We present VLT/MUSE spectroscopy, along with archival Gemini/GMOS spectroscopy and Magellan/Megacam imaging for SPT-CLJ 0305-6225, a z = 0.58 galaxy cluster. A large BCG-SZ centroid separation and a highly disturbed X-ray morphology classifies SPT-CLJ0307-6225 as a major merging cluster. We characterise the central regions of the two colliding structures, namely 0307-6225N and 0307-6225S. We find velocity derived masses of $M_{200,N} = 2.42 \pm 1.40 \times 10^{14}$ M$_\odot$ and $M_{200,S} = 3.13 \pm 1.87 \times 10^{14}$ M$_{\odot}$ , deriving a merging angle of $\alpha = 39^{+13}_{-11}$ deg, and two possible times since collision; $0.96^{+0.31}_{-0.18}$ Gyr (outgoing scenario) or $2.60^{+1.07}_{-0.53}$ Gyr (incoming scenario).