With portable cranes means must be provided to ensure the requisite stability against overturning; this is done by weighting the tail of the revolving part with heavy weights, and in steam cranes the FIG.
Overturning backwards than forwards.
In the latter case the overturning tendency begins as soon as the load leaves the ground, but ceases as soon as the load again touches the ground and thus relieves the crane of the extra weight, whereas overturning backwards is caused either by the reaction of a chain breaking or by excessive counterweight.
If this pressure is not relieved in some way, the train may be derailed either (I) by " climbing " the outer rail, with injury to that rail and, generally, to the corresponding wheel-flanges; (2) by overturning about the outer rail as a hinge, possibly without injury to rails or wheels; or (3) by forcing the outer rail outwards, occasionally to the extent of shearing the spikes that hold it down at the curve, thus spreading or destroying the track.
From consideration of the rigid triangular frame described above, it is clear that the " overturning " force acts horizontally from the centre of gra'Vity, and that the length of its lever arm is, at any instant, the vertical distance from the centre of gravity to the level of the outer rail.
If therefore the outer rail is laid at a level above that of the inner rail at the curve, overturning will be resisted more than would be the case if both rails were in the same horizontal plane, since the tilting of the vehicle due to this " superelevation " diminishes the overturning moment, and also increases the restoring moment, by shortening in the one case and lengthening in the other the lever arms at which the respective forces act.
For example, what is a safe speed at a given curve for an engine, truck or coach having the load equally distributed over the wheels may lead to either climbing or overturning if the load is shifted to a diagonal position.
Armed with it he passed safely into heathen Germany and began a systematic crusade, baptizing, overturning idols, founding churches and monasteries, and calling from England a band of missionary helpers, monks and nuns, some of whom have become famous: St Lull, his successor in the see at Mainz; St Burchard, bishop of Wurzburg; St Gregory, abbot at Utrecht; Willibald, his biographer; St Lioba, St Walburge, St Thecla.
Interpreted in the most general sense, these decrees, which enacted that the council of Constance derived its power immediately from Jesus Christ, and that every one, even the pope, was bound to obey it and every legitimately assembled general council in all that concerned faith, reform, union, &c., were tantamount to the overturning of the constitution of the church by establishing the superiority of the council over the pope.
For safety against overturning they considered a factor of 2 sufficient.
Passive resistance; but it contained a military element who had more courage, and who had learned their power when Ismail employed them for overturning his constitutional ministry.
While Spanish navies were exploring the ocean, and Spanish paladins were overturning empires, Charles V.
In no case shall the overturning moment due to wind pressure exceed seventy-five per centum of the moment of stability of the structure.