Deck Officer



Information Sheet 1.10


Replenishment At Sea (RAS) allows the U.S. Navy to conduct sustained operations at sea, in accordance with Title 10 of the U.S. Code. It allows greater flexibility in power projection through increased on-station time. As a First Lieutenant/Deck Officer, your role in RAS will be vital. This lesson is intended to familiarize you with RAS operations. It will include a discussion of the personnel involved in cargo/missile transfer and a description of their jobs. The basic safety considerations for RAS will also be covered.


(a) NWP 4-01.4



1. Before beginning a discussion of the duties of the personnel involved in RAS operations, it is necessary for the student to have a basic understanding of the STREAM rig. The Navy operates two types of STREAM rigs: fuel and cargo. We will focus on the cargo STREAM rig, which is the preferred method of transferring solid cargo (e.g. missiles, repair parts, food, etc.) between ships at sea.

2. The basic idea behind the cargo STREAM rig is that the load of cargo moves by sliding along on a tensioned wire which is rigged between the two ships. The components of the rig and their functions will be briefly discussed (refer to Figure 1.10-1).

3. The STREAM rig on the delivery ship consists of the following components:

a. Kingpost - The structure used to support the STREAM rig on the delivery ship.

b. Highline - The tensioned wire along which the load moves. It must be kept taut during transfer operations since a load will not move easily along a line that has slack in it.

c. Highline winch - The winch that is used to pay out or retrieve the highline.

d. Ram Tensioner - A device that keeps the highline taut by adjusting the tension in the highline to compensate for normal ship movement during RAS. It is located between the highline winch and the kingpost.

e. Anti-Slack Device (ASD) - The ASD provides a constant pull on the highline while the line is being passed to the receiving ship. This keeps the highline from tangling up, or fouling, on the highline winch drum.

    1. Trolley - The device which slides along the highline from which the load is suspended.

Figure 1.10-1 Cargo STREAM Rig

g. Inhaul/Outhaul - The trolley is pulled back and forth between the two ships by the inhaul line (which moves the trolley toward the delivery ship) and the outhaul line (which moves the trolley toward the receiving ship). There are several different ways of rigging the inhaul and outhaul, and these methods will be discussed in later lessons.

h. Inhaul Winch - This winch is used to control the inhaul and is always controlled on the delivery ship.

i. Outhaul Winch - Although Figure 1.10-1 shows a tensioned outhaul controlled on the delivery ship, there are ways to set up the STREAM rig so that the outhaul line can be non-tensioned and controlled by the receiving ship ( See paragraph 4.5.2 of reference(a) ).

4. A wide variety of receiving stations are found on all classes of U.S. Navy ships. In general, the

STREAM rig on the receiving ship consists of the following components:

a. Bulkhead/kingpost/outrigger/tripod - The structure that provides a connection point and support for the STREAM rig may be any one of these.

b. Sliding padeye - Many ships are equipped with a receiving station which is configured with a padeye that slides up and down in guide tracks in the kingpost. A sliding padeye is moved up the tracks for transferring the load and moved down the tracks in order to lower the load to the deck of the receiving ship. Other types of receiving stations, including the fixed padeye, the pendant, and the STREAM support leg (on CV's only), will be discussed in later lessons.

B. Personnel assigned to the UNREP station

Required # Helmet Color

1. Safety observer One per station White (with a green cross)

2. Rig Captain One per station Yellow

3. Signalman One per station Green

4. Phone talker Two per station Green

5. Riggers As required Blue

6. Line handlers As required; 15 min Blue

7. Supply personnel/Checkers As required Orange

8. Corpsman One per side White (with a red cross)

9. Line throwing gun One per station Red

or bolo heaver

10. Repair personnel As required Purple

and winch checkers

11. Winch operator As required Brown

12. U/I personnel and all others As required Gray

C. Duties and responsibilities of UNREP personnel

1. Rig Captain - Enlisted person in charge of an UNREP station

a. Must be thoroughly familiar with all applicable UNREP instructions, especially:

(1) OPNAVINST 3120.32B, SORM

(2) NWP 4-01.4 (SERIES), Replenishment at Sea

b. Must possess a detailed knowledge of UNREP procedures, including:

(1) Preparation of the UNREP rig

(2) Operation of the UNREP rig

(3) Personnel safety precautions

    1. Briefs personnel on assigned duties

(1) UNREP procedures

(2) Emergency breakaway procedures

d. Inspects personnel prior to beginning the evolution

(1) Personnel working topside who are engaged in handling stores or lines or who are in the transfer shall wear life jackets.

(2) Personnel involved in cargo-handling operations on both the delivery and receiving ship must wear safety shoes.

(3) All personnel must be in battle dress.

e. Inventories gear

(1) Inspects working and repair tool boxes

(2) Ensure Gunners Mate on station has explosive bolt cutters

2. Highline winch operator - Once the highline is passed, the highline winch operator maintains tension in the rig using the highline winch and the ram tensioner.

3. Signalman - Sends visual signals between UNREP stations as directed by the rig captain.

a. Uses paddles during daytime operations

(1) One red/green

(2) One amber/yellow/green

b. Uses lighted wands during nighttime operations. Lighted wands are flashlights with colored cone tops.

(1) One red

(2) One amber/yellow

(3) Two green

4. Winch checker - Watches the winch for any sign of trouble. Possible winch casualties include:

a. Bird caging (occurs when the outer layer of wire rope is wound on the drum more tightly than the inner layers)

b. Overheating of the winch

c. Loss of winch control

5. Phone talker - Responsible for passing all information told by Rig Captain to other station.

6. Riggers

a. Responsible for connecting the rig, connecting all loads, handling tag lines, operating the cargo drop reel lanyard, and conducting breakaway.

b. Responsible to the rig captain for all instructions.

7. Sliding Padeye Operator

a. Controls the sliding padeye. This is used by the receiving ship to raise and lower the tensioning lines so that the loads can be attached or retrieved.

Figure 1.10-2 Inhaul and Outhaul Rig w/ Winches in TENSION CONTROL


8. Inhaul/Outhaul Winch Operators

a. The inhaul and outhaul winches at the delivery station move the trolley and suspended load along the tensioned highline. STREAM inhaul and outhaul winches can be operated in two modes: speed control and tension control.

(1) Speed Control Mode - Like in most cargo winches, the inhaul and outhaul winches operated in speed control respond only to the movement of the control handle.

(2) Tension Control Mode - the inhaul and outhaul winches respond to both the movement of the control handle and also a tension-sensing mechanism internal to the winch.

b. Inhaul and outhaul winch operators must act independently; this is especially important when passing the rig, during the transfer, and when retrieving the rig.

c. Operators should be in communication with station-to-station phone talkers, the rig captain, and the winch watchers.

9. Safety Observer

a. The Safety Observer is in charge of a specified RAS/FAS transfer station and ensures the safety of personnel and equipment.

b. Safety Observers are assigned no other collateral duties and should not become involved in handling any lines or performing any tasks that would prevent them from observing the entire station's performance.

10. Further information on personnel duties and safety requirements can be found in Chapter 2 of reference (a).