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International Engineering Congress (1901 : Glasgow.

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Donkin.

Mr. G. Gerald Stoney replied, and on the motion of the Chairman
a vote of thanks was accorded to the authors.



"SOME PARTICULARS OF THE RESULTS OF THE
COMPOUND LOCOMOTIVES ON THE BUENOS
AIRES GREAT SOUTHERN RAILWAY.

Paper by R. GOULD.



Abstract.

THE question of coal consumption of locomotives becomes in
countries like the Argentine Republic, which depends entirely on
the imported article, a matter of paramount importance, and an
endeavour to secure an economy in this respect led to the trial of
the compound engine.

The type of engine adopted on the Great Southern Railway was
the two-cylinder " Worsdell and Von Borries," as being the simplest
arrangement, and interfering least with the duplication of parts of
the standard simple engines previously in service. All these
engines, both simple and compound, were built by Messrs. Beyer,
Peacock & Co., under the instructions of Messrs. Livesey, Son &
Henderson, the Company's consulting engineers.

The first compound engines ordered were erected in 1889, and
the results obtained were so excellent that, with the exception of
shunting and local traffic engines, no simple engines (either goods
or passenger) have since been ordered.

The engines proved easy to handle, exhibited a high economy in
coal and water, and, owing to the reduced demand on the boiler,
showed less tendency to priming and scale than the original simples.
As an offset against these advantages, the first compounds some-
times showed a sluggishness in starting, or an inclination to jib, due to
the rapidity with which the automatic " Worsdell and von Borries "
starting valve caused compounding to take place, reducing the
power by cutting off the live steam from the low pressure cylinder
before (in the case of long and heavy trains) the whole weight was
fully taken on the drawbars, or the whole train in motion. In
this valve the exhaust steam from the high pressure cylinder is held
in check by a mushroom valve, which closes automatically by the
action of live steam from the boiler, admitted to a pair of small
pistons operating on the back of the large mushroom. With this
valve closed, no high pressure exhaust steam can pass, and the low
pressure cylinder is temporarily fed by a by-pass of live steam from
the boiler. The high pressure exhaust being completely bottled
up, compounding takes place very rapidly, as the back pressure
rising forces open the large mushroom and shuts the by-pass. The



104 SOME PARTICULARS OF RESULTS OF COMPOUND LOCOMOTIVES

defect was got over by an improvement made in the Company's
Works at Buenos Aires in introducing a hollow spindle in the
mushroom valve with an escape passage to the chimney, the office
of the passage being to relieve the H.P. back pressure to some
extent, and so delay compounding.

The effect of the alteration in the intercepting valve was to
entirely obviate the tendency to jib previously experienced, and
to ensure a certain and easy start, with the maximum power, whilst
retaining the automaticity of the valve's action, a most valuable and
important feature, putting it out of the power of the driver to work
non-compound longer than absolutely necessary, which by some
systems is possible, and tends to reduce the economy. This hollow
spindle arrangement was found so successful that the intercepting
valves of the whole of the compounds some 109 engines were so
fitted.

The diagrams accompanying showed the principal classes of
compound engines on the Great Southern Railway, and also the
corresponding simple engines for two classes. Classes 6 and 6A and
7 and 7 A compare absolutely. Class 10, designed by the author, for
working either goods or heavy passenger trains, represents the most
modern engines of the Company, whilst Class 6s shows an engine of
special interest as regards the compound question, in that it was
constructed from old engines similar to Class 6 at the Company's
works. Increasing weights of trains made it necessary to do
something to adapt engines of which the Company possessed a
large number to the heavier demand on their power. The
boilers of some of the older engines were replaced by new and
larger ones carrying high pressure, the cylinders being at the same
time changed for those of increased size, and the engines corn-
pounded, the new type being represented in Class 6e.

The engines have proved a great success, being from 25 to 30
per cent, more powerful than the old Class 6 which they supersede,
and showing an economy of fuel even better than that' of the
compounds.

The tabular statement attached shows the coal and lubricant
consumption, and also the comparative cost of repairs for the
mileages given.

It will be seen from the table that the engines, Class 6 A, burn
23 per cent, less coal per axle than their compeers, Class 6, the
load being practically equal, whilst the engines, Class 6e, actually
show an economy of 37 per cent., but as the latter have hauled
heavier trains (which always show a greater economy in consump-
tion per axle hauled) some of this economy must be discounted.

In the case of the engines, Classes 7A and 10, an economy of
14 per cent, over Class 7 is shown, but here again allowance
must be made for the fact that the simple engines hauled more



ON THE BUENOS AIRES GREAT SOUTHERN RAILWAY.



105



axles. The Classes 7 A and 10, especially the latter, were em-
ployed for the heavier passenger trains, whilst Class 7 were almost}
entirely employed on goods traffic, not being equal to the task
of the heavier passenger work at the higher speeds. If it were
not for these circumstances, the Classes 7 A and 10 would exhibit
an economy equal in amount to that of Classes 6A and 6s. In
the matter of lubricants the simple and compounds show practically
no difference.

In the comparison of the cost of repairs it must not be forgotten
that this is as between the simple and compound engine only. The
cost of wages in Buenos Aires is at present about 50 per cent, more
than in England, and the material, although imported duty free,
has to bear several extra charges, such as freight, packing, insur-
ance, etc., that greatly enhance its cost when delivered to the
Company's workshops in Buenos Aires.

The absence of heavy grades on the Buenos Aires Great
Southern Railway renders it a favourable field for the compound
engine, the grades of importance being in one district only, the bulk
of the line being practically straight and level. The character of
the traffic, with long runs and full trains as a rule, causing an
approximation to the fixed load of a stationary engine, is also
favourable for the compound system.



Consumption of Goal and Lubricants for the year 1900.
Engines, Classes 6, GA and GB, 7, 7 A and 10.





Passenger Engine.


Goods Engine.




Simple.


Compound.


Simple.


Compound.




Class


C ass


Class


Class


Ciass| Class




6


6A


6B


7


7A | 10


Coal consumed per train-mile Ibs.


36-00


28-05


29-25


55-68


45-0040-50


Average weight of trains - tons


162


1 66


211


624


S8S


526


Average number of axles per train


2 5


25'5


32 *s


96


90


81


Coal consumed per axle per"! 1U
mile -j lbs -


i*44


i-io


0-90


0-58


0*50


0*50


Lubricant consumed per ioo\
train-miles - - -/


770


6-45


6-28


7-I3


7-27


5-96


Lubricants consumed per ioo\ ,,
engine-miles - - -J s "


6-38


5-96


5-96


5'57


5-96


5'32


Ratio of coal consumed per axle\
per mile J


IOO


;76'4


62-5


IOO


86-2


86-2



106 SOME PARTICULARS OF RESULTS OF COMPOUND LOCOMOTIVES

Cost of Repairs (General and Maintenance).*
Engines, Classes 6, 6A, 7 and ?A.





Passenger Engine.


Goods Engine.


Simple. jCompound.


Simple. JCompound.


Class
6


Class

6A


Class ! Class
7 7A


Number of engines repaired
Average cost of repairs per engine)
per mileage shown /
Average number of engine-miles run)
for above engine repairs - J
Average number of engine- miles run)
per annnm J


32
^5 10
51,034
23,916


24
^470

55,865
28,920


22 43
/498 ! t47o

54,769 ! 55,224
20,556 ; 25,692



* The maintenance does not include wages of running shed fitters, but
is for materials and spare parts supplied during service.



The Chairman and Mr. Michael Longridge took part in the
Discussion, and on the motion of the Chairman a vote of thanks was
accorded to the author.



THE RATING AND TESTING OF ELECTRICAL
MACHINERY."

Paper by GISBERT KAPP.



Abstract.

WITH the growing application of electricity, the commerce with
electrical apparatus forms an important part of the general
commerce of every civilised country. Such commerce should be
put upon a safe basis by clearly defining the properties of the
articles bought and sold. Electrical plant also enters into inter-
national commerce, and the question of how it shall be rated and
tested appears to be a fit subject for an International Engineering
Congress. The rating of electrical machinery must always be
influenced by the condition of its use. Thus a tramway motor,
rated by the builder at so many H.P., will develop that power, when
in service, only occasionally. The time during which this
maximum power is required is short if compared with the total
running time. Under these conditions the motor will not overheat.
If, however, the same motor were used for driving a workshop,
and had to give out the rated power continuously, it would break
down from overheating. The same type of motor must, therefore,
be rated differently in the two cases. The question of efficiency
is frequently a source of trouble between buyer and seller, especially
in direct coupled generators. The combined efficiency can easily
be measured, but not the efficiency of each part separately.
According to the method employed, the separate efficiencies found
may vary greatly; hence, to protect buyer and seller alike, it is
desirable that there should be recognised methods for testing
efficiency. These methods should be simple and inexpensive,
and cause little disturbance to the regular working of the plant.
The German Association of Electrical Engineers has last yea*
appointed a Committee to investigate the question of rating and
testing electrical apparatus, and has this year at the annual meeting
provisionally adopted the report presented by the Committee. The
final adoption has been postponed until the values of the Association
" Standards for Rating and Testing Electrical Machinery " have
been found out by practical use. These standards are given in
an appendix. By issuing them the Association does not desire to
interfere in any way between buyer and seller if the two parties
.agree in detail upon the properties which the articles bought and



108 : THE RATING AND TESTING OF ELECTRICAL MACHINERY.

sold shall have. The standards are only intended to apply to
that extent which is not covered by special conditions of the
contract. The standards refer to electric generators, motors,
converters, and transformers, but not to switches, fans, and other
subsidiary apparatus. As regards the rating, three working con-
ditions are to be distinguished, namely, intermittent use, short time
use, and continuous use. The working conditions must be stated
on the name plate. The temperature rise is prescribed, and also
the extent to which apparatus must be capable of being overloaded.
A definite insulation resistance is not required, but a test for
dielectric strength by application of high pressure. For testing
efficiency eight methods are given, and the maker of the apparatus
is at liberty to select any of these as the method under which the
efficiency he guarantees shall be tested. The method selected
must be stated in the tender.



The Chairman, Mr. R. W. Weekes, Mr. Druitt Halpin, Col. P. E.
Huber, Mr. E. C. de Segundo, and Mr. Michael Longridge took
part in the Discussion.

The author replied, and on the motion of the Chairman a vote
of thanks was accorded to him.

The Meeting was then adjourned.



WEDNESDAY, 4th SEPTEMBER, 19O1.



Mr. WILLIAM H. MAW in the Chair.



" SOME EXPERIENCES AND RESULTS DERIVED FROM
THE USE OF HIGHLY SUPER-HEATED STEAM IN

ENGINES."

Paper by R. LENKE.



Abstract.

SUPERHEATED steam is generated by adding heat to saturated
steam. It is a very bad conductor of heat, and has a greater
volume per unit of weight than saturated steam. The higher the
pressure is, the smaller is the increase of volume. The question
may arise whether the increase of volume does not require more
additional heat than the benefit derived therefrom is worth. A
table has been prepared to show how many B.T.U. less are required
to produce one cubic foot of superheated steam than the same
amount of saturated steam. For instance, to produce one cubic
foot of steam at 115 Ibs. pressure and a temperature of 570 deg.

35- 2 97
Fahrenheit, - - =15 per cent, less heat is required; con-

35

sequently superheating must result in gain. Superheated steam
does not condense during the admission period if sufficiently super-
heated, which is another great advantage.

The use of superheated steam has always effected great economy,
and even a few degrees of superheat are sufficient to decrease the
steam and coal consumption considerably. To obtain the maximum
economy, 660 to 700 deg. is required, and the engines have to be
specially designed to withstand this temperature.

The introduction of superheated steam into engines largely in-
fluences the expansion of the heated parts. Engines always gave
great trouble when the distribution of metal in the cylinders was
not uniform, as parts with more metal expanded most, and forced
the cylinder walls towards the inside, and made the cylinder out
of shape. When using liners in the cylinders, the liners were
squeezed in at the ends, decreased the diameter, and jammed the
piston body if sufficient clearance was not provided. With steam
jackets heated with steam of 500 deg. Fahrenheit, the lubrication
ceased as the cylinder walls became overheated; consequently it



110 SOME EXPERIENCES AND RESULTS DERIVED FROM THE USE

was found necessary to do away with the jackets, or, if jackets were
already provided, not to pass steam through them. Pistons con-
structed on the Ramsbottom principle always worked satisfactorily,
except in the case of pistons fitted with steel springs when they
were in contact with highly superheated steam. Any kind of
gun metal gets brittle after a very short time; therefore valves,
seats, and all parts in direct contact with superheated steam must
be made of cast iron or other suitable mixture. Copper also lose?
about 40 per cent of its strength at that temperature ; consequently
copper bends in pipes are not practicable.

Glands and stuffing boxes at first frightened people, so that
engines were constructed single acting to avoid the use of glands,
but no serious difficulties have arisen on that account. It is
advisable to place the stuffing box as far as possible from the
cylinder end to keep it well away from the hottest parts, and to
allow of as much radiation as possible. Make sufficient clearance
in the neck bush to allow for the expansion of piston rod, and do
not use any metal with a melting temperature below that of the
steam. Valves and valve gears are influenced in the same way
by superheated steam. Valves containing many ribs or different
thicknesses of metal (in section), such as plain slide valves or
Corliss valves of the usual constructions, are not suitable for high
temperatures. A Corliss valve of medium size can stand 480 deg.
to 500 deg. Fahrenheit, but no more, and the latter temperature
very seldom^ The smaller plain slide valves are, the higher tem-
perature they can stand; large slide valves will hardly stand even
slightly superheated steam if no provision is made for forced
lubrication of the valve face. Piston valves have proved to be
most suitable for very high temperatures owing to their uniform
distribution of metal, but even with this sort of valve, a certain
amount of experience is necessary to get them into good working
order. Double-beat valves can also be recommended as being
safe, but they require a special arrangement which is not obtain-
able with all gears.

An engine constructed in accordance with the principles just
explained is as safe with superheated steam as any other engine
is with saturated steam. The use of superheated steam need by
no means be restricted to single acting engines. Besides economy,
other important advantages are connected with the utilisation of
superheated steam. It makes the steam consumption independent
to all intents and purposes of the size of the engine, and it does
not require high boiler pressures, 160 Ibs. being the highest to be-
really recommended, as no advantage is to be derived by exceeding
it With regard to the economy to be obtained from engines
working with superheated steam, the following comparison of
various types of engines may be of assistance. A single cylinder



OF HIGHLY SUPER-HEATED STEAM IN ENGINES. Ill

condensing engine with superheated steam works more economically
than a compound condensing engine with saturated steam, and it
must be remembered that 13^ Ibs. of steam per I.H.P. per hour has
been reached with a 120 horse-power horizontal single cylinder
Corliss engine, at 125 Ibs. boiler pressure.

A non-condensing single-cylinder engine with superheated steam
has about the same consumption as an average compound con-
densing engine, as 16 Ibs. steam per I.H.P. has been obtained; and
non-condensing compound engines have shown consumptions of
14 Ibs. per I.H.P. The compound condensing engine is the most
economical, and the economy obtained with superheated steam can
hardly be equalled by a quadruple expansion engine working at a
pressure of 300 Ibs. The steam consumption of such an engine
either compound or tandem at 140 Ibs. pressure only, never
exceeds 10 Ibs. per I.H.P. per hour, and usually remains below,
many tests having produced a consumption of 8.5 and 8.8 Ibs. per
I.H.P. To obtain the better utilisation of these temperatures, and
tu work under various loads with safety and practically uniform
economy, Mr. Schmidt has introduced the receiver heater with
automatic valve, the object being to keep the cylinder walls at a
steady mean temperature, not higher than will make the lubrication
unreliable for different rates of expansion.

The utilisation of superheated steam is recommended in con-
nection with all engines; the only question to be settled is the
degree of superheat, which largely depends on local circumstances
and on the type of engine, and this matter should be left to the
judgment of an experienced engineer.



The following members took part in the Discussion : the Chair-
man, Mr. Bryan Donkin, Mr. C. C. Leach, Mr. Henry Lea, Mr. J.
Hartley Wicksteed, Mr. Michael Longridge, Professor William
Ripper, Professor John Goodman, Mr. E. Hall-Brown, and Professor
W. H. Watkinson.

The author replied.

Communications have been received from: Mr. D. R. Todd,
Messrs. Hick, Hargreaves, and Co., and Mr. C. H. Moberley.

On the motion of the Chairman a vote of thanks was accorded
to the author.



"A PREMIUM SYSTEM OF REMUNERATING LABOUR."
Paper by JAMES ROWAN.



Abstract.

WITH a view to the adoption of a reliable and satisfactory method
of piecework, a premium system was decided upon, of which the
following is a description :

Work, as recorded on a job ticket, is given to a workman on a
time allowance, and if he reduces this time allowance his rate of
wages per hour, while he is working at the job, is increased by the
same percentage as that by which the time allowance has been
reduced. It is, of course, apparent that data must be collected
for the purpose of arriving at the time to be allowed to do work.
.For this purpose a special department (Rate-fixing Department) is
required, and when instituted, data accumulates very quickly. The
period occupied in doing work under the usual time payment con-
ditions may be accepted as the time allowance of the premium
system.

When a job is given to a workman, a job ticket is issued to him,
with a description of the work to be done, and the time allowed to
do it. On completion of the work the job ticket is initialled, and
the time of day recorded on it by the foreman, and this is the time
of commencing the next job. When the work has been examined
and passed by the works inspector, the job ticket is handed to the
Rate-fixing Department, which passes the same for payment. In
the case of a job being rejected by the inspector, any premium
which would otherwise have been earned by the workman, by reason
of his having reduced the time allowance, is forfeited. No clerical
labour devolves upon the workmen, and very little upon the foremen.

The time allowance for a job given to a workman, rated at say
8d. per hour, is 100 hours, and the actual time occupied on the job
amounts to 75 hours. We have then 100 hours at 8d. = 8oo pence,
against 75 hours at 8d. + 25 per cent. (2d.) = 75o pence, giving the
workman a premium = 150 pence, or 2d. per hour, and the employer
a reduced cost = 50 pence. Provided the time allowances are
equitable to employer and employed, and based on the average
attainments of hourly labour, it will be evident from the foregoing
that the higher the premium earned by the workman the greater
will be the saving in cost. The output of the machines is also
increased, but it is a hard matter to put a value to this.



A PREMIUM SYSTEM OF REMUNERATING LABOUR. 113

Occasionally a piece of work is begun on one machine and
finished on another. The job ticket in a case of this kind is passed
by the first to the second operator, and so on until the work is
completed, each workman engaged upon it receiving any premium
earned, in proportion to the total reduction of time made in com-
pleting the whole job. Any number of men may be employed on
the same piece of work, and it is not necessary that they should
all remain at the work for the same period, because a slump time
allowance is made to cover the time of all the men on a job, and the
total time spent upon the job fixes the premium percentage, which is
used in fixing the premiums of the different men only to the extent
of the time each has been employed upon the work ; that is, a job
for which the time allowance is 1000 hours may be performed in
800 hours one man might work 100, one 300, and one 400 hours.
Each of these men would have his hourly rate increased to the extent
of 20 per cent for the time he had been employed upon the job.
The reduction or increase of a workman's hourly rate is not affected,
as any change in either of these directions made during the time
he is engaged upon a job is calculated at a percentage on his hourly-
rate or rates. Neither is any difficulty introduced in respect to
overtime allowances, as the actual time worked upon a job deter-
mines the time upon which a premium is paid. The overtime
allowance, which in the Glasgow district is paid at the rate of 50
per cent, on the overtime worked, does not appear in the job ticket
as time, being only shown as such in the workmen's time and wages
book as a unit to fix the value of the overtime allowances. In the
job ticket this allowance appears at its value in money. Nor is
there any difficulty presented when working a night shift, as each of
the two men at a machine receives a share of premium earned in
proportion to the number of hours worked on the job.

It is advisable, where at all possible, that every man should work
on his own account; but in cases such as before mentioned, which
refer particularly to the erecting department, the inclusion of several
men on one job ticket cannot very easily be avoided. It may be
mentioned that in the erecting department the apprentices in their
first year are not given a job ticket. In their second and third years
they are junior apprentices, and half the time that they work is
counted; in the fourth and fifth years they are senior apprentices,
and three quarters of the time they work is counted. They are
allowed the same time as a journeyman. In the machine department
apprentices in the fourth and fifth year do the same kind of work
that is also done by journeymen, and they are allowed 25 per cent,
more than journeymen.

The payment of premiums does not take effect until 5 per cent,
premium has been earned, and thereafter only in multiples of 5 per
cent. The original time fixed upon as a time allowance has never



114 A PREMIUM SYSTEM OF REMUNERATING LABOUR.



Online LibraryInternational Engineering Congress (1901 : GlasgowReport of the proceedings and abstracts of the papers read → online text (page 10 of 37)