Hull

Hull of a wooden ship
(Fig. from the " Military Encyclopedia ")

The theoretical drawing of the hull fully defines its outer surface (shape), which determines the seaworthy and maneuverability of the ship. In the theoretical drawing, in three projections, the intersection lines (contours) of the theoretical surface of the body are shown with three mutually perpendicular planes parallel to the main planes of the projections, having the following notation ^[1] :

The diametrical plane (DP) is the longitudinal plane of symmetry of the ship's hull, occupying a vertical position under normal sailing conditions. The projection of the body contours on this plane is called the “side”;

The main plane (OP) is the plane perpendicular to the diametrical (DP) and passing through the middle rectilinear (usually horizontal) section of the keel. The projection of the contours of the hull on this plane is called "half latitude."

The plane of the midship frame (midship) is a transverse plane perpendicular to the diametrical and the main and passing through the middle of the estimated length of the ship. The projection of the contours on this plane is called the “body”. The intersection of the diametrical plane with the hull surface forms the keel line (lower part), the deck line (upper part) and the pin line (in the fore part - the stem and in the stern - the arch pin).

Curved lines (contours) formed when the surface of the hull intersects with planes parallel to the main — diametral (DP), main (OP) and midship planes — are called, respectively, “buttocks”, “theoretical waterlines” and “frames”.

The constructive waterline (KVL) is one of the theoretical waterlines along which the designed surface ship should sink, with normal design displacement. The position of the waterline determines the division of the ship's hull into surface and underwater parts.

Fore and aft perpendiculars - perpendiculars to the main plane, drawn through the points of intersection of the structural waterline with the stub lines.

The length of the ship along the waterline (Lqul) is the distance between the bow and stern perpendiculars.

Theoretical mid-frame - a frame located in the middle between the fore and aft perpendiculars (for the hull of a transport vessel), or in the plane of the widest cross section of the hull (the largest width of the hull) - for the hull of a high-speed vessel (without a “cylindrical insert”) ^[1]

Surface hull structure

The hull of a surface vessel consists of a set (skeleton), sheathing, decks, platforms, inner bottom, longitudinal and transverse waterproof bulkheads. Sheathing sheets together with the set beams form the corresponding overlap: side, deck, bulkhead, bottom. The presence of decks and bulkheads depends on the purpose of the ship, but the skeleton and lining are mandatory elements of each hull.

Enclosure Kit

A hull set is a system of rigidly interconnected longitudinal, transverse and vertical beams of various designs, to which the outer skin and deck deck are attached. The main longitudinal connection of the hull kit is a keel - a steel beam or a sturdy box running along the hull along its diametrical plane.

There are three hull recruitment systems (depending on the direction of the main beams relative to the ship):

1. transverse;
2. longitudinal;
3. longitudinal-transverse (or bracketing ^[2] ), which in turn is divided into:

• mixed - the distances between the longitudinal and transverse beams are approximately equal;
• combined - the bottom and decks are made according to the longitudinal system, and the sides along the transverse.

The first system is used in the construction of small ships, the second - in the construction of oil vessels, the latter - in the construction of warships and large ships ^[3] .

When using the transverse recruitment system, beams of the main direction go across the ship. They consist of frames on the sides (2), ^{[4] of} floras (6) on the bottom and beams (1) under the deck. The spacing , or the distance between the axes of two adjacent frames, with a similar set system is 45-60 cm.The number of longitudinal beams used in the transverse set system and acting as cross-links is small and usually does not exceed 3-5 ( vertical keel (5) stringer ) ^[3] .

In the longitudinal recruitment system, the main (continuous) beams pass along the ship and consist of a large number of stringers running continuously along the bottom (3) and sides (11), longitudinal beams under decks, a large number of simple longitudinal beams located along the bottom, sides and top deck (between stringers and longitudinal beams). With this recruitment system, frames are made of powerful frames with a spacing of 1.5-2.5 m, cut at intersections with longitudinal ties.

With a mixed set-up system, the bottom and deck are made according to the longitudinal system, and the sides and ends along the transverse ^[3] .

Bottom Set

The set of the bottom consists of mutually intersecting longitudinal (keel, bottom stringers) and transverse ties (flora). The main longitudinal connection of the bottom set is the keel, which runs along the entire length of the ship, coinciding with its diametrical plane. At the extremities of the ship, the keel is connected to the pins: with the stem - in the bow and with the stem - in the stern ^[5] .

The bottom stringers are longitudinal beams running parallel to the keel, and with it, provide longitudinal strength to the hull.

Floras are transverse beams, part of the frame frame. On ships with a double bottom, the floras are impermeable (made of solid sheets) and permeable (having cutouts for light weight) ^[5] .

Board Set

The board set consists of airborne stringers and frames. To reduce the size of the ship during rolling, lateral keels of various designs are attached to the sides. They also play the role of longitudinal bonds and, as a rule, do not go beyond the dimensions of the body in width ^[5] .

At the junction of the side and deck, there is a longitudinal inner beam - waterway. In order to protect the hull from touching the berth, bollard, other vessel or object, a girder can be installed outside along the side (one or several in parallel). Depending on the design, the girders can give the body additional rigidity.

Deck Set

The deck set consists of a system of intersecting transverse (going from side to side) and longitudinal beams, carlings and half-beams. To stiffen deck closures (hatches, necks) around them, longitudinal, transverse, or annular beams (carlings) are placed under decks. ^[6] Half-bims are called bims, which go not across the entire width of the hull, but from the side to the carlings of a hold, hatch or shaft. If heavy local loads (artillery, deck mechanisms, etc.) are located on the deck, then permanent or removable pillers (vertical racks) are placed under them in the interdeck spaces. To communicate with those of the rooms located below the decks, holes are made in the decks - hatches (round, oval or rectangular) ^[5] . In order to prevent water from entering the hatches, the hatches along their perimeter above the deck are bordered with waterproof sheets (coaming) and covered with covers. Manhole covers have zadraki and seals (to ensure waterproofness). The movement of the crew through the hatches is carried out using inclined or vertical ladders . The first have handrails, the second, as a rule, are installed in mines, at the exits from machine-boiler rooms (MCO) and ammunition cellars ^[7] .

Cladding and Bulkheads

The outer skin of the hull consists of side and bottom sections. It is a waterproof shell that separates the interior of the ship’s hull from the water, and also provides longitudinal and transverse strength of the ship. The unsinkability and strength of the hull are provided by the longitudinal and transverse (depending on the location) bulkheads. Bulkheads are waterproof (to ensure unsinkability), or permeable (to ensure the strength of the hull) ^[7] .

Bow of the ship

May have a bulb , a teardrop-shaped formation in the bow of the underwater part of the hull of the ship’s hull, designed to reduce wave resistance (up to 5%) during its movement; on warships in the cavity of the bulb, as a rule, a sonar station is located.

Mines and ship systems

The shafts are vertical pipes of a special design, round or quadrangular, which pass through the interdeck spaces. Typically, the shaft facing the upper deck has a neck with a waterproof cover on the lamb or zadraik ^[7] .

Ship systems are located inside the ship’s hull and are a combination of pipelines with valves and mechanisms, or cables with electrical fittings, which are used to move various liquids and gases (vapors) and / or energy inside the ship, which ensure the ship’s speed, survivability and other activities. The structure of ship systems includes: fuel, electric, fire, flooding and irrigation of the ammunition cellars, roll and trim, drainage, drainage, ventilation, heating, drinking, washing and sea water, sewage and others ^[8] .

Submarine Hull Design

• Hull // Naval Dictionary / Chernavin V.N. - M .: Military Publishing House , 1990 .-- S. 201 .-- 511 p. - ISBN 5-203-00174-X .
• Melnikov P.E. et al. Handbook of a marine paratrooper. - M .: Military Publishing, 1975 .-- 288 p.