Quote of the Day
Y2K was 21 years ago. Looking back, I think the only thing we learned is that if a bunch people work really hard to stop a problem from happening, lots of other people will assume it was never really a problem.
— Steve Lieber. I have seen many people work hard to ensure problems would never occur. This effort was never appreciated. I have also watched people who created problems win awards for fixing the problems they created. Very strange organizational behavior.
In this post, I will examine the fuel consumption of the three most modern battleship classes that the US deployed during WW2: North Carolina, South Dakota, and Iowa. The data is scraped from the Hyperwar website, which is one of my favorite targets for data extraction. In this case, the Hyperwar page contains a set of tables from the US Navy document FTP 218: War Service Fuel Consumption of US Navy Surface Vessels.
The fuel consumption (gallons/hr ) for a ship is a highly non-linear function of speed (knots), as my graphs will show. I also estimate each ship’s running time as a function of speed using their rated fuel capacity, which is called radius oil that is the sum of the fuel oil and diesel capacities.
For those who like to follow along, my Excel workbook is available here.
US Battleship Classes
I first look at the different battleship classes the US deployed during WW2. Fortunately, a table in Wikipedia makes this data easy to access. Table 1 shows the ten battleship classes that the US deployed during WW2, along with the main battery diameter and the number of main battery guns. The battleship classes are shown in the order they were deployed.
|Table 1: US Battleship Classes Deployed During WW2.|
US WW2 Battleships By Name
There were 18 battleships in US Navy service on the morning of 7-Dec-1941. All were WW1-era ships, except for the 2 North Carolina class ships that were just entering service. After Pearl Harbor, 8 of these ships were damaged with 6 returned to service after months of repair and refit. The battleships in service immediately after Pearl Harbor bore the brunt of the fighting, both in the Atlantic and Pacific, until newer ships were completed.
|Table 2: US WW2 Battleships By Name.|
Scraping the data from the Hyperwar website was straightforward using Power Query because all the data was contained in well-structured tables. Figure 2 shows the fuel consumption of the USS South Dakota, USS North Carolina, and USS Iowa versus speed in knots. Note how their fuel consumption was similar at low speeds but diverged as their speed increased. USS North Carolina, in particular, was comparatively inefficient. The USS Iowa was quite efficient, with its fuel consumption rate at 29 knots roughly the same as the USS North Carolina at 25 knots.
Knowing a ship’s fuel consumption as a function of speed and its fuel capacity, we can compute its sailing time before running out of fuel (Table 3). Ships normally would refuel their tanks regularly to ensure that they always had enough fuel to handle foreseeable needs (link). When they didn’t, problems occurred (see discussion of Bismarck’s fuel issues).
|Table 3: Battleship Running Time Versus Speed.|
It is hard to imagine ships that consume 9000+ gallons of fuel per hour. It is also impressive how fuel-efficient the USS Iowa as compared to the earlier classes.
We are fortunate that the US was able to to keep 9 battleships as museums ships:
- New Jersey
- North Carolina
I hope to see them all in the next few years.