TENDING LINES

Tending lines are used as a precautionary measure to help rescue an investigator or fire fighter who is wearing an oxygen breathing apparatus, air-line mask, or similar equipment.

A 50-foot nylon covered, steel wire tending line (fig. 6-27) is used aboard ship with the oxygen breathing apparatus or the air-line mask. The tending line has a stout hook on each end that is closed with a snap catch. The line is pliable and can slide freely around obstructions.

If necessary, the rescue should be accomplished by having another person equipped with a breathing apparatus follow the tending line to the person to be rescued. Do not attempt to drag the person out by the tending line. The line may become fouled on some obstruction or part the wearer's harness. This will mean a loss of time,

Figure 6-27.-Tending line.

CAUTION A stricken person must never be hauled by a line attached to the waist. A person may be dragged by the waist a short distance along the deck, but his/her weight must never be suspended from the waist. If the wearer lacks any sort of shoulder harness, the line must be made fast so that it passes around the upper part of the body and under the arms, and meets either in front or the back. The tender should wear rubber gloves and shoes when handling steel tending lines or cables.

and it will still be necessary to send another person in. If the rescue is to be effected promptly, someone must be equipped with an OBA that is ready for immediate use and must be standing by ready for immediate entry. Tending lines may also be used by fire fighters to find their way back to fresh air to change canisters when the visibility is poor because of heavy smoke.

When the OBA is used to inspect damage or to fight fires, a team of one wearer and one person to handle the tending line should work together. If two or more OBAs are used in the same compartment, the tending lines are not used. However, the personnel wearing the OBAs should keep in constant sight or touch with each other.

The OBA wearer and the line tender should both know and use the following system of line signals

OBA TRAINING CANISTER KIT

The OBA training canister kit-FSN 2H-424000-238-9959--(fig. 6-28) is designed to provide realistic training in the classroom for 40 trainees. These trainees don the OBA and properly activate the quick-start OBA (training) canister. The training canister is red in color and is functionally identical to the regular green quick-start canister.

Figure 6-28.-Training canister assembly-exploded view.

However, there is one important distinction: The training canister contains a chemical filler (baralyme), which only absorbs the carbon dioxide (CO2) from exhaled breath. It does not produce oxygen. There is enough baralyme to absorb the CO2 that will be exhaled by the 40 trainees who use the canister for 5 minutes each AT REST.

NOTE: The canister should be discarded after it is used by 40 trainees, or when the chemical in the view window of the canister body changes color from pink to solid blue, whichever occurs first.

The oxygen candle assembly produces about 10 liters of oxygen. In the training canister, this is enough to provide 5 minutes of oxygen for one person AT REST. The danger of a training canister being used during an actual casualty is obvious. To prevent inadvertent use and possible serious injury or a fatality, the training canisters should NEVER be stowed in OBA lockers or in the vicinity of damage control equipment.

For the initial charging of a training canister, use the following procedures:

1. Remove the cover from the firing mechanism. Remove the firing mechanism and storage plug. Save the plug to reuse when storing a partially used canister to prevent moisture from entering the canister body.

2. Insert a candle assembly into the candle recess of the canister. Make sure the gasket is flat against the bottom of the canister.

3. Place the firing mechanism over the candle assembly with the primer housing projecting through the center hole and with the notches lined up with the tangs. The notches and tangs are positioned so that the unit can only be assembled in the correct position.

4. Rotate the firing mechanism clockwise to lock the candle in place. Tighten the firing mechanism until the frame contacts the tangs. Do not overtighten.

5. Fold the lanyard into the candle cover and secure the assembly on the firing mechanism frame. The training canister is now ready for use with the OBA.

To recharge a canister that has just been used, use the following procedures:

1. Position and secure a new metal tear-off cap on the canister neck so that the tab points toward the instruction label on the convex side of the canister.

2. Remove the firing mechanism from the bottom of the canister by turning it counterclockwise until the tangs line up with the notches.

3. Remove the used candle and place it in a regular trash can after it has cooled.

4. Hold the firing mechanism (fig. 6-29) with the slotted end of the frame pointing toward you. Raise the firing hammer to the cocked position.

5. While holding the firing hammer in the

cocked position, insert the cotter pin through the holes in the frame from the same side as the rivet head. Secure the cotter pin by bending the long leg slightly.

The remainder of the recharging procedure is the same as steps 2, 3, 4, and 5 of the initial charging procedure.

To start a training canister after it has been charged, use the following procedures:

1. Remove the tear-off cap from the top of the CHARGED canister by pulling it straight backward and downward; remove the disk to expose the gasket.

2. Remove the candle cover by rotating the swivel plate 180; push the swivel plate and cover down toward the center of the canister. Let the cover dangle on the lanyard. DO NOT PULL THE LANYARD.

Figure 6-29.-Detailed assembly of firing mechanism.

3. Insert the training canister into the OBA to the standby position.

4. Move the training canister into the operating position by lifting the handle upward, ensuring that the canister is snug in the canister guard.

5. Don and adjust the facepiece, and check it for an airtight fit.

6. Pull the lanyard straight out away from your body. This removes the cotter pin and fires the candle, which inflates the bag with oxygen within 15 seconds.

7. Set the timer on the OBA by turning it clockwise to 60; then, return it to 5.

To remove the canister, you should follow the same procedures used for removing an unused canister (discussed earlier in this chapter). However, you must wear protective gloves because the canister will be hot. If the canister is to be reused by another person, charge it as previously discussed.

Training Kit Stowage

Training canister kits are to be stowed in a special locker provided or in a locked compartment. This kit is to be kept locked at all times, except when it is in actual use. The keys should be controlled by the damage control officer

to ensure that the training canisters are used only for training.

After training sessions or for breaks in training of 1 hour or more, a partially used canister should be sealed. To seal the canister, place a metal tear-off cap on the canister neck, remove the oxygen candle, and lock the plastic storage plug in the candle recess in the canister bottom by the firing mechanism. The canister should be returned to the special locker or compartment and locked. Where lockers are not provided, stow the canister in a cool, dry storeroom.

Training Kit Disposal

After the chlorate oxygen candles have been burned, they contain sodium chloride (table salt) and partially oxidized iron. They may be discarded in a regular trash container after they have cooled.

Expended training canisters do not have the hazards of the regular quick-start canister. However, for the training benefit, they should be disposed of in the same manner as the regular quick-start canister.