Submarines have anchors, but shouldn’t
No, really! Nuclear submarines, especially boomers, are required to be assisted to pier moorings by several tugboats. What do you need an anchor for?
One of our missions whilst in Charleston on shakedown was to test the ship’s anchor (skimmers call this Ground Tackle, pronounced “take-ell”) by actually going out of the harbor, lowering the thing to the sea floor, dragging it around a bit, then reeling it back in. So, one bright and sunning morning, we set the Maneuvering Watch (skimmers call this the Sea & Anchor Detail) and made for the Atlantic.
The process for anchoring is fairly straight forward, and simple enough that practically any marginally competent skimmer can do it. First you stop making headway, then you walked the anchor out with the anchor windless, until it rests on the sea floor. Coral reefs make good anchorages, but the tree huggers object to this use ‘cause the anchor usually bashes the reef but good. Once your anchor reaches the bottom, you run out even more anchor chain (skimmers call the chain “rode”), usually three to five times the depth. This length of chain between the ship and the anchor is called the “scope of the rode”. Now that the anchor rests serenely on the bottom, you back down and drag it (like a John Deere plow) across the bottom until it “sets” by snagging something big or digging itself into the bottom.
Once the anchor is properly set, you stop and secure the engines. You are now “at anchor”. To get underway from being “at anchor”, you start you engines and move the ship up over the anchor. Next you use the anchor windlass to take up the slack in the rode. Ideally, when the slack is out of the rode, you take a slight strain on the rode and easily pull the anchor free from the bottom. The anchor is now “aweigh”. Maybe you’ve heard of a song that starts, “Anchors aweigh my boys, anchors aweigh.”
After finding a suitable spot, out of the traffic lanes, not too deep and not too shallow, we anchored. With the ease and proficiency of any ship-of-the-line, we hove to, ran out the anchor with a goodly scope of rode, and set it. Ta-Da! We were at anchor. All that remained was to up anchor and head back for liberty call. But first, lunch!
After lunch, with the afternoon watch set, we began the un-anchoring process. We moved the boat up over the anchor and started hauling in the rode. Suddenly, the windlass stalled. Our anchor chain had hockled.
The anchor chain on the boat was a special double link type of chain, designed specifically for anchoring ships. The Navy paid lots of good taxpayer money for this special chain, and uses this type of chain on all of its ships. It was design such that no matter how much you twisted it while the ship was at anchor, it absolutely would not double up and form a kink. This kink is called a “hockle”. If the chain hockles, you can’t pull it back into the ship because it won’t ride through the windlass. You have to un-hockle it first.
The anchor on the submarine is special in and of itself. It isn’t an anchor like on a Chief’s collar device. This thing is made of a curved plate that fairs smoothly with the underside of the hull when the anchor is drawn up under the torpedo room and stowed. The shank of the anchor attaches to the center of this plate. The anchor chain attaches to the other end of the shank with a large shackle. The anchor has four flukes, the large blade-like projections that dig into the sea floor. The flukes are welded to the four corners of the anchor plate. Because the anchor plate is curved and the flukes stick out from the corners like airplane propellers, the anchor has a tendency to pin-wheel when it moves through the water; a real hockle generator.
What to do? What to do? The plan was to run the chain back out, move the ship, which would shake out the hockle, then haul in the anchor. We ran the chain back out, and moved the ship. The hockle did not shake out. One definition of insanity is doing the same thing over and over and expecting different results. We ran the chain out, moved the ship, and hauled it back in many times. The windlass stalled every time.
Possibly, when we moved the ship, we didn’t really move the ship. I happened to be the Throttleman this particular afternoon. The basic job of the Throttleman is to operate the main engine steam throttles. Open the ahead throttle. The steam engines turn the propeller. The propeller generates thrust that pushes forward on the submarine, overcoming its thousand tons of inertial mass, causing it to move forward. Open the astern throttle and same process takes place but in the other direction. The boat moves backwards or astern.
Along with running the steam throttles, there is a little bookkeeping requirement that goes with engine orders. When the Helmsman turns the little dial on the engineer order telegraph on the Ships Control Panel, through the magic of electricity, the dial makes an indicator move on the Steam Plant Control Panel, and dings a large bell to alert the Throttleman of a new engine order. The engine change orders are called “bells” because of the bell dings. The Throttleman acknowledges the new bell by turning the little dial on the engine order telegraph on the SPCP, which turns an indicator on the engine order telegraph on the SCP. This tells the Helmsman that the Throttle man is still alive and has received the new engine speed change order.
After the Throttleman acknowledges the bell change, he enters the time, the bell order, and the shaft turns counter reading on the Bell Log. This is a legal document that is maintained to show what speeds and when the ship’s engines were operating. This log entry takes ten to fifteen seconds to complete. Once the bell change is logged, the Throttleman opens or closes the ahead or astern throttle to execute the engine order, and “answer the bell”.
During the next hour and a half, I received over two hundred and ninety bell change orders from Control. Ahead one third. All stop. Back one third. All stop. Ahead two thirds. All stop. And so on and on and on. That works out to an ordered change of propeller push on the hull, on average, of about every eighteen seconds. Many of the entries in the Bell Log had the same shaft turn count value. It should be fairly obvious to the most casual observer that these bell changes were having no real effect on generating way on the ship, so no hockle shake out.
By mid afternoon it was decided to send the diver down to the anchor with a mooring line. He would secure it to the anchor and we would pull the anchor up onto the topside with the capstan. The anchor would be made fast to the cleats with more mooring lines, then the excess anchor chain would be pulled up topside and secured in the same fashion.
We returned to Charleston under cover of darkness with our deck cargo securely lashed in place.
Submarines have anchors, but we couldn’t.
As an aside, our “DV” was very apprehensive about swimming in the open ocean. There were sharks around, you know. His fears were alleviated when one of the torpedomen was stationed on a fairwater plane with an M-14 rifle to “cover” him. After the Anchor Recovery Party was secured, DV had stowed his gear and was passing through the mess decks, where the torpedoman was cleaning the rifle. DV thanked the torpedoman for backing him up. The torpedoman’s reply was something like, “The rifle wasn’t for the sharks.”
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