Crossing time vs tidal strength, zoomed in on the area from Q_trip > −3 for better visualisation. Symbol style indicates the morphology of the triplet where the galaxy corresponds, as in Fig. 3. Grey dots represent the full sample of triplets, while blue dots represent galaxies showing signs of interaction, green dots represent galaxies showing slight signs of interaction, and red dots represent galaxies with strong signs of interaction. The blue shaded area represents systems that may have a level of interaction of all types from −2 < Q_trip < −0.45, while the green area represents mergers or ongoing merger types from Q_trip > −0.45. Three example cases are indicated (black squares): SIT 263, SIT 45, SIT 133.