( ( Once ( in ( ( the confines ) ( of ( ( the ( round ( , ( six-foot ( diameter ( , ( four-inch-thick ( titanium ( pressure sphere ) ) ) ) ) ) ) ) ) ( of ( this ( deep ( submergence vehicle ) ) ) ) ) ) ) ) ) ( , ( they ( ( ( traveled ( 2,276 meters ) ) ( to ( the ( ocean floor ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Once) (PP (IN in) (NP (NP (DT the) (NNS confines)) (PP (IN of) (NP (NP (DT the) (NN round) (, ,) (JJ six-foot) (NN diameter) (, ,) (JJ four-inch-thick) (NN titanium) (NN pressure) (NN sphere)) (PP (IN of) (NP (DT this) (JJ deep) (NN submergence) (NN vehicle)))))))) (, ,) (NP (PRP they)) (VP (VBD traveled) (NP (CD 2,276) (NNS meters)) (PP (TO to) (NP (DT the) (NN ocean) (NN floor)))) (. .)))
Once in the confines of the round, six-foot diameter, four-inch-thick titanium pressure sphere of this deep submergence vehicle, they traveled 2,276 meters to the ocean floor.
(ROOT (S (NP (NNP Remote-control) (NNS vehicles)) (VP (VBP are) (ADJP (JJ able) (S (VP (TO to) (VP (VB go) (PP (TO to) (NP (DT the) (JJS deepest) (NN ocean) (NN floor)))))))) (. .)))