They sure were. An unsung American institution. In 1979, an A.O. Smith publication stated that when they opened the World's First Automated Construction Assembly Line in 1921, it took... "One hour and a half from raw steel to suspension by the hind leg, and a minute or two more to freight car if there is any rush. Every eight seconds a completed frame went swinging into storage, 420 an hour, 10,000 a day." They produced frames for Chrysler and every GM line. They also produced Ford frames exclusively from 1906 on... and made frames for just about every other auto and truck manufacturer. A.O. Smith developed the world's first pressed-steel automobile frame, for the 1902 Peerless.
couple of other notes-back in the stock car days,putting a decent roll cage in an x-framed car was a S.O.B. and boy they needed it.another thing,watching a well hooked up x-frame car launch at the strip is amazing to see!right rear corner dug in the asphalt and left front couple of feet higher than the other-watch some 409 videos on you tube
From what I gather , even though Henry Ford is largely credited with creating the assembly line , it appears A.O.Smith preceeded his effort , being that Henry bought his frames from Smith from 1906 forward .....my uncle's father-in-law was an engineer for C AO Smith at the Kankakee plant 50 years ago...
@2OLD2FAST Actually, Ford did precede A.O. Smith with the assembly line in 1913 (Smith in 1921). It is just that Ford was buying their frames from Smith starting in 1906 (all made by hand) when Ford presented them with a challenge they took and Smith met, impressing old Henry. There is a difference between "assembly line" and "automated construction assembly". The assembly line is a conveyor belt of sorts where people add on parts where with construction assembly, make the pieces the assembly line people use to build a car... in this case, the frame. So in essence, each was "first" in their field.
@oldtom69 It was a challenge to put a roll bar in but it is the body of the car being protected. The attachment points were where the sill had been reinforced at the door post and cowl attachment. In the rear, was at the kickup rail in the trunk area. Here is a diagram I put together circling where the attachments were for the cage with the 1958 Chevy.
@4EyedTurd This is of a 1959 but the mounting bracket is the same. Extra ones at the end of the tunnel for the convertible. You can also see the welded on plating on the top side of the rails and tunnel for the convertible (is the same on the bottom of the rails.
Looks like Cameron is still a member of this site but has not been active since 2008. I do want to answer the original question posted about 1960s Convertibles. In short... Impala (1958-1964) Chevelle (NO) Skylark (NO) To answer correctly, one must go back to the basics and get into the mindset that if the frame incorporates some sort of X then it is an X Frame. Remember that GM did not call even the Chevy frames, an X Frame. Chevy called it a "Safety-Girder Frame" and the correct structural name is a "Cruciform" (per the designer) and called a "Tubular-Center X" by GM. Starting around 1932, there was a worldwide explosion with the use of X reinforced frames. That was due in part by two reasons. Chrysler's introduction of their Floating Power engine support design which was both licensed and copied (that is a story in itself) and Independent suspension. There was no differential of chassis design between the sedan and open models in those early years except large wheelbase cars used heavier gusset plates (Wolf Plates) where the legs of the X converge in the center on the convertible models. Buick started in 1933, Cadillac in 1934, LaSalle in 1934, Oldsmobile in 1933, Pontiac in 1937. Both Pontiac and Chevrolet used a K-Y configuration prior (1934-1936 Pontiac, 1934-1935 Chevrolet and Chevy had a one year only X on the Standard model for 1935). Chevy was the breakaway division who went to a boxed girder ladder frame in 1936 and only used an X brace for their convertibles from 1940-1957 as in 1958-1964, all body styles used the same design frames. The other divisions always used a form of X frame until 1961 for Pontiac and Oldsmobile while Cadillac until 1964 (1965 on the Series 75 limo) and Buick skipped 1959-1960 by using a unique K frame under the front floor area. Then Buick picked up the Cruciform design in 1961 and continued to 1964 on their Full-Size models and until 1970 on Riviera. In general, from 1965 on (1961 some models), no GM car would use an X brace even on convertibles, except for 1984-1996 Corvette Convertibles which came with factory installed bolt on X bracing.
Hi Eric, Seems you know everything that is worth knowing about these frames and I hope you can help me with the following... Are the geometry of the seamless and the welded C-channel frames exactly the same? The reason for asking is that on my '63 Impala, the frame is a welded version and the beams are slightly lowered in front of the center tube. Seems it is made like this to give more space between the foot-wells on the body and the frame. It needs to be replaced because if rust and I have found a seamless frame that is supposed to fit (from a 61 Impala(?) ). But this has straight beams in front of the center tube, so I am afraid the body will clash on the frame. Can it be that the C channel frames are slightly differen from the seamless frames? It is not shown in any of the dimensional diagrams of the frames, but I have seen the lowered section in pictures of other '63 (welded) frames. (But I have not found any pictures of '63 seamless frames...)