Talk:Implacable-class aircraft carrier

5 sorties per aircraft
81 x 5 = 405 sorties. 94650/405 = 233ig/sortie which is far more than a Seafire could carry per sortie even assuming maximum external fuel per sortie, and that each aircraft landed on with completely empty tanks, which of course is impossible. Implacable carried 48 Seafires, 12 Fireflys, and 21 Avengers there's just no way that this combination of aircraft could ever consume that much fuel. I suspect that this must have been a reference to the Illustrious class which operated larger aircraft, F4U Corsairs, and had a smaller fuel capacity.Damwiki1 (talk) 08:03, 20 January 2014 (UTC)
 * So why do you insist on making your calculation as if all of the aircraft were Seafires? I don't know off hand the fuel capacity of a Firefly, but I do know that Avengers could carry over 700 US gallons, which makes a mockery of your hypothesis. I'm positive that these other planes would use whatever fuel remained. Another point to remember is that the Admiralty didn't know the aircraft types that the ships would be flying when they finalized the design so I think you're too focused on the exact numbers rather than the idea that the lack of avgas was a serious constraint on their combat power. And it's definitely not a reference to the Illustrious class because Friedman says the same thing.--Sturmvogel 66 (talk) 10:02, 20 January 2014 (UTC)
 * Where does Friedman state that? Internal fuel capacity of the Firefly was 191IG and 275IG for the Avenger. Neither the The Avenger or Firefly could carry external tanks and still carry out a strike mission so maximum fuel for 81 sorties would be 48 x 175 + 12 x 191 + 21 x 233 x = 16467ig, and this works out to 5.7 sorties per aircraft assuming that every aircraft returns with completely empty tanks, which is absurd. However if we do the same calculation for an late war Essex class carrier USS Bennington June 1945, we get almost the same results when the fighters use one external drop tank; 37 f4u x 387usg = 14319 + 37 f6f x 400usg = 14800 + 15 helldiver x 320usg = 4800 + 15 avenger x  335usg = 5025 = a total of 38944 US gallons and this works out to only 5.3 sorties per aircraft in the late war Essex class (209000 USG capacity - Friedman US Aircraft Carriers, page 153 Avgas, capacity reduced to enhance safety) or 5.9 sorties per aircraft for the early Essex class with 231650USG of avgas. So do you propose to add a similar statement for the Essex class carriers? If not then remove it from this article.Damwiki1 (talk) 18:24, 20 January 2014 (UTC)
 * I may have confused Friedman for Hobbs, who says the same thing on p. 107. You screwed up your math for the Avenger. Max internal fuel is 278, not your figure of 233. Nonetheless the ultimate figure is 5 sorties and some change and thus reasonable on its face; even if they didn't land on dry tanks as you say. The statement isn't mine, but Brown's, and I haven't seen if anybody makes a similar statement for the Essexs, so for me to add it there would be inappropriate and OR.--Sturmvogel 66 (talk) 20:41, 20 January 2014 (UTC)
 * I used 275IG for each Avenger in my calculations(48 x 175 = 8400 + 12 x 191 = 2292 and 21 x 275 = 5775 = 16467), so the result of 5.7 sorties per 81 aircraft is correct and this assumes empty tanks! Can you provide a verbatim quote from Hobbs? Again, the statement is clearly incorrect and it is also a fact that the large majority of any carrier sorties will be for fighter CAP so the Seafire will always predominate. Simple arithmetic is allowed in Wikipedia without being considered OR.Damwiki1 (talk) 21:28, 20 January 2014 (UTC)
 * "Some increase was made in the quantity of avgas that could be stowed, but these ships only had enough for five sorties per aircraft, hardly sufficient for sustained strike operations."--Sturmvogel 66 (talk) 22:21, 20 January 2014 (UTC)
 * Simple arithmetic shows that this statement is incorrect. I'll add a footnote to it explaining that it cannot be true using the historical Implacable class air complement. Damwiki1 (talk) 23:46, 20 January 2014 (UTC)
 * Why bother? Do you really think that the difference between five, 5.7 or even six sorties per aircraft is really significant? Seems very pedantic to me to do this. And why do you think that CAP sorties would use less than max external fuel? Seems sensible to me to do so to maximize time aloft per aircraft.--Sturmvogel 66 (talk) 02:33, 21 January 2014 (UTC)
 * When simple arithmetic can show that a statement is incorrect then why insist on including it in an article? Why include something that you know is wrong - don't you care about the integrity of wikipedia? The difference between 5, 6 or 7 sorties (7 would be about right with 20% fuel remaining per sortie, which was a typical safety factor) is 405, 486 or 567 sorties, which is a significant difference. Even with full external fuel a Seafire can only carry 175IG and a reasonable safety factor will preclude using more than about 80% per sortie - otherwise half of all sorties would run out of fuel!
 * If you want to add a footnote challenging Brown and Hobbs' arithmetic feel free, but I don't feel that it's necessary to delete the statement.--Sturmvogel 66 (talk) 05:38, 22 January 2014 (UTC)
 * First, let me congratulate you for improving the article and to apologize for my previous remarks which were a little harsh. I will work on a footnote and will post it here first for discussion.Damwiki1 (talk) 18:50, 22 January 2014 (UTC)
 * That will be fine. If you see anything that needs further expansion or should be covered, let me know as I'm pretty well done with the basics of the ships themselves and will be starting on an abbreviated account of their careers.--Sturmvogel 66 (talk) 21:10, 22 January 2014 (UTC)
 * I can't find any mention of fuel usage or sorties per aircraft in Friedman, on page 144 so I think he should be removed from reference 8. Proposed wording for footnote: "A simple calculation of fuel capacity for 48 Seafires (48 x 175 imperial gallons (including a 90 gallon drop tank)), 12 Fairey Fireflys (12 x 191 imperial gallons) and 21 Grumman Avengers (21 x 278 imperial gallons) shows that 94650 imperial gallons of fuel should suffice for 5.7 sorties per aircraft. Since aircraft will not return with completely empty tanks it seems that a figure of 6 to 7 sorties per aircraft is more likely." Damwiki1 (talk) 19:43, 24 January 2014 (UTC)
 * Ref 8 covers the entire paragraph, not just the fuel storage. Your wording's fine aside from the fact that Seafires carried 2x 45-gal drop tanks, not a single 90-gal one.--Sturmvogel 66 (talk) 21:24, 24 January 2014 (UTC)
 * I think the Friedman reference should be moved to an earlier sentence in that paragraph. The Seafire II or III (the only variants in use by 1944/45) had a single, centre-line, attachment point for external tanks and usually carried a single 30-45-90IG slipper tank. Late in 1944 the Seafire III was modded to use a single 90IG P-40 teardrop tank. There was a 1942 Malta mod for the Spitfire V to use paired 45IG Hurricane drop tanks as a single centre-line tank. Post war Griffin engined Seafires could carry wing mounted drop tanks but not the WW2 variants (confirmed via the Seafire III Pilot's Notes).Damwiki1 (talk) 22:02, 24 January 2014 (UTC)


 * An Imperial gallon is 20% larger in volume than a US gallon. Seafires and Fireflys would have had their tanks calibrated in Imperial gallons, Avengers and Corsairs would have their tanks calibrated in US gallons. Unless the FAA's Avengers and Corsairs were to a special British order, their tank capacities were most likely measured in US gallons, not Imperial ones. OTOH, Tomahawks and Kittyhawks ordered earlier in the war for the RAF had their tank capacities stated in Imperial gallons and their fuel gauges similarly calibrated.


 * FWIW, in addition, a long ton - used in all contemporary British measurements - is also 240 lb heavier in weight than a US (short) ton as used by the US. Some writers, including some 'historians', appear to be unaware of these differences and unless they have been allowed-for in their figures, comparisons may be misleading.


 * "You screwed up your math for the Avenger. Max internal fuel is 278, not your figure of 233." - first figure is tankage for Avenger in US gallons. Second figure is approx tankage figure for Avenger in Imperial gallons. Actual converted 278 US gals figure for Imperial is 231.4.


 * "Seafire ... single 30-45-90IG slipper tank" - these capacities converted to US gals are 36, 54, and 108 respectively.


 * BTW, actual tank capacities always include a specified amount of air space to allow for expansion, etc. A tank can usually be overfilled beyond its stated capacity up to the breathers if required, although with some spillage. — Preceding unsigned comment added by 95.150.18.158 (talk) 11:05, 27 November 2016 (UTC)