Lancaster as an escorted, daylight bomber ala B-17/24?

[IdahoRenegade]

I'm curious about something. My understanding is that the Lancaster was largely used as a night-bomber, due to the lessons learned by the British about losses encountered with unescorted daylight bombing, particularly with their lack of availability of a long-range, high performance, high altitude fighter to escort them, at least early in the war. Were Lancs widely used as escorted daylight bombers later in the war (without perhaps much fanfare)? If not, with the escorts the '17 and '24 got by the end of '43 on, could they have effectively done the job of a daylight bomber? Or did their relative lack of firepower (8-.30 caliber MGs vs 11/13 .50s) mean that even with escorts that they would have been too vulnerable? I realize that from a standpoint of managing 24 hour bombing, it might simply have made more sense to keep the British bombing campaign focused on night raides, leaving it to the Americans for daylight, rather than the unsuitability of the Lanc for the job.

 

[Greyman]

Were Lancs widely used as escorted daylight bombers later in the war (without perhaps much fanfare)?

I'm not sure if 'widely' is the word everyone would use, but yes RAF heavies did many escorted (and unescorted) daylight operations from mid 1944 on. Armament centred around the Browning .303, single-stage engines, and almost zero formation training would preclude the RAF heavies from embarking on the types of campaigns the US heavies did.

As you say .303-inch guns were certainly weaker than .5-inch, but the defences of the Fortress/Liberator still weren't enough.

That said, the British were certainly eyeing up the self-defending bomber concept again -- once they had their gyro-sighted, 20-mm cannon turrets in service.

 

[Greyman]

A reasonable summary from Harris' postwar despatches:

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Prior to the invasion of France in June, 1944, the main effort of the Command was employed almost entirely at nights. No attempt was made to employ the Command in a sustained daylight offensive which would have certainly failed, in view of the inadequate defensive armament of the bombers and the absence of suitable fighter cover.

During this period, however, it was possible to make occasional surprise attacks, using small and medium forces of heavy aircraft, and this was done. In April, 1942, a small scale attack was made against the M.A.N. Diesel Factory in Augsberg in which 12 Lancasters used low-level tactics attacking the target at dusk. In October, 1942, forces of approximately 100 heavy aircraft flew to Le Creusot and to Milan in daylight and returned in darkness.

After the invasion of France, it was possible for the Command to increase its freedom of action and to operate against short range targets, mostly in support of the Army and requiring extreme accuracy, in daylight. This was done using the marking technique which was built up during the operations against French marshalling yards during the previous three to four months, but without attempting formation tactics. As France was progressively overrun and the enemy fighter bases were pushed further back, the range of the attacks was extended and greater numbers of aircraft were used. A loose formation known as a "gaggle," in which aircraft flew in company but not in a fixed formation, was adopted. Long range fighter aircraft became available in small numbers.

By November, 1944, large scale attacks, using at times up to 1,000 aircraft, were carried out against German targets in the Ruhr. The total time over target in these attacks was worked out on the basis of 30 aircraft per minute and although peak concentrations sometimes reached a much higher figure it was found that this was the most satisfactory average rate. For these raids the P.F.F. marking technique and special equipment developed for night operations against similar targets was used.

It was about this time that G.H. was introduced in quantity into No. 3 Group. This was a precision blind-bombing device with an accuracy of the order of 300-500 yards, and could handle up to 80 aircraft at any one time. Until this equipment became available, daylight attacks were ordered only when there was a strong probability of clear weather conditions at the target. G.H. provided a method whereby medium-sized forces could make an accurate attack against precision targets which were obscured by cloud. The device had a range of the order of 200-250 miles and the method normally employed was for aircraft to fly in vics of three, of which the leading aircraft was equipped with G.H. and the wing aircraft released their bombs on a prearranged signal. This method increased the freedom of action of the Command and was particularly successful against oil targets in the Ruhr during the winter months when it was necessary to sustain the attacks and the chances of clear weather conditions were small. Because of the success of this method, 3 Group were employed more often than any other Group on daylight operations.

As previously stated it was not found possible or desirable to use standard close formations. Although this made the task of the fighter escort more difficult it reduced the losses to flak as compared with the conventional formations adopted by the American Fortresses and Liberators. As the penetrations became deeper, however, it was considered advisable to reduce the length of the stream and as a result the concentration of aircraft over the target was increased, and every effort was made to prevent straggling. The "gaggle" formation, however, remained the standard method throughout.

During this period, the Command was called upon from time to time to carry out special operations in support of the Army. In these, the tactics described above were used except that bombing was generally from a low to medium level and special precautions were taken to prevent gross errors in bombing. For this reason, in addition to the Master Bomber who directed the attacks, an experienced captain was detailed to make a special assessment of all markers and drop yellow smoke on any marker which was wide of the aiming point as an indication to the force that it should be ignored. With this precaution it was found possible, in clear weather conditions, to attack targets of which the aiming point was no more than 3,000 yards from the front line.

Although the enemy fighter reaction remained slight, it was known that the bomber forces were accurately plotted as soon as they came within range of his Radar coverage. For this reason, tactics such as signals and Radar silence and the low level approach across Northern France which was used with success at night, were continued. It is probable that had the enemy been given the opportunity to make an early assessment of the composition and nature of the approaching force he would have attempted more frequent interceptions.

 

[Mike Williams]

Here are a couple documents I have readily at hand showing Lancasters and Halifaxes being escorted by RAF fighters during daylight operations:

Spitfire IXs +25 lbs. of 1 and 165 Squadrons escort Lancasters and Halifaxes at Homberg. 27 August 1944
Spitfire XIVs of 350 Squadron escort Lancasters over Ruhr. 11 September 1944
Spitfire XIVs of 130 Squadron escort to Halifaxes bombing Wenne Eickel. 12 September 1944
Spitfire XIVs of 402 Squadron escort Halifaxes to Danne Eickel. 2nd mission - Target cover to Halifaxes at Dortmund. 12 September 1944
Mustang IIIs of 129 Squadron escorting Lancasters to Bremen. 23 March 1945

 

[Piper106]

I am assuming that the bombers retained their night camouflage (black underside), since there were not used enough times on day missions warrant a change to day camouflage.

 

[nuuumannn]

Harris decided that raids against targets in France were to be conducted in daylight hours and at lower altitudes for two reasons. The first was owing to the fear of killing civilians, since France was an ally and so to improve accuracy the ops were flown at lower heights and during mid to late afternoon for greater visibility which also gave the bombers the ability to escape over the Channel under cover of twilight/darkness.

The bombers didn't change colour schemes, primarily because of their predominant night role. As for the reasons for the RAF not doing daylight raids like the USAAF, the Americans were warned about the perils of doing so and it is worth remembering the first US 8th AF daylight raids in 1942, the units suffered high losses. This tended to shaken the resolve by the AAF commanders, particularly since the doctrine had been the staple of the USAAC/AAF bombing corps, and before it became the force to be reckoned with that it became there was lots of soul searching and it needed to be recognised that changes needed to be made. It is worth pointing out that the USAAC/AAF initially advocated unescorted raids and operational experience proved this to be utter folly. The Brits had advised of this and deliberately chose night bombing because of the perils of unescorted daylight raids.

 

[Koopernic]

Here is the thing about the US 50 calibre Browning US Bombers used versus the 303 Calibre Browning the RAF used on bombers.
1 It doesn't matter. Neither Calibre Worked against coordinated attack by daylight fighters.
2 The 303 Browning was effective against a lone enemy fighter. Sensible Luftwaffe Night fighter's who were spotted and engaged by the turrets of a British bomber broke their engagement and hunted another bomber. Luftwaffe pilots that didn't have this habit died and shot down few aircraft. Some Luftwaffe Nachtjagt pilots experienced accurate 303 fire at 1200 yards.

The Lancaster couldn't be expected to operate far above 20,000ft.

Here is the thing. The 8.8cm FLAK 37 had an engagement envelope of 11 seconds at 30,000ft. Perhaps 3 rounds could be fired off. At 25,000ft however things in theory were better the reality is that gun was already relatively inaccurate. There was much more powerful German guns, the 10.5cm FLAK and 12.8cm FLAK as well as the 8.8cm FLAK 41 with a much higher velocity but they were about 5 times less common. At 20,000ft the plain 8.8cm FLAK 37 gun is quite dangerous.

The Me 109 and Fw 190 had single stage superchargers whose full pressure altitudes were slightly above 20,000ft and therefore these aircraft achieved their peak speeds at around 20,000ft. By fighting at this altitude the German fighters are no longer at an disadvantage against P-47, P-38 or even P-51.

Finally, though stories abound regarding the Lancasters prodigious bombload this is a furphy. If a Lancaster is forced to fly above 20,000ft, if a Lancaster is given the same armour and redundancy as a B17 (multiple generators and hydraulic systems) its bomb load drops to similar levels if not less.

It would be practical if escorts were provided but it would not be quite so effective. Assume some extra armour, reduced bomb load and fitting of ventral turrets and maybe 50 calibre guns for the tail and maybe nose turret. Leave ventral gun and dorsal guns at 303 calibres to maintain speed. The rear and front guns on RAF heavies clearly have an enormous field of fire that meant they were less reliant on waist, dorsal and ventral gun positions..

 

[nuuumannn]

Finally, though stories abound regarding the Lancasters prodigious bombload this is a furphy. If a Lancaster is forced to fly above 20,000ft, if a Lancaster is given the same armour and redundancy as a B17 (multiple generators and hydraulic systems) its bomb load drops to similar levels if not less.

Not necessarily. It depends on what you are trying to get your Lancasters to bomb and how far away they are from the UK bases. Weight of load has less effect on aircraft performance compared to drag, but increased height presents problems with accuracy. A Lancaster III with a take-off weight of 63,000lbs was capable of operating at 23,000 feet. Clean it up and remove turrets would increase height, but might decrease range and speed. Of course though, with an MTOW of 72,000lbs carrying a Grand Slam, a Lancaster B.I (Special) can only reach a height of 18,000 feet with a reduced range and speed compared to the standard Lancaster III, but that's a given and was under very special circumstances - B.I (Specials) were extensively modified compared to standard Lancasters.

 

[daviemax]

The primary reason for the Lancaster not being viable as a day bomber was its low ceiling - 21,500 feet loaded. This was even lower than that of the B-24 (23,500 feet) and far below that of the B-17 (at least 30,000 feet). This low ceiling rendered Lancasters operating in daylight very vulnerable to both flak and fighters. Very late in the war, as the German threat declined, some Lancasters were operated in daylight under heavy escort; however, this was very much an exception. It is good to recall that a major reason why the B-24 began to phase out of the 8th AF from the summer of 1944 was due to its relatively low ceiling. With its even lower ceiling the Lancaster was a non-starter.

 

[RCAFson]

The primary reason for the Lancaster not being viable as a day bomber was its low ceiling - 21,500 feet loaded. This was even lower than that of the B-24 (23,500 feet) and far below that of the B-17 (at least 30,000 feet). This low ceiling rendered Lancasters operating in daylight very vulnerable to both flak and fighters. Very late in the war, as the German threat declined, some Lancasters were operated in daylight under heavy escort; however, this was very much an exception. It is good to recall that a major reason why the B-24 began to phase out of the 8th AF from the summer of 1944 was due to its relatively low ceiling. With its even lower ceiling the Lancaster was a non-starter.

Of course this is with single stage Merlins, optimized for low/mid altitude performance. With the two stage Merlin 85 the Lancaster could cruise at 254mph TAS at 27000ft @ 2650rpm and 4.2lb boost at 62000lb, this with both forward turrets and radome. Full throttle would be 3000rpm and ~7lb boost at the same altitude. So if you wanted a high altitude Lancaster for daylight bombing, you could have one, as long as there was sufficient supply of two stage engines.

 

[pbehn]

I think the operating altitude of Lancasters and other night time bombers was decided by the height vapour trails form.

 

[Milosh]

The primary reason for the Lancaster not being viable as a day bomber was its low ceiling - 21,500 feet loaded. This was even lower than that of the B-24 (23,500 feet) and far below that of the B-17 (at least 30,000 feet). This low ceiling rendered Lancasters operating in daylight very vulnerable to both flak and fighters. Very late in the war, as the German threat declined, some Lancasters were operated in daylight under heavy escort; however, this was very much an exception. It is good to recall that a major reason why the B-24 began to phase out of the 8th AF from the summer of 1944 was due to its relatively low ceiling. With its even lower ceiling the Lancaster was a non-starter.

How do you explain the use of the B-24 in the 15th AF.

 

[Airframes]

And yet the Lancaster ( a night bomber due to policy, not because of its "low ceiling") often flew above 23,000 feet, and at 25,000 feet, according to a number of first-hand accounts, and operations briefing notes etc.

 

[SaparotRob]

How do you explain the use of the B-24 in the 15th AF.

Doctrine and training.

 

[Glider]

Some time ago a member of this forum did a huge amount of research into the losses of the Lancaster and the B24, tracking every mission flown over Europe, by day and by night of the two aircraft. At the end the loss ratio was exactly the same for both aircraft, by day and night.

So to sum up, yes the Lancaster was a viable day bomber and the numbers proved it. You could take this a stage further and say that as the Lancaster carried a payload that on average was 50% more than the B24 and had fewer crew, it was the more efficient bomber.

 

[nuuumannn]

The primary reason for the Lancaster not being viable as a day bomber was its low ceiling - 21,500 feet loaded.

Yet in the previous post I posted that Lancaster IIIs could fly at 23,000 feet carrying a full load, with an MTOW of 63,000 ft, and RCAFson pointed out that later more advanced variants had even better performance.

 

[Koopernic]

Some time ago a member of this forum did a huge amount of research into the losses of the Lancaster and the B24, tracking every mission flown over Europe, by day and by night of the two aircraft. At the end the loss ratio was exactly the same for both aircraft, by day and night.

So to sum up, yes the Lancaster was a viable day bomber and the numbers proved it. You could take this a stage further and say that as the Lancaster carried a payload that on average was 50% more than the B24 and had fewer crew, it was the more efficient bomber.

Was this over the same time period? After August 1944 the Reich was running out of fuel, out of well trained pilots, out of propellant for FLAK and out of quality explosive fillers to burst its FLAK shells properly. Many of their radars were jammed or degraded with only a few receiving anti-jamming circuits able to penetrate the hundreds of allied "carpet" jammers and hundreds of tons of Windows dropped.

It's not hard to see that the B24's advantages would not benefit it over the Lancaster when in essence the Reich for the most part is defenceless against either.

Not necessarily. It depends on what you are trying to get your Lancasters to bomb and how far away they are from the UK bases. Weight of load has less effect on aircraft performance compared to drag, but increased height presents problems with accuracy. A Lancaster III with a take-off weight of 63,000lbs was capable of operating at 23,000 feet. Clean it up and remove turrets would increase height, but might decrease range and speed. Of course though, with an MTOW of 72,000lbs carrying a Grand Slam, a Lancaster B.I (Special) can only reach a height of 18,000 feet with a reduced range and speed compared to the standard Lancaster III, but that's a given and was under very special circumstances - B.I (Specials) were extensively modified compared to standard Lancaster's.

I'm sceptical of this.

The Performance of the Lancaster is described here: Lancaster Performance Trials (wwiiaircraftperformance.org)
In essence what can be said about the Lancaster I (with 4 x Merlin XX engines) and the much later Lancaster III with much more capable Merlin 24 engines is that in both cases the aircraft achieves its maximum speed at 16,000ft but then both climb and speed decrease until the aircraft reaches its service ceiling of 23,000ft. An The Lancaster III can simply carry 10,000libs more weight. An aircraft at its service ceiling is at a climb rate of 100ft/minute (0.5m/sec) and is on the edge of a stall with little margin for manoeuvring. With reduced load we can get the Lancaster III operating at 23,000ft but the aircraft will be much slower in speed and climb than a B17G.

The B17 Data shows the aircraft achieving peak speed at not 16000ft like the Lancaster I or III but 25,000f, moreover the speed is higher.
B-17 Performance (wwiiaircraftperformance.org)

Of course this is with single stage Merlins, optimized for low/mid altitude performance. With the two stage Merlin 85 the Lancaster could cruise at 254mph TAS at 27000ft @ 2650rpm and 4.2lb boost at 62000lb, this with both forward turrets and radome. Full throttle would be 3000rpm and ~7lb boost at the same altitude. So if you wanted a high altitude Lancaster for daylight bombing, you could have one, as long as there was sufficient supply of two stage engines.

Two stage Merlin's would be absolutely essential in my view. The Lancaster VI so equipped being significantly faster than B17 at 24000ft but trailing of rapidly beyond that. A B17 can keep climbing to 36000ft compared to 28,000ft in a less armed Lancaster VI (which never entered service).

How feasible is this in August 1942, the date the USAAF conducted its first raid over Ruon France escorted by RAF Spitfire V or even August 1943 the date of the Schweifurt Raid. I understand Merlin 61 engines were in service on Spitfires by 1942.

I'm not a cynic regarding the technical ability of the Lancaster but apart from the ability to produce the engines for it in numbers.

The aircraft would need maybe 1000lbs more armour, secondary hydraulic pumps and generators and 50 calibre guns int he tail and nose.

Spitfire VIII had more range than early P-47C and should be able to escort almost to Berlin so long as waves of aircraft were used so that the longer range wave of escorts were not forced to jetison their fuel tanks.

 

[Glider]

Was this over the same time period? After August 1944 the Reich was running out of fuel, out of well trained pilots, out of propellant for FLAK and out of quality explosive fillers to burst its FLAK shells properly. Many of their radars were jammed or degraded with only a few receiving anti-jamming circuits able to penetrate the hundreds of allied "carpet" jammers and hundreds of tons of Windows dropped.

It's not hard to see that the B24's advantages would not benefit it over the Lancaster when in essence the Reich for the most part is defenceless against either.

It covered all raid from the date of entry into service. Raids such as the first daylight unescorted raids undertaken be the Lancaster's were in the mix, nothing was left out.

I'm sceptical of this.

The Performance of the Lancaster is described here: Lancaster Performance Trials (wwiiaircraftperformance.org)
In essence what can be said about the Lancaster I (with 4 x Merlin XX engines) and the much later Lancaster III with much more capable Merlin 24 engines is that in both cases the aircraft achieves its maximum speed at 16,000ft but then both climb and speed decrease until the aircraft reaches its service ceiling of 23,000ft. An The Lancaster III can simply carry 10,000libs more weight. An aircraft at its service ceiling is at a climb rate of 100ft/minute (0.5m/sec) and is on the edge of a stall with little margin for manoeuvring. With reduced load we can get the Lancaster III operating at 23,000ft but the aircraft will be much slower in speed and climb than a B17G.

The B17 Data shows the aircraft achieving peak speed at not 16000ft like the Lancaster I or III but 25,000f, moreover the speed is higher.
B-17 Performance (wwiiaircraftperformance.org)

http://www.wwiiaircraftperformance.org/B-17/B-17.html
I suspect your missing one point. Max speed and climb are of secondary importance when in actual combat. Far more important is cruising speed and my understanding is that the Lancaster had a higher economical cruising speed than the B17 when at maximum weights

The aircraft would need maybe 1000lbs more armour, secondary hydraulic pumps and generators and 50 calibre guns int he tail and nose.

Generally speaking the nose turret was of little benefit but some Lancs were equipped with 0.5 in the Dorsal position and some in the tail. Some tail mounts were very sophisticated with radar directed blind fire sights far in advance of anything fitted to the B17 / B24

As for armour the Lancaster seemed to be average in its ability to take damage and armour would simply slow it down undoing any benefit.

 

[drgondog]

One of the major factors which argued strongly against 8th AF abandoning strategic daylight bombing was that the entire training program was mobilized for close formation daylight operations, including navigation and window of daylight for Norden bombsight.

A little mentioned factor arguing against 'switching' was the risks of combining day and night operations into night operations. Doubling the amount of bombers into a night window posed many problems which didn't have solutions, namely nav aids and standardized processes for launching and returning in bad weather/low visibility in fall/winter 1943-1944.

As for RAF daylight ops change as early as summer 1944 was a distinct lack of adequate supply of Mustangs for deep penetration. The RAF force could be compared on ratio of squadrons to multiple groups (8th AF) - and there were zero P-37D equipped RAF squadrons suitable for intermediate range escort duties.

Aside from the above factors I see zero reason why Lancasters could not have performed very well as Mustang escorted precision daylight bombers. Higher cruising speed below 22K (average B-24 bombing altitude), heavier bomb load and excellent bombsight, augmented by RAF electronic bombing aids..

One comment made above gave the impression that the 2BD/AD experienced a major transition in B-24 strength in summer 1944. the 389th was transferred to Pacific (Dec 44) and the the 492nd was tasked from Bombardment to Carpetbagger/night ops (Aug 44). Conversely the B-24 equipped BG more than doubled in size in spring 1944.

While both the 1st and 3rd BD were equipped with Bomb Groups equipped by the B-17, the 2nd BD steadily gained relative strength of B-24 groups reaching a peak in July1944. One thing is true however, the loss to combat ops of the 389th and 492nd did reduce the total strength of 2AD but it did not further reduce. Another note - the 3AD 34th BG and 493BG converted from B-24 equipped to B-17 equipped in Sept 1944.

 

[Milosh]

Doctrine and training.

The 15th flew the same kind of missions as the 8th, even having to fly over mountains to get to their targets which the 8th didn't have to do.