So larger airfields can't be made before 1943?, how did bombers take off?.
British escort fighter--what might it have been like?
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drgondog
Major
The same principles apply to Ruhr valley. Conserve internal fuel when external tanks are also available. I your concern is about being attacked while climbing there isn't a great difference beween airplane fully loaded internally, and 'nearly fully loaded' by buring 20 -40 gal compared to 7000 pounds GW.
Shortround6
Major General
The problem with the 1940 and early 1941 escort fighter is the engines when trying to compare them to 1942-43 aircraft.
The Merlin 45 offered about a 15-20% increase in power at around 20,000ft compared to the Merlin III & XII or X engines. And did it for only a dozen pounds of weight.
An escort Spit V can carry around 75-80 imp gal of internal fuel over a Spit I or II and still have a better climb rate at 20,000ft. It will have a better power to weight ratio.
That is important thing, you have to able to fight and get home. Trying to use the Spit I & II means you need to chose one, not both, which does make the thing rather pointless regardless of what kind of drop tank you fit to the bottom.
The Spit V opens the possibility, at least to adding 40-80 gallons of internal fuel and not having performance (climb and turn) not fall below Spitfire I & II levels. If that level of performance is good enough for which months in 1941-42. As the German fighters get better (109F-4s and Fw 190s) you either need to fit Merlin XX engines, which actually only help at lower altitudes and not at 15-25,000ft area you need to stop German fighters from diving on the bombers, or you need to reduce the fuel load to lighten the plane when the external fuel is dropped which shortens the escort range.
The two stage engines added almost 1000lbs when all is said and done, but they added over 200hp more than the Merlin 45 in the 18,000ft and up range so the power to weight ratio went up again. A Spit IX with standard armament (two cannon and 4 MG) carrying a 30 IMP G drop tank can out climb a Clean Spit II by around 200fpm or a bit under 10%.
If you keep the eight .303s you can save about 240lbs over the two belt feed cannon in any model or about 33imp gal of fuel.
Going from the MK II to the MK IX you add about 1000lbs of airplane but you gain around 380hp. Or you gained 16% of aircraft weight (gross) but gained 26% in power.
And that is using 12-15lb boost limits on the Merlin 61, later two stage Merlins got better.
Porter may have been right in 1940 and earlier. But he refused to change his mind when the conditions (power to weight of the engines) changed.
Sure you can, just stop working on the bomber airfields and you can better fighter airfields
One of our members has given use the knowledge that the British airfield construction program of WW II was the largest construction project undertaken in Great Britain during WW II. They were working on more, larger or improved, air fields since the late 30s, you need money, equipment, men, materials. All of which are needed for other projects (finishing up some shadow factories) anti-invasion fortifications, more barracks/army facilities and so on.
You can build a few larger fighter fields earlier if you allocate the resources (don't build something else as soon) but was two or three escort wings really going to change much Using Wellington bombers as the escorted bombers?
(my bold)
As they say: not with that attitude
Material ingredients were there - engine, aerodynamics, structure, weapons. What was not there was a doctrine that requires fighters to escort bombers, and without a doctrine there will be no effort to have a Spitfire with, say, 130 imp gals of fuel + drop tank. Spitfires of 1938-40 were a bit faster than Bf 109s, not the case in 1941.
British were perfectly capable to make longer strips.
A LR Spitfire with Merlin X and at least 2-speed prop goes a long way to cut the take off distance.
Merlin XX offers barely any advantage vs. Mk.45 unless the fight descends to 12000 ft. It was also heavier engine than the Mk.45, thus the RoC above 15000 ft will be worse.
What Mk.XX offers is earlier availability, by some 5 months? Spitfire can be made a bit faster by better streamlining (as it was done by the Mk.III), by 1941 it was getting the drag creep.
Shortround6
Major General
The Spitfire II with the under wing held 124 imp gal, I am not arguing about drop tank/s at the moment just simply combat capability with drop tank gone an greater internal fuel.
You still have speed but climb and sustained turn have gone to pot.
Spitfire II used a Rotol prop and the Merlin XII engine used higher boost limits for both take-off and climb than the Merlin III and should be fairly close to the Merlin X engine.
engine.....................................take-off limit...........................climb limit
Merlin X (low gear)..........1280hp/10lbs...........................2600rpm/5 3/4 lbs
Merlin XII.............................1175hp/12 1/2lbs...................2850rpm/9lbs
Not sure when the 12lbs was cleared for take-off on the Merlin XII engine but they were using the 2850rpm/9lb boost for climb in testing May/June of 1940.
Merlin IIIs were upgraded with 100 octane fuel, but even at worst, the Merlin XII engine was running pretty close the X engine and was a bit better at high altitude. 9.089 supercharger gear vs 8.75 gear in the X. not much.
Now the take-off is not that complicated by adding in 40-60 imp gallons of internal fuel, the take off is complicated by using both added internal fuel and external fuel.
How much external fuel do you need to get to the No-go point?
No-go is the fuel left after the combat allowance and reasonable reserve are taken out.
90 imp gal is probably too much (?) but somewhere around 60-75 might work.
But now we are up to around 115-125 imp gallons over the standard fuel load (860lbs plus weight of the tanks) and that maybe pushing things from a "standard" 1940 Airfield.
Ok but you may want to forget about the wing clip. Cutting about 10% of your wing area when you are trying to take off with heavy loads is not usually a good idea.
Spitfire II introduced the metal Ailerons so it had better rolling than the MK Is. (or planes converted from MK Is?)
Nowhere I've suggested that underwing abomination is to be used.
As for the climb - I've already climbed. It is the Germans that needed to climb to my altitude, not vice-versa. Altitude advantage means something, right
We're in no worse situation than Japanese taking off with Ki-61. Or Spitfire V pilots taking off with 170 + 29 + 84 gals from ground, let alone aircraft carriers.
I'm fine with 90 gal of fuel at don't-go-further point. 60-75 is not worth bothering.
We're in better situation than Zeros and Ki-61s with full internal fuel, and in ballpark with Bf 109E with drop tanks.
Yes, use the 'full', normal Spitfire wing.
Shortround6
Major General
The Altitude advantage lasts how long in combat? Right up until the first turn or pull-out from the first dive?
I doubt very highly there is much altitude advantage left after even 5 minutes. You are down to the power to weight ratio (unless you are running in a straight line)
Japanese had 2-3 years to build longer runways.
Again, the arguments against a 1942-43 long range escort are different than the arguments against a 1940-41 long range escort.
Also not sure about how well the Ki-61 would have done against Bf 109Gs. Or even 109F-4s. Ki-61s were facing off against P-40s and P-39s in 1943, in the land of the blind the one eyed man is king when it comes to climb
Ferry flights have somewhat more discretion as to take-off conditions.
to add to the numbers listed earlier for the P-40 at 8900lbs with a 75 US gallon drop tank the take off run (at 0 degrees) drops from 1600ft to 950ft with a 20mph head wind and to just 500ft with a 40mph head wind.
Wonder what you could do with a 20kt carrier, plus a 15-20kt wind plus a catapult?
British really screwed up the escort fighter plan when they stopped building catapults on the 500yds (to the trees) airfields
You would be relaying aircraft as the raid goes further out so by the time combat starts just the rear 33G main and wing tanks are full, the MkIX had no handling issue's with 33G in the rear and MkVIII's XIV's and Seafire III's didn't have handling issue's with full leading edge tanks so we can assume the MkIII wouldn't either. The MkIII was capable of handling the 109F and on par with the FW190 so warm up taxi on the upper rear 42G, switch to main for take off then back to rear upper for climb out from 2,000ft, continue to use it to climb to 25,000ft and cross the channel, once gone switch to drop tank, have the DT return go to the main tank before overflowing back to the DT so not only are you running on the DT it's refilling the main, once in combat switch to main and manage from there.
drgondog
Major
All interesting - bottom line is that Spit IX turned back after shallow penetration escort for 8th AF. All that you describe was over and done with before getting to Paris.
Merlin III offered better power than DB 601A above 15000 ft, Merlin X was still better. 100 oct fuel improves the odds for Merlin family further.
Escorting fighters are not in for one vs. one battle. RAF can deploy a few hundreds of bomber and a few hundreds of bombers in 1939-40, vs. LW deploying a few hundred fighters against these. LW fighters are not tasked with dilly-dialing with RAF's escorts, but with killing RAF bombers - not easy since they have roughly 1 bomber and 1 fighter per each LW fighter. Conversely, if LW fighters are trying to get RAF escorts, bombers are left unmolested.
British can do it too, early enough, if the doctrine calls for LR fighters. No doctrine = no LR fighters = no long runaways for the fighters packed with fuel.
Again, the arguments against a 1942-43 long range escort are different than the arguments against a 1940-41 long range escort.
Also not sure about how well the Ki-61 would have done against Bf 109Gs. Or even 109F-4s. Ki-61s were facing off against P-40s and P-39s in 1943, in the land of the blind the one eyed man is king when it comes to climb
As before - I'm not expecting the escort to climb like a homeless angel.
Mentioning the Ki-61 was to reinforce my point wrt. technology being there and doctrine being absent for the RAF in 1930s.
Cheers.Ferry flights have somewhat more discretion as to take-off conditions.
to add to the numbers listed earlier for the P-40 at 8900lbs with a 75 US gallon drop tank the take off run (at 0 degrees) drops from 1600ft to 950ft with a 20mph head wind and to just 500ft with a 40mph head wind.
Wonder what you could do with a 20kt carrier, plus a 15-20kt wind plus a catapult?
British really screwed up the escort fighter plan when they stopped building catapults on the 500yds (to the trees) airfields
yulzari
Tech Sergeant
Building runways and all the buildings, hard surfaces, bomb and fuel storage etc. in Britain during the war was the biggest ever British civil engineering effort. There was no spare capacity to do more. If you extend fighter runways, possibly rebuild the whole runway for the extra weight, then you make fewer or shorter bomber runways/airbases. The was no more 'more' to add.
I might be wrong, but UK existed before ww2.
drgondog
Major
I have the same habit when I want specifics regarding Britain, Scotlane, Northern Ireland, Wales.
But WW2 didnt. The runway building programme was huge, not only for RAF Bomber Command but for Fighter and Coastal command too in addition many airfields assigned to American bomber fighter and training groups. A daylight bombing adventure into Germany would take its place behind all the other priorities for planes men and infrastructure
Don't worry about that, many here don't understand it. For example the "UK" before WW2 was not the same as the "UK" before WW1.
History of RAF airfield construction including details of expansion of individual airfields as well as numbers built.
The Development of Britain’s Airfields.
The development of Britain’s airfields has been both rapid and complex. The design, layout and specific requirements of airfields changing as the need for areas suitable for larger and more p…
aviationtrails.wordpress.com
The ultimate Class A airfield spec.
Class A airfield - Wikipedia
So a Spitfire with over 200G of internal fuel plus a 90G drop tank can only get to Paris from say Biggin Hill, about 280 miles???
Shortround6
Major General
But the Germans were not sticking DB 601A engines in 6200lb fighters (Spit 1 & II with normal fuel) , they were sticking them in 5500-5800lb fighters. Being 6% lighter is not much but it does help to level the playing field a bit. 100 octane doesn't do quite as much for the escort fighters as if they get sucked down to lower altitudes where the 100 octane makes a difference they are no longer protecting the bombers (they are below them and while German fighters they shoot down today cannot attack tomorrow, Spitfires below the bombers are not stopping German fighters attacking form above today. )
It varied practically by the month. What the RAF could do in Nov 1940 was far different (better) than what it could do Nov 1939.
British had to change their doctrine in 1936-37. You need different airfields for both bombers and fighters, you need to build another propeller factory (or two). You need more gun turrets, you need at least one different bomber, Hampdens in daylight are not going to work
, Whitley was ordered as a night bomber, they knew it could not fly in daylight and survive and that was against biplanes. I hit something a bit interesting in the early pages of "The Spitfire story" by Alfred Price. It gives the original specification No F.7/30 1 Oct 1930 which covers pages 33-40 in appendix A, the book also gives 3 further modifications or specifications that lead to the Spitfire. It includes all sorts of stuff, like the required impact requirements for the "alighting gear" which in 1930 was vertical velocity of 10fps and the load on the alighting gear must not be more than 3 times fully loaded weight of the aircraft. And a bunch of other interesting stuff.
However as far as this discussion goes it spells out the load to be carried. The actual weight of the aircraft is not specified, that is up to aircraft designers.
Now in the 1930 this load was 660lbs + the fuel needed for the selected engine for 1/2 hour at full throttle at ground level plus 2.0 hours at full throttle at 15,000ft. Oil was required for the same plus 50% and water (if required) was the same.
Now in 1930 with fixed pitch props and barely 500hp engines this may have made sense (or been hold over from earlier specifications)
From a design perspective the Military load is interesting as to what could be changed and what could not be changed.
item.....................................................removable..................fixed...................total
Crew.....................................................180lbs............................--.....................180lb
Oxygen..................................................15..................................8........................23
Instruments............................................1................................25.......................26
R/T apparatus.....................................46...................................6.......................52
Electrical Equipment........................41...................................17.....................58
Parachute & Belt...............................20......................................3.....................23
Armament
4 guns and C.C. gear*..................120......................................20................140
Gun sights..........................................--..........................................5.....................5
200 rounds S.A.A. *.......................145......................................--.................145
Signal pistol & Cartridges .............7.........................................1..................8
Military load........................................575...................................85...............660
*Later on it spells out the exact gun armament, 2 Vickers guns installed in the cockpit under control of the pilot with C.C. gear and either two more Vickers guns in the fuselage with C.C. gear or in the wings OR two Lewis guns in the wings (which do not heating). 2000 rounds of ammo (number in the table may have been a misprint) with links or drums as necessary. 400 rounds minimum for any gun. 400 round drums will be available for the Lewis (which never happened even 10 years later)
now over the years the Instruments could change a bit (And in section 6 (c) the instruments are listed) as could the R/T equipment and the electrical equipment.
Long winded explanation but in 1930 the 660lb load plus fuel and oil was supposed to hauled around by a RR Goshawk engine of about 600hp.
Now since several of the Prototypes built to this specification could not make 200mph at max speed actual range with 2 hours of fuel was not that great
The thing is that engine power increased the part of the Load that was NOT guns, ammo, fuel didn't change all that much and became a smaller percentage of the total weight.
I would also note that a Spitfire II was carrying about 50% more guns/ammo than the Goshawk fighters were supposed to carry. The Spitfire had nearly 2 twice the power.
The Spitfire V at around 20,000ft had roughly 20% more power for just about the same weight. It can afford to trade some climb performance for fuel.
Spitfire I & IIs could not carry a significant amount (40imp gal ?) of internal fuel without a performance penalty.
Maybe they could have figured out how hang a droppable 45-60 gal tank for climb and cross over to Holland so they would enter combat with most of their 87 gallons available for combat and the trip home but that is about all.
All the doctrine in the world cannot over come physics. Or physical plant. You need the engines/props/aerodynamics to come together with proper sized airfields (and fuel supplies and training/equipment) to support/enable the doctrine.
The British, unfortunately, did not even have a useable doctrine for daylight bombing. They had a "doctrine". It didn't work and needed an lot of work and changes to even begin to work. Just because you can find a test range in England by flying down railroad tracks and flying low enough to read the station name on the building to fix you location does not mean you can do that in a real war in a foreign country.
You also need effective bomb sights and you might actually want to look at effective bombs.
for your long range escorts you better figure out how you are going to get them home if the weather gets bad.
Clayton Magnet
Staff Sergeant
- 902
- Feb 16, 2013
Also note, that drop tanks aren't always as simple as they would appear. Spitfires sometimes had trouble safely releasing them
