* A large truck losing its cargo overboard as it rounds an overhead freeway bridge is a sight none of us ever want to see. And yet that happened as a truck dropped its load of heavy steel tubes onto the I-5 Freeway just north of San Fernando. It was another of many truck disasters.
I don't know what the trucking industry uses for design of truck cargo supports. I do know that standard aircraft design practice for many decades has required that all cargo supports be designed for a turning side load equal to one-half the weight of the cargo.
In support of this requirement, I'll never forget the sight which occurred some 30 years ago in Burbank. Our Lockheed "Skunk Works" chief, C.L. (Kelly) Johnson was racing his new Ford sedan around a previously cleared runway. Kelly was trying to see if he could find cause to reduce the required one-half "g" side load to something less for the design of the still-secret SR-71 Blackbird airplane.
In addition to confirming that the original requirement was a good one, Kelly ended up scaring the engineers half to death who accompanied him around the curves.
With this picture in mind, I seriously doubt that the tubing supports on the freeway truck were sufficient to withstand a side load of anything near one half its own weight.
The FAA is not the least bit reticent about issuing airworthiness directives to control situations existing in the aircraft industry. It seems that it is time for the Transportation Department, in the interest of public safety, to exert some control over the design of these large trucks. Our lives are worth more than dollars.
One criteria could be that any such truck should be capable of rolling over at say 55 m.p.h. and still retain its contents, be they liquid or solid. We've had enough of these dangerous and disastrous spillages on our freeways.
THOMAS C. POLLACK
Pollack is a retired structures department manager for Lockheed Advanced Development Corp.