How do hull points work

Dakka 5. Member List. Recent Topics. Top Rated Topics. Forum Tools Forum Tools Search. Subject: Advert. Ravenfate Brainless Zombie Germany. Yeah, bad copypasting, yes, it would be 1SP, 1 HP. What chart in the errata are you talking about? Are you looking at the right PDF? This is affected by everything and anything that would normally affect vehicle damage rolls like AP bonuses. Once a vehicle loses all of its structure points i. This ensures minimum crossflow at the propeller, therefore ensuring maximum propeller efficiency.

The sections forward of the midship are drawn on the right side of the center line, and all the sections from the midship to the stern are drawn on the left side.

The reference lines in the body plan are the buttocks vertical grid-lines , and the waterlines horizontal grid lines. The body plan, along with the reference lines can be self sufficiently used to develop the profile plan and half breadth plan of the ship.

It is also useful in developing the sectional area curve, and bonjean curves of the ship. The complete lines plan of a ship is arranged by placing the profile view on top, with the half breadth plan just below it, and the body plan to its right, as shown below. The lines plan provides for the foundation of developing not only the three-dimensional hull model, but also developing frame-wise structural drawings, general arrangement, and loft drawings at the shipyard.

The structural design of the hull of a ship amounts to approximately 70 percent of the total structural design of the ship. The stages in designing the hull structure are as follows:. Step 1: Calculation of Loads on the Hull: This is where the classification society rules come into play.

The still water bending moment, wave bending moment, and shear forces are to be calculated using these formulae. These load values act as set points in the entire structural design process.

Step 2: Scantling Calculations for Midship: The dimensions of all the structural members of the ship plates, stiffeners, girders, beams, pillars, etc. The loads calculated in Step 1 are used to arrive at the scantlings, and this is calculated for structural members at every frame. Step 3: Midship Section Modulus: The midship section structural drawing is prepared according to the calculated scantlings. This is followed by locating the neutral axis of the midship section and calculating the section modulus of the midship section.

Two criteria are to be satisfied at this stage:. Figure 6: Midship section drawing of a passenger vessel. In the above midship section drawing, the blue line NA is the neutral axis of the section.

The bending stress graph is drawn with the neutral axis with the reference origin , and the top-most and lowermost ends of the graph would denote the stress values at the deck and keel respectively, as shown in the stress graph below. Why do you think it is important to design the structure of the midship section of the ship before any other sections?

Read this article to find out what makes midship the structurally most important region of the ship. Step 4: Frame-wise Scantling Calculation: Once the midship scantlings satisfy the criteria, the scantlings for structural members at each frame are calculated, and corresponding frame-wise structural drawings are prepared. Special formulae are applied for the forward and aft sections, and bulkheads, and drawings are prepared for the same.

Step 5: Calculation of Steel Weight: The obtained scantlings are the used to calculate the steel weight of the ship. This is where the iteration begins. If the calculated steel weight lies outside the empirically and statistically obtained values, the designer might have to look at using lighter weight steel at suitable regions or take other decisions to keep the lightship weight within limits.

Step 6: Development of 3D Structural Model and FEA Analyses: With the structural drawings at each frame, a three dimensional structural model is prepared for the entire hull. This process takes the longest time because the accuracy of this model would directly impact the results of the finite element analyses that are to follow. Three-dimensional meshing is carried out on the 3D model, followed by finite element analyses for various conditions.

In other words, its manoeuvrability. In order to evaluate the manoeuvrability of the bare hull, we evaluate the following aspects:. For this various tank, tests are carried out at model basins and the hydrodynamic coefficients are measured for the bare hull.

For example, a skeg is often added to the hull in later stages of design to improve on its straight line stability, after the model basin test results are obtained. It has been observed that the presence of a superstructure on the main deck reduces the bending stress at the deck from the stress value predicted by the beam bending theory.

This is because of the interaction of the shear stresses with the bending stress at the ends of the superstructures. However, this leads to deformations at the superstructure ends. So would a ship not work similarly? Improve this question. Attonwizard Attonwizard 1, 1 1 silver badge 18 18 bronze badges. Ships have health and AC, but unlike NPCs, there are rules for breaking down the subdivisions of ships and other large objects: for possibly destroying them without taking down most its HP.

Add a comment. Active Oldest Votes. In summary: A ship is divided into sections: Hull the main ship body , Control the helm , Movement sails or oars , and Weapon any ballistas, rams, cannons or the like.

Each is its own independent object, with its own hit point value, armor class and damage threshold. The only way to sink the ship is to reduce its Hull to zero hit points.

You cannot focus-fire on one section of the hull to sink the ship faster. Damaging other components like the sails or oars can hinder the ship, but doesn't help to sink it. This is clear if you compare the ship statistics in the DMG to their statblocks in Saltmarsh. To answer your questions directly: Does a ship sink only when it reaches 0 HP? Improve this answer. Community Bot 1. Quadratic Wizard Quadratic Wizard Featured on Meta.

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