One basic version of a "wheeled" form of a Triskelion or Triple Spiral symbol, containing three double spirals which branch out into partial circular arcs which enclose the whole figure.  Inspired by various Celtic decorative motifs, but this version is constructed from mathematical Archimedean spirals.   For a more ornate "wheeled" triskelion, with an enclosing spiral instead of a partially enclosing circle, see Image:Triskelion-spiral-threespoked-inspiral.svg .  For other versions, see Image:Roissy triskelion iron ring signet.png or Image:Triple-spiral-wheeled-simple.svg .

For other, non-wheel versions of the triskelion or triple-spiral symbols, see Image:Triskele-Symbol-spiral-five-thirds-turns.svg , Image:Triple-Spiral-Symbol-filled.svg , Image:Triple-Spiral-Symbol-4turns-filled.svg , Image:Triskele-Symbol-spiral.svg , or  Image:Triple-Spiral-Symbol.svg . For a spiral triskelion with a hollow triangle in the center, see Image:Triskele-hollow-triangle.svg .  For versions of a triple-spiral labyrinth, see Image:Triple-Spiral-labyrinth.svg and Image:Triple-Spiral-labyrinth-variant.svg .
SVG version of Image:Wheeled-Triskelion-basic.png .
Own work -- 
Converted from the following PostScript code:

%!
/archimdouble{
%%%%%%%%%%%%%%%%
% PostScript program to display an Archimedean spiral by approximating
% it with Bezier curves.  Can display a double spiral (two spirals
% rotated by 180 degrees with respect to each other).
%%%  Parameters:
                 % centerx = horizontal coordinate of center of spiral
                 % centery = vertical coordinate of center of spiral
                 % rotf = degrees to rotate
/sepwid 110 def  % width separating successive turnings of spiral
                 % (half this if double spiral is selected)
/incrm 15 def    % insert a curve point after this number of degrees
                 % CHANGED TO 30 FOR INNER SPIRALS
/double 1 def    % change to 0 to display single spiral
/quadruple 1 def % change to 0 to display single/double spiral only
%%%  Procedures:
/pi 3.1415926535898 def/radians 57.295779513082 def
/sepwid sepwid pi div 2 div def
gsave centerx centery translate rotf rotate
/aspiral{/prevbezy 0 def/first 1 def
    lower incrm sweeps 360 mul{8{dup}repeat
        phase add cos/costh exch def
        phase add sin/sinth exch def
        costh mul radians div/thcosth exch def
        sinth mul radians div/thsinth exch def
        thcosth sepwid mul/x exch def
        thsinth sepwid mul/y exch def
        0 eq phase 90 eq phase 270 eq or and{/slope 999999999 def}{/slope
            sinth thcosth add costh thsinth sub div def}ifelse sinth 0 gt
            sinth 0 eq costh -1 eq and or{/flag -1 def}{/flag 1 def}ifelse
        /A exch def phase 90 eq phase 270 eq or not{A 49.29348 lt A 180 gt
            A 196.273450852 lt and A 360 gt A 368.8301 lt and A 540 gt A
            545.9907 lt and A 720 gt A 724.5217 lt and A 900 gt A
            903.6281968 lt and or or or or or{/flag flag neg def}if}if
        incrm sub 3{dup}repeat phase add cos sepwid mul mul radians div
            /prevx exch def phase add sin sepwid mul mul radians div
            /prevy exch def
        incrm add 3{dup}repeat phase add cos sepwid mul mul radians div
            /nextx exch def phase add sin sepwid mul mul radians div
            /nexty exch def
        /prevdist x prevx sub dup mul y prevy sub dup mul add sqrt pi
            div def
        /nextdist x nextx sub dup mul y nexty sub dup mul add sqrt pi
            div def
        /normaliz slope slope mul 1 add sqrt def
        0 eq{0 0 moveto/prevbezx phase cos nextdist mul def/first 0 def
            }{first 1 eq{x y moveto/first 0 def}{prevbezx prevbezy x 1
            flag mul normaliz div prevdist mul sub y slope flag mul
            normaliz div prevdist mul sub x y curveto}ifelse
        /prevbezx x 1 flag mul normaliz div nextdist mul add def
        /prevbezy y slope flag mul normaliz div nextdist mul add def}ifelse}
    for stroke
    x y moveto x 1 flag mul normaliz div nextdist mul pi mul const mul add y
    slope flag mul normaliz div nextdist mul pi mul const mul add lineto
    stroke}def
/sweeps 1.1714 def % number of 360 degree turnings to show
/const 3.7453 def
/phase 0 def aspiral
double 0 ne{
/sweeps 0.958514 def
/const 2.2743 def
/phase 90 def aspiral}if
quadruple 0 ne{/const 0 def
/sweeps 1.344446 def
/phase 180 def aspiral
/sweeps 1.083617 def
/phase 270 def aspiral}if
grestore
%%%%%%%%%%%%%%%%
}def
/curvedge{/const 0 def/lower 503.407 def/incrm 10.092 def
/sweeps 1.45648 def/phase 90 def
gsave centerx centery translate rotf rotate aspiral grestore}def
-40 30 translate
gsave
807 -103 translate -0.825 0.825 scale -9 rotate
/lower 0 def
/disp{27.5 rotf 11.05 sub}def/trnslx{disp sin neg mul disp cos mul
translate}def
gsave
/centerx 304 def/centery 550 def/rotf 285.67 def trnslx
gsave archimdouble grestore curvedge grestore
/lower 0 def
gsave
/centerx 634 def/centery 550 def/rotf 45.67 def trnslx
gsave archimdouble grestore curvedge grestore
/lower 0 def
gsave
/centerx 469 def/centery 835.7884 def/rotf 165.67 def trnslx
gsave archimdouble grestore curvedge grestore
grestore
0.825 setlinewidth
341.567 362.2645 11.34375 360 0 arcn stroke
341.567 362.2645 234.173 1.2853 90 arc stroke
341.567 362.2645 256.716 90 -8 arcn stroke
341.567 362.2645 234.173 121.2853 210 arc stroke
341.567 362.2645 256.716 210 112 arcn stroke
341.567 362.2645 234.173 241.2853 330 arc stroke
341.567 362.2645 256.716 330 232 arcn stroke
showpage
%EOF
AnonMoos