Hey Col_Nasty,
As some captains have pointed out the Sims torpedoes have a longer range but you do you seem to have the captain skill "torpedo acceleration" selected. The funny thing about the Sims torpedoes are they are so slow but the detectability and the short reload make them great for area denial. The Sims is a fun boat and has a lot going for it.
When looking at torpedoes to use the torpedo acceleration captain skill, I look for ships that have long range torpedoes i.e. Shimakaze and even the Gearing. The trade off in range for the speed for the Sims is not great enough because you really want to be putting out a large volume of "sea mines" at a consistent pace. The torpedoes will not do much alpha damage but you can get decent floods and making your enemies move for your teammates is immeasurable.
Good luck with the Sims!