Even prior to any formal orders
being received for the twin-engine Avro Manchester, Roy
Chadwick, Avro's Chief Designer, had unofficially
proposed a four-engine variant of the Manchester to the Air
Ministry.
Although, the initial
four-engine proposal was not given the total support of
either Avro or the Air Ministry, with the Manchester design
not fully finalized, a group of six draftsmen were assigned
to the project. The Type 683 four-engine variant named
Manchester Mk.III was already well under way long before the
first Manchester rolled off Avro's production lines.
The new design called for
the use of the basically sound Manchester fuselage and
center wing section. To which it was proposed to mount an
increased main wing with a span that was initially to be
90'-0" (27.43 meters), this would later be increased to
102'-0" feet (31.09 meters.) The tail plane was also to
be enlarged, but the early design retained the Manchester's
tri-fin design. This too would be revised shortly after the
first flight of prototype and would also include the
deletion of the central fin and an increase in the size of
the twin rudders.
With the initial design
nearing completion; design calculations showed that the
four-engine Manchester, which was now unofficially being
referred to as the Lancaster, showed significant improvement
in performance over the twin-engine version. The design team
surmised that even with a new all up weight of nearing
58,600 lbs, the aircraft would be capable of reaching a top
speed slightly over 300 mph at 18,000 feet and a have a bomb
lifting capacity of 12,000 lbs.
By August 1940,
correspondence between senior members of Avro, Avro's
sub-contractors and the Air Ministry reveal all
parties were actually discussing the new four-engine design.
But as yet no commitment had made towards producing a
prototype aircraft.
At about the same time as
the correspondence discussing the new Manchester version was
occurring a decision was made high in governmental echelons
that the entire bomber force should be equipped entirely
with four-engine types.
Within twenty-four hours of
this decision being made, a letter arrived at the Air
Ministry suggesting that once the original order for the two
hundred twin-engine Manchester's, currently under production
with Avro, was completed the entire Avro manufacturing
facility should be converted for production of the
Handley-Page Halifax.
This suggestion can only
have been received in the most unfavorable way by the
management of Avro. As their reaction was immediate and they
submitted a counter-proposal to the Air Ministry for the
production of the four-engine Manchester variant.
The speed with which Avro was
able to react to the Air Ministry's suggestion that they
convert to the manufacture of the Halifax makes two things
obvious.
Firstly, that Avro had in
fact conceived of the four-engine Manchester variant a full
two years prior to the delivery of the first twin-engine
Manchester, and that Avro was in fact ready to produce this
version prior to even the first Manchester being delivered
to a squadron.
Secondly, that Avro
successfully argued that since over 70 percent of the
components required to build the four-engine variant were
currently being used on the twin-engine version. There by
allowing for a far quicker conversion from manufacture of
the twin-engine version, to manufacture the four-engine
version being attained; than could be achieved by converting
to a the manufacture of a totally different aircraft type.
Although by November 1940,
all efforts were being made to bring the Manchester up to
specified performance levels. Both Avro and the Air Ministry
were more than aware of the Manchester's operational
shortcomings. And it was at about this time that the Air
Ministry finally instructed Avro to proceed with the
development of the four-engine Manchester variant, which was
then officially deemed the Manchester Mk.III.
Once again Avro was quick
off the mark. Deciding, that in order to speed up the
development of the Mk.III an existing Manchester Mk.I
airframe complete with its then standard central tail fin
and 22'-0" span tail plane assembly, should be used.
One was quickly allocated and soon removed from the
production line for conversion and it was not long before
the revised main wing assembly complete with its four Merlin
engines was mated and the aircraft made ready for flight.
On January 9th, 1941, only
six weeks after the preparations had begun, the first
prototype Manchester Mk.III (BT308) took to the air.
Initial test flight reports
were good, with the only comment being that the aircraft
lacked directional stability. This observation was not
unsurprising as it will be recalled that the original design
Mk.III design required the tail plane to be modified to a
39'-0" span twin rudder configuration.
The second prototype DG595,
which represented the production version of the Mk.III
quickly followed and first took to the air on May 13, 1941
and was soon joined BT308 at the A&AEE testing
facilities at Boscombe Down, for flight and operational
trails.
As testing continued and
with results proving to be favorable and in some case
actually exceeding those originally estimated. A decisions
was made to officially renamed the aircraft Lancaster Mk.I.
The decision must have been partly made with the hope that
this promising new aircraft could begin its service life
with a clean slate; rather than being introduced under the
tarnished image of the Manchester.
The first Royal Air Force
squadron to re-equip with the Lancaster was No. 44 Squadron
based at Waddington in December 1941. The squadron in fact
had the received the first prototype BT308 on strength in
September for crew training. But this one aircraft could
hardly be considered a total re-equipment of an operational
squadron. No. 44 Squadron also had the honor of launching
the first Lancaster offensive sorties, these being against
Essen on the night of 10/11 March 1942.
Four major Lancaster
variants were produced namely the Mk.I, Mk.II, Mk.III and
the Canadian built Mk.X. Although, specialized variants and
marks were also manufactured and included:
The Mk.I and Mk.III Specials
which were both cleared to carry bomb loads in excess of
12,000 lbs, but were restricted to flying with an maximum
all up flying weight of 72,000 lbs.
Examples of their use
included: the attack the Ruhr Dams with the bouncing bomb,
attacks on specialized targets such as the Battleship
Tirpitz and underground flying bomb storage sites; using the
22,000 lbs Grand Slam and the 12,000 lbs. Tallboy bombs
respectively. All three of "special" weapons being
designed by Barnes
Wallis.
The Mk.VI was produced for
operational trails of the Rolls-Royce Merlin 85 and 87
engines. Only ten such aircraft were ever built, but served
with several operational squadrons and took part in
offensive operations.
The Mk.VII(FE) was primarily
designated for use with Tiger Force and operate in the Far
East against Japan. Although most of the modifications were
to allow the aircraft to operate in the extreme weather
conditions that the Far East theatre would demand. This
variant also included the installation a mid-upper turret
equipped with twin .50 caliber machine guns.
Other minor
variants also existed, but by and large none of these
saw significant operational wartime service.
The accepted number of total
Lancaster's produced is 7,377m, it is interesting to find
that the actually total number of Manchester and Lancaster
airframes order was 8,747, the breaking down as follows:
Assuming a standard crew of
seven, the loss of 3,498 aircraft represents the loss of 24,486
aircrew either killed, captured or injured.
In all, Lancaster Squadron's
carried out 156,308 operational sorties dropping 604,612
tons of bombs, 51,513,105 incendiaries and laid over 12,000
sea mines. However, the aircraft's finest hours may have
come in "non-offensive" operations just as the war
was either about too or had just come to a close.
The first of these was
during Operation Manna where Lancaster Squadron's dispatched
a total of 3,156 sorties to drop 6,684 tons of food supplies
to the starving Dutch in May 1945.
The second Operation Dodge,
saw many of the Lancaster Squadron's tasked to perform
another act of humanity. Although, this time its was to
return Allied Prisoners of War from various locations
throughout Europe back to England. In a period of 24 days, a
total of 2,900 round trips were flown and 74,000 ex-POW's
were returned.
With the end of hostilities
both in Europe and the Far East, the Lancaster was by no
means finished in its service to the various Air Forces who
operated them. The RAF continued to use the aircraft in
various rolls including photographic and maritime
reconnaissance up until October 1956. The Royal Canadian Air
Force, who flew back many of the surviving Mk.X's to Canada,
also continued to use the aircraft again in photographic and
maritime rolls until the late 1950's.
Additionally, surplus
aircraft, some almost brand new, were sold to the Air Forces
of Argentina, Egypt and France. Where they were to be used a
variety of rolls until replaced by newer aircraft types.
Other's still were sold to private companies and were
converted for use as airliners, transports, jet engine test
beds or were equipped to act as mid-air refueling tankers.
Today only 26 identifiable
airframes are known to exist in the world. Of these only
two, The Battle
of Britain Memorial Flight's PA474 and the Canadian
War Plane Heritage Mynarski Lancaster FM213 continue to
fly and allow future generations to witness the aircraft in
its true element, namely the air. The remainder are by and
large persevered in various locations throughout the world,
but remain well and truly grounded.
