Boeing B-17F Flying Fortresses on the Seattle production line.
Boeing B-29 Superfortresses on the Renton production line.
A paper written by Major Nannette Benitez for the UK Air Command and Staff College (found at http://www.uk-us.org/stinet/warproduction.pdf) on why the B-17 and the B-24 were both produced at the same time to accomplish the same mission by the US ARMY during World War II. 34 pages.
A PDF paper by William F. Willingham about the role that Bonneville Dam and the Bonneville Power Administration had in War production in the Pacific Northwest.
The idea of deceiving the enemy as to what you are doing is not new. Trying to hide individual items from observation is not new, trying to hide whole factories from aerial bombing during The Second World War was new.
Boeing Seattle Plant under Camouflage in WW II
B-29s under construction inside - and under- camouflage on
the Seattle production line in late 1945(?).
Dozens of B-29s are lined up on the tarmac.
After December 7, 1941 the Lockheed and Boeing aircraft factories along the West Coast were put under netting to try and hide them from Japanese aircraft attack. The Boeing plant went even further with fake houses and trees over the factory. The effectiveness of this was never tested - no Japanese aircraft got anywhere near these factories, but it did instill the sense of the war, the collective threat, to the people not on the front lines in those areas.
The Germans went to elaborate lengths to hide factories with netting and smoke screens - even so far as to build dummy oil refineries with similar reference points to fool bombardiers trying to hit it instead of the real factory a few mile further on - it actually known to have worked once.
However, asides from that rare case, hiding a factory would ONLY work if no aerial - or any type of images - of the factory was in possession by the enemy before the pre-mission photo-recon picture had been taken. Hiding a SINGLE item this big never worked - the bridges, rivers, prominent intersections etc would all still be there to allow a proper bomb drop on the factory. You have to hide everything around it within a mile so that the person toggling the bombs could not be sure exactly where it is. Off by 10 seconds means you miss the whole target. Thus you need to fake the scale in the camouflage or shift it over by 1/2 mile by making a new complete factory along with roads, intersections etc to match the original.
Oblique view of Seattle Boeing Plant in World War Two
Looking East from around 1500 feet at the production plant.
A B-29 is on the tarmac, one on the runway a B-17
on the other side of the field.
Today the Boeing plant builds about 70% of the commercial airliners
used for first class and cheap flights around the world.
Early in the war they may not have helped - 60% of American bombs dropped often missed the real target aiming point (a 1000 foot circle) and hit everywhere around it so doing the camouflage work then may have actually caused more damage. By late 1943 it had changed so that 60% of bombs dropped usually hit within the 1000 foot radius of the aiming point.
Early in the war a typical mission would have between 250 to 350 B-17s hitting a single target - which means anywhere from 3,000 to 4,200 individual 500 pound bombs exploding within 1000 feet of the aiming point - which would utterly destroy any target. This never happened. The longer the distance flown the less bombs carried. So a deep raid would have only eight 500 lb bombs in the bombay and the forward part of the bombbay had an extra fuel tank. With the accuracy so poor higher numbers of aircraft had to be sent so that statistics would ensure enough actually hit the target. By late 1944 they would send a single group - 56 a/c, to hit a single target and it would be destroyed. The accuracy had gone up due to better ballistic calculations and training of the bombardiers plus better bombing formation tactics employed.
Joyce Howe and behind her Susan Heidreich walking
over the camouflaged Boeing plant Number 2.
Joyce was a receptionist for Boeing's engineering department
and the woman behind her is her good friend who worked in
another division at Boeing. Under this detailed walkable
camouflage roof of fake housing, Boeing B-17 Flying Fortresses
were being produced in 1942-1945. The two women show the
detailing done to make it look real.
John Stewart Detlie, a Hollywood set designer, helped "hide" Boeing's Seattle plant using his Hollywood design techniques with this camouflage. The fake housing development covered nearly 26 acres with netting, plywood and other material over the Seattle plant.
Boeing plant aerial photo taken from around 5000 feet.
This was taken in either 1944 or 1945. You can see the
B-29s on the tarmac and other aircraft around the field.
As bombing became more accurate deception techniques actually worked better since every second of flying meant at least a 227 foot error. A person at 25,000 feet looking through a scope cannot see both ahead to see what is coming up and the immediate view of the traversing ground at the same time. A bombardier had just 120 seconds to line up and drop after the IP. Thus if the target comes into view just 10 seconds earlier than he thought it would and he drops - and at this time of the war the whole group dropped on the signal of the lead plane's smoke marker - so the whole group drops early and you can save the real target.
B-17 Flying Fortress at Seattle on the tarmac
G model Flying Fortresses just off the production line in Seattle await delivery to the combat modification center in Kansas. You can easily read the B-17G tail numbers 297385, 297386, 297387 on these natural finish Flying Fortresses. This was taken in July and by September of 1944 four of these aircraft had already been lost in combat. The very last B-17 rolled off the production line on April 13, 1945. On that date all the Boeing factories had now converted to the production of the Boeing B-29 Superfortress with the Seattle plant being the last one to convert from B-17 to B-29 production.
In January of 1944 a change in policy stated that all aircraft were to be left in a natural metal finish. This cut down the production time (no painting) plus it saved weight - which meant either more fuel or bombs could be carried. The weight of paint could reach 500 lbs or more on a Flying Fortress. Modern pigment paint weights up to 10 pounds per gallon and it takes only 2 mil of coverage at the high end to cover the surface. The primer that goes on first weights about the same. The real high tech modern paint (see http://www.loehle.com ) weights 1/2 as much at 4.89 pounds / gal with a coverage 530 sq ft / gallon. This is the Endura paint which is a two-component polyamine primer. A B-17 has 1420 square feet of wing area on top, and for the bottom, about the same for the rest of the a/c so that puts it around 4200 square feet of surface. Modern paint would add around 100 lbs of extra weight if the $300 gallon type is used.
I have not been able to find an authoritative source as to the weight of paint used during WW II, though I have crewman reports anywhere from 65 to 500 lbs of paint. but if it was 20 lbs/ gal at around 200 sq feet a gallon, that would add in around 500 pounds of paint.
I am going to guess that the paint used, which was almost certainly lead-based and probably copper fortified (those with boats will recognize this as bottom paint) weighed a lot more than 10-12 pounds. I once put a can of it on a paint shaker, and it must have weighed over 30 pounds. It was so heavy that it counter-balanced the other standard gallon of paint, and pulled the mounts and shaker right off it’s reinforced bench – shaker and both gallons hit the floor. Damn near broke my legs before I got it shut off. If it took ten gallons to paint, that puts the weight closer to 300 lbs. Total. This jives with information that the late Charlie Busa of the paint and dope shop once told me. He said it was close to 300 lbs to paint the whole plane. Fine sandpaper, right down to a polishing grit of 10000, which was called crocus cloth, was used by ground crews to shine and polish the paint, and a plane done in this fashion was said to gain another 5 mph in flight speed. - Gordy Alton
I would have 'guesstimated' a gallon of paint around 10-12 pounds - but that can't translate straight to the weight of the applied & cured paint on the airplane, as you have to figure the evaporation of the carrier. In other words, 'de-liquefy that same gallon of paint (once the thinner has evaporated/paint dried) and the gallon is going to probably be closer to 2-3 pounds at most. And as far as the paint being a performance limiter, I would bet a pint at the pub that the drag of the flat finish of the paint was the problem, rather than the overall weight of it.
Also, a majority of the interior of the B-17 (and most other multi-crew position combat aircraft) were unpainted from the factory. Check out archival photography of interior shots of the crew positions - waist gunners in particular - and it's bare Alclad.
Respectfully, Gerry Asher
Mike: Although our sheet metal crews patched up battle damage, we never painted the repairs to match the painted B171s. I do recall that the whole paint job was said to be over well over 100 pounds weighed, and that when the non painted B-17s started to arrive, they were faster than the painted ones. Not much, but every MPH meant a lot to the flight crews. Boeing might have the real weight, and speed increases on those B-17 that had not paint other than the Nose art, the Number if missions, and number of verified enemy aircraft kills.
Mike and Tom,
I did a little sleuthing on the web and found one reference for a gallon of insulating paint at 12 pounds. Figuring a little low (10 pounds per gallon) I can't imagine you can paint a B-17 with primer and exterior paint with six and a half gallons (65 pounds). I heard a reference once to unpainted B-17's saving 300 pounds making thirty gallons of exterior paint a reasonable amount using a spray gun. Figuring the interior was sprayed in most areas, I would guess around 400-500 pounds per aircraft.
There is my two cents worth.
Our combat crew had the job of removing paint from our B-17. The paint weighed 65 pounds and we removed the paint with 100 octane fuel. Unusual duty for a combat crew.
At the February 9 Oregon 8th Air Force Historical Society meeting a member spoke up and stated that 35 gallons of paint were used in painting a B-17. He worked in the paint shop. If the 30 pounds per gallon, and evaporation rate of 40%, that puts the weight at 630 lbs. This is painting the zinc-cromate preservative inside the aircraft and the paint on the outside.