type called the Lancaster in about 6 versions. It went through several manifestations beginning life as a twin engine bomber called the Manchester with a 24 cylinder liquid cooled engine, the Vulture, which was basically 2 smallish Merlin style engines, one upside down, the other right way up, both driving a common drive shaft. The engine was a disaster, and although the Mancester went to squadron service in Aug 1941 its replacement was already in the building stage. The British were sufficiently for aircraft to hit back at Germany desperate that they used the Manchester on operations and lost a lot to engine failure.
The Lancaster took the Manchester fuselage and wing, slapped an entirely new wing centre section with a nacelle for an extra engine each side of the fuselage. Presto a 4 engine bomber out of a two without having to mess up the factory too much with new tooling and new machines. Slap four Merlins of 1750hp each on the wings and put a new tail with egg-shaped oval fins on the ends, an' Bob's yer Uncle as the Brits said.
Operations with the Lancaster started in Mar 1942 and the Lancaster took part in the 1000 bomber raid at the end of May that year. From that point on it was the choice ride. The Lancaster carried heavy defensive armament 4x.303 cal machine guns in the powered tail turret, 2x303 cal mg in the powered mid upper turret, 2x.303 cal mg in a powered belly turret under the mid upper, and 2x.303 cal mg in a powered nose turret, just above the dome for the bomb aimer. Sometimes the 4x.303 tail turret was up gunned to 2x.50 Brownings for better reach and punch, as was the front turret. Crew was 7 comprising Pilot, Engineer, Navigator, Bomb aimer/Gunner, Wireless operator/Gunner, and the dedicated Mid-upper Gunner and Tail gunner. The only crew member with easy egress (for bailing out) was the Tail gunner who could rotate his turret past 90 degrees, open the turrets back doors, his only minor problem being that he couldn't wear his chute while acting as gunner, so he had to stop, open the back doors, find his parachute in its stowage on the aircraft wall, clip it onto his parachute harness and then rotate and jump. The Mid upper gunner had to find his parachute and open the side door of the aircraft and jump. The cockpit crew had a tougher time of it with one little square hatch in the floor which was hard to fit through with a parachute or climb through a tight tunnel over the top of the wing Mainspar and exit either through the bomb bay or the previously mentioned door.
American casualties from bomber operations were 3 times less because all American aircraft were designed to be easy to get out of. Not so the British.
The Lancaster could and was modified to carry larger and larger bombs first the Bouncing Bomb for the Dam Busters raid at about 4 1/2 tons, then the Tallboy, at nearly 7 tons, and finally the Grand Slam at 11 1/2 tons. They were the most numerous heavy bomber for the RAF, over 7,300 were built.
Comparisons with US aircraft.
Lancaster bombload: 7 tons, B17 bombload: 3 tons, B24 bombload: 4tons. B29 bombload: 10 tons.
Thge RAF had two other 4 engined bombers, the Short Stirling, an ill-conceived and unhappily received aircraft with a short wingspan and in consequence a low service ceiling making it vulderable to light flak, and the Handley Page Halifax, a very happily received aircraft with a better survival rate than the Lanc but less adaptable and with a lesser bomb-load.
And I guarantee it makes the ground shake especially when you consider squadrons of from 15 to 18 a/c all taking off at 20 second intervals and flying off at 200 feet to stay below German radar. Ther is a very good color film called Night Bombers about the Lancaster that I reccommend. Otherwise. how close are you to Toronto, wanna come visit when the Mount Hope airshow is on?