aDoes not include surface or subsurface navigation system. bAssumed on-site power available, no generator shipped, and 500-foot umbilical.

aDoes not include surface or subsurface navigation system. bAssumed on-site power available, no generator shipped, and 500-foot umbilical.

The MiniROVER* MKII is suitable for operating to 130-foot water depths where water currents of less than 1 knot are present. With no current, the vehicle can effectively be used to depths of approximately 500 feet.

The MiniROVER* MKII is not equipped with electrical safety circuits and is not approved for diver in-water interaction.

CAUTION Divers must maintain a minimum distance of 5 feet from the MiniROVER* MKII while in the water.

The PHANTOM DHD2+2 vehicle is suitable for operating in water depths to 2,000 feet when water currents of less than 3.5 knots are present. The PHANTOM DHD2+2 system is equipped with electrical safety equipment«! approved for Navy use for diver in-water interaction.

The PHANTOM DHD2+2 vehicle is much more powerful and versatile than the MiniROVER* MKII and therefore can operate with a larger payload capacity and in higher water currents. The MiniROVER* MKII is easier to transport, handle, and maneuver in small working areas.

2.9.2 Training Requirements

ROVs are complicated systems that are not foolproof. They require technical decision making and troubleshooting during setup and use. Ideally, ROV operations should be conducted by full-time operators. Since this is not practical for UCT operations, successful completion of the missions will depend heavily on the experience of the operating crew and on the condition of the vehicle.

Operators should be trained in both ROV maintenance and operation. Training should include formal instruction which includes maintenance, operation, and troubleshooting. There is no substitute for hands-on vehicle training conducted at an in-water site with sufficient space to accommodate maneuvering in currents, umbilical handling, and navigation.

In addition to formal training, it is highly recommended that operator crews train with the vehicle prior to deployment. Specific work functions required on the job should be practiced. At the conclusion of this training, the vehicle should be thoroughly checked out before being shipped to the deployment location.

2.9.3 Vehicle Deployment and Recovery

Typical support platforms suitable for ROV operations include:

• Vessel/barge (30-foot length and greater)

The MiniROVER* MKII can be deployed and recovered by hand (no additional overboarding hardware needed) with one or two persons. This depends on sea conditions and weather during operations. However, if at all possible, it is best to plan to overboard either system with the use of a davit, small crane, articulated boom, or some other device that can lift the vehicle and extend it away from the side of the platform. Tag lines are required to control vehicle movement during lifting, and overboarding procedures should be carefully planned and practiced.

For through-ice deployment and recovery, a small tripod can be used to support either of the vehicles.

Beach and small boat operations are special cases (Figure 2-48). Beach deployment can be done where surf is not excessive: Common sense prevails! Essentially the vehicle is carried out to a water depth of 3 to 4 feet (enough to provide maneuvering). It may be necessary to add floats to the umbilical as longer lengths of umbilical are payed out.

CAUTION For safety reasons, recommend that power not be supplied to the vehicle until it is released by the vehicle handlers.

Two people are needed to carry the MiniROVER* MKII vehicle, and a minimum of four people are needed to carry the PHANTOM DHD2+2.

Operations from small boats such as inflatables provide several challenging problems including deployment of the vehicle and protection of the electrical controls and equipment. Neither system has splash-proof controls and monitors as stan dard equipment, so small boat operations are usually limited to very calm water.

2.9.4 Umbilical Handling and Management

Umbilical management is important to the success of the dive. Too much umbilical in the water can result in tangling and excessive drag. Maintain only the length of umbilical that is needed in the water.

Care must be taken to reduce the possibility of umbilical damage from propellers and tangling with objects in the water column and on the seafloor. As the operation progresses, it is advisable to construct a rough map of the area being inspected, including any obstructions or entanglements encountered. The map can then be referred to as an additional navigation aid during the remainder of the dive. Always maintain good communications between the vehicle operator and the umbilical crew.

When swimming the vehicle within structures or around moorings, it is important for the operator to keep track of the umbilical. Tide shifts and accompanying current reversal can result in the umbilical becoming wrapped around objects.

2.9.5 Typical ROV Operational Configurations

Figure 2-49 shows the general configuration for shallow water ROV operations performed from an anchored vessel or fixed structure (such as a dam or pier), where very little water current exists in the operation area.

For ROV operations in areas where water currents impede the maneuverability of the vehicle, a depressor weight should be used. This is especially true when conducting live boat operations. Figure 2-50 shows the general rigging and configuration of the umbilical for dives requiring a depressor weight. Larger weights may be required with long umbilicals and high currents.

2.9.6 Navigation and Tracking

The navigation and tracking support required to complete a task depends on the task, water depth, water visibility, the hori zontal distance from the support platform, and the site distance away from shore.

Table 2-23 lists the navigation and tracking instruments available for use with die UCT ROV systems, and a brief discussion of applications. A technical description of navigation systems is found in Chapter 4.

2.9.7 Cold Weather Operations

Operation of the vehicles in conditions where the air temperature is below freezing (such as the Arctic) must be conducted from a warmed shelter. Neither the MiniROVER* MKII nor the PHANTOM DHD2+2 is designed to operate at below freezing temperatures.

Placing a cold soaked vehicle in the relatively warm seawater (28 °F and lower) will result in ice forming on the vehicle. Expansion of the ice and contraction of vehicle components will almost certainly result in seal failures or damage to components and is therefore not recommended.

Submarine Max Depth

'Maximum depth recommended - 60 feet for MiniROVER® MKII

- 300 feet for PHANTOM DHD2 Water currents must be considered

'Maximum depth recommended - 60 feet for MiniROVER® MKII

- 300 feet for PHANTOM DHD2 Water currents must be considered

Figure 2-49. Shallow water configuration.

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