▁first ▁gy ro ▁will ▁produce ▁a ▁control ▁tor que ▁in ▁the ▁same ▁direction . ▁ ▁In ▁ 1 9 7 2 , ▁the ▁Canadian ▁Government ' s ▁Division ▁of ▁Mechan ical ▁Engineering ▁rejected ▁a ▁mon or ail ▁proposal ▁largely ▁on ▁the ▁basis ▁of ▁this ▁problem . ▁Their ▁analysis ▁ ▁was ▁correct , ▁but ▁restricted ▁in ▁scope ▁to ▁single ▁vertical ▁axis ▁gy ro ▁systems , ▁and ▁not ▁universal . ▁ ▁Max imum ▁spin ▁rate ▁ ▁Gas ▁tur bine ▁engines ▁are ▁designed ▁with ▁peri pher al ▁spe eds ▁as ▁high ▁as ▁ 4 0 0   m / s , ▁and ▁have ▁operated ▁reli ably ▁on ▁thousands ▁of ▁aircraft ▁over ▁the ▁past ▁ 5 0 ▁years . ▁Hence , ▁an ▁estimate ▁of ▁the ▁gy ro ▁mass ▁for ▁a ▁ 1 0 ▁t onne ▁vehicle , ▁with ▁c g ▁height ▁at ▁ 2 m , ▁assuming ▁a ▁peri pher al ▁speed ▁of ▁half ▁what ▁is ▁used ▁in ▁jet ▁engine ▁design , ▁is ▁a ▁mere ▁ 1 4 0   kg . ▁B ren nan ' s ▁recommendation ▁of ▁ 3 – 5 % ▁of ▁the ▁vehicle ▁mass ▁was ▁therefore ▁highly ▁conserv ative . ▁ ▁See ▁also ▁▁ ▁Ad hes ion ▁railway ▁ ▁B icy cle ▁and ▁motor cycle ▁dynamics ▁ ▁Gy ro car ▁ ▁Seg way ▁HT ▁ ▁Lit ▁Mot ors ▁ ▁References ▁ ▁Bibli ography ▁ ▁External ▁links ▁▁▁ ▁Mon or ail ▁Society ▁Special ▁Fe ature ▁on ▁Sw in ney ' s ▁mon or ail ▁ ▁Gy ros cope ▁Rail road ▁ ▁Category : Mon