In article ,
John Halliwell writes:
In article , The Revolution Will Not
Be Televised writes
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. The
B1 Specials had virtually everything not nailed down stripped out, lost
their armour and most of their guns. The Lanc achieved its greatest
bombload in 1944-5 by daylight.

The BI(Specials) had 1500# stripped out to them, _and_ a special
clearance for a maximum weight of 72,000# vs. 65,000#, and Merlin 24
engines vs. the normal Merlin 22s to allow them to get off the ground
with a 22,000# Grand Slam on board. The Grand Slam missions were all
fairly short-ranged, and very heavily escorted. The missions, and the
aircraft that flew them, should not be confused with normal daylight
operations.


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

And were much more effective, being both harder hitting and
longer-ranged. Late model Lancasters, notably the Tiger FOrce
aircraft intended for the invasion of Japan, and the Canadian Mk X,
also had 2 .50 cals in a Martin top turret, as well.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster