#1 Jet of World War II

The Revolution Will Not Be Televised wrote:

On Wed, 23 Jul 2003 13:49:11 +0100, John Halliwell
wrote:

They evolved that way, from roughly similar airframes as a starting
point. Lancasters flying by day would soon develop heavier armour,
especially around the engines, less bombload in exchange for more fuel
to burn for higher height on the ingress route, and heavier armament
like .50 calibres in the rear turret - all of which they were adopting
by 1945, which cut into their bombload margin over the B-17.

Interesting point, any sources for this. I haven't heard about
increasing armour for daylight ops, or trading bomb load for fuel.

Look at the trend evident in the Rose turreted B.1/B.IIIs, and the
engine installation in the Lanc IV which directly influenced the
Lincoln (two-stage Merlins with armoured, annular radiators), let
alone the massively increased armament in the Lincoln (e.g. twin 20mm
Hispanos in the mid-upper turret). The only way to get more fuel in
the Lanc for Tiger Force operations was in the bomb-bay, which had
obvious implications for the bombload carried. This just represents a
gradual and evolutionary change in operational emphasis.

snip

The 50s in the rear turrets were IIRC fitted only as a pair instead of
the quad 303s.

Sure, but this still represented an increase in effectiveness at
daylight engagement ranges.

And let's remember that each .50 weighed 65 lb., while each .303 weighed 24
lb. As a perfect example of the apples to oranges comparison I'm talking
about, the 8 .303s carried by the typical Lanc weigh a total of 192 lb.
while the 13 .50s carried by the typical (in late '43) B-17G weigh 845 lb.
Oops, there goes 653 lb. of bombs/fuel right there, and then we've got to
carry extra fuel to haul that extra weight back from the target. And we're
ignoring the extra weight and drag of a ball turret and waist guns plus the
gunners and their equipment, which means carrying extra fuel to haul all
this extra weight both ways, which the night bombers didn't have).

Guy

"Joe Osman" wrote in message
...
Peter Stickney wrote:



Actually, power is the product of the amount of force
required to move a certain mass a certain distance in a
certain time times that distance and the reciprocal of that
time.

Joe

Huh

If the body is in steady motion then neglecting friction the power
requirement would be zero, since friction varies enormously this
is clearly NOT a valid definition

Quite simply power is a measure of energy production per unit
time or put another way the rate of doing work

The velocity of the engine or the vehicle its mounted in is irrelevant.

Keith

In article , Guy Alcala
writes
No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's.

But why drag the performance of an aircraft down by using it in a way
that is clearly inefficient? All this discussion has confirmed to me is
how inefficient the big box formations actually were. Dragging the
performance of a heavy bomber down to the point where it is carrying a
similar load to a Mossie, whilst remaining considerably vulnerable (and
with a crew of ten), doesn't make much sense to me.

A couple of Mossies with a light load, perhaps 2,000lbs each start to
sound more and more promising. Small, fast formations may have been very
effective.

Nowhere did I say that you
had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

The B-17 bomb bay was not the best arrangement for carrying large loads.
As such had it been used in night ops, the range/payload may not have
been able to be improved to compensate for lighter fuel (or fewer
guns/crew) loads. On that basis, it's easier to drag the Lanc down by
hampering it with US practises than boost the B-17 by using RAF
practises.

--
John

John Halliwell wrote:

In article , Guy Alcala
writes
No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's.

But why drag the performance of an aircraft down by using it in a way
that is clearly inefficient? All this discussion has confirmed to me is
how inefficient the big box formations actually were. Dragging the
performance of a heavy bomber down to the point where it is carrying a
similar load to a Mossie, whilst remaining considerably vulnerable (and
with a crew of ten), doesn't make much sense to me.

Who says it was inefficient, under the prevailing circumstances? Clearly, the RAF
heavies would have suffered much heavier losses than U.S. heavies if they had tried
to operate by day, in formation, in the same time frame (especially before air
superiority had been won). Out of formation, they would have been slaughtered on an
even more routine basis than the U.S. heavies were, because they had no effective
daytime defensive armament, lacked armor, altitude performance, co-pilots etc. etc.
And they would have been knocked out of formation much more easily, lacking all the
above.

A couple of Mossies with a light load, perhaps 2,000lbs each start to
sound more and more promising. Small, fast formations may have been very
effective.

Small 'formations' for point targets, sure. For large industrial targets covered by
smoke and clouds, almost certainly not. A Mossie could carry at most 6 x 500 lb.
bombs (2 external), while a B-17 could carry twice that internally, i.e triple the
bmb load you recommend. If the Mossie's extra speed prevents more intercepts and it
can bomb from a lower altitude, it may well be more efficient than carrying more
bombs and dropping from higher up, but it's by no means certain that's the case
(unlike some on the NG, I don't rule out the possibility, but the only way to find
out for sure would have been to actually try it, and that didn't happen).

Now, could a B-17's performance be improved by removing some or all of the defensive
armament? Sure, which was done starting mid-44. At first, they removed the radio
room gun and left one of the waist gunners behind; less ammo was usually carried as
well. By 1945, one combat wing ordered one of its groups to remove the ball turret
from their a/c, another group the chin turrets and the third group both waist guns
(and their gunners). A different group in '45 was given permission to remove the
chin turret, ball turret AND either both waist guns or the top turret (forget
which). It boosted cruise speed by about 25 mph, or allowed a tradeoff of fuel,
bombload, and/or height. But it was possible (and made sense to do so) because by
then the fighter threat was rapidly shrinking. Defensive armament doesn't help
against flak, which was the primary threat in that period, but speed and altitude
do.

Nowhere did I say that you
had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

The B-17 bomb bay was not the best arrangement for carrying large loads.

Certainly (the same was true to a lesser extent with the B-24), but that was due to
the structural design decisions made, not an inherent effect of design for day vs.
night bombing. Just look at the B-29 and B-36. I don't know why U.S. heavy bomber
designers pre-war went for short and tall bomb bays rather than long and shallow
oones like the RAF's; FAIK it was considered to give a better bomb pattern, or maybe
there was some different reason. It certainly wasn't universal among U.S.
bomber/attack a/c, as I can attest having had to slide over the wing spar (just like
a Lanc) to go from fore to aft in a P-2 Neptune.


As such had it been used in night ops, the range/payload may not have
been able to be improved to compensate for lighter fuel (or fewer
guns/crew) loads. On that basis, it's easier to drag the Lanc down by
hampering it with US practises than boost the B-17 by using RAF
practises.

The question is, what was the typical load actually carried by Lancs? In 1943, it
was about 8,000 lb. (effective bombload was something like 7,450 lb. The difference
represents aborts and a/c shot down before bombing ). In 1944 and '45 it increased,
both because there were more short-range tactical missions (to more lightly defended
targets), the defenses were lighter, and because friendly terrain was closer
(allowing more fuel efficient flight profiles and more divert possibilities if low
on fuel, i.e. less reserve fuel needed to be carried). Can a B-17 carry 8 x 1,000
lb. bombs in the bomb bay? There seems some question about that - it could
definitely carry 6 (the B-24 could carry 8), and could carry a pair externally.
Could a British heavy carry more individually larger bombs internally? Yes (with
the possible exception of the Stirling), but again that was a design decision, not
an inherent effect of the type of bombing to be done.

Guy

Subject: #1 Jet of World War II
From: Guy Alcala
Date: 7/23/03 7:33 PM Pacific Daylight Time
Message-id:

bombs and dropping from higher up, but it's by no means certain that's the
case
(unlike some on the NG, I don't rule out the possibility, but the only way to
find
out for sure would have been to actually try it, and that didn't happen).


I guess it is possible to destroy Berlin one house at a time, But that isn't
the best way to get the job done.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

The Revolution Will Not Be Televised wrote:

On Wed, 23 Jul 2003 15:35:11 +0100, "Keith Willshaw"
wrote:

John H.

snip

Close formation flying both increased the concentration of the bomb
pattern and the effectiveness of return fire from the gunners. The
RAF were extolling this in 1939 with Wellingtons over Heligoland
Bight, and continued to do so in "large-scale" daylight ops (e.g. the
Lancasters in the Augsburg raid).

Which were unmitigated disasters.

Of course they were. The point is that the RAF when flying in
daylight, did rely on some extent to formation flying and gun defence.

And immediately after the Heligoland mission, when it was found that the nose
and tail turrets were unable to bear to the sides where Mfighters were
deliberately making high deflection passes, the RAF added waist guns to their
Wimpeys before going over to night bombing. IIRR, some of the early 9 Sq. a/c
had a sliding hatch on the top of the fuselage with a gun deployable from it,
but this was removed in later production. As it happened, the .303 was pretty
useless when facing cannon-armed (and armored) fighters, but there was at least
some deterrent value in the tracer, and they could always get lucky.

Guy

On Thu, 24 Jul 2003 02:33:56 GMT, Guy Alcala
wrote:

[snip agreed points]

The question is, what was the typical load actually carried by Lancs? In 1943, it
was about 8,000 lb. (effective bombload was something like 7,450 lb. The difference
represents aborts and a/c shot down before bombing ).

Actually, that's valid for the Berlin raids, but shorter distance
tonnages were higher, even before 1944-45. Middlebrook gives figures
of 10,000 - 13,000 lbs bombloads for the Hamburg raids in 1943,
against approximately 5,000 lbs for the B-17s which seems relatively
constant regardless of the penetration (e.g. mentioned again for the
first Berlin raid, according to Ethell & Price). The B-17s also had a
reduction in percentage of bombload carried to target due to losses,
even if the use of air spares reduced the abort percentage.

[snip other agreed points]

Another point is the actual numbers of bombs on target; daylight raids
were preferable to both forces, when this was regarded as practicable,
even with weather and visual constraints (smokes screens & dust).

Gavin Bailey

--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003

ArtKramr wrote:

Subject: #1 Jet of World War II
From: Guy Alcala
Date: 7/23/03 7:33 PM Pacific Daylight Time
Message-id:

bombs and dropping from higher up, but it's by no means certain that's the
case
(unlike some on the NG, I don't rule out the possibility, but the only way to
find
out for sure would have been to actually try it, and that didn't happen).


I guess it is possible to destroy Berlin one house at a time, But that isn't
the best way to get the job done.

That assumes that destroying German houses was our (the U.S.A.A.F.) avowed policy
and doctrine. It wasn't, although as a practical matter the U.S. stopped worrying
about doing area bombing with the heavies from the fall of 1943 on to the end of
the war. If we could see to bomb visually, great; otherwise, we'd bomb by radar
or other radio navaids with a 2 or 3 mile CEP, which is area bombing by anyone's
standard. Of course, even when the heavies could bomb visually, 'precision' was
relative. Here's Elmer Bendiner, a B-17 Nav. in the 379th BG(H), talking about
the June '43 mission against the I.G. Farben synthetic rubber plant at Huls, in
the Ruhr. Writing some 35 years later, he says:

"Our losses, including those of the main and diversionary forces, amounted to 20
planes, two hundred men, roughly ten percent. Nevertheless, our superiors were
pleased with us because we had dropped 422 tons bombs and, according to the
reconnaissance photos, only 333.4 tons had been wasted on homes, streets, public
parks, zoos, department stores and air-raid shelters. This passed for precision.

"Actually Huls might have been put out of comission permanently if there had been
a follow-up. After our mission the city went almost unscathed right to the end of
the war. We had devastated buidlings and shaken morale, but tire production,
although on a limited scale, was resumed within a month. Synthetic-rubber
production suffered perhaps six months but soon was reaching new peaks. I have
searched the records and find no explanation for our failure to return and finish
the job. The Germans were astonished at the time. After the war American
scholars of our air strategy were surprised, but nobody nitpicks a victory. A
cold analysis of the balance sheet at Huls indicates that the lives lost that day
-- American and German, in the air, on the ground, and in shelters underground --
had not brought closer the end of the war or of Hitler. But at the time we did
not know the price and thought we had a bargain."

As Bendiner writes, the Huls raid was considered by us at the time to have
achieved excellent bombing results. IIRR, "Impact" devoted an article to the
mission.

Guy

The Revolution Will Not Be Televised wrote:

On Wed, 23 Jul 2003 11:40:46 GMT, Guy Alcala
wrote:

[Lanc bombing height]

The most common bombing heights (excluding exceptions like the
Peenemunde raid) seem to have been around 18,000 feet.

Odd that you should mention that, as Middlebrook ("The Nuremberg Raid") says
that a/c of all the Groups on the mission (with the exception of No. 1 GP;
see below), whether Lanc or Halifax, were evenly assigned to one of four
cruise heights -- 20, 21, 22, or 23 thousand feet.

This was common practice: although I was suprised to see 3 Group
getting the lower height bands even as they started to re-equip with
Lancasters in early 1944. The raids I researched may not be
representative, however, and I think those might have included some
late Stirling raids, which would explain it, although they were
normally banded by Group and by type within that, just like the wave
timings for TOT.

The other cause may be that 3 Group had a couple of Lanc Mk. II squadrons in
roughly that period, 115 and 514. Come to think of it, 61 Squadron had a single
Lanc Mk. II flight early in the a/c's career, but I don't know if the crew you
were studying was flying Merlin or Hercules-engined a/c. The latter seem to have
had a service ceiling a two or three thousand feet lower than the Merlin-engined
a/c, so possibly that explains it.

Guy

On Thu, 24 Jul 2003 07:27:35 GMT, Guy Alcala
wrote:

Actually, that's valid for the Berlin raids, but shorter distance
tonnages were higher, even before 1944-45.

The 7,450 lb. figure was apparently the average effective Lanc load over all missions for
1943, and was the one used by Freeman (the Air Marshal, not Roger) when justifying use of
the Mossie for the LNSF.

That's interesting, as "four tons" seems to be the normal planning and
statistical summary of the average Lanc bombload that I've seen.
Nevertheless, they were carrying more than 8,000 lbs from the very
beginning, e.g. to the Ruhr and on mining ops. Even in 1943 I suspect
this was a conservative estimate, but nonetheless a reasonable one for
planning purposes.

With a 4,000 lb. cookie, the Mossie would have an average
effective load of 3,735 lb given the assumed abort/loss rate.

This must date to the end of 1943, then. I suppose that might be
consistent with the lower tonnages on the deep penetration raids the
Lancs were then bearing the brunt of.

Hamburg is a bit of a special case, as like Emden and the other
coastal ports most of the cruise part of flight could be made over the North Sea,
allowing a much more gradual climb profile and more limited exposure time to the
defenses.

The loads seem to be similar for raids on the Ruhr and higher for
occupied Europe. Even for the Battle of Berlin Middlebrook gives an
average over over 8,000 lbs for the participating Lancasters (8 Group
excluded).

Another point is the actual numbers of bombs on target; daylight raids
were preferable to both forces, when this was regarded as practicable,
even with weather and visual constraints (smokes screens & dust).

Yes, if you could see the target the bombing accuracy was higher, and (pilotage)
navigation tended to be better by day as well.

BC could minimise some of the inherent inaccuracies of night bombing,
e.g. by refreshed and off-set ground and sky marking along with radio
raids, and in the process achieve some degree of all-weather
capability, but even with looser formations and a bigger inherent
spread of bomb concentration they wanted to bomb by day if they could.
Even fractional glimpses of ground references through heavy overcast
was a critical navigational advantage largely lost on night operations
when basics like drift and groundspeed were much harder to calculate
accurately.

Gavin Bailey

--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003