Annual Report to the President and Directors of the Board of Public Works, 1850

When proposed and the first efforts made in 1850, the Blue Ridge Tunnel was to be the longest tunnel in North America. Claudius Crozet, as chief engineer, warns his Board of Public Works against comparing its progress with other tunnels. The condition of the rock and the scale of the project were different and unprecedented, respectively. Crozet tries to educate the Board on the nature of the project.

Office of the Blue ridge railroad.
Albemarle
October 1850.

Annual Report

To the President and Directors of the Board of Public Works,

Gentlemen,

I have the honor to lay before you my annual report on the operations on the Blue ridge railroad, up to the first of October.

In my report of last year, I gave a description of the location of the road which had, but a short time before, been put under contract.

beginning. The construction began in February on the 2^d, 3^d, and 4^th Sections, which constitute the extent of Mordecai Sizer's contract.

On the 5^th & 6^th sections, John Kelly contractors, the work commenced in March: back section contains one of the minor tunnels.

Col. Ths. J. Randolph, broke ground on the 7^th and 8^th sections in April.

In consequence of the failure of the first contractor to comply with the terms of his contract, the first section which consists of the main tunnel and approaches, was re-let to John Kelly and Co.; this circumstance delayed, to the month of April, this important section which would otherwise have been undertaken before the others.

The State of the work on the first of the month was as follows:

1^st Section. On the west side 1200 feet of road and the masonry of a viaduct nearly finished.

The heading of the main tunnel, which was entered on the 1^st of August, at the western end, had penetrated a distance of 80 feet.

On the east side, the approaches were very near the opening of the tunnel, whose heading was opened on the 28^th of September.—the length of the approaches (nearly completed) is 350 feet.

It was desirable that the East side should have advanced faster than the western extremity; But, though the western approaches are much longer than the eastern and equally deep, the reverse has taken place, owing to the greater hardness of the rock in the shorter deep cut.

Besides the deep cut at the western end, the stream which occupies the bottom of the narrow valley in which the approaches are made was turned from its natural bed. The Staunton and James river turnpike was likewise turned in two places and some other minor additional works made.

The abutments of the viaduct, by which the railroad is to pass over the turnpike are good piece of work, built by Geo. A. Farrow, with whom, as I had the honor already to report, I was obliged to enter into a separate contract; these being no price stipulated for this kind of work of masonry in the bid of the contractors for the section, and not having been able to agree with them as to the price. The masonry will cost more than I had expected, owing to the singular scarcity of the building stone in this vicinity, which compelled us, after having exhausted a shallow quarry close to the work, to go a distance of several miles for limestone.

On the 2^d, 3^d, and 4^th Sections, 6,000 feet(say 1¼ mile) are nearly completed besides many considerable culverts.

On the 5^th and 6^th Sections, 2500 feet are made and also about 70 feet of the western heading of the second tunnel, which was entered on the 23d of August, here the progress has been more rapid than on the main tunnel, owing to the softer character of the rock. The approaches at the eastern end have not yet reached this tunnel.

At the western extremity of the third tunnel the excavation of the deep cut is in progress; and, at the Eastern end, they are slopping off the face, preparatory to effecting an entrance.

The culvert in Dove Spring hollow is considerably advanced, besides filling up this creek as well as that in Robinson's hollow with lose rocks.

On the 7th and 8th Sections, 4700 feet are completed including 14 (fourteen) culverts, being all of the culverts, but one, on this contract.

The whole amount of work done may, therefore, be estimated at three miles, in a space of time, which may be averaged at about, seven months.

So that the time of completion of the railroad which embraces eleven miles may be stated at very little over eighteen.

The force employed has varied a great deal: it may be averaged for Mr. Sizer at 140 hands, mostly negroes.

• Mr. Larguey from 55 to 80 white laborers at the tunnel
• Mr. Kelly from — 50 to 60 [?] on sections 5 and 6
• Col. Randolph at 35 — mostly negroes.

In all from 280 to 315 hands.

The expenses have been as follow:

1^st Section —

• approaches — $10,882.58
• Tunnel proper 980.00
• Viaduct — 1,394.85
• $13,257.43
• which is per month
• $2,210

2^nd Section

• 12,443.19—1,555

3^rd Section

• 7,545.89—943

4^th Section

• including Robinson's hollow 9,966.00—1,246

5^th Section, including 2^d Tunnel & Dove Spring hollow

• $17,555.35—2,507

6^th Section, including 3^d Tunnel

• 4,350.88—628

7^th & about

• 7,960.34—1,137

Total amounts

• $73,094.08—$10,219

Which, in a year, would be nearly $123,000, to meet which the unexpended part of the appropriation is ample: indeed, the force employed might even be increased, but for the probability that the disbursement will soon be augmented by the tunnels, and by putting under contract the western section between the Blue ridge and Waynesboro', mentioned below.

In comparing the above statement with the estimates I laid before your honorable body last year, it will be readily perceived, both in the details and the aggregate, the cost, in dice proportion, will probably fall short of the estimate; except as regards the main tunnel, which was re let at a price higher than that of the first contract on which my estimate was predicated, besides the probability that a greater amount of arching will be necessary than was anticipated.

One of the causes, which contribute to reduce the cost, is the fact that, while the ruggedness of the surface seemed to indicate the existence of solid rock beneath, the excavation has generally disclosed a large proportion of clay; though this cause has not operated quite to the extent of the proportion between the price of rock and clay excavation; not only because the cuts through clay are made wider and more open at top, but also be on account of immense and repeated slides which have occurred in several of the deep cuts, in some cases, when the smooth surface of a ledge of slate rock, dipping at an angle even less than 45° with the horizon formed the side of the cut, with every appearance of solidity and permanency, the whole stratum has slid down the large fragments, leaving frequently the superincumbent earth suspended as an arch above the vacant place. These slips, however, will not altogether cause an additional expense: they generally occur in very deep cuts, and will serve to strengthen the high adjoining embankments and, in one instance, to form an indispensable siding.

Four sidings or turnouts have been located; that is, one for every two miles. The principal one is at Blair Park, where a Station will be established as mentioned in my report of last year. The other will be made at convenient points; but not constructed in the way of ordinary passing places. Each of these last sidings is to be connected at the upper end only with the track, and then it is to be formed with a gradually increasing reversed grade; in order effectually to stop a train, or accidentally detached car, impelled downwards by its own gravity. For this purpose the siding should be opened as soon as a train has passed along the main track, so that a loose car would necessarily enter the turn-out and there be checked, if the break should fail, by the reversed grade and by the rougher surface of the rising extremity of the siding track, which for this purpose should not be plated with iron at the steep end.

The first siding will necessarily be placed, at the point where the railroad crosses the Staunton and James river from pike, nearly one mile east of the main tunnel. This location will be convenient to the business & traveling from Nelson County, and will more over be particularly useful until the tunnel is completed, as a station for the short portage over Rockfish gap between the eastern and western sections of the railroad.

The main tunnel, though not the most difficult work on the Blue ridge railroad, is nevertheless its most interesting feature. Many inquiries are made concerning it and especially the probable period of its completion to this it would be difficult to give a precise answer, as it depends altogether on the nature of the excavation, about which no one can form any exact conjecture. At the western end, for example, the rock has been found, so far, by no means as solid as at the other extremity, where it consists of hard shale and green stone irregularly mixed; so that an arch will be indispensable, so far as we have progressed, at the western entrance, while the roof will support itself at the eastern end.

Opinions in regard to time of completion are occasionally given by reference to other tunnels, without adverting to the circumstance, that here the main tunnel cannot be subdivided into short sections by shafts, on account of the great elevation of the mountain; so that the construction cannot be hastened by this means.

It would be incorrect also to predicate calculations on the amount of excavations made in about 50 days at the west end, namely 80 ft, which, for both ends, would be 160 feet, or upwards of 3 feet per day; for, on one hand, very little work has been done at night so far; because the heading having been opened, to accelerate the work, in advance of the deep cut, it became necessary, at least, to bring the excavation of the cut and the working railroad up to the breast of the tunnel, in order to remove the obstruction occasioned by the accumulation of materials carried out of the heading; an operation which was even performed at night, weather permitting; But, when double shifts shall be employed, the progress may be expected to be more rapid. Still, on the other hand, greater difficulties may be encountered, and probably will be, when the work has penetrated farther, from greater hardness of materials, more hauling, ventilation and water.

So far, however, my expectation that we should meet with very little, if any, water has been realized; and the excavation is free from it on the west side, where interruption from this cause was most apprehended. Some small veins of water have been formed on the east side, which here will cause us obstacle, the tunnel declining in that direction.

The second tunnel has likewise been open on the west side, the deep cut being much shorter on this than on the east side. Between the 23d of August and 1st of October, in about 32 days, the heading, as already stated, advanced as much as 70 feet; which would be a progress, for both ends, of 140 feet or upwards of 4 feet; this more rapid advance is due to the softness of the rock, which is a kind of soap stone, so slippery that the embankment formed therewith keeps sliding down and has acquired as yet no cohesion, within a short time, however, the excavation has become harder and the roof apparently safe enough for self support. This tunnel will easily be completed as soon as the railroad itself.

The third tunnel was attached at first from the east side where the excavation has been a mixture of clay, hard pan, and soft rotten slate, altogether of a most imfavorable character for tunneling: here the roof will have to be supported by props, notwithstanding the necessity of blasting: Great care will be required for the protection of those engaged in it, within a few days , approaches have been made at the west end, which exhibit somewhat harder rock, different from the other side, though the distance is but little over 400 feet.

Culverts. One of the greatest difficulties experience on this work, has been the want of building stone and good brick clay: no good quarry has been as yet discovered, and for the construction of retaining walls and the numerous culverts which pass under the road, we have had nothing but slate rock to depend on. Most of the frequent ravines, which furrow the face of the mountain, discharge at times large volumes of water, which must be passed under embankments from 30 to 75 feet high, by culverts seldom under 100 feet in length. Slate rock may answer for square culverts of small dimensions, but could not be used for arches to span a large stream. In the two deep valleys, known as Robinson's & Dovespring hollows, large culverts, not far from 200 feet in length, would have been required: But the channels of the streams being deep and very crooked, it would have been both expensive and insecure to have placed the culverts in the bed itself, where no safe foundation could be formed, the whole valley being filled with large loose rocks, mixed with clay and gravel, to a depth which we have not been able to measure; After due examination of the localities, I concluded to fill up the deep channel of each creek with large loose rocks, through which the water might percolate under the high superincumbent embankment. There might be some apprehension, however, that the interstices might in time be obstructed by leaves and sediment; indeed, though the water passes now pretty freely through the stones, there was a period in the spring, when the mass was choked up by leaves and brush, and when the over flowing stream ran over the bed of stones. In view of this apprehension, and considering that accidents to so stupendous a structure would be attended with vast expense and loss of time and business, I thought it prudent not to rely altogether on this arrangement, and to provide a vent for the water in case of an overflow. I, accordingly, have built a culvert in Dovespring hollow, consisting of two gothic arches 5½ feet wide each, and 8½ feet high of large blocks of slate rock laid in cement.

In Robinson's hollow and another ravine above it, regular arches are to be built: They will cost less than gothic arches, provided suitable rock can be formed within a reasonable distance.

Land damages have not been assessed, as yet, in any case; it might be supposed, that, along the face of this rugged mountain, the land, heretofore of very little value, would be benefited by a work, which would furnish an avenue for timber, before this of no importance, and a convey once for other produce; and that in view of these evident advantages, claims for damages would not be thought of; yet, in a few instances, claims for damages would not be thought of; yet, in a few instances, exorbitant claims have been set up: one case only, however, has been tried; but the commissions having failed to agree, nothing has been decided about it.

Western connexion. I have already stated that the bed of the road may be completed early in 1852, ready to receive the track, if the heavy banks are formed, by that time, to have settled sufficiently for the purpose. This brings out considerations relative to the connexion of this link at both ends, which I beg respectfully to lay before the Board.

In the first place, when the road was put under contract, the distance from Staunton to Waynesboro' had not been undertaken, and it appeared unadvisable to construct the western section of the Blue ridge railroad, between the tunnel and Waynesboro', until the tunnel was near its completion, but since then, the construction of the Staunton & Waynesboro' road has progressed with such rapidity that it becomes a subject of inquiry, whether it would not be expedient to place also the 2¾ miles of this western section under contract at an early day, instead of increasing the force on the others.

This inquiry leads to another: By whom is the bridge over the South river to be made, and where shall the terminus of the Blue ridge railroad; or, in other words, at what point is it to connect with the line advancing towards it from Staunton?

In order to enable your Board to decide upon this point, I have made a survey of the premises near Waynesboro; the result of which is that the location of the Central railroad might be changed for about half a mile, without detriment to the said road, or rather to the manifest advantage of both.

In the first place, the new location would not cross the river so obliquely nor at so wide a place; it would save about 100 yards in the distance and, I believe, suit the owners of property better.

As regards the Central railroad alone, the intended location was certainly much cheaper than that I would propose; but in connection with the Blue ridge railroad, which in fact is one and the same improvement the case is different. In order to reach the river, we have to construct an embankment very nearly half a mile long, across rich low grounds, which near the river are not more than 7 feet high, so that the embankment there will be no less than 18 feet high. To construct this, materials can be obtained, on the east side, only by borrowing from the low grounds, and thus destroying much valuable land, or hauling nearly half a mile from the hills whereas, when the bridge is constructed, if the location north of Waynesboro be made to cut across the hill at that point, materials for the embankment may be obtained and conveyed over the bridge, at the same, time so much of the railroad at Waynesboro' made.

From my experimental survey and estimate, it appears that by this location, if the cut encounters but little rock, the cost of the embankment will be lessened; and that, if the cut be chiefly through rock, it may be somewhat increased; but, on the other hand, as an offset, nearly half a mile of the Central railroad will be thus made and one hundred yards of distance saved, besides also reducing the grade.

The bridge would be 25 feet high and I would construct it of wood, in preference to either stone or iron.

Your instructions on these points are respectfully solicited.

The eastern connexion between Blair park and Woodville, the present terminus of the Central railroad, is also a subject of urgent importance there does not appear to be any provision or measure in progress relative thereto; and yet the Blue ridge railroad can be of no manner of use until this link of about 8 miles has been constructed, though it is far less difficult than the mountain section and will require less time, this has so much the start, that it will be completed before the needed link, even if it were put under contract immediately.

Should the construction of this intermediate section devolve upon the Board, I would respectfully suggest that an experimental location and estimate would be desirable and might be undertaken during the remainder of the fair season; so that the necessary means might be provided upon correct data.

Of the young gentlemen employed as my assistants I could only repeat what I stated last year; and that the operations of this year have, not only confirmed, but increased the confidence and favorable opinion of all who have become acquainted with them. Mr. Carrington has left the corps to engage in other pursuits, carrying with him, the esteem, good wishes and regrets of his associates and of his acquaintances in this quarter; of the former corps, there remains with me a [Meprs Dupuy], Myers, O'Mian & Blair.

The place of Mr. Carrington has been supplied by Captain Vaisz, one of the sons of the noble Hungarian nation, which defended so bravely the outposts of European freedom, and which the selfishness or supineness of European free governments allowed to be crushed by the overwhelming hordes of the northern autocrat; forgetting that this unhallowed aggression and unjustifiable interference were a direct attack, and should have been considered as a positive declaration of war, against them own existence and all free institutions. Not only as one of the victims of his principles & patriotism is captain Vaisz entitled to our sympathy and regard, but also for his own personal deserts; a man of distinguished education and a gentlemen, raised at the Polytechnic School of Vienna to the profession he has now embraced, a mathematician and skilful draughtsman, he is qualified to hold an office more useful to himself and the public than my employment I can offer him in my limited field of operations; and I, therefore, recommend him to the favorable notice of your honorable board, and to that of other bodies having the direction of internal improvements.

Very respectfully submitted

C. Crozet
Engineer Blue ridge railroad