The closest the convoy came to a complete blockade was during a particularly intense phase of the attacks on July 5th, 1942. The German battleship "Tirpitz" and other surface vessels attempted to intercept and engage the convoy, while Luftwaffe bombers relentlessly targeted the ships from above. The convoy was dispersed, and many of the merchant vessels scattered in an effort to avoid destruction.
However, it's important to note that the convoy was never completely blockaded. Despite facing heavy losses and enduring sustained attacks, some ships managed to break through and reach their destination. The convoy's dispersal strategy and stubborn resistance eventually led the Germans to call off the full blockade attempt, and the remaining ships were able to continue on their journey.
In summary, the Convoy PQ 17 experienced critical moments during the attacks, but it was not completely blockaded by German forces.