The Collaborative International Dictionary of English v.0.48:

Titan crane \Ti"tan crane\ (Mach.)
   A massive crane with an overhanging counterbalanced arm
   carrying a traveler and lifting crab, the whole supported by
   a carriage mounted on track rails. It is used esp. for
   setting heavy masonry blocks for piers, breakwaters, etc.
   [Webster 1913 Suppl.]