Here's a question for you

[stall]

I know that around 1935 or so it was a very big deal when GM developed a way to stamp out a solid steel roof. They called it the turret -top and marketed it as much better than the fabric insert to fill a hole in the roof on most cars.

Have you noticed that almost 100% of the new cars in the last 15 or so years have an insert that forms the roof. Its pretty much across the board on foreign and domestic cars and seemed to happen all at once.

My question is why was this adopted, it would seem to be at cross purposes with roll=over safety .
Whats your best guess?
Murray

[Dean McHenry]

Hello Murray I have no idea but Ill take a guess that it has to do with the ability of the stamping technology now adays to be able to press an entire "side" of a car in one piece. This is a pretty complex operation as this includes the door openings,sills,rocker panels,front and rear window openings, all one piece. As far as rollover protection it would be structurally more ridged once welded up with the inner stamping making the whole thing somewhat of a rollbar. The inset is just to keep the rain out. Thats my story and I'm sticking to it. (till some one who really knows tells me otherwise) DMc

[52 Ragtop]

A lot of the new cars have a glass roof insert. The new Lincoln MKC's do. They are pretty nice, but, the one that had transport damage, had a sticker of about 48K!

For years, the windshield is considered a "structural" part of the vehicle. That is why when you get a windshield replaced, ask which ureathane they use! There are the cheap ones, (more profit) or the good ones. On "most" new vehicles, there are at least 3 layers of metal on the A,B and C pillars. Usually in the inner reinforcement is about twice as thick as the outer skin. There are also specific ways that these can be sectioned in properly.
As with anything, "You get what you pay for, and you pay for what you get"

Jim

[8E45E]

Its pretty much across the board on foreign and domestic cars and seemed to happen all at once.

It did not happen 'all at once' I remember Honda Civic had that since the early 1970's, and Mercedes Benz started sometime in the late 1970's early 1980's.

Craig

[Swifster]

Dean and Jim are both correct. But it also has to do with cost. There are far less stampings on a new car compared to 20 or 30 years ago. This is true with the inner structure as well. These newer stampings are also stronger to help get those 5 star crash ratings. The roof panels, other than the front and rear headers, are no stronger than older cars. But as mentioned, the side panels going over the top of the doors is much stronger and made from High Strength Steel (HSS).

[8E45E]

But as mentioned, the side panels going over the top of the doors is much stronger and made from High Strength Steel (HSS).

I suspect you mean HSLA (High Strength Low Alloy) steel. The HSS designation in steel use refers to Hollow Structural Section, either in square or rectangular profile with consistent wall thickness for the entire length.

Craig