Looking at that link, I see that it quotes the fuel burn of the Skycrane as 525 gallons per hour, which is about 3,500lbs/hr.
I used to fly S61's, and although I realised the Skycrane was a much bigger lifter, I hadn't realised it was Sooooo much bigger - I see it has a MTOW of about 42,000lbs, and around 3,500 SHP per engine - amazing machine