Sizing and specification

Separate the maximum from the norm. A requirement tends to be written around the heaviest trip, but specification follows the normal one. If most moves are under two tonnes with the occasional heavy one, handing those few to a second machine or to a person costs far less overall. If four tonnes really is every trip, two machines working together are usually more flexible than one very large one, and carry less single-point risk. Beyond the standard range the machine becomes a bespoke build, with lead time and price to match.

Height and weight are better stated separately. A requirement such as “1.5 tonnes to eight metres” usually stacks two worst cases, when in practice not every level holds something both high and heavy. Separated, two cheaper routes open up. Lighter loads higher and heavier ones low — lifting 1.5 tonnes to eight metres is not safe in any case. Or different models by height band: one for six to eight metres, standard machines below, with the scheduler allocating tasks accordingly.