I have seen cable tramways in operation, and for some time I have been interested in both cable tramway traction and electrical traction, and am able, to a great extent, to compare the two.

I will begin by comparing cable with electric traction. The cable system, as used at Melbourne, may, I think, be taken as the most improved means of transmitting power from a central station to tram cars, mechanically, that is to say, through the medium of any known combination of ropes, pulleys, and other gear which directly transmit the power by their own mechanical motion. The general objections, in my opinion, to the cable system are :

1. A steel rope, travelling up and down the street at some 10 or 12 miles an hour, upon which there is a strain of several hundred horsepower, and consequent necessity for constant inspection in order to prevent accidents.

2. The heavy loss in transmission, due to heat generated by the rope and pulleys in motion. This loss entails the laying down of engines and boilers (with consequent consumption of coal and labour) of about three times the actual power necessary to draw the whole of the cars which can be used at one time. (This varies according to circumstances.)

3. Difficulty in maintaining a punctual service when cars have lost time at some stopping place and cannot "pick up" again by going a trifle faster than the normal speed - that of the cable being the limit. For the same reason a slower service than that now worked by the steam motors must follow, because the speed of the cable would be limited by that at which the cars might safely run in the more crowded parts of the city, consequently, where the road was clear, they could not make up time as is now done.

4. If an accident should happen to the cable, all the cars on the line are stopped.

5. The cars cannot be reversed, even for a couple of yards – a very inconvenient point in shunting, etc.

Transmission of power by electricity, on the other hand, is carried through a motionless and noiseless medium - viz., a copper wire or bar - and, no matter how irregular the street may be, there is no more strain upon the electrical conductor than if the road were a straight line. It is, perhaps, for this reason that electrical has superseded mechanical transmission in collieries with such good results.

The objections to electrical transmission are not easy to define, but I may, perhaps, class them as follows:

1. Objections connected with special systems.

2. Want of technical knowledge combined with experience in those concerned in the design and construction of the system, making it more likely that defects will appear in the working of electrical transmission as compared with mechanical……

………The cost per car mile, at Blackpool, in the season, does not, I believe, exceed 3½d. In winter the town is empty. In spite of this, however, the line is a sound commercial success, and has, I think, been at work much longer than any other electric tramway of any importance in the world. The fact that, although the Blackpool line has been in operation five or six years, no other tramway company in Europe has yet converted their system, applies equally to all improved modes of traction, and may be accounted for by the hesitation or inability of the tramway companies to make any change entailing fresh expenditure of capital…..

……The description of the network of overhead wires used on the American systems, viz., two large wires down the middle of the road, four (?) guard wires running parallel with them, two poles and a cross wire every forty yards, and numerous guy wires at all curves, is, to say the least, not attractive - although it may prove very tractive - but the system appears reliable and economical.

The tendency in large cities, at present is to put all wires underground, out of sight and danger to the public, with facilities for alteration or inspection without disturbing the street surface. Now, the question is whether an underground conductor is not quite as reliable and as economical in cases of heavy traffic, whilst there cannot be two opinions from an aesthetic point of view. In this climate, insulation in a conduit presents no difficulty, whilst the safety from accidents, facility with which a completely insulated circuit can be used, the low rate of wear and tear as proved by actual experiments etc., all point towards its adoption in preference to overhead wires.

Like the cable system, the conductor is laid in a conduit with a slot on the surface of the road, but unlike the cable, it is not necessary that the conduit be between each pair of rails. One conduit will suffice for a double line, the slot for each pair of rails being placed so as to pass below the foot-board or outer edge of the cars; also the slot may be narrower than in the cable system. (At Boston, the conduit was evidently far too confined, besides this, a conduit does not work well with snow on the line.)

On city lines this conduit might be a subway, used also for telegraph wires, etc., and there would be no necessity to syphon the gas or water service when the pipes crossed the conduit…..

…….Now, for an extra cost of about 25 percent the conductor may be put underground, in sections, with a completely insulated circuit, when fires and even the mildest "shocks" to either human beings or animals would be practically impossible, and all the elements of rapid, punctual, and comfortable travelling would be ensured.

I do not wish it to be assumed that the conduit system, as laid down six years ago, is absolute perfection, but I do think that, if well designed and carried out under the favourable conditions obtaining in Sydney, after a most thorough and successful experience under unfavourable circumstances in England, no fears could reasonably be entertained as to the result.

I may here mention that, two years ago, I took the Chief Engineer for Roads and Streets of Paris to inspect the Blackpool line, it being a question of using a similar arrangement in Paris, where a one-minute service was required to carry some 50,000,000 passengers annually over only 8 miles of line, and he had no hesitation in recommending the system to the Council in a very full and carefully considered report. The Exhibition and political matters have delayed progress since then.

I have purposely deferred the consideration of the method of traction by accumulators, because it is utterly unsuited to the gradients of the special line in question. An accumulator car with fifty passengers cannot well be made to weigh less than 10 tons, and this can only include about 2½ tons of accumulators. Now, to drive such a car up a gradient of 1 in 12 at only 5 miles an hour, about 30 horsepower would be required, say a discharge current of at least 24,000 watts from the accumulators. The maximum rate of discharge of the lightest type of cell specially constructed for this purpose is given by the makers at 3,000 watts per ton. Consequently, 8 tons of cells would be required to do the work with any regard for economy, and such a weight is, of course, impracticable.

As regards annual cost for renewal of accumulators: From the latest report of the working at Brussels, where great experience has been obtained, the cost per car-mile is 1½d. and, although the gradients at Brussels are heavy, those at Sydney are still more trying. Now, at that rate, on a mile of double line with a service of two cars every four minutes, the cars averaging 100 miles a day, the annual charge for renewal of accumulators would be £1,825, a sum which would pay 10 percent on a capital outlay of £18,250, or several times as much as the most perfect system of conduit would cost, and almost as much as a complete cable system……

……A word in conclusion, upon the efficiency in transmission of power by cable as compared with electricity. It is both unfair and misleading to make such statements as “the gain in haulage of electricity over cables is 75 to 80 percent.” (see daily papers). Not that such a statement is untrue, under certain conditions, but because the “gain” in question must always vary, according to circumstances. A fair method of comparison would be to take the actual consumption of coal per car-mile on the Melbourne system and compare it with what may reasonably be expected in working an electric system in Sydney. Losses in electrical transmission are easy to calculate accurately, and, as it is certain the cable system would require more power per car mile in Sydney than in Melbourne, by reason of the irregularity in the streets, the comparison would be a vary safe one.

A combination of overhead and underground systems might be used - the underground for heavy traffic, the overhead for suburban lines. No alteration would be required in cars or motors, when running from one system to the other. In any case - I strongly recommend a completely insulated circuit, and no use of rails as conductors.