Anvendes anden energikilde end førerens muskelkraft, kræves kun en enkelt energikilde (hydraulisk pumpe, kompressor osv.), men denne energikildes drivanordning skal være så sikker som muligt.
Where use is made of energy other than the muscular energy of the driver, there need not be more than one source of such energy (hydraulic pump, air compressor, etc.), but the means by which the device constituting that source is driven must be as safe as practicable.