Anchor

An anchor is a device by which a vessel is moored on ground or on ice, to avoid being drifted by wind, current, waves or other influences. The process is called anchor. Anchors hold due to their weight and shape.

As allegory is the anchor for the fidelity in Christian symbolism for hope.

Anchor forms

On the one hand, there are weight anchor that hold mainly because of their weight. This mainly older types of anchors or in the simplest case a heavy stone. On the other hand there is godfather tanker or lightweight anchor which dig because of their shape under tensile load on the anchor chain with one or more flukes into the ground. These include the plow anchor, plow anchor or CQR anchor, Danforth anchor or anchor plate, the Heuss- anchor, the bow anchor, the d' Hone anchor or HKG- clip anchor, Bruce anchor with no moving parts and many other. A special role is played by the mushroom anchor, moored with fire ships or navigation mark for a long time. The four - or six-armed grapnel is used predominantly in the Mediterranean by fishermen and as Faltdraggen on small pleasure boats. In addition to the forms that are used for anchoring, also ( folding ) grapnel find with very narrow flukes, which are used to fish lying on the bottom longline. Finally, there is sand anchors that have a spiral tip and must be screwed into sandy seabed or on the shore in the sand, so that they can work.

Stern anchor

Stern anchor apply as an additional anchor and applied especially during storms, or to make sure to close anchorages that the boat or ship remains fixed in one direction at anchor and not other vehicles rammed by it around on its long chain around his anchor moved ( schwoit ). In practice, it requires good seamanship but that one so anchored the vehicle that waves can roll in from the bow of her against the vehicle.

In the commercial shipping of the stern anchor is especially common there, where with them offshore towing maneuvers are driven by delivering the anchor to a salvage or tow vehicle, secures itself and the anchor chain used as a " pull rope ". Especially often can be observed in the deep sea oil industry, when an oil tanker of oil island utilities and tugs for loading must be put in place during a storm.

Anchor gear

The anchoring system consists of an anchor, the anchor shackle (often one swivels ) and the anchor chain. The anchor chain can be replaced on smaller ships with a shorter chain flow (a few meters directly on the anchor chain ) and an anchor rope ( anchor line ). Since the weight of the anchor cable plays an essential role in the holding force of the ground tackle, anchor lines are occasionally inlaid with lead weights to compensate for the lower weight of the cable to the chain. To this end, riding weights on the cable can be attached.

Anchors on ships

The now common on ships anchor is the godfather tankers. For ships of the navies, special service vessels, formerly lightships, light buoys, etc., there are specific, appropriate for these types of ships anchor.

The armature is attached to a shackle on the anchor chain, welded or forged compounds are today uncommon. The chain itself is composed of lengths of 25 meters, which are connected by shackles. Each shackle is marked with a bright color to the weighing anchor easier to include the information gathered can shackle; it is determined how much anchor chain is already outdated. The anchor chain runs when hoisting the anchor through the hawse-hole on the ship's deck, from there by a mechanical chain stopper in the train wheel, the gypsy windlass and further into the chain locker.

Every large ship has on the back two windlasses, each with an anchor and to at least one spare anchor, the spare anchor with an approval of the classification society shall not be carried. This has the consequence that the spare anchor must be brought to the ship in the loss of an anchor as soon as possible, which can be problematic for large vessels (anchor weight 20 tons and more).

Length of the chain

The anchor chain or cable must be plugged in as long ( extended) that the armature remains above the anchor chain still flat on the ground even under tensile load, otherwise it will be torn out of the ground and no longer holds. If this is not the case, the ship is hove short. This should only immediately before the lights ( breaking out of the ground ) and hoisting ( raising ) the case, since the holding power of the anchor is still low then.

Seagoing vessels usually have 10-12 shackle (1 shackle corresponds to today 25 m, previously 15 English thread = 27.432 m) chain length on each side (port and starboard ); the built in recent years, cruise ships to 14 per side, which corresponds to a total length of 770 m.

The length of the extended anchor chain is specified in shackles ( to 25 m). Thus the statement can be in front of the anchors: " 5 shackle to water " or "3 shackle at the capstan ." It mainly depends on the water depth at the berth and soil characteristics from (mud, sand, Schill, stones, vegetation, etc.). In the first few meters, the chain is on the seabed, and then leads into a bow ( bay ) up to the ship. The weight of the fallen chain contributes significantly to the holding force. The bay in which the chain from the vessel depends on the reason, stretched at short-term effect of force on the ship, eg by pitching in rough seas or swell slightly and thus acts as a shock absorber against power spikes that would otherwise damage the capstan or could result in breaking the chain. With decreasing force the chain or hawser decreases by her weight back to the ground and the ship will thus pulled back to its original location. The greater the expected forces on the ship ( due to wind pressure, current, sea state, ice conditions ), the more chain must be plugged. If a lighter cable used instead of the chain, so it's according to choose longer. With little wind and no swell three to four times the water depth is large enough as the chain length. In rough seas and strong winds, the water depth must be plugged in chain length up to ten times.

Since a ankerndes ship under the influence of wind and current around the anchor schwoit, there is a danger that it collided on a narrow harbor with an adjacent vessel or with tons or solid structures when the chain length is too large. Can not be shortened without risk this, the ship must go " anchor on " and seek a more suitable anchorage under certain circumstances.

Process of anchoring

Selection of anchorage

General should be established before initiating the anchor maneuver, which anchorage should be seized. Here, the water flow, the wind conditions, the anchorage, the water depth and location with respect to the shipping lanes are taken into account. It is also noted how much mass has the ship and which anchors and their number must be applied. The anchorage should offer little resistance as possible, be visible from all sides, and the traffic is not unduly hinder ( in some places there is prohibition on anchoring ). When Schwoien the ship should stay clear of other anchored ships, tons, fixed structures and shoals.

Close to many ports, the raids are set by the local authorities and recorded in the chart. Often gets a seagoing its anchorage by the competent authority or the traffic control system assigned.

Water flow

We anchored in general only in the stagnant waters in order to ensure the car a bit of comfort can.

Wind and waves

For recreational craft shall: One anchored only in the case offshore winds (wind and shadow in the lee of the coast). It should be noted that the wind to rotate. For onshore wind, the boat turns around the anchor with the radius of the chain length to the shore. The water depth decreases and the risk of ground contact to. Also increases due to the longer start-up segment of the wind over the water of the seas. With each wave, the chain is streamlined and heavily loaded anchor. Thus he moves closer to shore or tears, and the ship is stranded. With a rotating wind and swell increasing so a new secure anchorage is time to look.

On ships, it may be inevitable, even with strong winds to anchor. The bridge must while the armature laytime permanently be occupied ( anchor watch ), and the machine must be kept available for immediate use clear, there are signs of deteriorating weather. The watch officer must constantly monitor the ship's position to determine a possible Dispel immediately. If a Dispel seen as either more chain must be plugged, or it must be the anchor hoisted and to leave the anchorage. In general: If the ship at anchor maneuvers before an anchor, the second anchor is in any case always be kept clear for the fall. With cautious machines maneuvers chain and anchor can be relieved somewhat, but this may only be a temporary measure until the anchor is eingehievt.

Water depth

Anchor is only possible if the anchor chain with respect to the water depth is sufficiently long. The decisive factor is the angle between stretched anchor chain and anchor reason: the flatter the better. Therefore, the entire chain must be at least five times as long as the water depth. If instead of a chain leash used, the line length must be at least ten times the water depth. One way of reducing the chain or rope length ( with consistently shallow angle to the anchor ) is the use of a riding weight which is attached to the anchor line be moved ( for example, with a shackle ).

On ships, it sometimes happens that the anchor is thrown on to deep water and later can not be eingehievt again because the power of the windlass for the combined weight of anchor and chain is not sufficient. The classification societies Write a tensile force before that ensures a heaving anchor and chain at 50 m. Therefore, one should avoid to anchor to greater depths it.

At greater depths should we not drop the anchor from the beginning, since it absorb too much speed and may be damaged by hitting the ground. From about 30 m water depth, it is safer to first auszuhieven the armature to the spill until it is about 10 m above ground, and only then disengage the spill and let the anchor drop the rest of the way.

Anchorage

Depending on the type and condition of the ground anchor types with different levels good hold:

• Sludge ( Schl. ) was formerly entirely unsuitable for anchoring (no liability for Stockanchor )
• Schlick ( Sk ) has a very bad primer and was formerly unsuitable for longer anchors ( stock anchor sinks to the deep )
• Gravel (K.) and stones ( pieces) are regarded as difficult to perfect, depending on the grain size of the stones, or of the gravel and nature of the anchor
• Large stones ( g St. ) are problematic as to wedge the anchor and then it is difficult to applied
• Sound ( T. ) is a good reason, since it is composed uniform and large porosity
• Sand ( Sd. ) is the best anchorage.

The nature of the appeal is referred to in the chart.

To improve the maintenance of a stock anchor in loose anchorage, were used earlier, sometimes an anchor shoe, i.e., a wooden clothing of plowing.

Implementation

An anchor is not "thrown", but dropped. When mounting with only one anchor the vehicle can rotate freely around the armature ( schwojen ). The choice of an anchorage is done according to several criteria, such as water depth, anchorage, wind direction and flow. There are several ways to connect the anchor to the ship: by means of a chain, a leash, or a combination of both.

If anchored with a Godfather tanker, the anchor is deployed in reversing slowly in the direction of the expected main force ( wind, current ). The aim is to first just possible deploy the anchor gear on the ground. The anchor is thereby slowly dragged across the ground ( " grazing " ) and digs with the lying on the ground fluke into the ground. Often once again pulled strongly at the end of the anchor maneuver on the chain ( by machine power astern ) to dig deep to anchor and to check the maintenance of the anchor. If the anchor broken out there and dragged across the ground ( " streaks " ), can be felt or palpated at this jerky chain movements.

To bring up the anchor again, can be done to drive him slowly to relieve the chain and thus to facilitate the work of the windlass. The process of bringing up- called Lichten or hoisting. The command for the lights is on anchor! . The message anchors on after full completion of the maneuver means that the anchor aufgehievt (but not necessarily eingehievt in the hawse pipe ) is. You may then have to be reported in the hawse pipe after the (often difficult ) Vorhieven the anchor: anchor is a and vorgehievt.

The term " anchor " is seen in the commercial shipping as a sure sign of a landlubber - he's not in use. The same applies to the command " Heave anchor ".

Anchor ball and anchor light

After the fall of the anchor anchor ball must be set ( after sunset or in poor visibility, the anchor light is shown), so that other road users know. About the anchor a buoy is to be set. During the anchoring is constantly maintain an anchor watch, these are crew members, (anchor ) make soundings and watch the traffic. Report especially the outbreak of the anchor to the ship's officers.

Anchor weight

The anchor weight is used to increase the weight of the anchor chain and is particularly prevalent in the marine leisure, since the anchor often not on a chain, but on a leash (if thicker: hawser ) is being driven. However, since the weight of the chain on the ground only allowed the anchors must be simulated with anchor weights on the anchor end of the leash an "anchor chain ".

Reasons for the anchors

Reasons for the anchors can be of help (eg as Notankern for maneuverability or Manövrierbehinderung ) or waiting for a berth the Abwettern ( Waiting for better weather or better lake ), the Waiting. In addition, the anchors may itself already constitute lying at a mooring. Anchoring is generally more difficult and risky than creating.