The generator matrix

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

generates a code of length 10 over Z3[X]/(X^2) who´s minimum homogenous weight is 15.

Homogenous weight enumerator: w(x)=1x^0+720x^15+1680x^18+3240x^21+900x^24+20x^27

The gray image is a linear code over GF(3) with n=30, k=8 and d=15.
As d=15 is an upper bound for linear (30,8,3)-codes, this code is optimal over Z3[X]/(X^2) for dimension 8.
This code was found by Heurico 1.16 in 0.359 seconds.