Page 612 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

612 CHAPTER 22 It’s the Little Things That Matter
22.1.5.3.2 Small vehicle procedural modifications
Procedural modifications to account for a smaller system include the following:
• Consider breaking the vessel inspection into smaller segments (perhaps half, quarter, or eighth sections), so that shorter lengths of tether are in the water.
• Consider moving the tether handling point away from the operations platform to assist in tether mechanics (in the above example, the operator would be able to control the system from the RB, while someone aboard the inspection vessel handled the tether).
• Consider changing from a longitudinal search pattern to a lateral search pattern (as depicted in Figures 22.5 and 22.6).
• Consider the use of clump weights to cut down on the cross-section drag presented to the oncoming water flow.
• Consider moving the deployment platform closer to the work site (Figure 22.7).
• Consider changing the direction of pull to the work site to a more direct pull, increasing the
mechanical advantage of the vehicle’s pull on the tether.
FIGURE 22.5
Example of procedural change to lateral search in order to lower tether length in water (top view).
FIGURE 22.6
Lateral search pattern to lower tether length in water (side and stern views).
Bad Good
FIGURE 22.7
Try to keep the vehicle as close as possible to the deployment platform.