>>1114424>american made bike.I don't think there are any, anymore. everything's Chinese now, including Cannondale. Maybe boutique brand like Rivendell is still in the US? The US does have good custom framebuilders, but no factory produced, i don't think.
anyway, by "heavy duty, industrial" bikes I assume you mean low maintenance and durable? the golf carts just hauled people and hand-baggage? or do you need to haul cargo because there are cargo bikes for that or you could get trailers.
For no-nonsense get-on-and-go bikes that are friendly to non-bike people, I'd honestly look into the Ikea bike. they're designed to be low-maintenance. 2 speeds with a step-through frame seems like exactly what a factory situation would need. there are baskets and trailers for them, too.
http://www.ikea.com/us/en/catalog/products/30326728/anyhow, are there any opportunities for fleet maintenance with y'all?