Black Lancasters: The story of heavy British bomber and first atomic bombs

Everyone knows that the first atomic bombs were dropped from American B-29, "Superfortresses," but the Avro Lancaster was also considered.
Christopher McFadden
The Avro Lancaster was one of the most important bombers of WW2.
The Avro Lancaster was one of the most important bombers of WW2.

Cpl Phil Major ABIPP/MOD/Wikimedia Commons 

  • The Lancaster bomber, also known as the Avro Lancaster, was a British four-engine heavy bomber used extensively during World War II.
  • With its distinctive silhouette and powerful performance, the Lancaster became one of the war's most recognizable and iconic aircraft.
  • But did you also know that it was almost chosen to drop the first atomic bombs?

During World War II, the Lancaster bomber was undoubtedly one of the best bomber planes. It was also known for its versatility and was used in many missions, including bombing raids, maritime strikes, and special operations. Despite its formidable reputation, the Lancasterit's most intriguing mission may be the one it never completed.

First, let's talk about the incredible history of this amazing aircraft.

What is the Lancaster bomber?

The Avro Lancaster was a British four-engined heavy bomber used by the Royal Air Force (RAF) during World War II. It was made by Avro, which also designed it. And was one of the most successful bombers of the war and was a key part of the RAF's strategic bombing campaign against Germany.

Black Lancasters: The story of heavy British bomber and first atomic bombs
A squadron of special Lancasters almost dropped the first atomic bombs.

The Lancaster was known for its high operational ceiling, long range, and heavy payload capacity, which made it well-suited for nighttime bombing raids.

A twin-tailed, mid-wing aircraft, the Lancaster had a wingspan of 102 feet (31 meters), four 1,460 horsepower Merlin engines, and a length of 69 feet (21 meters). A basic crew of seven people, comprising the pilot, copilot, bombardier, navigator, radioman, and gunner, operated the ship.

A 14,000-pound (6,350-kg) bomb load could be carried by the aircraft at a range of 1,660 miles (2,670 km) at a speed of 200 miles (320 km) per hour.

It could travel at a top speed of 280 miles (450 km) per hour with a ceiling of 24,500 feet (7,500 meters). Due to a lack of Merlin engines, air-cooled radial Bristol Hercules engines were also used to power Lancasters, although these proved less effective than the Merlin-powered versions.

Eventually, Packard-built Merlins imported from the U.S. remedied the issue with engine manufacturing capacity.

The Lancaster can trace its specific origins to the development of the twin-engined Avro Manchester that was created in the late 1930s.

This bomber was built in response to the British Air Ministry Specification P.13/36 for a medium bomber for "worldwide usage" that could carry a torpedo internally and conduct shallow dive-bombing operations.

The Lancaster was designed by Roy Chadwick and powered by four Rolls-Royce Merlin and, in one form, Bristol Hercules engines. It was first conceived as an upgrade of the Manchester (which had proven problematic in service and was decommissioned in 1942).

Black Lancasters: The story of heavy British bomber and first atomic bombs
Lancaster PA474 during an RAF "Battle of Britain" memorial flight.

The plane entered service with RAF Bomber Command in 1942, and when the strategic bombing campaign over Europe gained steam, it served as the primary aircraft for nighttime bombing operations.

It replaced the aging British Halifax and Stirling, two more frequently used bombers, as the type was built in more significant quantities by the Royal Air Force (RAF), the Royal Canadian Air Force (RCAF), and squadrons from other Commonwealth and European countries operating under the RAF.

As one of the most frequently employed night bombers during World War II, the "Lanc," as it was referred to colloquially, delivered 608,612 long tonnes (618,378,000 lb) of bombs over 156,000 missions.

A Lancaster was modified in 1943 as a Metropolitan-Vickers F2 turbojet engine test bed. Later, various engines, such as the Avro Canada Orenda and STAL Dovern turbojets and the Armstrong Siddeley Mamba and Rolls-Royce Dart turboprops, were tested using Lancasters.

After the war, the Avro Lincoln, a bigger version of the Lancaster, replaced the Lancaster as the primary strategic bomber of the RAF. The Lancaster was used for long-range anti-submarine patrol (later replaced by the Avro Shackleton) and air-sea rescue missions.

The aircraft was also put to other uses, including as a flying tanker for aerial refueling, photo-reconnaissance, and aerial mapping, and as the Avro Lancastrian, a long-range, high-speed, transatlantic passenger, and mail delivery airliner.

A Lancastrian belonging to British South American Airways (BSAA) took off on the first regularly scheduled flight from the brand-new London Heathrow Airport in March 1946.

How good was Avro Lancaster in battle?

Almost all of the Lancaster aircraft built during the war were used to bomb German cities at night strategically. The large bomb bays of these aircraft typically carried a mixed load of high-explosive bombs for these missions, such as the cylindrical 2,000–4,000 pound (900–1,800 kg) high-blast "cookie" or several 1,000–2,000 pound (450–900 kg) bombs, with the remaining bomb load typically being made up of small incendiaries.

Most Lancasters had a powered tail turret holding four 0.303-inch (7.7 mm) machine guns, a powered twin-0.303 turret on the upper rear fuselage, and two 0.303s in the nose; a few also had twin-0.303 belly turrets.

Given Lancaster's armaments and bomb-carrying capacity, it was involved in many famous bombing campaigns of the war.

The famed "Dambusters Raid" aside, one of their most critical roles was the sinking of the German battleship "Tirpitz" on November 12, 1944, by 31 Lancaster bombers dropping 12,000 pounds (5,400 kg) "Tallboy" bombs in the isolated Kaa fjord of Norway.

Some Lancasters had receivers for the "Gee" and "Oboe" radio guidance systems and H2S ground-mapping radar starting in 1943 and subsequently upgraded H2X radar. When targeting targets close enough to Britain to be directed by the radio bombing aids, radar-equipped Lancasters could bomb at night with high accuracy by the spring of 1944.

By performing precise assaults on bridges, rail yards, and other transportation targets, Lancasters played a significant part in the buildup to D-Day (June 6, 1944).

However, German night fighters equipped with passive radar receivers adjusted to home on "Monica" signals soon proved fatal for Lancaster aircrews as the fighters could quickly home in on the tail-mounted range-only "Monica" radar warning system, adopted in mid-1943 and intended to warn bomber crews of assault from the rear.

For around six months, Bomber Command was unaware of the German homing capabilities, and many bomber crews paid the price for this ignorance with their lives.

Additionally, the lack of armament or even an observer in the majority of Lancasters cost Bomber Command crews dearly, as the Luftwaffe began arming night fighters with upward-firing 20-mm (0.8-inch) cannons in the rear fuselage in late 1943 (unknown to the British for a considerable amount of time).

The Germans termed this weapon Schrage musik, or "jazz music," and Bomber Command was never able to establish a reliable defense against it. As a result, numerous British heavy bombers were destroyed by German fighters firing covertly at close range.

However, Lancaster was still the most productive British heavy bomber of World War II. It dropped significantly more bombs per worker-hour spent on production and maintenance than its major rival, the Halifax.

Its superior numbers were especially revealing in bombs dropped per lost aircraft: 107 tonnes for the Lancaster versus 48 for the Halifax for each aircraft destroyed during missions during the summer of 1943.

After the war, Lancasters continued to be used as patrol bombers well into the 1950s, and a Lancastrian civilian airliner version was manufactured in modest quantities.

How many Lancaster bombers got shot down in World War 2?

As impressive as the Avro Lancaster was, it was not invulnerable like other era bombers. Many planes were lost with, all too often, their entire crew with them.

According to Sky History, over 55,000 of the approximately 125,000 men who served in Bomber Command during World War II died, and another 8,400 were injured, making the human cost of the RAF's bomber campaign appalling.

A further ten thousand crew members who were shot down and survived ended up as prisoners of war. This means that the possibility of a bomber crew member emerging from the war unharmed was only around 2 in 5 or 40%.

Not all these losses were from Lancaster bomber crews, but given Bomber Command's reliance on this aircraft, a significant proportion was.

The Lancaster was the most well-known and effective RAF heavy bomber of World War II, yet more than half of the 7,377 produced were destroyed by enemy action or training mishaps. Only one in twenty Lancasters finished more than one hundred sorties during the war.

Furthermore, only one in forty airmen were anticipated to survive a second tour of thirty operations by 1943, making them less likely to survive than the soldiers in the First World War's trenches.

The bravery of these young men, most of whom were in their early 20s, is impressive, given the overwhelming odds against them.

What was the plane used in the "Dambusters Raid"?

We'll bet you've already figured this out, but yes, the famed "Dambusters Raid" was carried out by several Avro Lancasters and their ace aircrew.

Also known as "Operation Chastise," the raid was a daring military operation carried out by the Royal Air Force during World War II. On May 16, 1943, a group of Lancaster bombers, led by Wing Commander Guy Gibson, set out to destroy three strategic dams in Germany's Ruhr Valley - the Mohne, Eder, and Sorpe dams.

The mission aimed to severely disrupt the region's German industrial and military capabilities by damaging the hydropower plants, power stations, and factories that relied on the dams for electricity.

These dams were considered virtually indestructible, and their destruction was seen as a major strategic and psychological blow to the Germans.

To carry out the mission, the RAF developed a type of bomb, the so-called "bouncing bomb," designed to skip across the water's surface and sink to the dam's base, where they would explode.

The Lancaster bombers had to fly low over the dams, avoiding heavy anti-aircraft fire, which significantly impacted the drop of the bombs successfully.

The raid was a success, with two of the three dams being severely damaged, leading to widespread flooding and destruction of infrastructure and facilities in the Ruhr Valley.

"Dambusters Raid" significantly impacted German morale and industrial production and was a major victory for the Allies.

However, the mission also had a high human and material cost, with eight of the 19 Lancaster bombers and 53 of the 133 crewmembers being lost in action.

The bravery and sacrifice of the aircrew involved in the raid are remembered as significant moments in British military history.

In conclusion, the "Dambusters Raid" was a bold and innovative military operation that significantly impacted the outcome of World War II. It demonstrated the bravery and skill of the RAF aircrew and the ingenuity of British military planners and engineers.

The legacy of the "Dambusters" lives on as a symbol of the bravery and sacrifices made by those who fought in the war.

How many Avro Lancasters survive today?

Despite their large production numbers during the war, very few remain today. Even fewer, sadly, remain even remotely airworthy.

Of the 17 surviving and largely intact Lancasters known to exist, only two are airworthy.

PA474, based at Coningsby, Lincolnshire, U.K., is operated by The Battle of Britain Memorial Flight (BBMF). The other, named "Vera" (coded VR-A, FM213), is in Canada and is operated by the Canadian Warplane Heritage Museum in Mount Hope, a suburb of Hamilton, Ontario.

There are hopes to make another Lancaster, "Just Jane," NX611, a B MkVII, airworthy in the future. "Just Jane" is based at the East Kirkby Lincolnshire Aviation Heritage Centre. Bazalgette FM159, located at the Bomber Command Museum of Canada in Nanton, Alberta, is the fourth Lancaster with working engines and the ability to taxi. It was painstakingly repaired after being vandalized and is now a popular tourist attraction.

In 2014, the BBMF and the Canadian aircraft performed several joint shows throughout the U.K.

The Lancaster KB 882 officially retired in 1964 at RCAF Station Downsview, along with all other remaining Lancasters flying with the RCAF. It was then purchased by the City of Edmundston and displayed KB882 for 53 years at their municipal airport until being delivered to the National Air Force Museum of Canada, Ontario, in 2017, where it still resides.

The National Air Force Museum of Canada has informed IE that there are plans for restoring it, but it is currently unknown where KB882 will be exhibited after the works are complete.

The Canadian Warplane Heritage Lancaster was painted with the markings of Guy Gibson's 617 Squadron aircraft (Code AJ-G, ED932) when he oversaw the "Dambusters" raids for the 2018 flying season to honor the 75th anniversary of "Operation Chastise."

What aircraft were used to drop the first atomic bombs?

The first use of atomic weapons in warfare was extremely significant and had far-reaching consequences. The bombings of Hiroshima and Nagasaki in Japan marked the first and only time nuclear weapons were used in armed conflict.

Black Lancasters: The story of heavy British bomber and first atomic bombs
One of only two remaining flying B-29 bombers in the world.

They resulted in many casualties and devastating destruction. The bombings also marked the beginning of the nuclear age and the recognition that the world had entered a new era of geopolitical and military tensions, which would have far-reaching implications for international relations, global security, and the future of warfare.

The first use of atomic weapons led to the creation of the nuclear deterrence concept and the development of large nuclear arsenals by many countries, as well as efforts to limit the spread of nuclear weapons and negotiate arms control and disarmament agreements.

But what aircraft was chosen for this regrettable event? In short, the impressive Boeing B-29 "Superfortress."

The B-29 was chosen as the delivery aircraft for the first atomic bombs because it was the most advanced and capable heavy bomber available. It had the range to fly the mission from Tinian Island, the ability to carry the large and heavy bomb, and the altitude to drop the bomb from above the reach of enemy air defenses.

Additionally, the B-29 had been used extensively in bombing campaigns in the Pacific Theater during World War II. It was well suited for the long-range and high-altitude bombing mission required for the atomic bomb drop.

However, history could have been very different if the B-29 wasn't ready in time for the end of the war. As it turns out, that "honor" could have been given to a set of specially modified Lancaster bombers.

Let us tell you the story of the so-called "Black Lancasters."

Is it true that Lancaster bombers almost dropped the first atomic bombs?

The B-29 "Superfortress" was a formidable and capable bomber. Still, for a payload as large and unwieldy as the first atomic bombs, it didn't quite cut the mustard in its original configuration.

Each had two bomb bays 12 feet (3.7 meters) long and 17 feet (5.2 meters) tall. As soon as the first B-29 was delivered on July 1, 1943, plans were made to modify them so they could carry the bombs, especially after it was discovered that the "Thin Man" atomic bomb was 5 feet too long to fit into one of the B-29's bomb bays.

This was, obviously, a problem.

By comparison, the Lancaster bomber had gigantic bomb bays that could handle such a giant bomb. For this reason, it was, albeit for a short time, considered the ideal aircraft for the job.

Avro engineers were confident that Lancaster could do the job with relatively minor modifications of the existing airframe and bomb bay designs.

By comparison, the B-29 would require substantial modifications from its "factory settings" to make the grade. Called "Project Silverplate," this was a top-secret project during World War II to modify B-29 bombers to carry atomic bombs. The U.S. Army Air Forces initiated the project to develop the capability to deliver atomic bombs by air.

Engineers on the project worked to modify a set of B-29s to accommodate the size and weight of the bombs and to improve their ability to carry and drop the bombs accurately.

The modifications included strengthening the bomb bay and internal structure of the aircraft, installing a more powerful electrical system to support the bomb's complex mechanisms, and developing a specialized release mechanism to ensure the bomb could be dropped accurately.

These modifications allowed the B-29 to carry and drop the atomic bombs with sufficient accuracy and reliability to achieve the desired military objectives. According to some sources, the total cost of the modifications was $32,000, making each Silverplate aircraft worth $814,000 (about $13.7 million today).

So, why was this program so expensive?

What was "Project Silverplate"?

Before we get into that, we need a little overview of each of the bombs dropped on Japan.

Black Lancasters: The story of heavy British bomber and first atomic bombs
The history of the first atomic bombs could have been very different.

"Little Boy," the bomb dropped on Hiroshima, relied on a simple mechanism called a gun-type design, where two sub-critical masses of uranium-235 were brought together to form a supercritical mass, initiating the fission reaction.

The mechanism was similar to firing a bullet from a gun. However, the actual trigger for the reaction was not a bullet but rather the rapid assembly of the two sub-critical masses.

"Fat Man," the bomb dropped on Nagasaki, used a more complex implosion-type design, where a shell of conventional high explosives surrounded a sub-critical mass of plutonium-239.

The high explosives were detonated simultaneously, compressing the plutonium-239 into a supercritical mass and triggering the fission reaction. The high explosives served as the trigger for the reaction.

These were, to put it lightly, no ordinary bombs, so housing all the complex gubbins for these weapons required large bomb casings.

As a consequence, the atomic bomb's developers immediately determined that "Little Boy," a tubular "gun-type fission weapon," and "Fat Man," an oval plutonium implosion weapon, would be too big to be dropped from a standard bomber-like the B-17 or the B-24 due to their unusual size and weight.

Dr. Norman Ramsey, a Los Alamos National Laboratory Group member, proposed in October 1943 that the B-29 "Superfortress" was the only aircraft in the U.S. arsenal which could transport either of the proposed weapon forms. However, to accept the massive weapon, even the B-29 needed to undergo major upgrades to its engines and bomb bay, as we've already seen.

Black Lancasters: The story of heavy British bomber and first atomic bombs
The Lancaster was, first a time, the best option for dropping "The Bomb."

Military leaders had given the British Avro "Lancaster," which the Royal Air Force had used to carry the 5-ton "Tallboy" bombs produced in 1944, significant consideration before deciding to utilize the B-29 to deliver the weapon.

The Manhattan Project's commander, Lieutenant General Leslie Richard Groves Jr., and the head of the U.S. Army Air Forces, General Henry H. Arnold, wanted to employ an American aircraft, which, they believed, would have required significantly less modification to the Avro "Lancaster."

For example, while an impressive aircraft, the Lancaster lacked the speed and range that the B-29 enjoyed. By comparison, the maximum speed of the B-29 was about 350 mph (560 kph), while the maximum speed of the Avro Lancaster was about 282 mph (454 kph).

The B-29 had a maximum range of around 5,830 miles (9,382 km), while the Avro Lancaster had a maximum range of approximately 2,530 miles (4073 km). Additionally, the service ceiling of the B-29 was around 31,850 feet (9,707 meters), while the service ceiling of the Avro Lancaster was around 24,500 feet (7,500 meters).

The B-29 was, therefore, deemed the better bet if it could be modified in time.

Plans were employed to either add extra fuel tanks or conduct mid-air refueling, but its lower service ceiling and slower speed could have left the aircraft prone to being exposed to the nuclear blast.

The Army Air Forces Materiel Command at Wright Field, Ohio, received instructions from the United States Army Air Forces on November 30, 1943, for a highly secret B-29 modification project.

By the middle of December, scientists working on the Manhattan Project would send scale models of the "Little Boy" and "Fat Man" weapon designs to Wright Field, where technicians would alter the B-29 and outfit it for use in bomb flight tests.

On December 2, the first B-29 arrived in Wright Field, Ohio, where the bomb bay received major modifications. Engineers removed the B-29's four bomb bay doors and the fuselage portion between the bays and replaced them with a single 33-foot (10-meter) bomb bay to handle the length of the gun-type weapon.

"Little Boy," for reference, was initially planned to be about 17 feet (5 meters) but was eventually shortened to 10 feet (3 meters).

The entire array of rear gun stations was also eliminated due to this upgrade operation. Each aircraft was built to accommodate either device: a "Little Boy" type in the front or a "Fat Man" type in the back.

Separate twin-release systems were fitted in each bay, along with new bomb suspensions and bracing. Engineers also installed motion image cameras in the bays to film the testing of the new release mechanism.

Black Lancasters: The story of heavy British bomber and first atomic bombs
Colorized image of the "Fat Man" bomb.

The adjustments required a lot of time and were entirely made by hand. The first B-29 prototype was not finished until February 20, 1944, after more than 6,000 worker-hours of labor.

Military officials started testing the various bomb configurations as soon as the first substantially modified silverplate B-29 arrived at Muroc Army Air Field in California in March.

Engineers tested a "Little Boy"-inspired "Thin Man" bomb on March 6 and two "Fat Man" tests on March 14. The "Fat Man" forms showed many wobbling characteristics due to the tail fins being out of line, while the "Thin Man" test was successful.

Additionally, none of the three devices detonated right away. The B-29 suffered substantial damage when a "Thin Man" shape was prematurely released on a fourth test flight while traveling to the test range. Due to the massive weight of the bombs, the modified release mechanism was quickly replaced with British-style releases as used on the Avro Lancaster.

On August 22, 1944, a production phase of Silverplate B-29s was ordered following the testing of successful bomb shapes. The first three Silverplate B-29s were handed over to the USAAF by the middle of October and flown to Wendover Army Airfield in Utah.

The "weaponeer station," a new crew job, was created in the cockpit with a panel to watch over the bomb's release and detonation during the actual combat operations. For bomb drop testing to be carried out at Wendover, 14 production aircraft were allocated to the 393rd Bomb Squadron and three to the 216th AAF Base Unit.

Black Lancasters: The story of heavy British bomber and first atomic bombs
As it turned out, the "Silverplate" B-29s were the best plane for the job.

Throughout 1945, the USAAF kept modifying and enhancing the Silverplate series. T

he last series of Silverplate modifications, which featured fuel-injected engines, reversible-pitch propellers, and pneumatic actuators for swiftly opening and closing the bomb bay doors, were added to the final B-29 wartime Silverplates.

By removing both gun turrets and armor plating, engineers could also considerably reduce the aircraft's weight. These B-29s significantly outperformed the standard variants in terms of performance.

And that is your lot for today.

The Avro Lancaster bomber remains an iconic symbol of Britain's bravery and determination during World War II. With its impressive performance and versatility, the Lancaster played a crucial role in the Allied victory and will forever be remembered as a true masterpiece of aviation engineering.

Today, only a handful of these magnificent planes survive, serving as a testament to the skill and dedication of the engineers and airmen who designed, built, and flew them.

Whether you are a history buff, an aviation enthusiast, or appreciate the sacrifices made by generations before us, the Avro Lancaster is a must-see and must-learn piece of our shared history.

Disclaimer: The views expressed in the content are solely those of the author and do not reflect the views and beliefs of Interesting Engineering or its affiliates.

*This article has been updated after requested corrections from the National Air Force Museum of Canada regarding KB882.

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