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Weinspect, buy and ship good. SECONDHAND PLANT & MACHINE TOOLS to suit bustomers' requirementa,
R. THOMSON, LTD.,
1141 BATH STREET, GLASGOW, C.2;
2. Ade: BAMBENDOCO, Ojasgow.. Colar Denayas A (LO, BIH: Kendalls: Engispering, sta.
THE EXPRESS LIFT CO., LTD.
WITH WHICH IS INCORPORATED THE BUSINESS OF
SMITH, MAJOR & STEVENS, LTD,
EXPRESS SMS
LIFTS
MODERN LIFTS
FOR
MODERN BUILDINGS
SPEEDY RELIABLE SERVICE
FOR DETAILS APPLY TO
THE G.E.C., QUEEN'S BUILDING, CHATER ROAD.
The
EVERYTHING (SE.C.) ELECTRICAL
your guatanico"
Matroil
DISTEMPER
as
Berger Product
FOR ALL INTERIOR WALLS STOCKS CARRIED IN 24 SHADES.
W. R. LOXLEY & CO. YORK BUILDING.
ORATEE ROAD.
HONG KONG DAILY PRESS, SATURDAY, JANUARY 23, 1932.
ENGINEERING AND BUILDING
The Crane In Modern
Building Operations.
ELIMINATING THE DANGERS OF
COLLAPSE AND OVER-LOAD.
THE APPLICATION OF AUTOMATIC
INDICATORS.
limit had been exceeded; and, if so, the extent of the overload,
I will be at once appreciated that such a dovico is cf invaluable service, especially when is re- memborod that without subh an in- dicator every reasonable precaution | which may have been taken by the operator may be, frustrated by any slight entanglement of the elevat- ing load with the not infrequently complicated structure Through which the loads" have usually to bu raised.
ין
DETAILS OF THE In all the important business the material and firinncial loss, and
· APPARATUS. " centres in England and other altogether? some precautions on the countries the phat docado or two minimising of the 'possibilities are The load is weighed against have witnessed important develop. more warranted.
spring reaction. The resistance of ments in building operations. On! Tag ofteri it happens that the this spring in turn is varied with every hand new and larger build operator of the crane is quite un the angle of the jib, It ings than heretofore have com>;
aware of the load he is taking, und cannot vary
in direct propor- } inte bring. Their erection has been in such ignorance there is tha tion, since the safe londa. do not ncomplished in record timos, and natural tendency to speed up the vary in direct proportion. The
mechanism has therefore to surprise has often been occasioned work by handling loads in ox
take
by the rapid rate
cess of those possible under the materials brought from the contres conditions of the lift., Safety mea- of fabrication have been put into sures have for some time been their allotted positions, so that under consideration by both Build the largest structurbs : ing and ongineering circles, and a even with there has been a considerable sating Home Office Order came into force of time.
(on Nov. 1) in respect of cranes used
mum
AL
which
into account the crane maker's per missible loads at the varying b radius. Withal the apparatus is of an extremely robust and lookproof nature, and yet gives necurate! roadings.
in certain, building operations havon the bond rope tends to turn the
To this rapid progress the mc- dorn crane, loftily perched againatting & fixed jib or a derricking jib. This Order calls for an automatic the sky, makes an important con. tribution, and a number of these, indicator to be fitted to all such cranes (with certain date reserva suitably disposed over the site, co-
to effect the maximum tions) of a type approved by the ordinate transfer of materials in the mini-Chief Inspector of Factories. It is time. Many materials allaid down in this Order that such ready shaped prior to their. ccn- indicators shall show clearly to the veyance to the building site are,
or porn operating the with a simple movement, transferrerane when the load being moved ed exactly to the spot at or on
approaches the safe working load which they "will make their per- at any inclination of the jib, and manent abode, or within an inca shall also give an efficient sound signal when the load being moved is in excess of the 'safe working load of the crane at any inclina tion.
62 two
driver
”- !?
An eccentric sleeve is interposed between the jib head pulley and in such a manner that the weight and the jib hind spindle, and sel
eccentric. Fixed to the eccentric is to a spring inside the indicator a tension arm, which is connected case by a fod which is led down the jib through one or mors roller guides. The jib head pulley is car red on an eccentric, which in turn is mounted upon the jib bend spindle, ball or roller anti-friction bearings being used.
The indicator is actuated by two reds, an upper tension rod from the jib head eccentric and a lower rod pivoted to the base of the crane. The tension rod pusses through the compression spring, which is com- pressed by any weight on the band. The spring does not abut against
axed point, but against a tran ion carried upon a rocker, the movement of which varies the stress upon the spring.
THE SAFE LOAD..
The correct relationship of sufe load to jib radius is secured by means of a com out with a special" profile to effect this, and this cam is connected to the lower red of the indicator. The cam moves on its pivot, with a rise of the jib tilting the rocker and thereby increasing the stress in
compression
of it. Steel girders are hauled into position, and the temporarily fastened with a few bolts until after correct align ment, they can be riveted together
A SAFE-LOAD INDICATOR. ACCURATE PLACING. ·
These are mesures designed to Large blocks of stone shaped to ensure the future safety of opera fit the contour of the building are tion of these appliances, and the raised and lowered over the exact benefits to be derived are not a few. spot on which the required cement It is one thing to insist that such lies waiting to receive and frmly safety precautions shall be put into Bucure them. These methods con.practice, but quite another to
remarkably trus
those guarantee that they can be effec-spring, so that a heavier load in with formerly cbtaining in the days. tively carried out, and that there required to bring the pointer to
be danger mark. when a simple type of man-handled 'bro available types of apparatus rulley represented the usual limit which will do all that is required, of lifting appliance
not only to give the driver a clear knowledge of the details of the Not the least interesting feature
load he may be transporting, but of the operations is the delicacy also to make it well nigh impos with which the largest lifting apible for him unconsciously to ex- pliances can be operated and the ceed the safe limits which have fine adjustment which becomes prs previously been determined by the
sible with the exact methods of control over the movements whien permit the operator of the crane. who may be outaide the range of vision of the materials he is hand. ling, to effect their transport and place them within the fraction of an inch of their ultimate position.
These modern crance are prodigi. ous machines and they are called upon to discharge very difcult tasks, tasks which are, more often than is usually realised, fraught | with
grave duties have,bilities. These
maker of the crane.
Fortunately, such น
device is available, and, morcover, it has the approval of the Chief Inspector of Factories. In the Vickers-Nash Safe Lood Indicator it is possible do realise with practical certainty these conditions, and the doubtful judgment of a crane-driver or his slinger is superseded by a reliable indication as to whether a given lift can be anfely undertaken.".
This removal of any element of moreover, recent uncertainty not only eliminates all risks of breakdown, but it gives the
ly been attended by catastrophes
which have startled the public and operators a clear knowledge of the orgally surprised designers and juphrators of the machines.
On
-J
THE FACTOR OF IGNORANCE.
料 number f Occasions
recently accidents have occurred
which have brought the safety of
tasks which they are essaying. Moreover, with a definite know ledge of the limits to which they may wafely extend their machines, there is the possibility of handling
much larger total load. over
a given period, and the daily tous,
nage is thereby increased by the
continuous use of the machine to
these machines under particular its full capacity. Further, such an indicator clearly informs the crane- driver when he has taken, the weight before any attempt is made actually to lift the article,
notice. These mishaps have, too, been of such frequent recurrence, that it is aid that they have doubled within the past three
years...
the
With the lowering of the jib 2 converse action takes place, decreasing the stress on the spring, so that & fighter load indicaten danger.
17
Use Green Island Cement
for
Constructural Work of
Every Description.
"ROW GREEN ISLAND CEMENT IS MADE
Green Island Cement is manufactured from hard limestone and clay, It is necessary that these materials should be finely ground in order that they may come into intimate contact with one another in the burning process.
The finely pulverised materials are mixed in a certain definite, proportion, roughly one "part of clay to three of limestone, and are fed to
the Rotary Kilns.
In these kilns they meet the hot gases and flames. generated by pulverised coal blown in at the other end of the kilns, and after various chemical actions have taken place, they combine to form Portland Cement Clinker.
The Clinker is ground down with a small percentage of gypsum to regulate the setting time, and Green Island Portland Cement is thus produced.
Although sounding so simple, in reality the process is an intricate combination of mechanical, physical and chemical operatione, needing great skill and care. Nothing but constant and accurate supervision will yield the results 80 well-known with Green Island Cement, namely, strength, uniformity and reliability.
USE GREEN ISLAND CEMENT
Issued by the
GREEN ISLAND CEMENT CO., LTD.
2ND FLOOR,
EXCHANGE BUILDING.
RIV
GARAGES and CAR
OWNERS
Precaution, goes even further, in LARGE STOCKS BALL BEARINGS CARRIED
Their increasing dangers to life that a dangerous load is auto- and limb ans morover," impored matically registered on" the indica upon an unsuspecting public; who tor by coloured signs and a small cannot be expected to realise the addilica to the mechanism admits dangerous possibilities of a break of the ringing of an electrical down of one of these machines, mechanical alarm bell as an addi' which for the time in attracting tional warning. Finally, a sealed attention and admiration from the tell-tale is fitted, so that, in the cnlookers. Further, on the construc event of a mishap, it will be pos tional ride auch diensters, may toca sible to tell whether at the time of sion lengthy delays, in addition to the accident this absoluto safo
FOR ALL MAKES OF CARS
APPLY TO
DODWELL & CO., LTD.