Friday, November 16, 2007

U / W REPLENISHMENT AT SEA

EQUIPMENT USED IN REPLENISHMENT AT SEA
The equipment used in replenishment operations is only in general terms, because the details of each individual type of operation.
The following items of equipment are common in replenishment operations.
• Line-throwing guns or bolos are used to pass shot lines between ships. Normally this is done by the delivery ship except in the case of carriers and other ships with aircraft on deck. Communications such sound powered phones, hand signaling by flag or paddles,or colored wands. In the span wire method of fueling,the hose rides from the delivering ship to the receiving ship on trolley blocks that travel on the span wire stretched between ships. The main objective of the rig is to keep the hose out of the water when the distance between ships closes unavoidably, and to prevent it from parting when the distance opens.
The hose on the delivery ship runs from its deck its deck connection up and over the inboard saddle. Saddles are of the flow-through type-curved metal pipes with a fitting at each end to which is attached a section of hose. The inboard and saddle are controlled by a wire saddle whip that runs through a fair-lead block to a winch.
From the inboard saddle the hose runs down bights and back up again to the outboard saddles, being shackled to a retrieving wire saddle whip, a 450- to 800-foot long length of 1/2- or 3/4-inch wire rope running to a winch through a block on the boom. The saddles are attached to trolley blocks for riding the span wire.
From the outboard saddle the hose leads down and up in another bight to hose clamps, which also are on trolleys. A hose messenger, 800 feet of manila that graduates continuously in size from 12 thread up to 3 inch, is shackled to the outboard riding line fitting, and at 3-foot intervals is stopped to the hose with 21 thread. The hose messenger is the means by which the receiving ship heaves over the hose and wire span .
A stress wire rigged to prevent the hose from taking any strain from the riding line, is stretched between the outboard saddle and inboard hose clamp.
The span wire is a 3/4-inch improved plow steel wire 600 to 800 feet long, to the receiving ship end of which is attached a pelican hook. The pelican hook is a connecting fitting that can be released instantly, whether under a strain or not, by knocking reeves through all trolley blocks, the inboard saddle being supported by the saddle whip. A free trolley is so called because it is cast free from the hose when the hose reaches the receiving ship.
Passing and Tending Span Wire and Hose
As the receiving ship completes her approach and steadies alongside, heaving lines or line­throwing gun lines are sent over from each station on the delivering ship to corresponding stations on the receiving ship. By means of these first lines the telephone/distance line and hose line messengers are started over.
If the delivery ship has difficulty getting her gun lines across, the receiving ship uses her own line ­throwing guns, when requested to do so by the delivery ship. In all cases, gun lines are passed back at the earliest convenience to the ship furnishing them.
The moment the telephone jackboxes reach the deck of the delivery ship, connections are made and communications established.
On the receiving ship, the hose messenger is led through a 12-inch snatch block shackled to a padeye located about 6 feet above the deck and over the fuel trunk or manifold, As much of the messenger as possi­ble is run in by hand, and then taken to a winch; aboard the delivery ship the messenger is paid out by hand, The span wire is payed out from a drum as the messenger hauls it across"
When the span wire comes aboard the receiving ship, the pelican hook is made fast to a tie-in padeye, and the stops securing it to the messenger are cut. The oiler now begins to tend the span wire, making sure that a good catenary is formed at all times. The span wire should never be allowed to slack off enough for the hose to touch the water.
When the hose messenger is cut free from the span wire, the receiving ship resumes heaving it in while the delivering ship pays out on the retrieving line and saddle whips. The saddles should be positioned so the span wire can carry the weight of the hose, but the saddle whips can be used to keep the hose high.
When the hose end comes within easy reach of the men on the receiving ship's deck, the stops seizing it to the messenger are cut, one by one, until the bight of the riding line can be slipped over the riding line hook. Then the end of the hose is tended and controlled by the receiving ship, and the messenger is returned to the delivering ship where it is made up in preparation for the next ship.
When all is secure, the receiving ship opens the hose valve and notifies the oiler to begin pumping.
Retrieving Hose and Span Wire
When pumping is completed, the receiving ship uncouples and, by using the riding line, eases the end of the hose out clear of the ship's side.
The delivery ship heaves in and two-blocks the inboard and outboard saddles, stops off the inboard saddle whip, removes the whip from the winch gypsy head, and belays it to a cleat. The retrieving line is then placed on the winch gypsy head, and the hose is hauled aboard the oiler.
When the hose is retrieved, the span wire is slackened by the oiler, and the receiving ship trips the span wire pelican hook and eases out the end of the span wire on the bight of an easing out line rove through the long link of the pelican hook.
The delivery ship then hauls in her span wire, phone lines, and messengers; and returns the B/B phone/distance line to complete the operation.
SAFETY PRECAUTIONS
If you are going to a underway replenish­ment transfer station, you must be aware of the following safety precautions (there are a number of others-these are are just a few).
1. Only essential personnel are allowed at a transfer station-if you are not assigned to one, you have no business there.
2. When a line-throwing device is used, unless directly involved take cover and remain there until word is passed that shot lines are secure.
3. If topside, you must wear a life jacket; you may be required to wear a safety helmet, gloves, and/or safety shoes.
4. Keep at least 6 feet away from blocks through which lines pass.
5. Do not get between a load and the rail.
There is much more to u/w replenishment and a lot of improvements and new methods this is just something of interest to some but has been forgot in the last few years.