Report from the Select Committee on Steam Carriages/Macneil
Martis, 6o die Septembris, 1831.
Mr. John Macneil, Civil Engineer, Daventry, called in; and Examined.
State your profession?—A Civil Engineer; I am at present the resident and assistant Engineer, under Mr. Telford, to the Parliamentary Commissioners, on the Holyhead Road between London and Shrewsbury, and London and Liverpool.
What is the weight of a Coach, a Van and a Waggon, each carrying what would be considered an average load; state also the breadth of the tires of their wheels?—The weight of four-horse Stage Coaches vary from fifteen cwt. and three quarters to eighteen cwt.; most of the Birmingham day and night Coaches weigh about sixteen cwt. and frequently carry, the night Coaches in particular, upwards of two tons of goods and passengers, exclusive of the Coach; yet taking into consideration the number of times they travel with very light loads. I should say that from two tons five cwt. to two tons ten cwt. including the Carriage, would be a fair average weight during the year. The tires of the wheels are mostly two inches, but some of them are less;, those constructed by Mr. Brown, and used on his patent Coaches have the edges chamfered off, so as to give a flat bearing of one inch and a half, but from the peculiar manner in which those Coaches are mounted with springs. I am inclined to think the injury done to the roads by these wheels is not so great as it otherwise would be. Some Coach wheels that I have seen are rounded off, so as to form in the cross section a segment of about one inch and three quarters in di. The bearing in this case on the road, where the surface is hard and smooth, is reduced almost to a point and must be extremely injurious. The men remark that Carriages with such wheels run wild in descending hills in summer, but heavy in winter, and when the roads are soft and muddy. The Mail Coaches weigh very nearly twenty cwt. Some of them, the Holyhead Coach for instance; frequently carries upwards of a ton of letters and parcels, independent of passengers and their luggage. The average weight of the whole may probably be taken at two tons. Some others, the Liverpool day Mail for instance travel very light, and probably will not average one ton and a half. The breadth of tire of Mail Coaches is two inches and a quarter; the four-horse Vans, which travel about six miles an hour, weigh on an average four tons and a quarter, including the Carriage; the breadth of tire of one which I measured was two inches and a half, but I am not prepared to say that this is the general size of such wheels; the horses used in these Carriages are of the very best and largest description, which added to so great a weight on narrow wheels, probably renders this Carriage more injurious to the public roads than any other description of vehicle at present employed. There are four descriptions of Waggons in general use, the eight-horse Waggon, the six-horse waggon, the four-horse Waggon, and the Farm Waggon, which is drawn sometimes by two, three or four horses, according to the load. The eight-horse Waggons, though frequently weighing, with the load, seven tons, may probably be averaged at not more than six tons the year round; the wheel is nine inches in the tire, but from a very improper plan followed in its construction the bearing on a hard solid road is only three inches, for these wheels are generally shod with three hoops of three inch iron, the centre one of which is of a greater diameter than the others, and projects full half an inch beyond them, which on weak roads such as in the Neighbourhood of London, must be most injurious. I have measured one since I came to London, which travels on the Bath and Bristol road, the outer rim is conical, and can certainly never come in contact with the road surface, unless it be one on which the wheel would sink two or three inches; the section of the wheel is represented in the following sketch: The six-horse Waggons with their load, generally weigh four tons and a half; their wheels are six inches wide, and of a better description than the former, though sometimes one of their hoops projects beyond the other, as in the case of the nine-inch wheel; the four-horse Waggons, with their load, commonly weigh three tons and a half, their wheels are four-inches wide, and are more upright than the others, and have a more level bearing on the road; the farm Waggon, used in Northamptonshire, weighs on an average one ton one cwt., the breadth of a wheel is three inches, and it carries from one top to three tons, according to circumstances, and lasts nearly twenty years.
On an average line of road of not less than 100 miles, on which in many places materials of very inferior description must have been used, both in its formation and subsequent repair, what is the maximum weight per wheel (say if not less than four inches width of tire) which should be carried on any kind of Carriage (carriage weight included,) without risk of injury to the road?—On a road, such as here described, the injury will be considerable by any wheel passing over it; but without a more defined statement of the quantity and quality of the materials used. I do not think this question can be answered with any.degree of certainty; on all gravel roads however made, without a foundation or bottoming. I should say the weight on a four-inch wheel should not exceed fifteen cwt., and on a wheel less than that ten cwt, on the generality of roads, throughout the country: I do not think it would be safe to run a Carriage with almost any-width of wheel if the load much exceeded ten tons; in fact there are some bridges even between: London and Birmingham, that it would be running a risk to pass over with a Carriage weighing ten tons.
Can you from observation' day what proportion the breadth of the tire of wheels should be to the weight?—The breadth of tire, in proportion to the weight, will depend entirely upon the description of road over which the carriage passes; on such a road as that lately constructed by the Parliamentary Commissioners of the Holyhead and Liverpool Roads, at the Highgate Archway. I have frequently observed Waggons, carrying upwards of six tons, pass over it; the weight of each wheel on the road was then about thirty cwt.; and though the bearing of the wheels; from the cause I have before stated, was not more than three inches, the effect produced was imperceptible; the pressure in this case was ten cwt on every inch which is unquestionably țoo much for the generality of roads; but if we take the road from London to Shrewsbury, as criterion to judge by. I should say that a wheel ought to be an inch: in width for every ton that a Carriage and its load would weigh; and that if every Carriage that now travels that road, was limited not to exceed that proportion, the roads would be better, and maintained at a cheaper rate than at present. According to the average weight of Coaches and Waggons, as before stated. I have calculated the following Table, showing the weight at present carried on each inch of bearing, and what I conceive might be the breadth of the different wheels if they were made cylindrical with an even bearing, and in the proportion of one inch of width for every ton including the Carriage.
| Description of Carriage. | Velocity in Miles per Hour. | Weight on an Average in Tons. | Breadth of the Wheels in Inches. | Pressure of each Wheel in Cwts. | Pressure in each Inch in Cwts. | Breadth of Wheel calculated in the Proportion of 5 Cwt. to the inch. |
|---|---|---|---|---|---|---|
| Mail Coach | 9 to 11 | 2 | 2¼ | 10.0 | 4.40 | 2 |
| Stage Coach | 8 to 11 | 2½ | 2 | 12.5 | 6.25 | 2½ |
| Van | 6 to 7 | 4¼ | 2½ | 21.25 | 8.29 | 4¼ |
| Waggon | 2½ to 3 | 6 | 9 | 25.0 | 2.77 | 6 |
| Ditto | 2½ to 3 | 4½ | 6 | 22.5 | 3.75 | 4½ |
| Ditto | 2½ to 3 | 3½ | 4 | 17.5 | 4.37 | 3¼ |
State your opinion as to the relative wear of a road by two Carriages, both drawn by four horses, one carriage of two tons weight, with two-inch tires, the other four tons, with four-inch tires?—My opinion is, that the wear of the roads would in each case be the same, as far as it was affected by the wheels of the Carriages, probably rather less, by the Carriage carrying four tons, on four-inch wheels, than by the Carriage carrying two tons, with two-inch wheels; but it must be recollected that both the Carriages are supposed to be drawn by the same number of horses, and as the horses drawing the Carriage of four tons must use greater exertions than those drawing the Carriage of two tons. I am of opinion that the aggregate wear of the road would be more by the transit of the four ton Carriage, than by that of the Carriage weighing two tons.
How would the foregoing answer be affected by an increase or decrease of velocity in either Carriage?—If the road over which the Carriages are drawn be hard, solid and smooth. I think there would be very little increase of wear from the effect of the carriage wheels by an increase of velocity; but if the road should be uneven or rough, there would be an increase of wear, in consequence of the impetus or blow with which the wheels would strike the road, after passing over the inequalities in its surface, particularly if the Carriages were made without springs; but whether the road be a good or a bad one, the wear occasioned by the feet of the horses will be greater when they travel with an increased velocity; for a coach-horse which travels at the rate of ten miles an hour, works on an average 270 miles in a month, and wears out in that time about four pounds of iron in shoes; whereas a waggon-horse, which travels at the rate of three miles an hour, and works twenty-six miles a day, for four days in the week, goes, on an average, 416 miles in the same period of time, and wears out 4.8 pounds of iron. If the coach-horse travels the same distance, the wear would be six-sixteenths, which exceeds the wear of the waggon-horse one thirty-sixth. In the same way might the relative injury caused by the wheels of the Waggon and the Coach be ascertained.
What is the operation of the atmosphere on roads?—Well made roads, formed of clean bard broken stone, placed on a solid foundation, are very little affected by changes of atmosphere'; weak roads, or those that are imperfectly formed with gravel, flint or round pebbles, without a bottoming or foundation of stone pavement or concrete, are on the contrary much affected by changes of the weather. In the formation of such roads, and before they become bound or firth, a considerable portion of the sub-soil mixes with the stone or gravel in consequence of the necessity of putting the gravel on in thin layers; this mixture of earth or clay, in dry warm seasons, expands by the heat, and makes the road loose and open, the consequence is, that the stones are thrown out, and many of them are crushed and ground into dust, producing considerable wear and diminution of the materials; in wet weather also, the clay or earth, mixed with the stones, absorbs moisture, becomes soft, and allows the stones to move and rub against each other when acted upon by the feet of horses or wheels of Carriages. This attrition of the stones against each other wears them out surprisingly fast, and produces large quantities of mud, which tend to keep the road damp, and by that means increases the injury.
Supposing the actual wear or deterioration of a road to be represented by 100, and that only Coaches. Vans and Waggons have passed over it during any given period, in what proportion would you estimate the effects; first, of atmosphere; secondly, of the Carriage; thirdly, of the horses?—This question can only be answered in a general way; do two lines of road would probably give results at all similar; much will depend on the manner in which the road is constructed, the materials of which it is composed, the care bestowed on its drainage, and whether it be in an open situation or shaded by trees; if the road be properly made, and in an open situation, the injury arising from the atmosphere will be little, compared with the actual wear caused by the wheels of Carriages and the feet of horses, probably not ten per cent, during the year; whereas on weak roads in clay countries every shower loosens the materials of which the road is composed, and causes considerable wear, perhaps thirty per cent, or even more in some situations, where the road is shaded by trees; to get at something like an average proportion between the wear occasioned by horses' feet and the wheels of Carriages. I have procured the following facts: the Coaches which run between London and Birmingham require an hundred horses on an average, to work the up and down Coach; the horses are generally shod, by contract, at about 2s. 6d. per horse per month; those near London are much larger and heavier, and therefore require heavier shoes than those twenty miles out of London, and from thence to Birmingham; near London in the flint districts the wear of horses' shoes is much more than it is in the quartz and limestone countries. At Stony Stratford, the weight of the four shoes of a Mail and Stage Coach-horse averages five pounds, and when taken off at the end of about twenty-eight days they weigh very nearly two pounds: in this period, the horses run 252 miles. At Towcester, Weedon and Daventry the weight of the new shoes is one pour and a half each, and when taken off weigh nearly three-fourths of a pound; the length of time which they remain on is about thirty days.; this would give a wear of three pounds per horse per month, but if the greater wear near London be considered. I think it would not be too much to allow the wear equal to four pounds per horse per month, which for 100 horses for ten weeks would give a wear of 1,000 lbs, of iron. The hind wheels of the Coaches are mostly font feet eight inches in diameter, and the front wheel three feet. The width of tire. I before stated is about two inches, and when new, the thickness of the iron is three quarters, of an inch. These wheels are found to last from two to three months, according to the state of the weather, the workmanship and quality of iron, (about twenty years ago they did not last seven days on an average;) suppose they now last ten weeks, in that time the tire is worn down to one-sixth of its original thickness; this would be equal to 163.4 lbs, or 326.8 for both Coaches; this would be to the wear of the horses' shoes as 326.8 to 1,000, or as 1 to 3-14ths nearly; now if the injury done to the road by the horses' feet and the wheels of Carriages be estimated in the same proportion. I think it would probably be near the actual effect produced, that is to say, the injury done by the wheels of fast Coaches is to the injury done by the horses which draw them as one to three in round numbers. The effect produced by slow Carriages and horses is different; a Waggon drawn by four horses, which travels regularly from London to Daventry at the rate of three miles an hour, is worked by fifteen horses; the waggon weighs twenty-five cwt, and carries on an average sixty-seven cwt.; the hind wheels are four feet eight inches in diameter, and the front ones four feet; the breadth of the wheels is six inches; they are nearly upright but not cylindrical; the iron tire, when put on, weighs on the fore wheels, 285 lbs., on the hind ditto, 396 lbs., making 621 lbs. When removed, the weight is on the fore wheels, 144 lbs.,, on the hind ditto 168 lbs., making 312 lbs.; wear in five months, 309 lbs. The number of miles travelled in this time is 6,048; the shoes that are put on the horses employed to draw this. Waggon, weigh when new from two pounds and a half to three pounds each; the average of a great many gave two pounds and three quarters, and when removed one pound and a quarter; they last from four to six weeks, according to the weather and state of the road; but we may assume five weeks as an average, and the wear in that time for each horse six pounds, and for fifteen horses for five months, it would be 360 lbs. The proportion in this case would be as 309 to 360, or as one to l.16 or nearly one to 1¼; on the generality of roads therefore,
| Atmospheric changes | 20 |
| Coach wheels | 20 |
| Horses' feet that draw them. | 60 |
| 100 |
| Atmospheric changes | 20 |
| Waggon wheels | 33.5 |
| Horses' feet that draw them. | 44.5 |
| 100 |
What is the effect of travelling by coaches and horses; whence and in what proportion does the injury or deterioration arise; the crushing of materials; their actual wear; their displacement?—If the wheels of Carriages be properly constructed, and cylindrical, the friction, and consequently the wear, on the surface of a well-made road, will be very little, and there will be no injury from displacement of materials, except what may arise from the few surface-stones that will sometimes be started out by the feet of horses on steep hills, when they are obliged to exert a great force to draw up a heavy load. When stones are thus thrown out on a hard and solid surface, the wheels of heavy Carriages will crush them, and cause an injury which would be much more than that caused by the actual wear of the wheels passing over the surface. If the roads be weak or elastic, and bend or yield under the pressure of the wheels, the particles of which it is composed will move and rub against each other, or perhaps break by the action of heavy wheels over them. On such roads. I conceive the injury caused by Steam Carriages will be much greater in proportion to the injury caused by light Carriages drawn by horses, than it will be on solid firm roads. In one instance, where an accurate experiment was made, the wear was found to be four inches of hard stone, when it was placed on a wet clay bottom, while it was not more than half an inch, on a solid dry foundation, (formed as described in the Report of the Select Committee on the Holyhead Road, on the 30th May 1830,) or with a pavement bottom, on a part of the same road, when it was subject to the same traffic. On the Highgate Archway Road before mentioned, the annual wear does not appear to be more than half an inch in depth. Now as this road is very little affected by wet, in consequence of its peculiar construction, and the care bestowed on its drainage, I attribute almost the whole of the diminution of materials to actual wear. On many roads, where the sides are weak, great injury arises from the crushing of materials, particularly by the action of waggon-wheels. In frosty weather, weak roads very frequently suffer more in one month than all the rest of the year. In such cases, the injury is caused by the wheels of Carriages, and not by the horses' feet.
If 30 lbs. be sufficient to move a Carriage of 21 cwt. 8 lbs. on a level platform, little affected by friction, and 266 lbs. be required to move the same Carriage up an inclination of 1 in 10, the pressure in the one case being exactly the weight of the Carriage, 21 cwt. 8 lbs. what would be the pressure on the road; or platform; on the inclination?—As the pressure on the horizontal is to the pressure on the inclined plane, as the length of the plane is to its base, we have this proportion, the pressure on the plane. In this example, w=2360. b=10. p=1, which gives or 1012 lbs. less than the pressure on the horizontal.
Taking twenty miles near London, 150 lbs. appears to be the average force actually engaged in drawing the Carriage of 21 cwt. 8 lbs. including hills, would the force required to draw a carriage of 42 cwt. 18 lbs. be on an average 300 lbs. and so on in proportion; the extreme traction of the Carriage being 343 lbs. what on this road would have been the maximum force required to draw a Carriage of four tons weight?—It does not follow that because a Carriage is twice as heavy as another, that its draught would be twice as much; the resistance arising from gravity on the inclined planes would, abstractedly considered, be ble, but that part of the resistance arising from the friction and penetration of the wheels into the surface materials, would much depend on the construction of the Carriage, and its wheels, and the different sorts of roads over which it was drawn. In order to ascertain the average draught of a Carriage of 42 cwt. 16 lbs. over the above road. I conceive that the friction of the surface or resistance opposed to the motion of such a Carriage, should be ascertained on each description of road within the above limits, and then by knowing the rates of acclivity, or the amount of gravity acting on each, the average draughts might be ascertained, if the same Carriage and wheels were used, but loaded so as to make up 42 cwt. 16 lbs. the average draught. It might probably be calculated pretty nearly from the following Table of Experiments, which as it may be of use in the present inquiry. I here, beg leave to hand in; but it must be remembered that the proportions given in this Table between the increase of weight and the increase of draught, will not be the same on every description of road. To be enabled to answer the second part of the question, it will be necessary to know the rate of acclivity on which the draught of the Carriage weighing 21 cwt. 16 lbs. was 343 lbs., and also to know the draught of the four ton Carriage on the horizontal; but even then a difference might arise from the construction of the Carriage, and the situation of its centre of gravity.
| No. of Planes | Waggon Empty weight 1 Ton. | Half a Ton in the Waggon. | 1 Ton 2 Cwt. in the Waggon. | |||
|---|---|---|---|---|---|---|
| 1 | Down 30 | Up 90 | Down 45 | Up 145 | Down 58 | Up 210 |
| 2 | 64 | 88 | 105 | 120 | 125 | 150 |
| 3 | 75 | 85 | 115 | 120 | 135 | (illegible text) |
| 4 | 75 | 85 | 105 | 125 | 135 | 165 |
| 5 | 80 | 88 | 105 | 125 | 135 | 165 |
| 6 | 85 | 93 | 105 | 135 | 135 | 170 |
Neither the rates of acclivity, or the lengths of the planes, were taken at the time, but it might still be done if thought necessary by the Committee, as the points are well ascertained.
| Weight of the Waggon and Load. | Powers required in Lbs. | Difference between Empty Waggon and Load. |
|---|---|---|
| 2,240 | 29 | |
| 2,800 | 74 | 45 |
| 3,360 | 104 | 7530 |
| 3,920 | 140 | 11135 |
If 266 lb. be required to move a Carriage of 21 cwt. 8lbs. up an inclined plane of one in ten, what amount of weight would be required to keep the Carriage stationary, or to allow it to descend with the slowest possible motion on the same inclination; this question has reference to the injury done to roads by "dragging" the wheels, and subsequently to the slow motion of the propelling wheels of Steam Carriages in descending hills?-If the base of the inclined plane be 10, and its height 1, the length will be
nearly, and we have the proportion 10.05 : 1 :: 2360 : 234.82 lbs. the weight which would be required to keep the Carriage stationary if the surface of the plane was hard and smooth, and the mass collected in a point; but as 266 is stated to be the moving power, the resistance arising from the friction of the surface, and the axle-trees would in this case be 31.18 lbs; it may be well to observe here, that the experiments made, on inclined planes, as detailed in the Seventh Report of the Parliamentary Commissioners of the Holyhead and Liverpool Road, were not intended for any thing further than to get practical results, the description of which could be easily understood by Road Surveyors and their Assistants, and even by men in the habit of driving Coaches; it could not be expected that experiments made with a large unwieldy waggon, mounted with common; axle-trees besmeared with tar, could furnish results, on which to found a refined mathematical calculation. I have however, within these few days, commenced a series of experiments, with a small Carriage constructed on purpose, and furnished with a very delicate instrument for measuring the draught. From the little way I have as yet gone in these experiments I cannot furnish any details at present; but I think I am warranted in saying that a very great benefit would arise in the saving of road-materials, by the adoption of a better method of hanging the Coaches, in a manner, perhaps, something similar to gentlemen's Carriages. Many of these weigh, when fully loaded, two tons, yet a pair of post-horses draw them with apparent ease, the rate of ten miles an hour; and on some parts of the road between London and Birmingham, where the road is tolerably level, at a much greater speed, some of the Birmingham and London Coaches travel the same ground, at twelve miles, and sometimes fifteen miles an hour. This velocity, however, may in a great measure be attributed to the level and perfect state of that road.
The details of various kinds of Steam Carriages have been given to the Committee; all act without propellers; without projection on the wheels, with cylindrical wheels; some with greater or less breadth of tire, even six inches wide; the power is applied either by crank or wheels to one or two propelling wheels, according as greater or less force may be required. Some of the experimental Carriages bad three, some six wheels; all will have four wheels—Some have the Engines in a separate Carriage, and draw the load; some carry the load and Engines on one Carriage. Taking the above circumstances into consideration, which would be most injurious to a road—a Stage Coach, drawn by four horses, weight of Coach three tons, horses two tons, breadth of tire two inches and a half; or Steam Coach, wheels four inches tire, weight four tons; in both cases velocity ten miles per hour?—Taking for granted that the injury which a road sustains by the wheels of Carriages and the feet of horses is proportional to the wear of iron on the wheels and on the horses, and that the statement before given as to the actual wear on each be found correct. I would say, the injury done to the road by the Steam Carriage weighing four tons with four-inch wheels, would be less than that occasioned by the Coach weighing three tons, drawn by four horses.
Would it be beneficial or otherwise to the roads, that Steam Carriages drawing heavy weights in Carriages attached to them should be substituted for Waggons drawn by horses, supposing that the weight of the drawing or propelling Carriage should not in any case exceed the weight of the number of horses that would have been used to draw a corresponding weight, e.g.
| Waggon | 8 | tons. |
| Eight horses, 15cwt. each | 6 | ditto |
| 14 | ||
| On Steam Carriage | 4 | |
| Carriage drawn | 10 | |
| 14 |
I am of opinion, that if the Steam Carriage and its accompanying Carriage be constructed with wheels of a proper width, and of the same diameter as the Waggon wheels, and travel with the same velocity, that the injury on well-made solid roads will not be more than that caused by the Waggon and horses; in fact, if the proportion of injury before stated be correct, it will be less; but it must be recollected that weak roads suffer more than solid ones from the heavy pressure of wheels, and in such cases the Steam Carriage and its tender would be more injurious.
In descending hills. Steam Carriages can regulate their velocity by reducing the action or number of revolutions of the wheels; this acts as a drag, but with the advantage to a road that the wheel moves continually round; which would be most injurious to 6 September; a road, the descent of a Carriage dragged as usual (not omitting the operation of the horses' feet,) or the Steam Carriage dragged or regulated in the mode described?—Not having seen a Steam Carriage descending a hill in the manner described (that is, regulated by the action of the Engine on the wheel,) I cannot give a satisfactory answer to this question; but as far as opinion goes. I should say that the joint action of the horses and drag would be more injurious than the Steam Carriage, the motion of which was regulated in the above manner, provided the wheels were of the proper width, and the total weight not greater than that of the coach and horses.
Various local Acts have passed, placing excessive tolls on Steam Carriages, it may be requisite to introduce a general Bill, which shall, on such roads, place Steam Carriages on a fair equality (so far as their relative injury or wear of road to common Coaches on each such road; the toll on a Coach on such roads may vary from one to two shillings, according to local circumstances, on a Waggon in the same proportion; what standard of charge would you suggest for Steam Carriages?—It has been stated to us, that one Steam Carriage has drawn a Carriage containing as many as thirty passengers, at the rate of even ten miles per hour, and nine tons weight at the rate of five miles per hour, but with smaller wheels, what regulation would you suggest as to the breadth of tire; or should tolls be chargeable in inverse proportion to the breadth of tire?—The toll.which Carriages propelled by Steam, or by any other mechanical means, should be required to pay, ought, in my opinion, to be in proportion to the injury they would do to the roads, compared with that done by the present description of Carriages and the horses employed to draw them, without reference to the weight or quantity of goods carried; but as I before stated. I do not believe an accurate estimate can be at present formed as to the injury that roads may sustain from Steam Carriages, compared with the injury done to them by Coaches drawn by horses; it may, however. I think be safely assumed, that the injury done to a road by a Steam Carriage would not be greater than that occasioned by a Stage Coach drawn by horses, the weight of the Engine and its load being supposed not to weigh more than the Stage Coach, together with its load and horses; if this be granted, and an Act passed limiting the width of wheel in a certain proportion to the weight carried, there would not be much difficulty in arranging a scale of tolls applicable to Steam Carriages, which would put them on an equitable footing with Carriages drawn by horses; if, for instance, a proportion, such I have already mentioned be adopted, viz., that a wheel should be an inch in width for every 5 cwt, it has to support, and a toll charged for each inch equal to the amount charged for a horse drawing in a Carriage which travels with the velocity of the Engine, it would, in my opinion, be a fair and equitable toll at least for some years, or until a correct proportion of injury was ascertained by experience and observation, when it might be altered or amended according to circumstances.—This mode of charging toll would be extremely simple, and not likely to be misunderstood by toll-collectors, or to occasion any disputes; but there should be a heavy penalty attached to the proprietors of Steam Carriages if they put a greater weight on the Carriage than the wheels were intended to carry. If the Engine, instead of carrying the load draws one or more Carriages after it, the toil should be collected and charged on each Carriage, in a similar manner as it is charged on the Engine, that is in proportion to its wheels. An example will illustrate my meaning more clearly; suppose an Engine, together with its load, to weigh nine tons (which is about the average weight of two Stage Coaches, including the weight of the horses which draw them) to pass through a toll-gate where horses drawing Coaches are charged 6d, each, the toll on the two Coaches would be 4s., and of the Steam Carriage 4s. 6d. Suppose that the Engine, instead of carrying the load draws a Carriage after it, and that the weight of the Engine is five tons, with five-inch wheels, and of the accompanying Carriage four tons, with four-inch wheels, the toll of the Engine would be 2s. 6d., and of the tender 2s., making 4s. 6d, as before. The only objection I can see to this mode of charging toll on Steam Carriages travelling over the turnpike roads would be, that in the event of their being able to carry a greater number of passengers at a cheaper rate than the present description of Carriages drawn by horses, it would lessen the amount of toll collected, as a fewer number of Carriages would do the work, and many persons who drive their own horses would travel by them if found cheaper to do so; and this circumstance, although it would not affect the state of repairing in which the road was previously maintained, it might lessen the value of property invested in the different turnpike trusts Throughout the kingdom, which is a very considerable sum; but such a circumstance should not militate against an invention likely to prove beneficial to the country at large.
Give your opinion on the probable extent of injury to roads from Steam Carriages?—Generally speaking. I should say that the injury roads will sustain by the introduction of Steam Carriages will be much less than is commonly supposed; but the actual amount of injury, or correct estimate of the comparative injury that will be done by a Steam Carriage cannot, in my opinion, be formed at present with any degree of certainty. Experience alone will decide the point. The only danger, in my mind, that is to be apprehended, is the injury which roads may sustain by the possibility of the wheel which is acted upon by the Engine, turning round without propelling the carriage, in which case the road would suffer considerably; and this would take place, if a train of Carriages were attached to the Engine, the draught of which was more than the friction or gripe of the Engine-wheel on the surface of the road. As long, however, as the weight is carried by the Engine, and not drawn after it, nothing of this kind will take place, even on our steepest hills.
Have you communicated your conclusions on these John Maoneil, subjects to Mr. Telford?—I have.
Does he coincide with you?—Quite so.
You stated, that the only probable injury to the roads from the travelling of Steam Carriages, would be the slipping of wheels; would it not be directly against the interest of the proprietor that the wheels should slip in any degree, there being a necessary Joss of power every time they do slip?—Clearly so.
From your observations of the effects produced by heavy Carriages drawn by horses, in ascending and descending hills, what would be the effect, under similar circumstances, of a Steam Carriage of a weight equal to the weight of the Coach and horses?—I am of opinion that the effect or injury to a road would be less by the Steam Carriage; for when hills exceed a certain rate of inclination, gravity overcomes the friction of the surface, and the Carriages, in descending, press upon the horses, unless a drag be applied to one of the wheels. This, in itself, injures the road, but not so much as when no drag is used, because the horses are then obliged to bear against the Carriage, and set down their feet very strongly; this often tears up the surface, particularly of weak roads. The time that is lost by the Coaches in descending some of the hills on the road between London and Birmingham, is full as much as is lost in ascending them, besides the imminent danger, even with the greatest caution on the part of the drivers. If proper springs were used, the draught would be lessened, and of course the injury to the road would be much diminished.
On every road there are numerous six-horse Waggons; you state the weight to be four tons and a half, the horses weighing four and a half more, making nine tons, should any objection be taken to a single Steam Carriage of this weight, or from nine to ten tons, provided the wheels be of a proper description?—No; I think in the general state of roads, a Steam Carriage of from nine to ten tons could run with perfect safety, without injury to the roads, if it was constructed with proper wheels.
The above question refers to a Steam Carriage carrying its load; if the Engine Carriage were of the 6 September, weight of four tons, drawing a second Carriage of the weight of six tons, thus dividing the weight over eight wheels, would the effect on the road be less injurious provided it was four and a half tire?—I think the injury would be less, provided the Engine had the power to propel itself, and draw a Carriage with six tons after it, without a slipping of its wheels.
Carrying this principle further, if the load were divided into two Carriages, each to weigh three tons, thus dividing the load over twelve wheels, would not less injury still be done?—Decidedly, particularly on weak roads.
If under these circumstances you can diminish the pressure on the road by multiplying the number of wheels, should not care be taken so to frame the tolls to be levied as not to discourage the use of those Steam Carriages, whose greater number of wheels could be least injurious to the roads?—I think that would be regulated by the mode I have suggested of charging toll.
Have you seen Mr. Gurney's Carriage, and examined its effect on the roads?—I have seen it.
What state were the roads in, at what velocity was it going, how many persons did it carry, and what was its weight?—I do not know the weight of the Carriage, there appeared to be eight or ten people on and about it; the road on which I saw it was excessively bad, one of the worst in the country; the velocity was probably five or six miles an hour. Were there other loaded Carriages passing along the road at the same time?-Several, both Coaches and Waggons.
Did you remark the effect of the Steam Carriage on the road, to see that it did less or greater injury than the other Carriages?—I could not perceive any difference.
If there had been any great difference, you would have perceived it?—As far as leaving a track behind, which would have been perceived. I could not ascertain the amount of injury; it was nothing more than that done by common Coaches.
Do you think it essential that the wheels of Steam Carriages should follow in the same track, provided they have a proper breadth of tire?—Not at all, as regards the injury to the road; it would require more power to work them if the wheels did not follow in the same track.
Supposing the Steam Carriages, either the propelling Carriage and the Carriage drawn, or the Engine Carriage carrying the passengers were generally to be four tons, what would you recommend to be the minimum breadth of tire to either of the Carriages?—In the present state of Steam Carriages, as applied to the working over turnpike roads, I should say you might limit them to not less than four inches for a few years.
Supposing their average weight never exceeded from six to eight tons, do you think four and a half would be a safe minimum?—I am inclined to think it would be rather too little.
Do you think it would be necessary to make any alteration in the form of the present line of turnpike road for the facility of working by steam?—I do not think it would be absolutely necessary; it would, however, be of great benefit to the country and every person in it, if the hills on the present lines of road were more reduced and the surface strengthened; no road should have a greater ascent than one in thirty or one in thirty-five; in almost every instance the expence would be saved in horse-labour in a few years: the following Table will show pretty nearly the increase of expence in transporting goods by stage coaches drawn by horses up planes of different rates of ascent. Roads in general have, in some parts, steep ascents; one in fifteen between this and Birmingham, for instance, is too much on a road of such traffic. The surfaces are not so good generally as they ought to be; the roads should be strengthened, either with a pitched bottoming of stone or a concrete mass, such as the Highgate Archway, or the new road near Coventry.
| Four-Hone Stage Coach, Average Velocity, 10 Miles per Hour. | Waggon, Four Horses, Average Velocity, 2½ Miles per Hour. | |||
|---|---|---|---|---|
| Rates of Acclivity. | Pence and Decimals. d. |
Rates of Acclivity. | Pence and Decimals.. d. |
|
| 1 in 10 | 77.24 | 1 in 10 | 52.07 | |
| 1 in 15 | 57.78 | 1 in 15 | 28.70 | |
| 1 in 20 | 50.47 | 1 in 20 | 22.83 | |
| 1 in 30 | 44.15 | 1 in 30 | 18.55 | |
| 1 in 40 | 41.25 | 1 in 40 | 16.79 | |
| 1 in 50 | 39.56 | 1 in 50 | 15.82 | |
| 1 in 60 | 38.46 | 1 in 60 | 15.20 | |
| 1 in 70 | 37.68 | 1 in 70 | 14.77 | |
| 1 in 80 | 37.09 | 1 in 80 | 14.46 | |
| 1 in 90 | 36.64 | 1 in 90 | 14.22 | |
| 1 in 100 | 36.28 | 1 in 100 | 14.04 | |
| 1 in 150 | 35.19 | 1 in 150 | 13.46 | |
| 1 in 200 | 34.64 | 1 in 200 | 13.18 | |
| 1 in 300 | 34.09 | 1 in 300 | 12.91 | |
| 1 in 500 | 33.65 | 1 in 500 | 12.69 | |
| 1 in 1,000 | 33.32 | 1 in 1,000 | 12.53 | |
| Horizontal | 32.98 | Horizontal | 12.36 | |
What would be the difference of expence of pavement and forming a good granite road, in the neighbourhood of London; say twenty miles?—If you take twenty miles, and also take the repairs of the roads for twenty years into account. I should say paving would be the cheapest. The great defect of all the London pavements arises from want of a strong and firm foundation. In Fleet-street, and some others, this has been partly accomplished of late, but certainly not as perfect as it might be. If on the road from this to Birmingham there was a portion laid off on the side of the road for Steam Carriages, which could be done without difficulty, and if it be made in a solid manner with pitching and well broken granite, it would fall very little short of a Railroad. My only reason for keeping it distinct from the other road, is the evident injury every road sustains from horses travelling over it and breaking up the surface, and the Steam Carriages would be able to go with greater velocity if they were not interrupted with droves of cattle; besides, it would be easy to fence it off from fifteen to twenty feet, without injury, to property; and the expence of making a solid mad of twelve or fifteen feet would not be very considerable.
But have you any doubt whatever that Steam Carriages can be brought into practical use, with great benefit to the public, even on the present lines of turn pike roads?—I am quite convinced they can.
Would the wear of such roads as you have described, be much affected by the greater or less velocity of the Steam Carriages?—It would be hardly affected at all, on a good road, by increased velocity; if any thing perhaps rather less.
Do you propose in your scheme of toll that weight should be the basis of toll, but that the wheel be an 'index to the weight?—Yes, that is the principle on which I have suggested the scale of tolls.
How would you check the frauds of proprietors of Steam Carriages, by their placing a greater weight in proportion to the breadth of tire?—I conceive the use of the Steam Carriage would be for passengers solely and their luggage; if the weight was ascertained in the yards at London. Birmingham, or Shrewsbury, the intermediate traffic would differ very little, for persons going short distances would go by the Coaches as at present.
Would you suggest that a license should be granted to Steam Carriages, limiting the number of passengers they should take in proportion to the breadth of tire of the wheel?—I think it would be quite as much as the Road Trustees could expect; and by marking in large characters the width of wheel on the Carriage, it would be a great preventive to the proprietors altering the wheels.
Do you think that considering the infant state of this invention, that the Road Trustees would practically suffer any great injury or inconvenience by merely for two or three years placing Steam Carriages, whatever weight they may be, on a level with ordinary Carriages, with reference to the toll charged for them?—Considering the present imperfect state of Steam Carriages for turnpike roads. I think it would do no injury to Road Trusts if such a regulation was adopted.
Would you place Steam Waggons on the same footing as Waggons drawn by horses?—Yes, provided the wheels are made as I described in proportion to the weight; there should be the same toll on a Waggon drawn by steam as a Waggon drawn by horses, that is, the width of wheel should be charged per inch as the horses are now charged.
Should a Steam Waggon be licensed as to its weight, in the same manner as a Steam Coach?—I think just the same.
Did you conduct the experiments made on the Holyhead Road as to the force of traction required on different inclinations?—I did.
Were they carefully made or otherwise?—They were carefully made as far as the materials would allow; the Waggon was a very large one, with common axle-trees; the result in some cases differed from two to three pounds; on the whole I should say the results stated in that Report do not exceed in any case five pounds beyond what they would be found if proved by the best practical instruments, and are confirmed by my subsequent observations and experience; the object we had in view, by these experiments, was to show to the Trustees and the Surveyors of the roads, that a road might appear a very good one, and still not be one adapted for traffic. By these means they have perceived the defective parts in the road; and within three months after the Report of the Parliamentary Commissioners became public, there was not a hedge on that part of the road where the draught was shown to be excessive, that was not cut down and improvements made on the surface.
When you followed Mr. Gurney's Carriage, did you perceive that any horses were frightened, or any inconvenience arose to passengers on the road?—I did pot perceive the least inconvenience; I saw several horses pass, both gig and saddle-horses, also coaches, and not one took the least notice of it.