This book represents the updated English version of the German edition from 1984. Carbon free fuels, currently considered unconventional, will gain more and more importance in the future. Hydrogen is, in the longterm, available in unlimited amounts and can be produced from water by means of nuclear or regenerative primary energy. The book gives a description of projects, based on liquid hydrogen as a fuel, performed in the last decade. The present state of development on hydrogen liquefaction and distribution, liquid hydrogen on board storage, refilling systems and fuel conditioning system is described. Because surface bound vehicles in the future will still use internal combustion engines - electrical drive will remain reserved for special applications - the book includes most recent results on internal combustion engine operation by use of cryogenic hydrogen, as well as preliminary experience made in liquid hydrogen vehicles accidents. Not only specialists in cryogenic technology, internal combustion engines or in energy technology, but also people, interested in environmental questions will find information on the leading and pioneering work performed in the last two decades in the US, Japan, and Europe.