Crane-driving, and it is probable that improvements in single and two-phase motors will eventually largely increase their use for this class of work.
He eschewed the pulpit and stood in front of the altar, looking like a caricature of Ichabod Crane, gaunt and gangling, but the words from his mouth were pure silver.
5 shows another type of fixed crane, known as a derrick crane.
Ower This fact has led to the introduction of the " crane rated " required.
The derrick crane introduces a problem for which many solutions have been sought, that of preventing the load from being lifted or lowered when the jib is pivoted up or down to alter the radius.
This type of crane used to be in great favour, in consequence of the great clearance it gives under the jib, but it is expensive and requires very heavy foundations.
Obviously, nearly every kind of crane can be made portable by mounting it on a carriage, fitted with wheels; it is even not unusual to make the Portable Scottish derrick portable by using three trucks, one under the mast, and the others under the two back legs.
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.
It contains all the essential elements of the hammer-headed crane, of which it may be considered to be the parent; in fact, the only essential difference is that the Titan is portable and the hammer-head crane fixed.
The Titan was the first type of large portable crane in which full use was made of a truly horizontal movement of the load; for the purpose for which the type is designed, viz.
When the cross traverse motion of a traveller crab is suppressed, and the longitudinal travelling motion is increased in importance we come to a type of crane, the use of which is rapidly increasing; it goes by the name of " transporter."
In either case the platform is fitted with a crane or cranes for lifting merchandise into and out of the wagons, and doors enable the shed to be used as a lock-up warehouse.
The Manchurian crane is common, as also are eagles, cuckoos, laughing doves, &c. Insects abound, owing to the swampy nature of much of the country.
The fire underneath the pot is again started, the crystals are liquefied, and one of the two pans, filled with melted lead, is tilted by means of the crane and its contents poured into the pot.
Prominent among the storks is the great black-headed white crane, called the jaburd (Mycteria americana), which is found along the Amazon and down the coast and grows to a height of 42 ft.
In the garzeros of Venezuela are to be found nearly every kind of heron, crane, stork and ibis, together with an incredible number of Grallatores.
On the east coast peafowl are found, and throughout the interior the argus pheasant, the firebacked pheasant, the blue partridge, the adjutantbird, several kinds of heron and crane, duck, teal, cotton-teal, snipe, wood-pigeon, green-pigeon of several varieties, swifts, swallows pied-robins, hornbills, parakeets, fly-catchers, nightjars, and many other kinds of bird are met with frequently.
The use of cranes is of great antiquity, but it is only since the great industrial development of the 19th century, and the introduction of other motive powers than hand labour, that the crane has acquired the important and indispensable position it now occupies.
Jib cranes can be subdivided into fixed cranes and portable cranes; in the former the central post or pivot is firmly fixed in a permanent position, while in the latter the whole crane is mounted on wheels, so that it may be transported from place to place.
The hydraulic crane is rapid in action, very smooth and silent in working, easy to handle, and not excessive in cost or upkeep, - advantages which have secured its adoption in every part of the world.
The principal motion in a crane is naturally the hoisting or lifting motion.
The hydraulic crane has a great advantage in possessing an almost ideal brake, for by simply throttling the exhaust from the lifting cylinder the speed of descent can be regulated within very wide limits and with perfect safety.
Crane brakes are usually under the direct control of the driver, and they are generally arranged in one of two ways.
A dock-side crane unloading cargo with high lifts following one another in rapid succession will require a higher load factor than a workshop traveller with a very short lift and only a very occasional maximum load; and a traveller with a very long longitudinal travel will require a higher load factor for the travelling motor than for the lifting motor.
This drawback can be corrected to a slight extent by furnishing the hydraulic crane with more than one cylinder, and thus compounding it, but the arrangement does not give the same economical range of load "as in an electric crane.
In first cost the hydraulic crane has the advantage, but the power mains are much less expensive and more convenient to arrange in the electric crane.
Per minute, and 100-ton crane with a speed of about 8 ft.
4 is a diagram of a fixed hand revolving jib crane, of moderate size, as used in railway goods yards Fixed and similar places.
This simple form of crane thus embodies the essential elements of foundation, post, framework, jib, tie-rods and gearing.
Where the face of the warehouse is sufficiently close to the water to permit of the crane rope plumbing the hatches without requiring a jib of excessive radius, it is a very convenient plan to place the whole crane on the warehouse roof.
18 shows a modern design of crane intended to command the maximum of yard space, and having some of the characteristics both of the Goliath and of the revolving jib crane, and fig.
Snipe, woodcock, ducks and rails, in vast flocks, haunt the banks of the Drina and Save; while the crane, pelican, wild-swan and wild-goose are fairly plentiful.
Comprises the midges, gnats, crane-flies, gad-flies, &c.
In 1913 he entered the U.S. Senate, succeeding Winthrop Murray Crane, but was defeated for reelection in 1919.
Gallinaceous birds, storkand crane-like waders, rails, birds of prey, cormorants, &c. Especially numerous bones have been found in the Paris basin, chiefly described by G.
A great number of birds' bones have been found in caves, and among them some bearing marks of human workmanship. In France we have a large and extinct crane, Grus primigenia, but more interesting are the numerous relics of two species, the concomitants even now of the reindeer, which were abundant in that country at the period when this beast flourished there,and have followed it in its northward retreat.
The number of peculiar genera, besides those just mentioned, is too great for them to be named here; some of the most remarkable on the continent are: Balaeniceps, the whaleheaded heron; Balaearica, the crowned crane; Podica, finfoot; Numida and allied genera of guinea fowls.
Nearly all recent advances in crane design are the result of the introduction of the electric motor.
It is now possible to apply motive power exactly where it is wanted, and to do so economically, so that the crane designer has a perfectly free hand in adding the various motions required by the special circumstances of each case.
Per minute, so that four men can by a crane raise 1 ton 9 ft.
This point is dwelt upon, because the speed limitations of the hand-crane are often overlooked by engineers.