STONE + STONE
PREFACE
Every human action gains in honour, in grace, in all true magnificence, by its regard to things that are to come. Therefore, when we build, let us think that we build forever. Let it not be for present delight, nor for present use alone; let it be such work as our descendants will thank us for, and let us think, as we lay stone on stone, that a time is to come when those stones will be held sacred because our hands have touched them, and that men will say as they look upon the labour and wrought substance of them, "See! This our fathers did for us. -John Ruskin, The Seven Lamps of Architecture, 1907
CONCRETE FACING ON A SANDSTONE BLUFF
The line of the Chicago, Milwaukee & St. Paul Railway Company, in the city of St. Paul, beginning at the crossing of Chestnut Street, extends with an ascending grade along the face of a bluff. This bluff is of a character common to the Mississippi River bluffs in that vicinity, and is composed of soft sandstone capped with an irregularly broken ledge of friable limestone, above which lie mixed together loose sand, gravel and boulders. This sandstone disintegrates readily, and is so soft that it wears away rapidly under the influence of the weather. The detritus from the bluff has frequently to be removed or it would cover the railway tracks, and the wearing away of the sandstone leaves the limestone ledge and the boulders which lie above it in a precarious condition, threatening the safety of the trains on the tracks below. From time to time it has been necessary to build masonry walls on the face of this bluff for the protection of the railway tracks. The photographs submitted with this paper show such masonry walls.
In the summer of 1897 it was decided to protect an additional stretch of the bluff, and the writer concluded to use a concrete facing instead of cut- stone masonry, for the reasons which follow: He assumed that the stability of the sandstone would be secured if it were protected from the rain and frost, and that a facing of concrete or brickwork would furnish protection equal to that of cut-stone masonry at a saving in cost. He had a precedent for this in similar work that he had put in at Fort Snelling to support some dangerous projections of rock under similar conditions. At Fort Snelling the danger seemed imminent, and the overhanging rock was supported by brick buttresses or pilasters, and the adjacent bluff was covered with brick work to shed the water from it. The Fort Snelling work had been exposed for three years, and had served its purpose without signs of deterioration to the brickwork. At St. Paul he concluded that it would not be wise to make a smooth face to the bluff, because it would cost less to support the projecting limestone with pilasters than to remove it. If the projecting stone had been removed it would have resulted in loosening the adjacent stone, and the excavation would have extended beyond the railway company's right of way into valuable city property. A description of the work will be better understood by reference to the illustration.
In Fig. 1 the tracks shown in the foreground are those of the Chicago, St. Paul, Minneapolis and Omaha Railway Company, which are on the level bottom land at the foot of the bluff. The double track line of the Chicago, Milwaukee and St. Paul Railway Company lies on the bench which is supported by a retaining wall of stone masonry. At the left is shown a protecting wall of cut-stone masonry. In the background is shown the work under discussion at an early stage of its progress.
The loose material was removed from the face of the bluff, and the next operation was to build brick pilasters under the projecting limestone. Three of these pilasters were built, the one nearest to the left is 6'0" wide and 4'3" thick; the second one is 12'0" wide and 4'9" thick; and the third one is 6'0" wide and 4'6" thick. The dimensions of these pilasters give an indication of the sizes of the stone projections which they support. While the work was in progress, a heavy section of limestone, located some 200 feet from the left, tumbled down and temporarily obstructed the railway track, but its unstable condition was known, and there was nothing in the way to be injured by its fall. By reference to Fig. 2, it will be seen that projecting bricks are built into the pilasters near their inner corners, which bind the pilasters and the concrete facing together.
The foundation for pilasters and concrete facing is in the sandstone, four feet below the base of rail of the railway tracks, the footing course being two feet deep and ten inches wider than the wall above it. The supporting frames for the concrete were put on in the following manner: Bolts were put into the sandstone at distances apart of eight feet horizontally and vertically. With special augers holes were bored into the sandstone from four to five feet deep, inclining downwards so that the bolts would stand perpendicular to the face. The bolts were three-quarter inch in diameter and were placed in the holes with nuts on the lower ends, the holes being then drilled around the bolts with mortar, a process easy of accomplishment on account of the downward inclination of the holes. The bolts projected about eighteen inches beyond the face of the sandstone with their ends terminating in cast iron nuts of cruciform section, and with the threads in the nuts long enough to engage a second section of three-quarter inch bolt. This second section of bolt held the uprights in place. The uprights consisted each of two planks 2x8 in section with the bolt passing between them. The planking supporting the concrete was placed against the inner edges of the uprights. This framework was built up in horizontal sections, the uprights and planking used at the bottom being afterwards used again higher up on the wall. To remove the planking it was only necessary to unscrew the nuts which held the uprights, and when the concrete wall was exposed, the short ends of bolts were screwed out, leaving the wall securely bolted to the sandstone, and the bolt holes were then filled with mortar. It was not considered necessary that the concrete should be bolted to the sandstone, but the bolts were required to secure the concrete frames, and the easiest way to dispose of them was to uncouple and remove the short ends, and such value as they give in holding the concrete in place is gained without The method of bolting the frames to the bluff is shown in Fig. 3.
The work had to be carried on in the limited space between the railway tracks and the bluff. The sand for concrete was brought on cars and deposited outside of the tracks on the edge of the bench supporting them, as shown in Fig. 1. The broken stone was brought by team to the top of the bluff and dumped through a chute built against the stone wall, as shown in Fig. 2. The mixed concrete was deposited by wheelbarrows, using for the lower courses an inclined runway and later the wheelbarrows were hoisted by a derrick located on the bluff. This derrick is shown in Fig. 1. It was operated by steam, the engine being placed at the foot of the wall.
When the concrete wall was built up to the limestone ledge, all loose stone and dirt was removed, and the vacant spaces carefully filled with concrete. In some places where it was difficult to place the concrete, brickwork was used. Fig. 4 shows some of this brickwork located between the projecting pieces of limestone. The concrete was continued from the top of the limestone ledge to the top of the bluff, and special care was taken to make the work tight at the top so that water would not get in behind the concrete.
The four engravings show the conditions in different stages and after the completion of the work, the finished work being represented by Fig. 4. No attempt was made to put in the concrete with a uniform slope, it being fitted against the formation of the bluff. This is plainly shown in Fig. 4, where a considerable depression or pocket appears at the left of the telegraph pole. The slope of the first pilaster is 11 1/4" in 24"; of the second pilaster 12 1/2" in 24"; of the third pilaster 13 1/2" in 24", while the slope of the concrete varies from 12 1/2" to 17" in 24", so that the general average slope of the work is approximately 1 horizontal to 2 vertical. The brickwork was laid up with Milwaukee cement mortar except the exposed bricks, which were laid in Portland cement mortar. The concrete was made with 4 parts of Milwaukee cement to 6 parts of sand and 15 parts of broken stone; and was faced with 1 1/2 inches of Portland cement mortar, composed of 1 of cement to 2 of sand. The mortar facing was placed at the same time as the concrete, so that it set with it, making a perfect union. Western Portland cement made at Yankton, S. D., was used except for a small portion of the work, for which Empire Portland cement was supplied to make up a shortage of the Western.
The work was expensive on account of the limited space for working between the railway and the bluff, and the expensive nature of the concrete frames; but the cost per yard was less than if cut-stone masonry had been used, and the quantity of material in the wall was also less. If the work were to be done over again, the only change the writer would recommend is that concrete should be substituted for brick in the pilasters, as being equal in quality and costing less than the brick work. The work has been in place for a year and no faults appear in it. For similar work the thickness of the concrete facing, may in many cases be safely reduced. On sandstone of this class all that is required is that it should be protected from the weather, but care must be taken to prevent the water from getting in between the concrete and the sandstone. In the work described, the walls are thick enough to support the broken limestone, boulders and earth, as well as to prevent the sandstone from wearing away.
Above cost covers all labor and material expended in preparing the bluff to receive the wall; 'building the wall complete and removing all debris and waste material; and rebuilding fence after completion of work. It also includes engineering expense, but does not include freight charges on cement, sand and brick. The work was done by the Bridge and Building Department of the St. Paul Railway Company, F. E. Rice being the engineer in direct charge. - Onward Bates, Civil Engineer
The following figures are taken from the records of the work:
DIMENSIONS
Height of sandstone 30 ft.
Height of limestone ledge 12 ft.
Height of layer of sand, gravel and boulders 14 ft.
Height of wall above footing 56 ft.
Depth of footing 2 ft.
Length of wall 256 ft. 6 in.
Average thickness of brick pilasters 4 ft. 6 in.
Average thickness of concrete footing 3 ft. 3 in.
Average thickness of concrete facing below ledge 2 ft. 5 in.
Average thickness of concrete facing above ledge 3 ft. 2 in.
QUANTITIES
Brick pilasters 141.5 cu. yds.
Brick face wall 67.5 cu. yds.
Concrete footing 61.2 cu. yds.
Concrete face wall below limestone ledge 1038.5 cu. yds.
Concrete face wall above limestone ledge 195.0 cu. yds.
Total brickwork and concrete: 1,462.2 cu. yds.
COST
Brickwork, labor $2.09; material, $2.91 total $5.00 per cu. yd.
Concrete, labor $1.83; material, $2.32 total $4.15 per cu. yd.
Brickwork and concrete (average) $4.64 per cu. yd.
Brickwork and concrete (256'6") wall $26.46 per lin. ft.
Total cost of wall (256'6") $6,787.36
STONE + STONE
Deep time–
the picture:
Precambrian craton earth basement rock
siltstone sandstone limestone dolomite
the silent floors of departed oceans…
Quaternary glacial drift glacial erratics glacial outwash
Glacial Lake Agassiz moraine eskers velocities and tectonics
sandstone limestone clay pits silica gabbro sheet sand glass talus rubble
Stone into Stone
American History–
the picture:
Manifest Destiny exploration expansion from sea to shining sea:
NARRATIVE OF 1853: A REPORT TO CONGRESS BY ISAAC I. STEVENS, GOVERNOR OF WASHINGTON TERRITORY, EXPLORATIONS AND SURVEYS FOR A RAILROAD ROUTE FROM THE MISSISSIPPI RIVER TO THE PACIFIC OCEAN; EXPLORATIONS FOR A PACIFIC RAILROAD BETWEEN THE FORTY-SEVENTH AND FORTY-NINTH PARALLELS OF NORTH LATITUDE ST. PAUL TO PUGET SOUND.
"St. Paul, beautifully located upon a high bluff"
sandstone limestone blasted back picked apart
caves: maze and tubular pigeon holes mole people spelean history walled up
roadcuts railcuts road beds ore into steel lay down sleepers lay down track dump ballast
Stone onto Stone
C M & SP RR at Chestnut Street–
the picture:
the line slopes upward, ascends along the bluff face
sandstone limestone ledged outcrops of rock
irregular friable loose sand gravel rocks and boulders break in the rain
rain down on the line must be reigned in
rubble masonry cut stone concrete brick and lime mortar wall over the bluff wall
Stone into Stone onto Stone
Present tense–
the picture:
Physical constant gravitational attraction expansion/contraction slippage of mass
subsoil moisture bad weather dirty water
low wages hard labor work strike bad mix
morale, moral and material failures cracks open
wind-blown dust urban dirt seeds of weeds trees root chiseling fissures
prying apart seams through seasons freeze and thaw and freeze
rust-jacked cummings spalling concrete pilaster bricks sooted coal-black
lime mortar crumbles in acid rain lashings
the falling wall face downcutting downwashing rubble on the rail line merging with ballast
Stone onto Stone onto Stone
COLOPHON
Stone + Stone was produced in an edition of 5; and a unique altered version. Bound in cloth covered boards with slipcase, the spine is covered in Cave Paper’s Degener Black flax paper. The text is set in Adobe Caslon and letterpress printed on Revere book finish paper. All images are hand-printed grauvure etchings on Johannot 240 paper: the historic images in the signature are from the article "Concrete Facing on a Sandstone Bluff," by Onward Bates, from "Stone, An Illustrated Magazine, Volume XVIII," New York: Frank W. Hoyt, 1899. The photographs by PMR were taken in 2008, 110 years after the construction of the wall. The codex signature and leporello sections of this book may be removed for display by sliding them out from the elastic cord on the book spine.