without fire, the faces of collateral great redans could not safely contribute to each other's defense without bringing the troops defending them under the fire of their friends.

Draw a right line of any length. This line will be the interior boundary line that includes the gorges and re-entering angles of the tenaille lines great and small redans.

In the same motion, divide the boundary line by locating the positions of the redan's capitals and limits of the gorges. The demi-gorge of each great redan will be 80 yards long; the full gorge 160 yards long; the demi-gorge of each small redan will be 34 yards long, the full gorge 68 yards long. Capitals of the great and small redans will, naturally, be located where two demi-gorges meet of the appropriate length meet.

Produce the capitals of the redans toward the exterior (or engaged side) of the interior boundary line. Capitals of the great redans should be 138 yards long; capitals of the small redans should be 20 yards long. These distances between points where the faces of the redans will be drawn set up a very nice defensive relationship between the faces of the small and great redans while giving the salients of the great redans sufficient open space for its defenders to conduct a good defense.

Produce right lines from the exterior extremities of the redan capitals to the locating points of division on the interior boundary that mark the limits of the redan gorges. This completes the trace of the alternating great and small redan tenaille line. Note that the salient angles of the great redans measure 60 degrees; salients of the small redans measure 120 degrees, the same angular relationship found in the alternating 60 and 120 degree tenaille line. This relationship insures that the faces of the small redans are perpendicular to the faces of the large redans so that troops lining the interior crests of the small redans can adequately defend the faces of the large redans with an effective enfilading fire.

This trace placed the capitals of the great redans 228 yards apart; the development of the interior crest would total 400 yards. 800 troops would be required to adequately man the interior crest when deployed in two ranks along the interior crest, far more than any of the other tenaille traces described in other period engineering manuals.

Mahan did offer a much more plausible and effective alternative that decreased the depth of the tenaille line and corrected the worst problems inherent to the first great and small redan tenaille line. In this trace the great redans were, so to speak, turned on their sides so that the 138 yard long capital became a 138 yard long demi-gorge. The small redans were given a 40 yard long gorge.

Capitals of the great redans were then made 80 yards long and the capitals of the small redans made 35 yards long to preserve the proportions of half-redans of the first great and small redan tenaille line.

Measures of the salient angles of this trace's redans were opposite those of the first alternative: great redan salients measured 120 degrees, small redan salients measured 60 degrees; these proportions once again insured that the faces of the small redans would be perpendicular to the faces of the great redans. Faces of the great redans were still 160 yards long while the faces of the small redans would retain their 40 yard length. But this trace placed the capitals of the great redans 316 yards apart, meaning that the same number of troops (800) could defend a lateral front that was 88 yards longer than the previous great and small redan tenaille trace.