Climb down the ladder here and look to the left to see a cart, pull it out as far as you can to the right. Climb up the ladder again and climb the rope here, you need to continue climbing upwards as you will be crushed between a pair of gears if you do not.
Once the rope stops coming, jump back to the platform and climb down the ladder quickly. Jump onto the mine cart and then quickly leap across to the rope before it recedes back up above the gears again to grab it. If you look to the right you will see that this rope controls a large weighted block in the next section, and just to the right you'll see a second rope which controls a second weight.
Make sure the first weight is touching the ceiling before swinging and jumping to the second, when the second rope is near the top, jump across to the platform and under the weights before they come back down again.