they are the torps of the type 93 torp launchers and classified by 2 types the M1 and M3

the M3 is stronger than the M1 and under that they got 3 MODs,

MOD 1 for weak damage but longer range in the water (mostly use by kitas in GB)

MOD 2 for normal damage and normal range in the water

MOD 3 for strong damage and short range in the water (effective in blitz as simakaze/kita especially in hobbit map :D )

Let's not forget MOD 3 torps are hella fast and a full volley from a simakaze can sink just about every ship in the game.

I have to disagree to most things said above (cause wrong or incomplete):

There are the type 93 M1 and M3 torps and launchers.
The M1 are lower level, weaker but have in general more range than M3.

Each type (M1 and M3) are divided into 3 MODs as mentioned above. The Mods of each type are same level but their differences are:
MOD1 has longest range, lowest damage and medium speed
MOD2 has shortest range, medium damage and highest speed
MOD3 has medium range, highest damage and slowest speed

The speed within eac MOD is the same (e.g. M1 MOD1 same speed as M3 MOD1)

conclusion:
Not the MOD3 are "hella fast". They go only 24/36 knots. I would prefer MOD2 for Sima any time cause MOD3 are evaded and outrun easily.

Kitas normally use the MOD1 due to longest range. Try if you prefer the 93 M1 MOD1 or the 93 M3 MOD3. The M3 do more damage (4700 vs. 7300) but have lower range (40000 vs. 30000). Because both MOD1 run same speed you might even want to try to combine them.

BTW: have a look at navyfield.com => game info => components might also give you these answers next time.

THNKS