The term ‘Rucksack’ is used to describe the orientation of the guides / mast in relation to the lift platform. Rucksack lifts have their guides to one end of the platform (along one of the short sides). Therefore, as the platform is ‘wearing’ its guides on its back (to back of the platform), this configuration is described as ‘ruck-sacking’.
Ruck Sack platform lifts are generally the exception as opposed to the norm and are designed to specifically overcome the issue of restrictive width on site.
When considering rigidity, side hung lifts are the best solution. Think of a diving board at the swimming pool, which is fixed at one end, the amount of flex is apparent (and in that situation purposely accentuated). Now imagine the same diving board reduced in length, the flex would be significantly reduced. To this end, rucksack lifts typically utilise smaller platforms than side-hung lifts in order to minimise platform flex.