Monocoques..Where did they come from ?

[BenL]

[ QUOTE ]
I believe the principle advantage to their adoption was that comparable chassis rigidity for a lighter weight at a lower cost. The alternate mode of construction when the mono gained popularity was the body on frame construction (think "truck") with a few outliers like Lotus who used spaceframes on some and their backbone structure on others. The backbone has a very strong structural member connecting the front and rear suspensions and drivetrain.

[/ QUOTE ]

Lotus came up with the backbone chassis idea by accident. While working on development of the suspension and drive train they needed something to bolt the components to. So they came up with a minimal structure that allowed everything to be tied together. After they started using it for testing the components, they realized they had a very nice, stiff chassis. So they scratched the idea of building another all fiberglass body/chassis like the Elite and built the Elan.

 

[Jim Glickenhaus]

Stiffning dimples.

 

[Lynn Larsen]

Hersh,

Of course, Jim is spot on.

Beads, dimples, call them what you will, they add huge amounts of stiffness to an otherwise flat and flimsy (except in tension) piece of sheet metal. Any bending of the metal makes it stronger and that is why early cars started having flowing rounded body panels. Not only did they look nicer, but they were much stiffer and required little to no framework underneath them as the plain flat panels required.

Regards,
Lynn

 

[Mike Dozier]

Many 1960's cars had grooves in the floor pans and trunk
floors for stiffness. They also served another purpose....
collecting chambers for water that frequently leaked past
the window seals, and inevitably rotted out the floors. /ubbthreads/images/graemlins/frown.gif

MikeD

 

[John W]

Hi Ben,

I was thinking of the original 58 to 63(ish) Elite. You are corerect though, it had a subframe for the engine & gearbox which was bonded into the lower front bodywork, as were some other bits such as the roll-bar/door hinge hangers, and not a full chassis.

The bonded body/chassis idea later used on the series 1 europa was a full chassis.

Looks like I didn't really clarify much after all /ubbthreads/images/graemlins/tongue.gif

 

Hersh: As previous posts have correctly indicated, the indentations in an
original 1960's Abbey Panels GT40 MKI floor pan were generally designed to
add stiffening. But, you and others on this forum might be interested in
"the rest of the story":

a. The first lateral indentation in an original MKI floor pan also allowed
the front anti-roll bar to be recessed out of "under car" air flow... and
away from possible track damage.

b. The other four lateral indentations in the floor pan not only added
rigidity, but they served to elevate the front to rear aluminum water tubes
& rubber oil cooler lines (housed in the center tunnel) up from the floor
pan and possible track damage.

c. The left side, front to rear indentation in the floor pan (adjacent to
the floor/fuel sponson pinch weld) was also originally designed as a
recessed area to route the brake & clutch hard lines. (Until Ford Advanced
Vehicles wisely decided to move these lines to the inside of the tub).

d. The front to rear indentations at the bottom of each fuel sponson
(adjacent to the floor/fuel sponson pinch weld) were also designed to
provide clearance for the (13) mounting screws that attach the bottom of
each fiberglass side cover.

Hersh, the above information is possibly more than you wanted to know...
Nonetheless, these design characteristics serve to identify an original
1960's Abbey Panels GT40 MKI tub.

OL

 

[Bob Putnam]

I vaguely remember that the '37 (or thereabouts) Chrysler one of the first production monocoques.

One of my favorite cars (that I never owneed...).

The Original Elite

 

"The first use of monocoque construction is easy to figure out from the word itseld. Single Shell/Egg.
Now you have to deceide if the chicken, the egg, or the clam came first. "


I thought the BANG! came first.

 

[John W]

Owen,
some interesting fact there. Have you got any others ? /ubbthreads/images/graemlins/wink.gif

May I ask where you unearthed this info from ?
Is it in a book or some papers or something ?

I've been trying to research the various design aspects of the chassis
(especially the mods made to the mkII cars), but asside from the SAE
papers haven't managed to dig up much.

Cheers,
John.

 

[Lynn Larsen]

Owen,

Very good info, indeed! Now I know why, despite some diligent searching, I could never see a front sway bar on the original Mk Is. I had come to the mistaken conclusion that many, if not most, just didn't have them.

Thanks again,
Lynn