« PreviousContinue »
taking the year through, two horses will do as much or more work with the same labour to themselves upon a paved road than three upon a
a gravelled road, if the traffic on the gravelled road is considerable ; and if the effect of this is brought into figures, the saving of the expense of carriage will be found to be very great when compared with the cost of paving. If the annual tonnage upon the Commercial Road be taken at 250,000 tons, and at the rate of only three shillings per ton from the Docks, it could not, on a gravel road, be done under four shillings and six-pence, say, however, four shillings, or one third per ton difference, which makes a saving of 12,500l. in one year.
“I think I am under the mark in all these figures; and I am convinced, therefore, that the introduction of paving would, in many cases, be productive of great advantages.” Mr. Walker further says, that “
during thirteen years that the East India Docks' branch has been paved, the paving has not cost twenty pounds in repairs, although the waggons, each weighing about five tons, with the whole of the East India produce, which is brought from the Docks by land, have passed all that time in one track upon it; and a great deal of heavy country traffic for the last eight years, when a communication was formed with the county of Essex.”*
This road has been referred to, not by way of showing a perfect specimen of pavement, but generally to point out the advantages of paved roads; for this road, in consequence of the plan of Mr. Walker not having been strictly attended to, was by no means originally constructed in so perfect a manner as it might have been.
Still, however, it was by far the best specimen of pavement that had been executed; and it has fully established, by experience, the great ad
, vantages which the public may obtain by making a paved road for transporting merchandise, when it is not possible to make a canal or railway.
The plan of paving this road was altered in 1829 : large blocks of granite, five or six feet in length, sixteen inches wide, and twelve inches deep, were laid for the wheels to run upon, as on a tramroad of iron, except that there is no flanche. The space between the granite blocks is paved. The plan has succeeded, as may be seen from the following Report of Mr. Walker to the trustees of this road :
“I beg to report the results of the expe
* See Report of the Committee of the House of Commons, on Turnpike Roads, in 1819.
riments made this day upon the stone tramway now forming on the Commercial Road, before you, accompanied by the Chairman of the West India Dock Company, and Mr. Colville, one of the directors. “ The experiments were made upon
space between the West India Dock-gate and the first turnpike upon the Commercial Road, with a very good town-made waggon, belonging to Messrs. Smith and Sons, distillers, and a stone truck, belonging to Messrs. Freeman.
“ The dust had been swept off the tramway in the morning. The distance is 550 feet, of which 250 feet nearest the Dock-gate rises 1 foot, or one in 250, and the other 300 feet rises about 2 feet, or 1 in 116.
“ The whole rise in the 550 feet is 3 feet, or 1 in 155.
“ The gravity of one ton upon the lower length is, therefore, 2240 lbs. divided by 250, or nearly 9 lbs. Upon the upper length it is 2240 lbs. divided by 116, or 19} lbs., and the average of gravity upon the whole length is 2240 divided by 155, or 14lbs.
Experiment 1st. The general average resistance of four tons gross (viz. waggon 1 ton 16 cwt. and goods 2 tons 4 cwt.), as ascertained by your chairman (C. H. Turner, Esq.) and Mr. Colvile,
by means of a spring weighing machine, was 127 lbs.; from which, if we deduct the gravity of 4 tons, or 19} lbs. multiplied by 4, say 77 lbs., there is left, for the friction of 4 tons, 50 lbs., which gives for the friction of 1 ton 12 lbs., Išoth of the whole weight moved.
“ This friction is not more than upon the best constructed edge railway. I consider that the greater size of our wheels, and there being no flanche, compensate for the roughness of the stones (from their being newly laid), as compared with an iron railway.
Experiment 2d. A pony 12} hands high, weight 4} cwt., drew upon the upper part in your presence, and afterwards upon the lower part in your and the directors' presence, six tons (gross). I was not aware that the differ
I ence of inclination of the two parts was so great, or he should have gone over the upper length again, — he had done it more than once before.
“ Taking, therefore, the upper part on the rise of 1 in 116, the pony's exertion was,
Ibs. Gravity 19} lbs. multiplied by 6, or · 116 Friction 12} lbs. multiplied by 6, or 75
Making together 191 and 191 lbs. divided by 12 lbs. (the friction of one ton) gives 15 tons.
“ The pony's work, therefore, was equal to fifteen tons drawn upon a level road.
Experiment 3d. The waggon, loaded as in the preceding experiment, being turned round and started by the pony's exertion, ran down the whole length to the Dock-gate with increasing velocity (the pony not drawing it), and for a distance off the tramway, before it could be stopped; consequently the average fall of 1 in 155 exceeded the resistance by friction.
Experiment 4th. A powerful horse (weight 14 cwt.) drew 12 tons gross (the waggon and truck loaded) from the West India Dock-gate to the turnpike, at the rate of 4 miles per hour.
“ Taking, then, the upper length, or a rise of 1 in 116, we have
Gravity 12 times 19} lbs., or
lbs. 232 150
and 382 lbs. divided by 12} lbs. gives 30 tons.
“ The horse's work was therefore the same as if he had been drawing 30 tons upon the level.
“ The full average work of a horse, per day, is 150 lbs. moved 20 miles ; consequently the pony was exerting one fourth more than the