The electric motor is carried on the front bogey, within a
frame, distinct from that which bears the weight of the car, and
not subject, therefore to the fluctuations of that weight which
take place in the course of traffic. The effect of this immunity
from depression and elevation, and of a further bit of ingenious
adjustment, is that the “pitch-line” is constant in all
circumstances, and that helical gearing, which is safer and
stronger than the chain gearing formerly suggested, can be used
to connect the motor with the four wheels of the bogey. In this
adjustment, and in the helical gearing, the real novelty of the
car may be said to lie, and much of the credit of it is due to
Mr. Dickinson.
It need hardly be nowadays explained that a self-contained electric
car, is a car in which the driving force is stored in accumulators
or batteries, which have been charged by steam power at a fixed
station from such a dynamo as those which are now to be seen at
Bingley Hall. The so-called “charging” consists simply in this –
that the electric energy generated by the dynamo spends itself in
working a chemical change in the constituents of the battery. The
change is of a nature which tends to undo itself as soon as
opportunity is given, and this reversal of the process gives out
again the electric energy which the dynamo passed to the battery.
There is some waste in both processes, but Mr. Thomas Parker affirms
that the net result in energy is 70 percent of that generated by the
stationary engine, which drives the charging dynamo. The economical
results of using electricity as a motive power are, if this be true,
remarkable. It takes 15lb. of coke, at 24s. per ton, to run a steam
engine and car a mile, and it will take 3lb. or 4lb. of slack coal,
at 8s. a ton, to propel an electric car the same distance. These are
theoretical figures, and it will be remarked that the chairman of
the company, in speaking to his guests, made a prudent and
considerable allowance upon them.
The accumulators, twelve for each car, are carried beneath the
seats, and are put in and taken out from the outside, being shut off
from view by sliding doors. They make an automatic connection with
the motor. Their present form is not likely to be long retained, for
they are enclosed in boxes of unnecessary weight and cumbersomeness,
made up of teak and lead. Glass or vulcanite would be preferred if
manufacturers could be induced to make the kind of box required.
Even as it is however, a set of exhausted motors can be replaced in
three minutes with a set of newly charged ones, and their
disadvantage consists mainly in the fact that they add very largely
to the burden which has to be carried.
A car without its compliment of passengers weighs 9 tons, and with
it 12 tons. One charge is sufficient to propel a loaded car 60
miles; but in practice no charge is allowed to get exhausted. The
accumulators undergo some wear and tear, but it is said to be
doubtful if their maintenance will cost more than that of steam
engines.
It is likely that two or three months will yet elapse before the
Bristol Road route is furnished with electric cars, even if the
Public Works Committee and the City Council should presently give
their sanction for the new system. Mr. Joseph Smith states that if
the order for twelve cars were given at once, it could not be
executed in less than two months.
The Public Works Committee on their part, still hold to the
requirement that the tramways company should demonstrate the
trustworthiness of the Elwell-Parker motor by running a car with it
for a month. With reference to this proposal, the company’s
engineers point out that in order to comply with it, they must
perforce put down the plant, which, in any case, will be needed at
the generative station. The station as designed by them, will be
furnished with large engines, and with the most modern appliances
for handling the accumulators.
It will probably be suggested, therefore, that the Council should be
asked to grant to the company provisional running powers for a
month, and only to make them absolute if at the end of that time
electric traction should become a proved success. If this concession
were granted, the hands of the directors would be materially
strengthened. They can hardly be surprised however, at the firmness
of the committee when they remember that at least one other local
authority has been induced to sanction a system of electric traction
which belies the hopes of its promoters, and that the Central
Company itself not long ago pressed hard for the adoption in
Birmingham of a motor, which is now admitted to have had grave
mechanical defects.
It was doubted, moreover, by a mechanical specialist who saw the
tramcar which made yesterday’s trial trip, whether the brake
attachment in use would prove of permanent value. If Messrs. Elwell,
Parker, and the company’s motor does not establish its claim to be
safe and efficient, its success will be attributable to the
combination in one inventor of both mechanical and electrical skill,
and to his regards for a consulting engineer’s knowledge of the
actual requirements of tramway work.
After the trial a luncheon was held at the Queen’s Hotel, at which
Mr. Joseph Smith presided. The health of “The Queen” having been
drunk, Mr. Smith proposed the toast of “Success to the system of
electric traction.” He said that among the buried treasures of
wisdom in the east, he believed there was a maxim that he who shot
at the sun would strike higher than a bush. He hoped that that maxim
would not encourage the Corporation of Birmingham to strike too high
or too hard, if he acknowledged that the result of that day’s
experience in electric traction was in no small degree due to the
absolute determination of the Corporation of Birmingham in general,
and of the Public Works Committee in particular, that nothing less
than the best illustration of electric traction would be good enough
for the City of Birmingham. (Hear, Hear).
Mr. Lawley Parker had that day seen a distinct advance upon anything
which had before been shown in this country or on the continent of
Europe. The improvement in mechanical details in the car upon which
they had travelled was most marked and most satisfactory, and so far
as the car itself was concerned, he ventured to state that it would
give satisfaction both to the Corporation and to the travelling
public. As to the commercial aspect of the experiment, which was
interesting to the shareholders of the Central Tramway Company, it
was one of the features of electric propulsion, and of the
self-contained car in particular, that power must be lost at the
fixed station in changing mechanical energy by dynamos into electric
energy in the accumulators, and in again that electric energy into
mechanical energy in the car motor.
Taking the average of opinions which had been given to him from the
highest sources, it appeared that probably 40 percent would be
placed as mechanical energy upon the wheels; but he preferred to
calculate the cost upon the supposition that they would only
preserve 25 percent of the original energy, and with that loss
electric traction emphatically justified itself as the coming power
of the near future. He was speaking in the presence of men who would
be able to check him when he said that one ton of ordinary coal
consumed at the generative station, meant as much efficient work as
three tons of coal expended in a steam locomotive. More than that,
the cost of hard coke was nearly three times the cost of the coal
which the company would use, and thus the cost of generation at a
fixed station was only one sixth; possibly less than that; of the
cost of steam locomotives. What cared he, therefore, as a tramway
man, if he got only 25 percent of the power generated, when he could
generate six times as much for the same expenditure of money,
representing a 20 percent profit upon their expenditure upon
electric trams? Working expenses would be less and the wear and tear
upon the roads would be less.
The average weight of a steam locomotive and car is 16 tons, the
weight of an electric car is only 9 tons. The economic results of
electricity were of course still better than those of horse
traction, and at the same time the electric car was only 26ft. long
whereas a steam engine and its car were 51ft. 6in. long (Hear,
Hear). He would call upon nobody to respond to the toast, because on
that showing he thought that electric traction was able to answer
for itself (Laughter and applause).
Councillor Lawley Parker proposed the toast of “The Visitors” and
said that the occasion was a very interesting one to the members of
the Corporation and to the public. They had witnessed a most
successful and interesting experiment. Birmingham had not been
afraid to venture upon several important experiments connected with
tramways, and now they saw another experiment which he believed, and
hoped, would prove to be practical on other tramlines in the
borough.
He desired, however, that they should first see the electric car at
work continuously for, say, a month. It was the desire of the Public
Works Committee that that should be required in order that they
might see the system thoroughly and fairly tried. As they did not
know much about electricity themselves, they were bound to consider
that the proof of the pudding lay in the eating, (Hear, Hear) and if
the month’s work was satisfactory, he was sure that the City Council
and the Public Works Committee would be very much disposed to favour
electric motors on other lines in the borough (Hear, Hear).
It was of course unfortunate that when the Bristol Road line was
completed the company would not at once be able to put electric
motors at work; but he hoped that they would be able to make some
temporary arrangements for a service of horse cars. As to the use of
electric motors on other lines, it was not for him to say what the
company should do; but if he might express a hope, it was that they
would boldly attack their depreciation fund, and write off their
steam engines pretty rapidly. They might depend upon the Council
dealing fairly and properly with their shareholders. (Hear, Hear).
Sir Saul Samuel responded on behalf of the visitors and said that
his interest was the greater in the experiment which had just been
tried, because the people of Sydney, whom he represented, were
extremely anxious to get rid of their steam cars, which were the
same pattern as the Birmingham cars. (Laughter). The trial had been
a perfectly successful one, and he regarded the system as the best
form of electric traction yet devised. He ended by giving the toast
of “The Mayor and Corporation of Birmingham”. (Applause).
The Mayor responded, and said that he hoped the Corporation would
soon be able to get rid of the smoky engines, which now traversed
the streets of the City. (Hear, Hear). Birmingham was smoky enough
without having smoke emitted in its thoroughfares. The electric car
was an immense improvement on the system of steam traction, and, for
the sake of the promoters, as well as of the public, he hoped it
might prove a success. He concluded with some remarks on the
importance of penny fares as a great advantage to the working
classes, and by proposing the health of the chairman.
Mr. Joseph Smith, in replying, welcomed the proposal that
electricity should be used on other routes than Bristol Road, and
said that if he had not been satisfied that the enhanced profit of
electric traction would pay for the abolition of steam engines, he
would never have advocated it. (Hear, Hear).
The proceedings closed when the health of Mr. Thomas Parker had also
been drunk.
The regular running of electric tramcars on the Bristol Road route,
began on Friday, 25th July, 1890.
A description of the Blackpool tramway, written
in 1890 for the Parliamentary Standing Committee on Public
Works in New South Wales, Australia. The committee was
considering a proposed tramway for use in Sydney, and looked at
some of the tramways in use, in various countries.
Birmingham Central Tramway Company’s Proposed
Installation on the Bristol Road, Birmingham
System
Each car carries a motor worked by accumulators
placed under the seats. These are recharged by a
fixed electrical generating plant.
Date opened
There are no cars yet in regular working, and the
necessary licenses from the local authorities have
not yet been obtained. A car has been fitted with
accumulators and has run experimentally. The Central
Tramway Company own the whole of the system; all the
electrical work is being carried out by the Electric
Construction Corporation.
Track
Three miles of double line; worst curve is a right
angle, one of 50 feet radius. Some heavy gradients,
the worst being 1 in 28 for 83 yards, and the
longest being 1,300 yards long and varying from 1 in
39 to 1 in 188. Rails set to 3ft. 6 inch gauge.
Cars
One only at present, but there are to be 12, each
seating 52 passengers, weighing as follows:
Car |
2 tons 10 cwt., empty |
Motor and gearing |
1 ton 0 cwt. |
Accumulators |
3 tons 6½ cwt. |
Total
|
6 tons 16½ cwt. |
They are double bogie cars,
each bogie having 4 wheels. The motor drives the 4
wheels of one bogie only.
Motors
Elwell-Parker's, series wound, running at 700
revolutions per minute, at a car speed of 8 miles an
hour, with a current of about 35 amperes. There is
only one pair of brushes constantly on, and they do
not want moving for either forward or backward
running.
The motors are carried in a
frame of steel or aluminium bronze, resting directly
on two bearings on one of the bogie axles at one
end, and at the other through a spiral spring on a
central bearing on the other bogie axle.
Gearing
The cradle carrying the motor also carries two
countershafts, and the armature spindle is geared
into wheels on them both. These countershafts each
gear into wheels on the two bogie axles. Helical
gearing is used.
Switches etc.
There are 72 cells, grouped in 4 batteries of 18
cells each, in each car, and at each end platform
there is a switch which can be turned into 6
positions:
1. Batteries
and motor all disconnected.
2. Batteries grouped in 4 sets of
18, all in parallel.
3. Batteries grouped in 4 sets of
18, all in parallel and connected to the
motor.
4. Batteries - 2 sets in parallel
and 2 in series, connected to the motor.
5. Batteries - 3 in series,
connected to the motor.
6. Batteries all in series and
connected to the motor. |
The switch is so constructed as
to "spark" on breaking the circuit on special
contacts, the regular contacts being thus saved from
burning. The cars are reversed by altering the
direction of the current by means of a "plug"
switch. This switch can only be reversed when the
main switch is in position, i.e. the handle has been
disconnected, thus preventing the car from being
reversed with the current on. The handles for
working the above are carried from end to end of the
cars as required, only one set being provided.
Accumulators
Seventy two, arranged in 12 trays carrying 6 apiece;
six trays are carried under the seat on each side of
the car, and can be slid in from the outside. They
have contact springs on each side, so that putting
them into place automatically connects them up. They
are connected to the "switches" in 4 groups of 3
trays (18 cells) each.
Electrical Power Storage type
of cell, 19 plates, 9 inches by 7½ inches. Outer
cases of teak; glass being tried. Charging current
about 40 amperes. Weight of 72 cells complete with
trays and fittings, 3 tons 16½ cwt. Life as yet
unknown.
Unloading and charging
arrangements
At present wooden tables are
placed in the car shed alongside the track on which
to unload the spent cells, but it is proposed in the
fixed installation to have two hydraulic lifts, each
with 8 shelves for carrying the trays; one on one
side of the car, will rise as the other falls. The
trays will be slid out of the cars onto one shelf,
the lift moved, and trays with good cells slid from
other shelves into the cars. Two pairs of these
lifts would thus accommodate 8 cars quickly
following each other, and would only take up 2 car
lengths of floor space. As each lift would be
balanced by its fellow, little energy would be
required to move them. There will be suitable
connections on the lifts for automatically
connecting up the trays for charging. Loading and
unloading would take but a few minutes.
Generating Station
At present the cells are
charged by means of an Elwell-Parker dynamo, run by
the engine in one of the fitting shops of the
tramway company; but it is proposed to put down
permanent plant as follows, all in duplicate.
Engine
Davey-Paxman "Colchester" horizontal compound fixed
engine, developing 100 horsepower when running at
150 revolutions per minute.
Boiler
Water tube type. Working pressure, 150 lbs.
Dynamo
Elwell-Parker, shunt wound machine. The cells will
be charged in sets of 36 in series, all the sets in
parallel. Each set will require about 40 amperes at
90 volts for 10 hours.
Efficiency of System
1. Dynamo -
say 85 percent.
2. Cells - say 80 percent.
3. Motor - say 90 percent. |
Patents
The Electric Construction Corporation hold patents
for electrical power storage, Julien and Sprague
accumulators in this country, and for the Elwell-Parker
motors and dynamos.
General remarks
There is a little noise from the brushes and a
little from the gear. The car started smoothly. Any
bogie cars can be adopted to this system. The cars
are lit by two lamps worked off one accumulator. The
figures given are chiefly estimated, as no practical
experience of the system has been obtained as yet.
Cost
Installation – Practically all estimates:
Items |
Total
cost |
Cost per car |
Car without electrical
fittings (12) |
£3,000 |
£250 |
Motor and gearing |
£2,280 |
£190 |
Accumulators and fixings |
£1,920 |
£160 |
Two steam engines,
boilers, etc. |
£3,320 |
£277 |
Two dynamos |
£950 |
£80 |
Four hydraulic lifts |
£1,930 |
£160 |
Total Cost
|
£13,400 |
£1,117 |
The above prices do not include
the cost of fixing the plant.
Maintenance - No data to
hand. |
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