In the manga the tank merely shot off her arm during the fight (just one). But anyway, I think in the movie she was desperate to get to the Puppet Master, so she had to fight the tank to prevent Section 6 from running off with it.

She really wanted to open the tank door.

@mechajutaro said:

Why did she keep pulling until her arms ripped off?

Being a PG-13 movie, they couldn't show her panties being ripped off. Had to make due thusly

Hell, I woulda took an R rating for that!

@Frenzie said:

In the manga the tank merely shot off her arm during the fight (just one). But anyway, I think in the movie she was desperate to get to the Puppet Master, so she had to fight the tank to prevent Section 6 from running off with it.

Yeah, I get that but it would seem in such a digital world where everything is perfectly calculated she would know that x amount of pressure is the most her limb's joints can stand and going past it would not only not get you the latch open but you lose your arms too. I guess it could be argued that her ghost was emotionally overriding these calculated decisions.

Plus, if the calculation was close then her arms were completely expendable, just wire and metal. Well worth the risk.

Even though she has a cybernetic body and an enhanced brain, she’s human, not a robot. I doubt there are any calculations she’s consciously making on how strong the tank is. It’s not likely that the Major has a build of materials and schematic for the tank to figure out what forces are needed to force open the hatch. You might recall, there are several scenes where we see a view through Major’s eyes. There weren’t any overlays of statistics or other details. She was simply willing to risk it all pursuing a glimpse of an answer to the question that’s been plaguing her. But if you doubt all that, maybe you’ll trust the whisper in my ghost.

@The_Stewart said:

Even though she has a cybernetic body and an enhanced brain, she’s human, not a robot. I doubt there are any calculations she’s consciously making on how strong the tank is. It’s not likely that the Major has a build of materials and schematic for the tank to figure out what forces are needed to force open the hatch. You might recall, there are several scenes where we see a view through Major’s eyes. There weren’t any overlays of statistics or other details. She was simply willing to risk it all pursuing a glimpse of an answer to the question that’s been plaguing her. But if you doubt all that, maybe you’ll trust the whisper in my ghost.

Actually, I do remember that scene! I'm actually impressed with myself becuz its been a while since I saw this film. Anywho, point well taken. Nothing was shown to indicate she had any idea what would be needed to open the hatch. I guess I am mixing up the TV series with the movie which shows them having access to ALL KINDS of technical wizardy.

In the Anime she was anxious to face the Puppet Master's ghost and went ahead without backup. She needed to get to the 'brain' of the large tachikoma. And the only way was to rip the shell of the tank.