Problems with SU Calculations for the Akira Class in SRM 1

With the torpedo launchers, the manual states that each launcher costs 13 SU's. Shouldn't this be 17?

5 + (6/2) + 5 + 4

Base cost for launcher + (Spread/2) + Firing Arc + Targetting system

I've been running through the SRM and little things like this are coming up all over the place

Bobby G

Actually, make that 16. It should only be 3 for the targetting system. 5+5+3+3 = 16