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Electric power entices us with its flexibility and adaptability. And that extends to our charging sources. We gain the ability to recharge our batteries from nearly any source, assuming everything works together. Discover the critical issues to combine multiple charging sources for electric propulsion.

Batteries for Electric Propulsion

Which battery to choose? The batteries form one of the most expensive components in electric propulsion. Today, review the basic battery chemistries out there, allowing you to quickly identify the best battery strategy.

Electric Yacht System Design

Going electric requires you to design a whole custom electric system for your ship. The challenge with electric systems is the interaction. The requirements for one minor component may determine key settings for the whole system. Today I cover some key settings for the electric system. After deciding these points, the complexity of shopping should simplify into a few simple paths.

Emergency Electric Propulsion

Engineering Business, Insurance

Designing an electric system requires more than just spinning a propeller. Much of an electric boat focuses around safety and emergency planning. This article covers several key decisions to design an electric system that delivers far more than propulsion. Instead, our electric system ensures reliable safety.

5 Myths with Electric Propulsion

Electrical

Electric power and electric propulsion are still growing industries for yachts and small ships. In this field, a few marketers may stretch the truth a little to make sale. This led to many myths and misunderstand about electric propulsion. Today I debunk five common myths.

Mvaltairgeneralarrangementplan Smallresolution

How to Design a Ship

Arrangements, Hydrostatics, Mechanical, Piping, Structural

How to design a ship? How to go from a blank sheet of paper to a sensible design for a ship, when you have nothing to start with? So here are my secrets revealed.

Lying with Numbers

Engineering Business

A critical review of my previous analysis with an eye towards statistics and the importance of context in numbers.

The Value of Life

Why would you pay more for engineering than for the ship? The value of engineering comes from the lives protected, not the design of the yacht. How much is that protection worth? This risk analysis has an answer to the value of safety.

Commercial Ship Safety

Auxiliary Systems, Hull Structure, Quality Assurance

Commercial ships are a world apart from recreational yachts. They contend with tougher requirements, and they need far more safety features. But what are those differences? How is the commercial ship safer?

How Propulsion Works: Classifying Ship Propulsion

Propulsion, Propulsion Plant, Propulsors, Waterjet Propulsors

No doubt, the math of propulsion devices is complicated. But it is all the same physics. By dividing each of these devices into their essential tasks, we find new opportunities. New methods of propulsion from different combinations of old tricks. Insight into this continuum allows us to better classify marine propulsion and dissect past successes to search for new combinations.

Ever Given: Maneuvering Options

Miscellaneous, Ship Maneuvering

How to maneuver a massive freighter into port? CAREFULLY. We design freighters around the scenario of open ocean passage at full speed. But each freighter needs to enter port, pass through canals, and a host of other precision maneuvers executed at a fraction of their design speed. How do massive commercial ships manage precision maneuvers every day?

Ever Given: What We Don’t Know

Command and Surveillance, Fluid Dynamics, Miscellaneous, Ship Maneuvering, Ship Motion Control, Ship Response

Like everyone else, I watched the story of the Ever Given and formed my own theories about what happened. Except I was wrong. As the events unfolded, new information came out and I learned the increasing complexity of the accident. Each time, I developed a new theory, which failed with new information. Over a year later, what is the answer? Let’s review what we know and still do not know about the Ever Given incident.

Stability Letters Explained

Fluids, Hydrostatics, Integration / Engineering

For small vessels, the major problem with stability letters is explaining it to the captains. Today I will review a stability letter and give plain English interpretation of all the boring mumbo-jumbo.

Three Neat Tricks with Marine Cranes

Masts, Kingposts, Service Platforms, Mechanical, Mechanical Handling Systems

Three neat things you didn’t know about marine cranes! Every now and then, it’s fun to step back and appreciate the innovation that allowed us to adapt industrial cranes to the marine environment.

Palfinger Marine Foldable Knuckle Boom Crane Pk150002m

Cranes on Ships: Introduction to Crane Integration

Auxiliary Systems, Mechanical Handling Systems, Miscellaneous, Replenishment Systems

In the marine world, we see cranes daily; they are very useful pieces of equipment. Despite their common appearance, we need to remember their potential for disaster. Cranes on ships generate new, subtle risks for lifting operations. Unless you know what to look for, the risks can go undetected. This article reviews the major dangers of cranes on ships.

Strength and Stiffness: Design of Structural Foundations

Hull Decks, Hull Structural Bulkheads, Hull Structure, Masts, Kingposts, Service Platforms, Miscellaneous, Shell and Supporting Structure, Special Purpose Structure

No foundation is perfect. Each design reveals new insight and opportunities for further improvement. The art of foundation design finds an efficient arrangement to redistribute concentrated loads into the general ship structure. I review basic strategies for foundation design.

Class Societies

Engineering Business, Legal, Project Management

On land, cities inspect new house construction. But who inspects new ships? And how does that work with an international industry?

5 Steps to (NOT) Build a Boat

Engineering Business, Hull Structure, Integration / Engineering, Production Engineering, Project Management, Shipyard And Support Services

When building a yacht, pick a design you finish. Here are several steps that help before embarking on any boat construction project.

Free Surface Moment

Fluids, Fluids Testing, Hydrostatics, Stability Test

The shifting liquid in a ship’s tanks can create a lethal scenario. For everyone's safety, learn about free surface moment.

Composite Materials

Engineering Business, Hull Structure, Materials, Special Purpose Structure, Structural

Don’t let composites disappoint you. If you understand their practical limits, composites far exceed the capabilities of steel.

Practical Stability Test: Naval Architect’s Guide

to run a stability test, naval architects need a little theory, and a LOT of experience. This guide passes on some of that experience.

Stability Test Theory

How do we extract scientific data from simply moving weights on deck? Today I explain some of the theory behind the stability test.

Practical Stability Test: Chief Engineer’s Guide

Time to prepare the vessel for a stability test. This guide covers the practical mattes that a Chief Engineer needs to know.

Practical Stability Test: Master’s Guide

Today, I highlight the major points the vessel Master needs to know when preparing for a stability test. Plain talk, simple answers.

Practical Stability Test: Owner’s Guide

As the vessel owner, how do you prepare for a stability test? Enjoy this practical guide on how to prepare for a stability test.

When You Need a Stability Test

Engineering Business, Project Management

When the inspector requires a stability test, what can you do? Learn the different types of stability tests and when regulations require them.

What is a Stability Test

Engineering Business, Fluids, Fluids Testing, Stability Test

What is a stability test? What exactly are you paying for? This article introduces a stability test and why you want one.

Weight Control

If we ignore weight control, we risk a potentially unusable ship. Understand the risks and the necessity of how to perform correct weight control.

Underway Replenishment

Auxiliary Systems, Engineering Business, Equipment Integration, Mechanical, Mechanical Handling Systems, Piping, Replenishment Systems, Ship Control Systems, Special Purpose Mechanical Systems

It’s difficult to see where systems integration adds value to ship design. So I want to show how none of this is possible without systems integration.

Which Engineer

Design Support, Engineering Business, Hiring Consultant, Integration / Engineering, Production Engineering, Project Management, Shipyard And Support Services, Support Services

If you want a modern vessel, expect a modern team of experts. So let’s meet all the different roles and learn who it takes to create a modern ship.

Ship Model Scaling

Engineering Business, Fluids, Fluids Testing, Propulsion Plant, Propulsor Shrouds and Ducts, Propulsors, Towing Tank, Transmission and Propulsor Systems

It is impossible to perfectly convert between model scale and ship scale. Learn how to get around the scaling correlation problem.

Next Level Hydrodynamics

Engineering Business, Fluid Dynamics, Fluids, Fluids Special Methods, Fluids Testing, Propulsion, Propulsion Plant, Resistance, Towing Tank

The modern towing tank expanded into a Swiss Army knife of experiments. Time to see what new tricks the tank holds for us!

The Ship Towing Tank

Engineering Business, Fluid Dynamics, Fluids, Fluids Special Methods, Fluids Testing, Propulsion, Propulsion Plant, Propulsion Units, Propulsors, Resistance, Towing Tank

It may look like a swimming pool, but towing tanks exist for a different purpose. They are a fundamental tool of ship design.

Guts of CFD: Multiphase Modeling

Multiphase CFD includes multiple fluids. How does VOF achieve this, and what are the implications for CFD modeling? Read on to learn more . . .

Practical CFD Modeling: Mesh Deformation

CFD Mesh deformation is incredibly frustrating, but unavoidable for body motions in CFD. Learn strategies to plan for your next mesh deformation project.

Practical CFD Modeling: Time Variation

When we add the time variation, CFD adds a few modeling requirements. Today we discuss these extra requirements. Get guidance for unsteady simulation.

Practical CFD Modeling: Volume of Fluid Modeling

CFD models multiple fluids with the volume of fluid method. Learn the practical details of this technique. Discover the world of VOF modeling.

Practical CFD Modeling: Turbulence

As the CFD engineer, you need to describe boundary conditions for your turbulence equations. This article typical turbulence values for normal simulations.

How to Cut the Bunker Bill

Energy Generation, Engineering Business, Fluids, Mechanical, Propulsion, Propulsion Plant, Propulsion Units

IMO 2020 promises to be a time of uncertain fuel prices. Here are eight practical ways to reduce your fuel consumption.

Guts of CFD: Near Wall Effects

Turbulence does tricky things near walls. Turbulence is most critical near the wall, so how to consider near wall effects? Learn more here.

Guts of CFD: Turbulence

Turbulence is the defining feature of modern computational fluid dynamics (CFD). What type of approximation, and which turbulence model should you select?

Guts of CFD: CFD Linear Solution

Fluid Dynamics, Fluids, Propulsion, Propulsion Plant, Transmission and Propulsor Systems, Waterjet Propulsors

How do we stretch the limits of linear algebra to accommodate non-linear CFD equations? How do we take the mathematics from one cell and apply them to millions of cells?

How to Design a Waterjet: Key Elements of Waterjets

What makes a waterjet work? Learn the common elements of all waterjets and best practices to expect from a decent waterjet design.

Practical CFD Modeling: Judging Convergence

CFD convergence is not an exact science. Monitors, flow patterns, and residuals. Learn how to use these tools and reliably juge convergence.

Guts of CFD: Interpolation Equations

If we want to solve the equations of computational fluid dynamics (CFD), we need a way to fake calculus. Enter interpolation equations.

Guts of CFD: Transport Equation

Transport equations form the fundamental language of CFD. Today we explain transport equations and the significance of their terms.

Guts of CFD: Navier Stokes Equations

Navier Stokes is essential to CFD. Today we review Navier Stokes Equation with a focus on the meaning behind the math.

Practical CFD: General Approach

Just fresh out of college, and the boss assigned your first project for computational fluid dynamics (CFD). You are excited. You can’t wait to begin the challenge. You sit down at your computer, start up the CFD software . . . and freeze like a deer in headlights. How to begin? What to do first? Today we discuss the general workflow for a CFD project and highlight some general modeling advice.

CFD Workflow

Engineering Business, Fluid Dynamics, Fluids, Fluids Special Methods

What happens behind the curtain when the CFD engineer goes to work? What goes into making a CFD simulation? As a project manager, you need to understand the workflow of a CFD project; this helps you plan the project and track budget expenses. When we understand the workflow, we know the right questions and can anticipate project delays.

Which CFD?

Is there anything that CFD can’t do? Practically speaking, we can achieve the result, but you may regret paying for the answer. Several CFD projects involve combinations of different CFD methodologies. Combined together, they evolve into a major project risk. Gain some insight about the risk factors for your next CFD project. Plan a strategy to minimize project risks so that you don’t get caught by combining unknown cost increases.

What is CFD