[Image from Futisaba]
Earlier this week in Lilongwe, Malawi, some enterprising fellows loaded up a truck with rebar. Unfortunately, they did not properly assess the weight bearing capabilities of the roof of the lorry cab. They could have benefited from a bit of Failure Mode and Effects Analysis or FMEA after the mishap. There are important to understand forces at play here, tension and compression are two that seem to be relevant


[Image from Futisaba]
In loading the truck, they likely saw that putting the rebar flat on the bed would make it hang off the rear, bouncing with every bump and pothole. As loaded, you can see that it just barely fits on the vehicle. In order to make the bars less floppy, they bridged it between the bed and the cab. This could have worked out if they had a more stable structure at the cab end, designed to carry the heavy load of the bar. Here in the states, you see trucks with a back rack to facilitate just this kind of loading.

How do you carry incredibly heavy and awkward loads on your vehicle? Africa and the developing world do not have a corner on the market of stupid transportation tricks. It seems that at least a couple times a month I see a vehicle being driven down the road with either: 1. the driver holding a piece of plywood on the roof by hand, or 2. some crazy thing hanging way out of the vehicle, or 3. a mattress on the roof of a car with air bulging up the front of the bedding.