Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886 by Various
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Various >> Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886
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Gross | 3000 | 6000 | 9000 | 12,000 | 15,000 |
Indicated | Ind. | Ind. | Ind. | Ind. | Ind. |
Horse Power | H.P. | H.P. | H.P. | H.P. | H.P. |
at Central | | | | | |
Works: | | | | | |
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Thousands of | 1,080,000 | 2,160,000 |3,240,000 | 4,320,000 |5,400,000 |
Cubic Feet at 45 | | | | | |
lbs. pressure | | | | | |
at engines | | | | | |
Deduction for | 17,928 | 70,927 | 154,429 | 267,529 | 409,346 |
friction and | | | | | |
leakage | | | | | |
Estimated net | 1,062,072 | 2,089,073 |3,085,571 | 4,052,471 |4,990,654 |
delivery | | | | | |
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CAPITAL | | | | | |
EXPENDITURE-- | | | | | |
Purchase and pre-| L12,500 | (amounts below apply to extension of works) |
paration of land | | | | | |
Machinery | 27,854 | L25,595 | L25,595 | L25,595 | L25,595 |
Mains | 10,328 | 10.328 | 10,328 | 10,328 | 10,328 |
Buildings | 8,505 | 4,516 | 4,632 | 4,614 | 4,594 |
Parlimentary and | | | | | |
general expenses,| 20,000 | .. | .. | .. | .. |
royalty, &c. | | | | | |
Engineering | 3,268 | 1,820 | 1,825 | 1,824 | 8,823 |
Previous Capit-| | 82,455 | 124,714 | 167,094 | 209,455 |
al Expenditure | .. | | | | |
Total Cap. Exp. | L82,455 | L124,714 | L167,094 | L209,455 | L251,795 |
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ANNUAL CHARGES-- | | | | | |
Salaries, wages, | | | | | |
& general working| L6,405 | L7,855 | L9,305 | L10,955 | L12,480 |
expenses | | | | | |
Repairs, renewals| 2,780 | 5,198 | 7,622 | 10,045 | 12,467 |
&c.(reserve fund)| | | | | |
Coal, water, &c. | 1,950 | 3,900 | 5,850 | 7,800 | 9,750 |
Rates | 370 | 674 | 980 | 1,285 | 1,585 |
Contingencies of | | | | | |
horse power = 5 | 575 | 881 | 1,187 | 1,504 | 1,814 |
per cent on above| | | | | |
Total Ann. Exp. | L12,080 | L18,508 | L24,944 | L31,589 | L38,096 |
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Revenue at 5d. | | | | | |
per 1000 cub. ft.| 22,126 | 43,522 | 64,282 | 84,426 | 103,971 |
(average) | | | | | |
Profit |12.18 p.ct.|20.06 p.ct.|23.54 p.ct.|25.22 p.ct.|26.16 p.ct.|
|= 10,046 | = 25,014 | = 39,338 | = 52,837 | = 65,875 |
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TABLE II.--_Cost of Air Power in Terms of Indicated Horse Power_.
Abbreviated column headings:
Qty. Air: Quantity of Air at 45 lbs. Pressure required per Ind. H.P. per
Hour.
Cost/Hr.: Cost per Hour at 5d. per 1000 Cubic Feet.
Cost/Hr. w/rebate: Cost per Hour with Rebate when Profits reach 26 per
Cent.
Cost/Yr.: Cost per Annum (2700 Hours) at 5d. per 1000 Cubic Feet.
Cost/Yr. w/rebate: Cost per Annum with Rebate when Profits reach 26 per
Cent.
Abbreviated row headings:
CASE 1.--Where air at 45 lbs. pressure is re-heated to 320 deg. Fahr., and
expanded to atmospheric pressure.
CASE 2.--Where air at 45 lbs. pressure is heated by boiling water to
212 deg. Fahr., and expanded to atmospheric pressure.
CASE 3.--Where air is used expansively without re-heating, whereby
intensely cold air is exhausted, and may be used for ice making, &c.
CASE 4.--Where air is heated to 212 deg. Fahr., and the terminal pressure is
11.3 lbs. above that of the atmosphere
CASE 5.--Where the air is used without heating, and cut off at one-third
of the stroke, as in ordinary slide-valve engines
CASE 6.--Where the air is used without re-heating and without expansion.
_____________________________________________________________________
| Qty. Air | Cost/Hr. | Cost/Hr. | Cost/Yr. | Cost/Yr. |
| | | w/rebate | | w/rebate |
| Cub. Ft. | d. | d. | L s. d. | L s. d.|
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CASE 1 | 125.4 | 0.627 | 0.596 | 7 1 1 | 6 14 01/2|
CASE 2 | 140.4 | 0.702 | 0.667 | 7 17 11 | 7 10 0 |
CASE 3 | 178.2 | 0.891 | 0.847 | 10 0 51/2 | 9 10 51/2|
CASE 4 | 170.2 | 0.851 | 0.809 | 9 11 51/2 | 9 1 101/2|
CASE 5 | 258.0 | 1.290 | 1.226 | 14 10 3 | 13 15 9 |
CASE 6 | 331.8 | 1.659 | 1.576 | 18 13 3 | 17 14 7 |
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The great thing to guard against is leakage. If the pipes were simply
buried in the ground, it would be almost impossible to trace leakage, or
even to know of its existence. The income of the company might be
wasting away, and the loss never suspected until the quarterly returns
from the meters were obtained from the inspectors. Only then would it be
discovered that there must be a great leak (or it might be several
leaks) somewhere. But how would it be possible to trace them among 20 or
30 miles of buried pipes? We cannot break up the public streets. The
very existence of the concern depends upon (1) the _daily_ checking of
the meter returns, and comparison with the output from the air
compressors, so as to ascertain the amount of leakage; (2) facility for
tracing the locality of a leak; and (3) easy access to the mains with
the minimum of disturbance to the streets. It will be readily
understood, from the drawings, how this is effected. First, the pipes
are laid in concrete troughs, near the surface of the road, with
removable concrete covers strong enough to stand any overhead traffic.
At intervals there are junctions for service connections, with street
boxes and covers serving as inspection chambers. These chambers are also
provided over the ball-valves, which serve as stop-valves in case of
necessity, and are so arranged that in case of a serious breach in the
portion of main between any two of them, the rush of air to the breach
will blow them up to the corresponding seats and block off the broken
portion of main. The air space around the pipe in the concrete trough
will convey for a long distance the whistling noise of a leak; and the
inspectors, by listening at the inspection openings, will thus be
enabled to rapidly trace their way almost to the exact spot where there
is an escape. They have then only to remove the top surface of road
metal and the concrete cover in order to expose the pipe and get at the
breach. Leaks would mostly be found at joints; and, by measuring from
the nearest street opening, the inspectors would know where to break
open the road to arrive at the probable locality of the leak. A very
slight leak can be heard a long way off by its peculiar whistling sound.
[Illustration: COMPRESSED AIR POWER]
The next point is to obtain a daily report of the condition of the mains
and the amount of leakage. It would be impracticable to employ an army
of meter inspectors to take the records daily from all the meters in the
district. We therefore adopt the method of electric signaling shown in
the second drawing. In the engineer's office, at the central station, is
fixed the dial shown in Fig. 1. Each consumer's meter is fitted with the
contact-making apparatus shown in Pig. 4, and in an enlarged form in
Figs. 5 and 6, by which a current is sent round the electro-magnet, D
(Fig. 1), attracting the armature, and drawing the disk forward
sufficiently for the roller at I to pass over the center of one of the
pins, and so drop in between that and the next pin, thus completing the
motion, and holding the disk steadily opposite the figure. This action
takes place on any meter completing a unit of measurement of (say) 1,000
cubic feet, at which point the contact makers touch. But suppose one
meter should be moving very slowly, and so retaining contact for some
time, while other meters were working rapidly; the armature at D would
then be held up to the magnet by the prolonged contact maintained by the
slow moving meter, and so prevent the quick working meters from
actuating it; and they would therefore pass the contact points without
recording. A meter might also stop dead at the point of contact on
shutting off the air, and so hold up the armature; thus preventing
others from acting. To obviate this, we apply the disengaging apparatus
shown at L (Fig. 4). The contact maker works on the center, m, having an
armature on its opposite end. On contact being made, at the same time
that the magnet, D, is operated, the one at L is also operated,
attracting the armature, and throwing over the end of the contact maker,
l, on to the non-conducting side of the pin on the disk. Thus the whole
movement is rendered practically instantaneous, and the magnet at D is
set at liberty for the next operation. A resistance can be interposed at
L, if necessary, to regulate the period of the operation. The whole of
the meters work the common dial shown in Fig. 1, on which the gross
results only are recorded; and this is all we want to know in this way.
The action is so rapid, owing to the use of the magnetic disengaging
gear, that the chances of two or more meters making contact at the same
moment are rendered extremely small. Should such a thing happen, it
would not matter, as it is only approximate results that we require in
this case; and the error, if any, would add to the apparent amount of
leakage, and so be on the right side. Of course, the record of each
consumer's meter would be taken by the inspector at the end of every
quarter, in order to make out the bill; and the totals thus obtained
would be checked by the gross results indicated by the main dial. In
this way, by a comparison of these results, a coefficient would soon be
arrived at, by which the daily recorded results could be corrected to an
extremely accurate measurement. At the end of the working day, the
engineer has merely to take down from the dial in his office the total
record of air measured to the consumers, also the output of air from the
compressors, which he ascertains by means of a continuous counter on the
engines, and the difference between the two will represent the loss. If
the loss is trifling, he will pass it over; if serious, he will send out
his inspectors to trace it. Thus there could be no long continued
leakage, misuse, or robbery of the air, without the company becoming
aware of the fact, and so being enabled to take measures to stop or
prevent it. The foregoing are absolutely essential adjuncts to any
scheme of public motive power supply by compressed air, without which we
should be working in the dark, and could never be sure whether the
company were losing or making money. With them, we know where we are and
what we are doing.
Referring to the estimates given in Table I., I may explain that the
item of repairs and renewals covers 10 per cent. on boilers and gas
producers, 5 per cent. on engines, 5 per cent. on buildings, and 5 per
cent. on mains. Considering that the estimates include ample fitting
shops, with the best and most suitable tools, and that the wages list
includes a staff of men whose chief work would be to attend to repairs,
etc., I think the above allowances ample. Each item also includes 5 per
cent. for contingencies.
I have commenced by giving all the preceding detail, in order to show
the groundwork on which I base the estimate of the cost of compressed
air power to consumers, in terms of indicated horse power per annum, as
given in Table II. I may say that, in estimating the engine power and
coal consumption, I have not, as in the original report, made purely
theoretical calculations, but have taken diagrams from engines in actual
use (although of somewhat smaller size than those intended to be
employed), and have worked out the results therefrom. It will, I hope,
be seen that, with all the safeguards we have provided, we may fairly
reckon upon having for sale the stated quantity of air produced by means
of the plant, as estimated, and at the specified annual cost; and that
therefore the statement of cost per indicated horse power per annum may
be fairly relied upon. Thus the cost of compressed air to the consumer,
based upon an _average_ charge of 5d. per 1,000 cubic feet, will vary
from L6 14s. per indicated horse power per annum to L18 13s. 3d.,
according to circumstances and mode of application.
A compressed air motor is an exceedingly simple machine--much simpler
than an ordinary steam engine. But the air may also be used in an
ordinary steam engine; and in this case it can be much simplified in
many details. Very little packing is needed, as there is no nuisance
from gland leakage; the friction is therefore very slight. Pistons and
glands are packed with soapstone, or other self-lubricating packing; and
no oil is required except for bearings, etc. The company will undertake
the periodical inspection and overhauling of engines supplied with their
power, all which is included in the estimates. The total cost to
consumers, with air at an average of 5d. per 1,000 cubic feet, may
therefore be fairly taken as follows:
Min. Max.
Cost of air used L6 14 01/2 L18 13 3
Oil. waste, packing, etc. 1 0 0 1 0 0
Interest, depreciation,
etc., 121/2 per cent. on
L10, the cost of engine
per indicated
horse power 1 5 0 1 5 0
-------- ---------
L8 19 01/2 L20 18 3
The maximum case would apply only to direct acting engines, such as
Tangye pumps, air power hammers, etc., where the air is full on till the
end of the stroke, and where there is no expansion. The minimum given is
at the average rate of 5d. per 1,000 cubic feet; but as there will be
rates below this, according to a sliding scale, we may fairly take it
that the lowest charge will fall considerably below L6 per indicated
horse power per annum.--_Journal of Gas Lighting_.
* * * * *
THE BERTHON COLLAPSIBLE CANOE.
An endeavor has often been made to construct a canoe that a person can
easily carry overland and put into the water without aid, and convert
into a sailboat. The system that we now call attention to is very well
contrived, very light, easily taken apart, and for some years past has
met with much favor.
[Illustration: FIG. 1.--BERTHON COLLAPSIBLE CANOE AFLOAT.]
Mr. Berthon's canoes are made of impervious oil-skin. Form is given them
by two stiff wooden gunwales which are held in position by struts that
can be easily put in and taken out. The model shown in the figure is
covered with oiled canvas, and is provided with a double paddle and a
small sail. Fig. 2 represents it collapsed and being carried overland.
[Illustration: FIG. 2.--THE SAME BEING CARRIED OVERLAND.]
Mr. Berthon is manufacturing a still simpler style, which is provided
with two oars, as in an ordinary canoe. This model, which is much used
in England by fishermen and hunters, has for several years past been
employed in the French navy, in connection with movable defenses. At
present, every torpedo boat carries one or two of these canoes, each
composed of two independent halves that may be put into the water
separately or be joined together by an iron rod.
These boats ride the water very well, and are very valuable for
exploring quarters whither torpedo boats could not adventure without
danger.[1]--_La Nature_.
[Footnote 1: For detailed description see SUPPLEMENT, No. 84.]
* * * * *
THE FIFTIETH ANNIVERSARY OF THE OPENING OF THE FIRST GERMAN STEAM
RAILROAD.
There was great excitement in Nuernberg on the 7th of December, 1835, on
which day the first German railroad was opened. The great square on
which the buildings of the Nuernberg and Furth "Ludwig's Road" stood, the
neighboring streets, and, in fact, the whole road between the two
cities, was filled with a crowd of people who flocked from far and near
to see the wonderful spectacle. For the first time, a railroad train
filled with passengers was to be drawn from Nuernberg to Furth by the
invisible power of the steam horse. At eight o'clock in the morning, the
civil and military authorities, etc., who took part in the celebration
were assembled on the square, and the gayly decorated train started off
to an accompaniment of music, cannonading, cheering, etc. Everything
passed off without an accident; the work was a success. The engraving in
the lower right-hand corner represents the engine and cars of this road.
It will be plainly seen that such a revolution could not be accomplished
easily, and that much sacrifice and energy were required of the leaders
in the enterprise, prominent among whom was the merchant Johannes
Scharrer, who is known as the founder of the "Ludwig's Road."
One would naturally suppose that such an undertaking would have met with
encouragement from the Bavarian Government, but this was not the case.
The starters of the enterprise met with opposition on every side; much
was written against it, and many comic pictures were drawn showing
accidents which would probably occur on the much talked of road. Two of
these pictures are shown in the accompanying large engraving, taken from
the _Illustrirte Zeitung_. As shown in the center picture, right hand,
it was expected by the railway opponents that trains running on tracks
at right angles must necessarily come in collision. If anything happened
to the engine, the passengers would have to get out and push the cars,
as shown at the left.
[Illustration: JUBILEE CELEBRATION OF THE FIFTIETH ANNIVERSARY OF THE
OPENING OF THE FIRST STEAM RAILWAY IN GERMANY--AT NURNBERG]
Much difficulty was experienced in finding an engineer capable of
attending to the construction of the road; and at first it was thought
that it would be best to engage an Englishman, but finally Engineer
Denis, of Munich, was appointed. He had spent much time in England and
America studying the roads there, and carried on this work to the entire
satisfaction of the company.
All materials for the road were, as far as possible, procured in
Germany; but the idea of building the engines and cars there had to be
given up, and, six weeks before the opening of the road, Geo.
Stephenson, of London, whose engine, Rocket, had won the first prize in
the competitive trials at Rainhill in 1829, delivered an engine of ten
horse power, which is still known in Nuernberg as "Der Englander."
Fifty years have passed, and, as Johannes Scharrer predicted, the
Ludwig's Road has become a permanent institution, though it now forms
only a very small part of the network of railroads which covers every
portion of Germany. What changes have been made in railroads during
these fifty years! Compare the present locomotives with the one made by
Cugnot in 1770, shown in the upper left-hand cut, and with the work of
the pioneer Geo. Stephenson, who in 1825 constructed the first passenger
railroad in England, and who established a locomotive factory in
Newcastle in 1824. Geo. Stephenson was to his time what Mr. Borsig,
whose great works at Moabit now turn out from 200 to 250 locomotives a
year, is to our time.
Truly, in this time there can be no better occasion for a celebration of
this kind than the fiftieth anniversary of the opening of the first
German railroad, which has lately been celebrated by Nuernberg and Furth.
The lower left-hand view shows the locomotive De Witt Clinton, the third
one built in the United States for actual service, and the coaches. The
engine was built at the West Point Foundry, and was successfully tested
on the Mohawk and Hudson Railroad between Albany and Schenectady on Aug.
9, 1831.
* * * * *
IMPROVED COAL ELEVATOR.
An illustration of a new coal elevator is herewith presented, which
presents advantages over any incline yet used, so that a short
description may be deemed interesting to those engaged in the coaling
and unloading of vessels. The pen sketch shows at a glance the
arrangement and space the elevator occupies, taking less ground to do
the same amount of work than any other mode heretofore adopted, and the
first cost of erecting is about the same as any other.
When the expense of repairing damages caused by the ravages of winter is
taken into consideration, and no floats to pump out or tracks to wash
away, the advantages should be in favor of a substantial structure.
The capacity of this hoist is to elevate 80,000 bushels in ten hours, at
less than one-half cent per bushel, and put coal in elevator, yard, or
shipping bins.
[Illustration: IMPROVED COAL ELEVATOR.]
The endless wire rope takes the cars out and returns them, dispensing
with the use of train riders.
A floating elevator can distribute coal at any hatch on steam vessels,
as the coal has to be handled but once; the hoist depositing an empty
car where there is a loaded one in boat or barge, requiring no swing of
the vessel.
Mr. J.R. Meredith, engineer, of Pittsburg, Pa., is the inventor and
builder, and has them in use in the U.S. engineering service.--_Coal
Trade Journal_.
* * * * *
STEEL-MAKING LADLES.
The practice of carrying melted cast iron direct from the blast furnace
to the Siemens hearth or the Bessemer converter saves both money and
time. It has rendered necessary the construction of special plant in the
form of ladles of dimensions hitherto quite unknown. Messrs. Stevenson &
Co., of Preston, make the construction of these ladles a specialty, and
by their courtesy, says _The Engineer_, we are enabled to illustrate
four different types, each steel works manager, as is natural,
preferring his own design. Ladles are also required in steel foundry
work, and one of these for the Siemens-Martin process is illustrated by
Fig. 1. These ladles are made in sizes to take from five to fifteen ton
charges, or larger if required, and are mounted on a very strong
carriage with a backward and forward traversing motion, and tipping gear
for the ladle. The ladles are butt jointed, with internal cover strips,
and have a very strong band shrunk on hot about half way in the depth of
the ladle. This forms an abutment for supporting the ladle in the
gudgeon band, being secured to this last by latch bolts and cotters. The
gearing is made of cast steel, and there is a platform at one end for
the person operating the carriage or tipping the ladle. Stopper gear and
a handle are fitted to the ladles to regulate the flow of the molten
steel from the nozzle at the bottom.
[Illustration: LADLES FOR CARRYING MOLTEN IRON AND STEEL.]
Fig. 2 shows a Spiegel ladle, of the pattern used at Cyfarthfa. It
requires no description. Fig. 3 shows a tremendous ladle constructed for
the North-Eastern Steel Company, for carrying molten metal from the
blast furnace to the converter. It holds ten tons with ease. It is an
exceptionally strong structure. The carriage frame is constructed
throughout of 1 in. wrought-iron plated, and is made to suit the
ordinary 4 ft. 81/2 in. railway gauge. The axle boxes are cast iron,
fitted with gun-metal steps. The wheels are made of forged iron, with
steel tires and axles. The carriage is provided with strong oak buffers,
planks, and spring buffers; the drawbars also have helical compression
springs of the usual type. The ladle is built up of 1/2 in. wrought-iron
plates, butt jointed, and double riveted butt straps. The trunnions and
flange couplings are of cast steel. The tipping gear, clearly shown in
the engraving, consists of a worm and wheel, both of steel, which can be
fixed on either side of the ladle as may be desired. From this it will
be seen that Messrs. Stevenson & Co. have made a thoroughly strong
structure in every respect, and one, therefore, that will commend itself
to most steel makers. We understand that these carriages are made in
various designs and sizes to meet special requirements. Thus, Fig. 4
shows one of different design, made for a steel works in the North. This
is also a large ladle. The carriage is supported on helical springs and
solid steel wheels. It will readily be understood that very great care
and honesty of purpose is required in making these structures. A
breakdown might any moment pour ten tons of molten metal on the ground,
with the most horrible results.
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