is remarkable and comes in a variety of forms depending on where it will be deployed. For deep water deployment, where the danger of a ship dropping an anchor on it or the likelihood of a fishing net getting snagged on the cable is relatively low, a fairly thin unarmored cable, shown in Figure 7-30, is used. In shallower water, how- Figure 7-29 Fiber splicing laboratory Figure 7-30 Deep water submarine cable: Note the lack of armor. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Transport Technologies Transport Technologies ever, where crushing incidents are more common, a heavier, armored cable is deployed, shown in Figure 7-31. Take a close look: The cable has four layers of armored strands, the largest of which is about the diame- ter of a pencil. The robotic cable-laying device is a remarkable piece of machinery (see Figure 7-32). Controlled by an operator using a joystick like for a video game, it is dropped on a cable to the bottom, where it either achieves neutral buoyancy or crawls across the bottom on tractor treads. It has thrusters to control its position, digging tools (including a giant Figure 7-31 Shallow water, heavily armored cable Figure 7-32 Cable laying robot: Note the grappling arms on either side of the device. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Transport Technologies Chapter 7 Figure 7-33 Cable tanks circular rock saw that looks like something out of Roger Rabbit), and massive grappling arms with which it can gently pick up a fragile strand of unarmored cable or tear apart a rocky obstruction. It can operate in water as deep as 6,000 feet. We then descended into the lower deck of the ship, where the cable tanks were located (see Figur