The generator matrix

 1  0  0  0  1  1  1 X^2  1  1  1  1 X^2+X  X  0  1  1  1
 0  1  0  0  0  1  1  1  X X+1 X^2+1 X^2+X X^2  1  1  0  0 X+1
 0  0  1  0  1  1  X X+1  0  X X+1  1 X^2 X^2+X+1 X+1  X  0 X+1
 0  0  0  1  1  0 X+1  1  1 X^2  1 X^2+X  1  X X^2+1 X^2+1 X^2+X+1 X+1
 0  0  0  0  X  0  0  0 X^2 X^2+X X^2+X  X  X X^2 X^2+X X^2 X^2  0
 0  0  0  0  0 X^2  0 X^2 X^2  0 X^2 X^2 X^2 X^2  0 X^2  0 X^2

generates a code of length 18 over Z2[X]/(X^3) who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+131x^12+424x^13+1068x^14+2412x^15+3261x^16+6316x^17+5428x^18+6488x^19+3258x^20+2400x^21+1044x^22+380x^23+130x^24+12x^25+12x^26+3x^28

The gray image is a linear code over GF(2) with n=72, k=15 and d=24.
This code was found by Heurico 1.16 in 5.66 seconds.