djm@castle.ed.ac.uk (D Murphy) (01/05/90)
From: D Murphy <djm@castle.ed.ac.uk> Apart from the tail gunner, how were the small defensive gun turrets on the B-29 aimed and operated ? Murff....
steve@pmday_2.Dayton.NCR.COM (Steve Bridges) (01/06/90)
From: steve@pmday_2.Dayton.NCR.COM (Steve Bridges) In article <12815@cbnews.ATT.COM> djm@castle.ed.ac.uk (D Murphy) writes: > > >From: D Murphy <djm@castle.ed.ac.uk> > >Apart from the tail gunner, how were the small defensive gun turrets on >the B-29 aimed and operated ? > >Murff.... They were remotely operated from sights in the nose, the waist blisters (sides and top). There was some sort of computer switching mechinisim so that if a gunner was aiming at a target, the computer would select the proper turret to use. For example, if a target was at 12:00 high, the top forward turret would be the one to fire. If it was at 12:00 low, the lower forward turret would fire. -- Steve Bridges | NCR - USDPG Product Marketing and Support OLS Steve.Bridges@Dayton.NCR.COM | Phone:(513)-445-4182 622-4182 (Voice Plus) ..!uunet!ncrlnk!usglnk!pmday_2!steve "Helicopter 4 Mike Bravo cleared low-level to the heliport"
Allyn@uunet.UU.NET (01/06/90)
From: <ames!ames!claris!portal!cup.portal.com!Allyn@uunet.UU.NET> All gun turrets on the B-29 were remotely controlled via a sophistocated electro-mechanical fire control system (GE designed). The gunner's aiming stations were the little plexiglass bubbles you see on the fuselage. Each station (by selsyn motors I suppose) was electrical connected to the turrets. My memory is fuzzy but I recall that each station, in addition to being able to control individual gun turrets, could also grab other turrets for coordinated fire. Pretty fancy for that era... Allyn Lai allyn@cup.portal.com
mayse@cs.uiuc.edu (Chip Mayse) (01/09/90)
From: Chip Mayse <mayse@cs.uiuc.edu>
Supposedly, the GE CFC (central fire control) system on the B-29 not only
enabled remote aiming (from the plexiglass bubbles), but also attempted to
compute proper lead and elevation to compensate for target trajectory and
range. Obviously trajectory could be estimated from the movement of the
sighting apparatus, but I don't know how range was estimated unless from
some combination of assumed values for target speed and range at initial
engagement plus sensed gunsight motion. An acquaintance of mine who was
a B-29 technician on Saipan during WW II once told me that the CFC computer,
which was located aft of the wings where the three "bubbles" are, was
"quite large."
The only book I've seen containing narratives of the use of this system is
"Hellbirds," by Wilbur H. Morrison. He was a B-29 bombardier, and sometimes
fired the forward turrets against head-on attacks. His accounts of these
incidents gave me the impression that the CFC system was accurate if given
a few seconds' tracking time, which engenders the suspicion that the
computing process was slow by modern standards.
Chip Mayse
cmayse@ncsa.uiuc.edu military@cbnews.ATT.COM (William B. Thacker) (01/11/90)
From: att!utzoo!henry >From: Chip Mayse <mayse@cs.uiuc.edu> >... Obviously trajectory could be estimated from the movement of the >sighting apparatus, but I don't know how range was estimated unless from >some combination of assumed values for target speed and range at initial >engagement plus sensed gunsight motion... I don't know exactly what the B-29 system did, but one approach to such things was to have the gunner turn a knob until the diameter of a circle in his sight roughly matched the wingspan of the target, with a switch for big vs small fighters. This actually worked tolerably well in theory, since there wasn't that much variation in fighter size and wingspan. >... gave me the impression that the CFC system was accurate if given >a few seconds' tracking time, which engenders the suspicion that the >computing process was slow by modern standards. Given the vintage of the equipment, this was probably a mechanical computer, not an electronic one, so it's not surprising that it would be a bit slow... Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu