a system for the safe braking of heavy trains on steep gradients
... that railroad engineer Jules Hanscotte developed a system for the safe braking of heavy trains on steep gradients, but its only significant use was on tourist tramways?
... that railroad engineer Jules Hanscotte developed <b id="mwBCQ"><a href="./Hanscotte_centre-rail_system" id="mwBCU" rel="mw:WikiLink" title="Hanscotte centre-rail system">a system for the safe braking of heavy trains on steep gradients</a></b>, but its only significant use was on tourist tramways?