I always liked the escort fighter idea. Thanks for the pictures.
I believe that its real heyday was during world war one, when fighters didn't carry cannons and a bomber could survive to fighter for a sufficient period of time. Fast two-seaters were regularly used as escorts and there were several prototypes of large multi-turreted fighters. I suppose the YB-40 would classify as one of the last escort fighters?
By the way, do you know if the Wellington with the Vickers (eg. http://i5.photobucket.com/albums/y189/mitchtanz/tyui.jpg) intended to be a testbed for future heavy fighters?
Its a bit OT but I thought I'd quote myself here regarding offensive rear armaments:
"There were many experiments with fixed rearward firing weapons (especially on bombers). Two problems are generally encountered: One is effective aiming and reduced velocity of the rounds (eg. if you're going 300kph backward instead of 300kph forward the bullets are going 600kph slower - this lower airspeed effects the ballistics of the round regardless of the effects of closing speed of the aircraft to the target).
Adding a gunner makes aiming easier but necessitates a larger aircraft, and while a larger aircraft can be usually almost as fast and sometime have a smaller turn radius, nimbleness (acceleration into a turn) generally suffers. Another feature in the failure of aircraft like the Bf-110 that was largely ignored prior to its modelling in Il-2 plays a role: The larger surface area of the aircraft provides a larger target and makes it very vulnerable to fighters that find it easy to aim at and hit.
The exception would be the Alekseyev designs which existed in a period where single seat fighters lost manoeuvrability (making them vulnerable to gunners), aircraft had enough power but top speeds were bounded by the sound barrier (making a heavy aircraft have similar kinetic performance) and heavy automatic cannons produced enough firepower to make any target fairly vulnerable at range.
It is also possible today as modern fly-by-wire systems coupled with electro-optical sights and laser range-finders and computers have already allowed fighters on autopilot to score kills. The GSH-301 is light enough and high enough performance that a rear firing defensive installation is feasible. "
S!