At least someone understands the argument, MkV's used slippers over France that didn't increase their range but instead the extra fuel allowed for a higher cruising speed so it made them harder to bounce, another advantage of extra fuel.
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At least someone understands the argument, MkV's used slippers over France that didn't increase their range but instead the extra fuel allowed for a higher cruising speed so it made them harder to bounce, another advantage of extra fuel.We can safely assume that the 29 gals from the rear tank is perhaps 10-15 gals before the German (or other Axis) A/C; or empty, since the manual prescribes that the rear tank is to be used up 1st. Once the drop tank is jettisoned, the influence at the CoG coming from the rear tank is negligible. Some re-shuffling of the counterweights might've helped, too.
Th early (talk 1941/42) and regular use of 29 gal tank on the Spitfires also puts the Spitfire IX and VIII in a better position, range- and usability-wise.
Spitfires with more fuel onboard can cruise on faster speed where the danger is suspected, so the German fighters have the harder time to dictate terms of combat.
You say there were no mods to fit these tanks so how did the Spitfire prevent its bags from collapsing and from chaffing on structure and how were they vented? I would love to know how this was achieved without any modifications to the wing
But is there space that could be sealed?View attachment 787505
Plenty of space between rib 5 and 1 to double the capacity without any additional modifications, your argument about chaffing and costly mods is null and void because the tank was already designed. Actually the only change was moving the gun camera, no biggy.
I was specifically discussing the BoB because that is what you said it was needed for.Yet they went to great lengths to develop all kinds of aux and drop tanks for this pointless issue?, makes you wonder why the MkV's over Darwin were all fitted with slipper tanks and the Seafire MkIII had the MkVIII leading edge tanks?, the FAA were so desperate for range they used surplus P40 droppers in the Med, but there wasn't a problem with range?.
I think you don't seem to understand what you are saying, given tactical advantage is defined as higher altitude at intercept. A full 29 gallon tank will add around 3.5% to the Spitfire I take off weight. The Spitfires are going to take off at the historical times, then climb harder thanks to the extra weight carried and extra altitude gained, because apparently Spitfire climb rates during the Battle of Britain were limited due to the fuel carried. Please provide the examples of Spitfires deliberately climbing slower as a fuel economy measure, lay out the mission profile historical versus 29 gallons more on board, with the same sortie length. Also consider the engine maintenance requirements when engines are pushed harder.You don't seem to understand what I'm saying, I don't want fighter command to fly more sorties or have more airtime, I simply want the extra fuel to gain a tactical advantage over raids they did intercept.
There was a firewall between the pilot and the tanks in front of him. Sitting on a unprotected tank would not be popularI think I may have thought of a reason pilots weren't keen on a 30 gallon tank under the seat to add to the 90 gallons they sat behind, hard to put into words though.
Thank you, I stand corrected.Sorry to disagree but the wording in the manual is Rear fuselage tank (used only with 170 gal, tank) and I read that as the 29 gal tank was only used when the 170 gal drop tank was used and could never be used otherwise.
You don't seem to understand what I'm saying, I don't want fighter command to fly more sorties or have more airtime, I simply want the extra fuel to gain a tactical advantage over raids they did intercept.
Why would you fit the 170G ferry tank and remove all the guns in the BoB????, I have no idea what you are talking about.
There was no need for a redesign of anything, the space for fuel was already there, in fact no changes were made to fit the 13G or 17G bag tanks in MkVIII's and XI's because the space they filled was empty. The MkV had a 29G aux tank fitted that required no structural changes, nor did the 170G ferry tank which was a huge tank.
At least someone understands the argument, MkV's used slippers over France that didn't increase their range but instead the extra fuel allowed for a higher cruising speed so it made them harder to bounce, another advantage of extra fuel.
It was used for fuel in the PR Spitfires,There must have been very good reasons for the designers NOT using that space for fuel. What else is in there? Everyone just assumes it was empty space.
But it was okay for P51 pilots to have 85G of fuel in the same spot, or Me109 and P47 Thunderbolts that had the pilots seat bolted to the fuel tank?. The rear fuel will be burnt off before engaging in combat, you know that.I think I may have thought of a reason pilots weren't keen on a 30 gallon tank under the seat to add to the 90 gallons they sat behind, hard to put into words though.
I will try and keep this simple so you can understand, the 29G ferry tank was only used for ferry operations but the MkIX which used the same fuselage was fitted with a 33G permanent tank in the same position, this is my argument, why fit a 29G ferry tank that doesn't create drag only to remove it and fit a 30G slipper tank that does?.I will try and keep this very very simple so that you can understand.
The 29 gallon tank and the 170 gallon FERRY tank for the mark V were for FERRY operations only. Darwin Spits carried the 30 and 90 gallon OVERLOAD tanks on take off and ejected them before combat.
One of the reasons Spitfires got shot up was because they had to fly slow to conserve fuel and yes the slipper tank added drag but an internal tank doesn't.The slipper tanks did not ALLOW a higher cruise speed. The slipper tanks REQUIRED a higher cruising speed for two reasons.
So simply increasing the original MkVIII/Seafire MkIII tank by 9 Gallons is out of the question yet they were able to design it to take not only four Hispano's but another complete cooling system for all the two stage Merlins?.Fitting leading edge tanks to a non folding wing will be a whole different exercise and involve lot of different design work and modifications.
The field mod to P47 in SWP to add 40gal aft of seat (where 100gal aux tank was placed) created severe aft cg issues and soon discarded.But it was okay for P51 pilots to have 85G of fuel in the same spot, or Me109 and P47 Thunderbolts that had the pilots seat bolted to the fuel tank?. The rear fuel will be burnt off before engaging in combat, you know that.
Bill,The field mod to P47 in SWP to add 40gal aft of seat (where 100gal aux tank was placed) created severe aft cg issues and soon discarded.
SOP was always to retain at least 20gal for both P-51 and P-47 auxiliary tanks as reserve. That said it was reasonably safe to retain 50-60gal in 85gal fuse tank for normal maneuverability.