The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X  0  0  0  0  0  0  0  0  X  X  X  X 2X 2X 2X  X 2X  0 2X
 0  0  X  0  0  0  0  0  X  X 2X 2X  X 2X  0 2X  0 2X 2X  0  0
 0  0  0  X  0  0  0  X 2X 2X 2X  X  X 2X  0  0 2X  0  X 2X  0
 0  0  0  0  X  0  0 2X 2X  X  X  0  X  X  X  0 2X  X  X 2X  X
 0  0  0  0  0  X  0 2X  X 2X  X 2X  0  0 2X  X 2X 2X  X  X 2X
 0  0  0  0  0  0  X  X  0  X  0  X 2X 2X  X  0  0 2X 2X 2X  0

generates a code of length 21 over Z3[X]/(X^2) who´s minimum homogenous weight is 30.

Homogenous weight enumerator: w(x)=1x^0+126x^30+222x^33+214x^36+294x^39+4734x^42+396x^45+330x^48+162x^51+62x^54+6x^57+12x^60+2x^63

The gray image is a linear code over GF(3) with n=63, k=8 and d=30.
This code was found by Heurico 1.16 in 13 seconds.