Avro Lancaster B Mk.I Grand-Slam Special

The Avro Lancaster saw many in field modifications, but there's one of them that it's really worth mention as it carried one of the biggest non-nuclear bombs of the World War 2, the 22000lb (10000kg) Grand Slam bomb.
Thirty-two Lancasters were modified to carry the super-heavy Tallboy (12000lb - 5400kg) bomb first and the Grand-Slam bombs later. Engines were modified by uprating them, with paddle-bladed propellers in order to get more power and gun turrets were removed in order to make it lighter and make it smoother. To carry the Grand-Slam the bomb bay doors were completely removed and the area faired over. For the Grand-Slam raids the middle upper turret was completely removed.
This special version was only used by the No.617 "Dambusters" Squadron of the Royal Air Force.
They received the Avro Lancaster when they were formed on 21st March 1943 and later, in March 1945 they received the modified special Lancaster and performed forty-two Grand-Slam raids all of them between March and April 1945.
After the war, some of the special variants were used as target-tow aircraft.

Sources:
1. https://en.wikipedia.org/wiki/Avro_Lancaster#Variants
2. https://en.wikipedia.org/wiki/No._617_Squadron_RAF
3. https://en.wikipedia.org/wiki/Grand_Slam_(bomb)
4. Signal Squadron - Aircraft In action  52 - Lancaster in Action