Steering gear
a set of mechanisms, assemblies and components that provide control of the vessel.
The main structural elements of any steering device are:
working body - rudder blade (rudder) or rotary guide nozzle;
stock connecting the working body with the steering gear;
steering drive, transmitting force from the steering machine to the working element;
steering gear, which creates the force to rotate the working body;
control drive connecting the steering machine to the control station.
On modern ships, hollow, streamlined rudders are installed, consisting of horizontal ribs and vertical diaphragms covered with steel casing (Fig. 1, a). The skin is secured to the frame with electric rivets. Inner space The steering wheel is filled with resinous substances or self-foaming polyurethane foam PPU3S.
Depending on the location of the axis of rotation, there are balanced (Fig. 1, e, c), unbalanced (Fig. 1, b) and semi-balanced rudders. The axis of rotation of the balance rudder passes through the rudder blade, and the unbalanced rudder coincides with the leading edge of the rudder. On a semi-balanced rudder, only the lower part of the feather protrudes into the nose from the axis of rotation. The moment of resistance to turning of a balanced or semi-balanced steering wheel is less than that of an unbalanced steering wheel, and accordingly the required power of the steering machine is less.
According to the method of fastening, rudders are divided into suspended and simple.
The outboard rudder is attached with a horizontal flange connection to the stock and is installed only on small and small mining vessels. A simple single-support balance rudder (see Fig. 1, a) rests with a pin against the thrust cup of the sternpost heel. To reduce friction, the cylindrical part of the pin has a bronze lining, and a bronze bushing is inserted into the heel of the sternpost. The connection between the rudder and the stock is a horizontal flange with six bolts or a conical connection. With a conical connection, the conical end part of the stock is inserted into the conical hole of the upper end diaphragm of the rudder and tightly tightened with a nut, access to which is provided through a cover placed on screws included in the rudder casing. The curved stock allows for separate removal of the steering wheel and stock (when they are rotated mutually).
Simple two-post unbalanced steering wheel(see Fig. 1, b) is closed on top by a sheet diaphragm and a cast head, which has a flange for connecting the steering wheel to the stock and a loop for the upper pin support. Backout, bronze or other bushings are inserted into the rudder post loop.
Insufficient rigidity of the lower support balancing rudders often causes vibration of the ship's stern and rudder. This disadvantage is absent in a balancing rudder with a removable rudder post (see Fig. 1, c). A pipe is built into the feather of such a rudder, through which a removable rudder post passes. The lower end of the rudder post is secured with a cone in the heel of the sternpost, and the upper end is secured with a flange to the sternpost. Bearings are installed inside the pipe. The rudder post where it passes through the bearings has a bronze lining. The rudder is attached to the stock by a flange.
Rice. 1. Working bodies of steering devices: a - single-support balancing steering wheel; b - two-support unbalanced steering wheel; c - balanced steering wheel with a removable rudder post; g - active steering wheel; d - rotary guide nozzle with stabilizer; 1 - stock; 2 - flange; 3 - rudder trim; 4 - fairing; 5 - vertical diaphragm; 6 - horizontal rib; 7 - sternpost heel; 8 - nut; 9 - washer; 10 - steering pin; 11 - bronze lining of the pin; 12 - bronze bushing (bearing); 13 - thrust glass; 14 - channel for dismantling the thrust cup; 15 - helmport tube; 16 - rudder post loop; 17 - rudder post; 18 - backout; 19 - rudder post flange; 20 - removable rudder post; 21 - vertical pipe; 22 - rudder propeller; 23 - gearbox with fairing; 24 - stabilizer; 25 - rotary guide nozzle; 26 - propeller shaft; 27 - propeller
The active steering wheel (Fig. 1, d) contains auxiliary propeller. When the rudder is shifted, the direction of the auxiliary propeller stop changes and an additional moment arises, turning the ship. The direction of rotation of the auxiliary screw is opposite to the direction of rotation of the main one. The electric motor is located in the steering wheel or in the tiller compartment. In the latter case, the electric motor is directly connected to a vertical shaft, which transmits rotation to the propulsion gearbox. The active rudder propeller can provide the vessel with a speed of up to 5 knots.
On many vessels of the fishing fleet, instead of a rudder, rotating guide nozzle(Fig. 1, d), which creates the same lateral force as the steering wheel at smaller shift angles. Moreover, the moment on the nozzle stock is approximately two times less than the moment on the rudder stock. To ensure a stable position of the nozzle during shifts and increase its steering action, a stabilizer is attached to the tail part of the nozzle in the plane of the stock axis. The design and fastening of the attachment are similar to the design and fastening of the balance rudder.
The stock is a curved or straight steel cylindrical beam, led through a helm port pipe into the tiller compartment. The connection of the helmport pipe with the outer plating and deck covering is waterproof. At the top of the pipe, a sealing gland and stock bearings are installed, which can be support or thrust.
The steering device must have drives: main and auxiliary, and if they are located below the load waterline, an additional emergency one is located above the bulkhead deck. Instead of an auxiliary drive, it is possible to install a dual main drive, consisting of two autonomous units. All drives must operate independently of each other, but, as an exception, they may have some common parts. main drive must be powered by energy sources, the auxiliary one can be manual.
The design of the steering drive depends on the type of steering machine. Electric and electro-hydraulic steering gears are installed on fishing fleet vessels. The first ones are made in the form of an electric motor direct current, the second - in the form of an electric motor-pump complex in combination with a plunger, blade or screw hydraulic drive. Manual steering gears in combination with a steering cable, roller or hydraulic steering drive are found only on small and undersized mining vessels.
Rice. 2. Steering drives: a - sector-type; b - sturtrosovy; c - hydraulic plunger; g - hydraulic blade; d - hydraulic screw; e - tiller-talk; 1 - steering wheel and steering column auxiliary drive; 2 - tiller; 3 - worm gearbox; 4 - gear sector of the main drive; 5 - electric motor; 6 - spring shock absorber; 7 - stock; 8 - balance steering wheel; 9 - gear sector of the auxiliary drive; 10 - worm; 11 - steering cable; 12 - guide rollers; 13 - buffer springs; 14 - sector; 15 - piston-plunger; 16 - hydraulic cylinder; 17 - pump; 18 - safety valve; 19 - body; 20 - sector-shaped chamber; 21 - lionfish with blades; 22 - glass with longitudinal grooves; 23 - ring piston; 24 - glass with screw grooves; 25 - cover; 26 - square head; 27 - working cavity of the cylinder; 28 - keyway; 29 - running end of the lopar; thirty - moving block; 31 - fixed block
Many small and medium tonnage vessels are equipped with sector gear steering drive(Fig. 2, a). When the electric motor is operating, the gear sector, loosely mounted on the stock, transmits force through spring shock absorbers to a longitudinal tiller rigidly attached to the stock. Shock absorbers soften shocks that occur when starting an electric motor or when waves hit the rudder. Worm gear provides self-braking of the drive. An additional gear sector rigidly mounted on the stock is provided as an auxiliary drive. The operation of the sector is ensured by a manual steering column through roller wiring and an additional worm gear.
On small mining vessels they use sector steering cable drive(Fig. 2, b). The steering force is transmitted through the steering cable to a sector rigidly mounted on the stock. Sturtros perform ie steel cable with a section of the Gall chain in the middle part or the entire chain. Both branches of the steering cable from the sector through the guide rollers go to the sprocket or drum of the steering machine. In the latter option, when the drum rotates, one branch of the steel cable is selected and the other is pulled out. The slack of the steering cable is selected using screw lanyards, the shocks are softened by buffer springs.
Most widespread The fishing fleet received hydraulic steering drives: plunger, blade, screw.
Hydraulic plunger drive pump(Fig. 2, c) during operation of the electric motor, it pumps working fluid from one hydraulic cylinder to another, which leads to the movement of a plunger pivotally connected to the tiller stock and rotation of the stock. When a wave hits the rudder blade, the pressure in one of the hydraulic cylinders increases and the safety valve transfers part of the working fluid to the other cylinder, absorbing the impact. Special device ensures automatic return of the rudder blade to its original position after the pressure in the hydraulic cylinder drops. Many vessels are equipped with dual plunger hydraulic steering actuators. Two pairs of hydraulic cylinders and two pumps operating in parallel provide the ability to shift the steering wheel with any pair of hydraulic pumps. In this case, the ship may not have auxiliary drive steering wheel
The tiller of a hydraulic paddle steering drive, made in the form of a winglet with blades, is located in a closed cylindrical housing, divided by fixed partitions into several working chambers filled with working fluid (in Fig. 2, d there are two chambers). The gaps between the blades and the body, the fixed partitions and the stock are sealed. When pumping working fluid from one chamber cavity to another, a pressure difference is created, causing the tiller and stock to rotate.
Screw hydraulic drive(Fig. 2, e) consists of a fixed body, middle part which acts as a cylinder. An annular piston is placed in the cylinder: it inner surface It has screw grooves in the upper part and longitudinal grooves in the lower part. A glass with longitudinal grooves is rigidly placed on the head of the stock. Another glass with screw grooves is fixedly attached to the housing cover. When liquid is supplied to the working cavity of the cylinder, the piston receives translational motion, moving along the helical grooves of the stationary glass, turns and turns the stock through the glass with longitudinal grooves.
In addition to those listed, other types of steering gears are occasionally found on fishing vessels, mainly as auxiliary or emergency ones. In exceptional emergency situations two tillers can be used.
A hoist is two blocks between which a cable is stretched (lopar, Fig. 2, e). The end of the lopar, for which traction is performed, is called the running end, and the fixed end is called the root end. The block consists of a housing, inside of which there are one or more pulleys rotating on an axis (pin). Hoists can be various designs. The simplest type of hoist is a fixed single-pulley block that allows you to change the direction of traction (guide block). Pride does not give any gain in effort.
Another type - khuttali - these are two and one-pulley blocks, and the root end of the lopar is fixed on a single-pulley block.
Hoists consisting of blocks with the same number of pulleys are called ghants, and those made of blocks with the number of pulleys more than three in each block are called gins. When the hoist operates, a force arises in all branches of the lopar equal to the force applied to the running end, therefore the total force transmitted by the hoist is equal to the sum of the forces in the branches of the moving block, including the force in the running end, if it comes off this block. One block of the hoist is attached with a bracket to the hole provided in the frame, the other - to the sector or tiller. The running plows are led through a system of guide blocks to the nearest winch. The operating principle is similar to that of steering cable drive.
Remote control of the steering gear from the wheelhouse is provided by teledynamic transmissions, called steering teletransmissions or steering telemotors. Hydraulic and electric steering gears are used on modern fishing vessels. They are often duplicated or combined into electro-hydraulic ones.
The electrical transmission consists of a special controller located in the steering column and connected by an electrical system to starting device steering machine. The controller is controlled using a steering wheel, handle or button.
The hydraulic transmission consists of a hand pump driven by the steering wheel and a system of tubes connecting the pump to the steering gear trigger. The working fluid of the system is a non-freezing mixture of water and glycerin or mineral oil.
The main and auxiliary steering drives (powered by an energy source) are controlled independently and are carried out from the navigation bridge, as well as from the tiller compartment. The transition time from the main to the auxiliary drive should not exceed 2 minutes. If there are control posts for the main steering gear in the wheelhouse and fishing room, failure of the control system from one post should not interfere with control from another post. Time for shifting a fully submerged rudder or rotary attachment by the main drive (with highest speed forward travel) from 35° of one side to 30° of the other should not exceed 28 s, auxiliary (at a speed equal to half the maximum forward speed or 7 knots, whichever is greater) from 15° of one side to 15° of the other - 60 s, emergency (at a speed of at least 4 knots) is not limited.
The angle and shift of the rudder are determined by an axiometer installed at each control station. In addition, a scale is applied to the steering gear sector or other parts rigidly connected to the stock to determine the actual position of the steering wheel. Automatic coordination between the speed, direction of rotation and position of the steering wheel and the speed, side and angle of the rudder is ensured by a servomotor.
The rudder shift limiters are made in the form of protrusions on the rudder and sternpost, which rest against each other at the maximum permissible rudder shift angle, or in the form of brackets welded to the deck, against which the rudder drive sector rests. All mechanical steering gears additionally have limit switches that turn off the mechanisms before the steering wheel reaches the turn limiter. In a hydraulic plunger drive, the steering wheel rotation limiter is the bottoms of the drive hydraulic cylinders.
The steering brake (stopper) is designed to hold the steering wheel during emergency repairs or when switching from one drive to another. The most commonly used is a tape stopper, which directly clamps the rudder stock. Sector drives have block stoppers, in which brake shoe presses against a special arc on the sector. IN hydraulic drives The role of a stopper is performed by valves that block the access of the working fluid to the drives.
Keeping the ship on a given course under favorable conditions weather conditions without the participation of a helmsman, it is provided by an autopilot, the operating principle of which is based on the use of a gyrocompass or magnetic compass. The normal controls are connected to the autopilot. When the ship is on a given course, the rudder is set to the zero position according to the axiometer and the autopilot is turned on. If, under the influence of wind, waves or currents, the vessel deviates from the set course, the system’s electric motor, receiving an impulse from the compass sensor, ensures that the vessel returns to the set course. When changing course or maneuvering, the autopilot is turned off and normal steering is switched over.
The steering device is used to change the direction of movement of the vessel, ensuring that the rudder is shifted to a certain angle in a given period of time. Its main parts are:
· Control station;
· Steering gear from the helm station to the steering motor:
· Steering motor;
· Steering drive from the steering motor to the steering stock;
· A rudder or rotary attachment that directly provides steering control of the vessel.
The main elements of the steering device are shown in Fig. 3.10.
Steering wheel- the main organ that ensures the operation of the device. It operates only while the ship is moving and in most cases is located in the stern. Usually there is one rudder on a ship. But sometimes, to simplify the design of the steering wheel (but not the steering device, which in this case becomes more complicated), several rudders are installed, the sum of the areas of which should be equal to the estimated area of the rudder blade.
The main element of the steering wheel is the feather. According to the cross-sectional shape, the rudder blade can be: a) plate-like or flat, b) streamlined or profiled.
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Fig.3.10 Steering device
1 – rudder blade; 2 – stock; - 3 – tiller; 4 – steering machine with steering gear; 5 – helmport tube; 6 – flange connection; 7 – manual drive.
The advantage of a profiled rudder blade is that the force of pressure on it exceeds (by 30% or more) the pressure on a plate rudder, which improves the maneuverability of the vessel. The distance of the center of pressure of such a steering wheel from the incoming (front) edge of the steering wheel is smaller, and the moment required to turn a profiled steering wheel is also less than that of a plate steering wheel. Consequently, a less powerful steering machine will be required. In addition, a profiled (streamlined) rudder improves the performance of the propeller and creates less resistance to the movement of the vessel.
The shape of the projection of the rudder blade on the DP depends on the shape of the stern formation of the hull, and the area depends on the length and draft of the vessel (L and d). For sea vessels, the rudder blade area is selected within 1.7-2.5% of the submerged part of the center plane area vessel. The stock axis is the axis of rotation of the rudder blade. The rudder stock enters the rear valance of the hull through a helmsman pipe. On the upper part of the stock (head), a lever called a tiller is attached to a key, which serves to transmit torque from the drive through the stock to the rudder blade.
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Ship rudders are usually classified according to the following criteria:
According to the method of attaching the rudder blade to the ship's hull, rudders are distinguished:
A) simple- with a support on the lower end of the steering wheel or with many supports on the rudder post;
b) semi-suspended– with support on a special bracket at one intermediate point along the height of the steering wheel;
V) hanging– hanging on the stock.
According to the position of the axis of rotation relative to the rudder blade, the following rudders are distinguished:
A) unbalanced– with an axis located at the leading (incoming) edge of the feather;
b) balancing– with an axis located at some distance from the leading edge of the steering wheel.
Fig. 3.11 Simple unbalanced steering wheel.
Fig. 3.12 Semi-suspended unbalanced steering wheel.
Fig.3.13 Suspended unbalanced rudder.
Fig. 3.14 Simple balancing rudder.
Fig.3.15 Semi-suspended balance rudder (semi-suspended)
Fig.3.16 Suspended balance rudder.
Steering gear is intended to transmit commands from the navigator in the wheelhouse to the steering machine in the tiller compartment. Most Applications find electric or hydraulic transmission. On small vessels, roller or cable drives, in the latter case, this drive is called a sturtrosovym.
Control devices monitor the position of the steering wheels and the proper operation of the entire device.
Control devices transmit orders to the helmsman when steering the steering wheel manually.
The steering device is one of the most important devices ensuring the survivability of the vessel. In case of an accident, the steering device has a backup steering control post, consisting of a steering wheel and a manual drive, located in the tiller compartment or close to it.
At low ship speeds, steering devices become insufficiently effective and sometimes make the ship completely uncontrollable. To increase maneuverability, some types of modern vessels (fishing vessels, tugboats, passenger and special vessels) install active rudders, rotary nozzles, thrusters or winged propulsors. These devices allow ships to independently perform complex maneuvers in the open sea, as well as pass through narrow areas without auxiliary tugs, enter the waters of the roadstead and harbor and approach the berths, turn around and move away from them, saving time and money.
Active steering(Fig. 3.17) is a feather of a streamlined rudder, on the trailing edge of which there is a nozzle with a propeller driven by a roller bevel gear passing through a hollow stock and rotating from an electric motor mounted on the head of the stock. There is a type of active steering wheel with propeller rotation from a water-based electric motor (working in water) mounted in the rudder blade. When the active rudder is moved on board, the propeller operating in it creates a stop that turns the stern relative to the axis of rotation of the vessel. When working propeller active rudder while the ship is moving, the speed of the ship increases by 2-3 knots. When the main engines are stopped, the operation of the active rudder propeller causes the vessel to have a low speed of up to 5 knot
Fig. 3.17 Active steering wheel with bevel gear to propeller.
Rotary nozzle, installed instead of the rudder, when placed on board, deflects the jet of water thrown by the propeller, the reaction of which causes the stern end of the vessel to turn. Rotary nozzles are a guide nozzle of the propeller mounted on a vertical stock, the axis of which intersects with the axis of the propeller in the plane of the propeller disk (Fig. 29). The rotary guide nozzle is part of the propulsion complex and at the same time serves as a control element, replacing the steering wheel. The nozzle removed from the DP works like an annular wing, on which a lateral lift force occurs, causing the vessel to turn. The hydrodynamic moment arising on the nozzle stock (both on the front and on the in reverse) tends to increase the angle of its shift. To reduce the impact of this negative point, a stabilizer with a symmetrical profile is installed in the tail part of the nozzle. The angle of rotation of the nozzle relative to the ship's DP is, as a rule, 30-35°.
Fig.3.18. Rotary nozzle.
Thrusters are usually carried out in the form of tunnels passing through the hull, in the plane of the frame in the aft and
Fig.3.19 Schematic diagram thruster
Purpose: ensuring the controllability of the vessel, i.e. his ability to move along a certain trajectory.
Steering device design.
General location One of the steering device options is shown in the figure.
Rice. 3.1.1. Steering device diagram:
1- rudder feather; 2 – flange connection; 3- stock supports;
4 – stock head; 5 – steering drive; 6 – steering gear;
7- steering wheel; 8 – steering gear; 9 – stock; 10 – helmport tube;
11 – rudder blade loop; 12 – pin; 13 – rudder post loop;
14 – rudder post; 15 – sternpost heel.
The main element that creates the force necessary for maneuver is rudder feather 1. To rotate the rudder blade at a certain angle relative to the DP, use baller 9 – shaft of variable diameter along the length. Areas with an increased diameter compared to the design diameter are provided in the locations of the supports of the stock 3 to increase maintainability. To connect the stock and rudder blade, either flange connection 2, shown in the figure, or a cone connection is most often used. The rudder stock enters the stern valance of the ship's hull through the helmport pipe 10, which ensures the tightness of the hull, and has at least two supports 3 in height. The lower support is located above the helm port pipe and has a gland seal that prevents water from entering the vessel's hull. Upper support located directly at the head of the stock, it usually takes the mass of the stock and rudder, so an annular protrusion is made on the stock.
The force required to turn the steering wheel on the stock is created by steering gear. The steering gear includes: steering gear 6; means of transmitting torque from the steering machine to the head of the stock 4 (steering drive - tiller or sector 5); steering gear 8; as well as the system remote control steering gear - a device for transmitting commands to shift the steering wheel from the navigation bridge (from the steering wheel 7) to the steering gear controls.
Classification of rudders.
Based on the distribution of the rudder blade area relative to the axis of rotation, the following types of rudders are distinguished (Figure 3.1.2):
Rice. 3.1.2. Classification of rudders by area distribution:
1 – rudder blade; 2 – anti-ice ledge; 3 – stock;
4 – rudder post; 5- bracket.
- unbalanced (ordinary ) (Fig. 3.1.2, a), the axis of rotation of which is close to the front (nose) edge of the rudder blade (distant from it at a distance equal to the radius of the rudder support);
- balanced (Fig. 3.1.2, b), the axis of rotation of which is shifted closer to the center of hydrodynamic pressure (distant from the leading edge at a distance greater than the radius of the rudder support), while the part of the feather area located in the nose from the axis of rotation is called the balance;
- semi-balanced (Fig. 3.1.2, c), in which the distribution of area in the lower part of the rudder blade corresponds to the balancer, and in the upper part - regular steering wheel;
- suspension (Fig. 3.1.2, d), stands out in the classification traditionally and is the same balancing rudder, differing in that the supports are not placed directly on the rudder.
Balanced and semi-balanced rudders are characterized by the balance coefficient k d:
where: F d - part of the rudder blade area located between the leading edge and the axis of rotation (balance), m 2; F – total area of the rudder blade, m2.
For balanced rudders, usually k d = 0.21¸0.23, for semi-balanced ones k d = 0.15.
The advantage of balanced and semi-balanced rudders: due to the smaller distance of the center of pressure from the axis of rotation, the torque on the stock is required less than that of unbalanced ones.
The disadvantage is that attaching such rudders to a ship is more difficult and less reliable.
Based on the profile shape, the following types of rudders are distinguished:
- flat single-layer, due to their low efficiency they are rarely used - mainly on non-propelled vessels;
- profiled two-layer ( streamlined), consisting of an outer skin and an inner set. The set is formed from horizontal ribs and vertical diaphragms welded to each other. The horizontal ribs are attached to the base of the rudder blade - the rudderpiece, which is a massive vertical rod. The ruderpiece is made together with loops for hanging the rudder blade on the ruderpost. The specific shape of the steering wheel profile is usually selected experimentally; accordingly, the profiles are named after the name of the laboratories in which they were developed.
Steering drives, their types, design and requirements for them.
Steering gear Designed to directly shift the steering wheel and control its position.
The following elements can be distinguished (rather conditionally) as part of the steering drive:
A device for transmitting torque from the steering gear to the stock (sometimes called the steering gear itself);
Steering machine - power point, creating the necessary force to rotate the stock;
Steering gear, which communicates between the control station and the steering machine;
Control system.
The following main types of steering gears are distinguished:
Mechanical (manual), which include tiller-steer-rod, sector-steer-rod, sector with roller wiring, screw tiller;
Having an energy source (hydraulic, electric, electrohydraulic).
Mechanical drives are used only on small vessels and as auxiliary steering drives.
Requirements for steering gears are contained in the Rules for the Classification and Construction of Sea Vessels of the RMRS (Volume 1, section III“Devices, equipment and supplies”, clause 2 “Steering device” and volume 2, section IX “Mechanisms”, clause 6.2 “Steering drives”). Among the main requirements are the following:
1. All vessels must be equipped with main and auxiliary steering gears, operating independently of one another.
2. The main drive and stock must ensure that the rudder can be shifted from 35 0 of one side to 30 0 of the other side in no more than 28 s at maximum operating draft and forward speed.
3. The auxiliary drive must ensure that the rudder can be shifted from 15 0 of one side to 15 0 of the other side in no more than 60 s at maximum service draft and a speed equal to half the maximum forward service speed or 7 knots (whichever is greater) .
4. On oil tankers, gas carriers and chemical carriers with a gross tonnage of 10,000 or more, on other ships with a gross tonnage of 70,000 or more, as well as on all nuclear ships, the main steering gear must include two (or more) identical power units. Accordingly, two independent control systems from the navigation bridge must be provided for them.
5. Control of the main drive must be provided from the navigation bridge and from the tiller compartment.
6. Control of the auxiliary drive must be provided from the tiller compartment, and if it operates from a power source, independent control from the navigation bridge must also be provided.
7. The design of steering drives must ensure a transition in the event of an accident from the main drive to the auxiliary drive in no more than 2 minutes.
8. Control of the steering wheel position must be ensured.
The following types of steering drives are distinguished:
Longitudinal tiller, in which a single-arm tiller mounted on the stock head is located in the longitudinal direction (Fig. 3.1.3, a);
Transverse tiller, in which the tiller is a double-armed lever (Fig. 3.1.3, b) - the name is conditional, because the tiller can be located both along and across the vessel’s DP;
Sector, in which the sector mounted on the head of the stock is rotated by the drive gear of the steering machine (Fig. 3.1.3, c).
A) 
b) 
V) 
Rice. 3.1.3 Types of steering gears:
a – longitudinal-tiller; b – transverse tiller; to sector.
Currently, on large ships, a transverse tiller drive with a four-plunger hydraulic steering machine combined with it has become widespread.
The following types of steering gears are distinguished:
Roller, in which the connection between the control station and the actuator (for example, the spool of a hydraulic steering machine) is carried out through a system of steel rollers (pipe sections) connected to each other using hinges or conical gears;
Hydraulic, which uses a volumetric hydraulic drive;
Electric, consisting of a system of self-synchronizing motors - when the steering wheel rotates, a current is excited in the rotor of the transmitting motor (generator), causing rotation of the receiver rotor connected to the actuator of the steering machine.
From various types steering machines, the most widely used are electric and electro-hydraulic steering machines.
The most common on modern ships are electro-hydraulic four-plunger steering machines with a transverse tiller steering drive. The design of such an EGRM with mechanical feedback is shown in Figure 3.1.4.
Rice. 3.1.4 Electrohydraulic steering machine (EGRM)
Two identical actuators The IMs (driven by electric motors 11 from two electric control lines) operate on one output control element - rod 12. The movement of the rod h (which is a task for shifting the steering wheel) using levers BD and FG connected at point C and rod 17 is transmitted to the pumps controlled supply 8, driven by electric motors 7. The pumps, according to the resulting movements e 1 and e 2 of the adjustable elements, create the supply Q 1 and Q 2, respectively.
When the pumps operate in the cylinders of the steering machine 6, a pressure difference p 1 – p 2 is created, as a result of which the stock 3 is rotated by means of plungers 5 and tiller 2, and the steering wheel 1 is shifted to a certain angle a.
In this case, the mechanical feedback 4 returns, through the levers DB and FG, the rod 17 to its original middle position, in which the total movement of the adjustable parts of the pumps is e = 0. The pressures in the cylinder cavities are equalized, the movement of the steering wheel stops and the specified angle a is maintained. Thus, this EGRM with mechanical feedback is an autonomous tracking system connected in series to a closed loop electrical system management.
The rudder position indicators on the bridge receive an electrical signal from sensor 14, actuated by lever 13 connected to rod 12.
To coordinate the zero positions of the rod and the pump controls, an adjustment device is used, consisting of screw connections 15 and 16 at the ends of the NL rod. Earrings AB and HG compensate for the mutual movement of the levers.
In case of refusal remote system control, the steering gear is driven by a steering wheel 10 connected to a gearbox 9.
The steering device is used to change the direction of movement of the vessel or keep it on a given course. In the latter case, the task of the steering device is to counteract external forces, such as wind or current, which could cause the vessel to deviate from its intended course.
Steering devices have been known since the appearance of the first floating craft. In ancient times, steering devices were large oars mounted on the stern, on one side or on both sides of the vessel. During the Middle Ages, they began to be replaced with an articulated rudder, which was placed on the sternpost in the center plane of the ship. In this form it has been preserved to this day. The steering device consists of a steering wheel, stock, steering gear, steering gear, steering gear and control station (Fig. 6.1).
The steering device must have two drives: main and auxiliary.
Main steering gear- these are mechanisms, steering actuators, power units steering gear, as well as auxiliary equipment and the means of applying torque to the stock (for example, a tiller or sector) necessary to shift the rudder for the purpose of steering the vessel under normal operating conditions.
Auxiliary steering gear- this is the equipment necessary for steering the ship in the event of failure of the main steering gear, with the exception of the tiller, sector or other elements intended for the same purpose.
The main steering drive must ensure that the rudder can be shifted from 350 on one side to 350 on the other side at maximum operating draft and forward speed of the vessel in no more than 28 seconds.
The auxiliary steering gear must be capable of shifting the rudder from 150 on one side to 150 on the other side in no more than 60 seconds at the vessel's maximum service draft and a speed equal to half of its maximum forward service speed.
The auxiliary steering gear must be controlled from the tiller compartment. The transition from the main to the auxiliary drive must be carried out in a time not exceeding 2 minutes.
Steering wheel– the main part of the steering device. It is located in the stern and operates only while the ship is moving. The main element of the steering wheel is the feather, which can be flat (plate-shaped) or streamlined (profiled) in shape.
Based on the position of the rudder blade relative to the axis of rotation of the stock, they are distinguished (Fig. 6.2):
- an ordinary steering wheel - the plane of the rudder blade is located behind the axis of rotation;
- semi-balanced steering wheel - only a large part of the rudder blade is located behind the axis of rotation, due to which a reduced torque occurs when the steering wheel is shifted;
- balancing rudder - the rudder blade is so located on both sides of the axis of rotation that when shifting the rudder, no significant moments arise.
Depending on the principle of operation, passive and active rudders are distinguished. Steering devices are called passive, allowing the vessel to turn only while underway, or more precisely, during the movement of water relative to the hull of the vessel.
The propeller system of ships does not provide them with the necessary maneuverability when moving at low speeds. Therefore, on many ships, to improve maneuvering characteristics, active control means are used, which make it possible to create traction in directions other than the direction of the center plane of the ship. These include: active rudders, thrusters
devices, rotary screw columns and separate rotary nozzles.
Active steering– this is a rudder with an auxiliary screw installed on it, located on the trailing edge of the rudder blade (Fig. 6.3). An electric motor is built into the rudder blade, driving the propeller, which is placed in an attachment to protect it from damage. By turning the rudder blade together with the propeller at a certain angle, a transverse stop appears, causing the vessel to turn. Active rudder is used at low speeds up to 5 knots. When maneuvering in tight water areas, the active rudder can be used as the main propulsion device, which ensures high maneuverability of the vessel. At high speeds the active rudder screw is turned off and the rudder is shifted as usual. 
Separate rotary nozzles(Fig. 6.4). The rotary nozzle is a steel ring, the profile of which represents the wing element. The area of the nozzle inlet is larger than the outlet area. The propeller is located in its narrowest section. The rotary attachment is installed on the stock and rotates up to 40° on each side, replacing the rudder. Separate rotary nozzles are installed on many transport ships, mainly river and mixed navigation, and ensure their high maneuverability.
Thrusters(Fig. 6.5). The need to create effective means control of the bow end of the vessel led to the equipping of ships with thrusters. The launchers create a traction force in the direction perpendicular to the centerline plane of the vessel, regardless of the operation of the main propulsors and steering gear. A large number of vessels for various purposes are equipped with thrusters. In combination with the propeller and rudder, the PU provides high maneuverability of the vessel, the ability to turn on the spot in the absence of movement, departure or approach to the pier with almost a log.
Recently, the AZIPOD (Azimuthing Electric Propulsion Drive) electric propulsion system has become widespread, which includes a diesel generator, an electric motor and a propeller (Fig. 6.6).
A diesel generator located in the engine room of the vessel generates electricity, which is transmitted through cable connections to the electric motor. The electric motor that ensures the rotation of the propeller is located in a special gondola. The screw is on the horizontal axis, the number of mechanical gears. The steering column has a rotation angle of up to 3600, which significantly increases the controllability of the vessel.
Advantages of AZIPOD:
– saving time and money during construction;
– excellent maneuverability;
– fuel consumption is reduced by 10–20%;
– vibration of the ship’s hull is reduced;
– due to the fact that the diameter of the propeller is smaller, the effect of cavitation is reduced;
– there is no propeller resonance effect. 
One example of the use of AZIPOD is a double-acting tanker (Fig. 6.7), which open water It moves like a normal ship, but in ice it moves stern first like an icebreaker. For ice navigation, the stern of the DAT is equipped with ice reinforcement for breaking ice and an AZIPOD. 
In Fig. 6.8. a diagram of the arrangement of instruments and control panels is shown: one control panel for controlling the ship when moving forward, a second control panel for controlling the ship when moving stern forward, and two control panels on the wings of the bridge.
Purpose technical means management
On ships of GDP and their types.
The basic requirements for technical controls for inland and mixed (river-sea) navigation vessels are determined by the rules of the Russian River Register (RRR), the Federal body for the classification of inland and mixed (river-sea) navigation vessels. These requirements take into account the type and class of ships.
Technical controls are designed to ensure movement, control and holding of the vessel on a given track. These include:
Propulsion control system;
Steering gear;
Anchor and mooring devices.
One of the main elements of technical controls is the steering device.
The steering device is used to change the direction of movement of the vessel and keep the vessel on the line of a given path.
It consists:
From a control element (steering wheel, joystick);
Transfer system;
Executive elements.
The controllability of ships is ensured with the help of actuators of steering devices. The following can be used as actuating elements of steering devices on GDP vessels:
Steering wheels of various types;
Rotary screw attachments;
Water-jet propulsion and steering devices.
In addition, on some types of ships the following can be used:
Steering devices;
Wing-shaped propulsion and steering devices;
Active and flanking rudders.
Ship rudders, their shapes and types.
Steering wheels of various types are most widely used as an executive element.
The steering wheel may include: rudder blade, supports, hangers, stock, tiller, etc. auxiliary devices(sorlin, helmport, ruderpies).
The steering wheel, depending on its shape and the location of the axis of rotation, is divided into simple, semi-balanced and balanced; according to the number of supports - suspended, single-support and multi-support. For a simple rudder, the entire feather is located behind the axis of the stock; for a semi-balanced and balancing rudders part of the feather is located in front of the stock axis, forming a semi-balanced and balancing part (Fig. 4.1).
According to the shape of the profile, rudders are divided into plastic and streamlined (profiled). The most widespread on inland navigation vessels are balanced, streamlined rectangular rudders.
The steering wheel is characterized by: height h p– the distance, measured along the axis of the stock, between the lower edge of the rudder and the point of intersection of the axis of the stock with the upper part of the contour of the rudder; length l p steering wheel; offset Δ l p part of the rudder area forward relative to the axis of the stock (for semi-balanced rudder, usually Δ l p up to 1/3 l p, for balanced ones Δ l p up to 1/2 l p).
Fig.4.1 Steering wheels
The most important characteristic the rudder feather is its total area ∑ S p. The actual rudder area is characterized by the expression
S p f = h p l p (4.1)
The total required rudder area to ensure vessel controllability is expressed by the equation
∑S p t = LT (4.2)
where is the proportionality coefficient;
L – length of the vessel;
T – maximum draft of the vessel.
To ensure controllability of the vessel, the required total rudder area must be equal to the actual rudder area, i.e.
