Assembly ships were the solution to a problem many faced during WWII, which was primitive navigation technology. This could cause logistical issues for aircrews. In particular, the organisation of the huge amounts of bomber aircraft into a coherent formation.
Formations like the combat box were used on bombing missions during the war to maximize defence against enemy fighters, and maximize the accuracy of bombs on the target. Organising these formations however, was a very tricky task.
Bomber formations would consist of sometimes hundreds of aircraft from different groups and different airfields. They all needed to meet up at the right time and place, while under radio silence to reduce the chance of informing the enemy of the impending attack.
In the 1940s, satellite guided navigation was many decades away, so a more practical solution to this difficult task was required. This was achieved with ‘Assembly Ships’ from the U.S. Air Force; brightly coloured bombers that helped with the organisation of missions.
In 1943 each bomber group was required to chose an assembly ship, usually a B-17 or B-24 bomber that was obsolete or deemed unfit for combat service in some way, but still airworthy. These aircraft had already fought hard and done their part in battle.
They had their weaponry removed and equipped instead with flares, lights and pyrotechnics, which were coloured specifically for certain formations. The aircraft were also painted in their distinctive bright colours, often being striped, checkered or polka dotted for the most recognisability.
Their extravagant, high contrast colours meant they could be seen from far away, and easily identifiable as the rallying aircraft. Upon finding them, the bombers would arrange into formations before heading out to Europe to attack the crucial industries of the Third Reich.
Their first use was in February 1944 with the 2nd Air Division.
On board, only a basic crew was needed to fly the aircraft, and one or two men to discharge the flares and pyrotechnics.
Without any defensive armament the assembly ships were sitting ducks. So they would take off ahead of the bomber forces, and fly to the rally point. Once there, they would use their flares and lights to organise their respective group into formation.
Then would then fly ahead in the direction of the mission, meeting up with the other bomber formations taking part in the attack. Once all aircraft were positioned and on the way to the target, the assembly ships themselves would turn around and head home.
This ensured these defenceless aircraft would never encounter enemy fighters. However there was one report of an unarmed assembly ship flying all the way Germany with its formation.
In the early days of using the assembly ships, there were a few incidents of accidental discharges pyrotechnics inside the aircraft, so a modification was made to mount the flair guns in the sides of the fuselage.
As they abandoned the formation before a battle, the Assembly Ships were grimly nicknamed by their fighting counterpart crews as Judas Goats.