The Drydock - Episode 165

I love this channel I can learn a great deal from it on not just the history but the engineering and scientific aspect.

David Stange Jr

His reasoning breaks down at several points, though. See my comment below.

I am sorry Drach, but your physics at around 00:30:00 is totally muddled. Kinetic energy isn't a vector quantity, i.e. the kinetic energy of the water going one way doesn't "cancel out" the kinetic energy of the ship going the other way. Chemical energy stored in the fuel is converted to kinetic energy of both the ship and the water. These movements are happening at the same time. The analysis should be in terms forces and momenta. Using the density of metal times the volume/cross-sectional area of the ship under water when calculating how much mass is moving forward is wrong because the ship isn't a solid piece of metal. If it were, it'd sink. This whole calculation just doesn't add up (harr harr). Your point comparing the speed of water behind the prop to the ship's speed is also a bit shaky: even if the water is initially(!) going away from the prop with 40 knots, it will slow down and very quickly drop below 30 knots. The hull, on the other hand, is moving through water with a speed of 30 knots along its entire length. There is also going to be an area in front of the prop where water is sucked in and therefore moving much faster. This area would have to be included in your point about friction and relative speed. However, your main argument - namely that a front-prop configuration would increase friction - still stands: turbulence! The flow of water behind the prop is much more turbulent and having that turbulence flow along the hull would greatly increase friction.

I realize you are inundated with specific questions Drach but I wonder if you could produce an article about ABC, Admiral Cunningham. As a subject he may not hit your YT demographics but he remains, to my eye, the most competent RN Admiral since Nelson.

Thank you for your explanation of the utility of fore and aft propellers, its good to hear you release the inner Engineer and use cogent reasoning. Hope you and Mrs D enjoying the Land Ironclad festival at Bovington, hope to get there next year.

(Theoreticolly) The Jellicoe Plan sounds like a possiblilty for RCN if they did keep those 3 QEs, Canadian Ark Royal(s) maybe? most likely going to build/ buy Leanders and County's, possibly even Towns for Cruisers, destoyers what ever is availble, thats if they get Canada its own space on the 1922 Naval Treaty. Could be an excuse to get British Investors/Investing Banks to put money in Canadian Industry and Infrstructure thus pulling the Canadian and British economy out of the Great Depression abit early than normal.

Duke of Petchington