Category Archives: Naval History

Correcting for Sextant Parallax Error

Navigators use the altitudes of solar system objects to assist them with determining their positions. The most commonly used solar system objects are the Sun, Moon, Venus, and Mars. There is a small error caused by the fact that navigators are making their sextant measurements from the surface of the ocean and not from the center of the Earth, which is the reference point used by nautical almanacs. Parallax has no practical significance when measuring the positions of stars because they are so far away relative to the radius of the Earth. Continue reading

 
Posted in Astronomy, Naval History, Navigation | 1 Comment

Correcting Sextant Measurements For Dip

I love to read stories of the sea and about the voyages made during the age of sail. I personally have never thought that I would have an opportunity for ocean sailing, but I recently began working with an engineer who is an avid sailor and teacher of sailing. He has sailed all over the world and recently trained another engineer in my group to sail. This newly trained sailor just returned from a trip to Bora Bora, which he found to be enjoyable and the sailing uneventful. Continue reading

 
Posted in Naval History, Navigation | 5 Comments

Ship's Course Correction for Cross-Current Rule of Thumb

I have lived most of my life in Minnesota, which is about as far away from the oceans as you can be in the United States. The idea of a planet mainly covered with water has always fascinated me. I will never forget the first time I saw an ocean (Pacific, Santa Monica, CA 1982). Fortunately, my work has provided me a bit of experience on ships and that experience was career changing − my early ocean experience involved laying fiber optic cable and that set the course of the rest of my career. Continue reading

 
Posted in Naval History, Navigation | Leave a comment

Sub Missile Launch Physical Model

I like it when instructors use physical models to illustrate how things work. I was watching this video on submarine design when I saw a physical model used to illustrate how a submarine launches a missile. The demonstration is excellent. … Continue reading

 
Posted in Naval History | Leave a comment

Submarine Fuel Math

Introduction I just read an interesting article about an arctic environmental problem being presented by a Soviet-era nuclear submarine that had been scuttled back in 1982 (Figure 1). Apparently, scientists are now concerned that the submarine's reactor could leak dangerous … Continue reading

 
Posted in General Science, Military History, Naval History | Leave a comment

World War 2 Submarine Hull Thickness Math

Quote of the Day How are the children? — Masai warrior greeting, intended to ensure that the warriors always keep their number one priority in mind. I was reading a blog post on Gizmodo that did a bit of math … Continue reading

 
Posted in Military History, Naval History | 2 Comments

A Problem Solved in Excel and Mathcad

I use both Excel and Mathcad in my daily work. Most people would consider me very proficient in both. I frequently get asked, "Which tool is better?" Like all other interesting questions in Engineering, the answer is "it depends".

As an example, I decided to work a simple problem in both Excel and Mathcad. A number of the advantages and disadvantages of both tools can be seen in this example. The key problem with Excel is its cell-oriented approach. While the cell-oriented approach works for small problems, it has major issue with large problem Continue reading

 
Posted in Ballistics, History of Science and Technology, Military History, Naval History | 2 Comments

Image of a Submarine At Periscope Depth

If you have ever wondered what a submarine looks like at periscope depth, here is a photo of the USS Key West (SSN-722). Source is the Wikipedia.  

 
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Battleship Rangefinders and Geometry

Quote of the Day Russia is a riddle wrapped in a mystery inside an enigma. — Winston Churchill. Introduction While reading a web page on WW2 naval warfare, I found some interesting material on how naval gunfire was spotted -- … Continue reading

 
Posted in Naval History, optics | 14 Comments

Torpedo on an Aruba Beach

I have read in a number of places about torpedoes being found on beaches during wartime, but I have never seen pictures of one on a beach. While researching possible diving locations, I ran across this excellent excellent web article … Continue reading

 
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