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The obvious utility of a work explaining the principles on which roads should be made, and
any regard to inclinations : no solid foundation was prepared ; a very superficial coating of very bad stones or gravel was all that covered the soil; the transverse sections were often just the reverse of what they ought to be; the draining was miserably defective, and either no protecting fences, or very weak ones, existing along steep hill-sides and tremendous precipices.
“On this district there were no less than seven distinct Trusts; the revenue arising from the tolls being very limited, the trustees could not afford to employ persons whose education and previous pursuits qualified them to act as surveyors. The consequence was, that the road got unto unskilful hands, and its state of repair was just as bad as the principle of its construction.
“ The increasing importance of this line of communication at length attracted the attention of Parliament. I was directed to make a survey of it in 1810; and, it having been satisfactorily shown to the successive Committees of the House of Commons, that the country through which the road passed did not in itself possess the means of providing funds for effecting any essential improvement, an Act of Parliament was passed in 1815, empowering commissioners, therein named, to expend the sum of 20,0001. in making such alterations as they might deem expedient.
“ Under the power of this Act (the 55th Geo. 3. c. 152.) the commissioners commenced their operations in the autumn of 1815 ; and according as further grants were from time to time voted by Parliament, the road progressively assumed its present character. Those parts which had been the most inconvenient and dangerous have been changed to perfect specimens of what roads ought to be ; steep declivities have been reduced to perfectly easy inclinations; and narrow, crooked, ill-protected portions have been converted into broad, safe, smooth, and well-constructed roads.
“ The value of these improvements was felt and appreciated; and it became of the highest importance to preserve them in a perfect state, by providing an efficient system of management.
containing an illustration of those principles by a reference to the plans, specifications, and contracts
“ By the Act of the 55th Geo. 3. c. 152. the new pieces of road, when completed, were to be made over to the local trustees, to be by them repaired and maintained. But the local Acts were imperfect; the old tolls too low; every Trust deeply in debt, and the mode of management not so perfect as it ought to be. Under these circumstances, it was thought advisable to apply to Parliament for an Act to secure to the public the lasting benefits of those improvements, by placing them under the care of one Board of Commissioners.
“Accordingly, in May 1819, the Act of the 59th Geo. 3. c. 30. was passed, in which six Trusts between Shrewsbury and Bangor were consolidated into one, and vested in fifteen commissioners therein named. The operations of this Act commenced from the first day of August following; and from that period a totally new system has been adopted on the whole line of road. At the first meeting of the commissioners they appointed a professional engineer as their general surveyor, also a clerk and a treasurer, and fixed upon a plan of management, of which the following is an outline.
“ The total distance from Shrewsbury to Bangor Ferry, being 85 miles, was divided into three districts; the first, being 23 miles, extending from Shrewsbury to the boundary between Shropshire and Wales, at Chirk Bridge; the second, of 30 miles, from Chirk Bridge to Cernioge; and the third, of 32 miles, from Cernioge to Bangor Ferry.
“Over each of these districts an assistant surveyor or inspector was appointed, care being taken to select these officers from good practical workmen. Under these inspectors, a working foreman was placed on every four or five miles, with such a number of labourers under his charge as were sufficient for maintaining the road in proper repair.
“ It was ordered that the labourers should be, as much as possible, employed by task, in quarrying rock, gathering field stones, getting gravel, breaking stones, scraping the road,
which have been made use of in constructing the new road in North Wales, through a country persenting every kind of difficulty, has suggested the present publication. The object of it is to point out, in a clear and concise manner, the best method of tracing and constructing roads, under every variety of circumstances; and it is confidently expected, that the course which has been pursued of proceeding on experience by inserting in this work the identical plans, specifications, and contracts by which so great an extent of perfect road has been successfully made, will be found to have attained
loading materials into carts, and all works that are reducible to
“ The duties of the general surveyor and clerk were, to go along the line every four weeks ; the surveyor to examine the practical operations, settle all accounts with each inspector, and give the clerk a certificate, showing all the money due. The clerk to collect the tolls, and to pay every one what appeared to be owing by the surveyor's certificate, and lodge the balance of his receipts with the treasurers, Messrs. Beck and Co. of Shrewsbury."
RULES FOR TRACING THE LINE OF A NEW ROAD.
This business of tracing the line of a road should never be undertaken without the assistance of instruments; and all local suggestions should be received with extreme caution.
To guard against errors in this important point, it is essentially necessary not to trust to the eye alone, but in every case to have a survey made of the country lying between the extreme points of the intended new road. For this purpose an experienced surveyor should be employed to survey and take the levels of all the various lines that, on a previous perambulation of the country, appear favourable. It is only by such means that the best line can be determined. These surveys should be neatly and accurately protracted and laid down on good paper, on a scale of sixty-six yards to an inch for the ground plan, and of thirty feet to an inch for the vertical section.
The map should be correctly shaded, so as to exhibit a true representation of the country, with all its undulations of high grounds and valleys, streams and brooks, houses, orchards, churches, and ponds of water adjacent to the line of road; and all other conspicuous objects should also be
laid down in the map. A vertical section should be made, and the nature of the soil or different strata, to be ascertained by boring, over which each apparently favourable line passes, should be shown; for it is by this means alone that it can be determined and calculated at what inclinations the slopes in cuttings and of embankments will stand. If it be necessary to cross rivers, the height of the greatest floods should be marked on the sections; the velocity of the water, and the sectional area of the river, should be also stated.
If bogs or morasses are to be passed over, the depth of the peat should be ascertained by boring ; and the general inclination of the country for drainage should be marked.
All the gravel-pits or stone quarries contiguous to the line should be described on the map, with the various roads communicating with them; and the existing bridges over the streams or rivers which are immediately below the proposed point of crossing them should be carefully measured, and the span, or waterway, stated on the section.
These preliminary precautions are absolutely necessary to enable an engineer to fix upon the best line of road, with respect to general direction, and longitudinal inclination. Without the unerring guide of actual measurement and calculation, all will be guess and uncertainty.
It may be laid down as a general rule, that the best line of road between any two points will be that which is the shortest, the most level, and the cheapest of execution : but this general rule admits