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Interruptions caused through weather conditions having a duration of less than 2 hours shall not be deducted from the pay of the employes.
It is also the inspector's duty to see that the regular hours of work are adhered to.
3. Public Traffic
During the prosecution of the work a footway is to be kept clean and unobstructed. At all crossings a safe foot-path is to be kept across the street. In case the neighboring streets are soiled through transportation of soil and other material, such streets shall be cleaned by scraping and sweeping, so that a state of general cleanliness exists.
The request of individual persons to drive to a certain house situated on a closed street in certain cases, such as removals or funerals, should, if possible, be granted; otherwise sufficient assistance is to be given.
4. Delivery and Removal of Material
The old paving material is to be collected carefully and removed. On delivery of new dressed stone blocks, the stones have to be handled carefully so as not to injure their corners. Laborers who, in spite of warning, injure stones repeatedly, shall be fined and the inspector should make the necessary recommendations to the engineer.
5. Laying of Curbstones
The curbstones shall be laid truly in level grade and height. The upper surface of curbstones 14 inches wide shall be in the same grade with the sidewalk. Curbstones 6 inches wide shall be laid so that the side facing the roadway is exactly vertical. The curbstones shall be carefully supported so that they are stationary and immovable.
In streets having a grade of 1:40 or more, where a rough usage of the curbstone through heavy traffic (using the curb as a brake for wagons) is expected, the right curb shall be set on concrete foundation. The setting of curbstones on concrete foundation shall also be necessary if curbstones of 6 inches width are used in permanent pavements.
In construction of the foundation, the packed earth shall be disturbed as little as possible and under no conditions be loosened with picks. In this case the surface shall be constructed to the height of the under surface of the concrete, or in streets with rammed pavement, the top surface of the foundation be 12 inches under the level of the pavement. Soft and loamy soil should be removed to a depth of at least 20 inches in streets of rammed pavements, 12 inches with course-stone, 4 inches in pavements of split stones, measured from the top surface of the pavement, and replaced with gcod sand, or material equally suitable for foundation, and should be tamped or rolled. In the construction of the surface in streets paved on concrete foundation, soft soil, loam or peat may remain for foundations on the streets if approved by the head of the division or the engineer.
New excavations existing in the road-bed which may sag, are to be tamped and, where practical, flushed previous to the beginning of the work.
In construction of surfaces for concrete foundation under compressed asphalt, wood or so-called bridgestone pavements, care should be taken that the height of the roadway corresponds to the lower surface of the concrete.
7. Compressed Asphalt and Wood Pavements
Compressed asphalt and wood pavement work is to be carried out by con. tractors according to specifications, and the supervising engineer, as well as the inspector, should insist upon strict enforcement of the specifications.
8. Course-stone Pavements
Two grades of stones are used in course-stone pavement, one for best and another for ordinary pavement:
Stones used for best course-stone pavement A and B.
Top surface, 5 to 10 inches long; 4 to 6 inches wide, 71⁄2 to 81⁄2 inches high. Top surface to be dressed so as to have as nearly as possible a plane rectangular face and clean, sharp square corners.
Stones used for ordinary course-stone pavement:
Top surface, 5 to 10 inches long; 4 to 61⁄2 inches wide; 7 to 81⁄2 inches high.
Top surface to be dressed not as carefully as grades A and B above. After the top surface of the roadway is prepared to a depth of 12 inches, as described in paragraph 6, the course-stone are set into a cushion, which consists of a layer of gravel spread to a thickness of 7 inches. The heads of the measuring sticks used to indicate the height of the pavement shall be set to a depth which will correspond to the rammed pavement. The measurement of this height will depend on the greater or lesser hardness of the roadway, and this height will be decided by the inspector with the approval of the engineer. At first two rows of stones are laid along the edges of the sidewalks, then the stones are laid across the whole roadway, normally to the axis of the roadway. At street crossings the direction of the rows are determined according to the instructions from the engineer. In regard to the width of the stones, it is desired to select the smallest stones for the steeper grade and to have the maximum and minimum width of the stones so that they shall not vary more than 14 of an inch in a single row.
In setting the stones care has to be taken that the stones are hammered to the right height with a stone paving hammer, so that the stones do not move if walked upon. The ramming of the stones shall be done in at least three stages. At each ramming the stones shall be struck exactly in the middle of the face to prevent splitting of the stone and abrading of the corners. After the first ramming the pavement shall be thoroughly watered so as to properly wet the cushion material. After completion of the ramming, all injured stones have to be replaced by new and perfect stones, which have to be fitted and properly rammed.
Permanent course-stone is to be finished with asphalt filler (paragraph 1).
9. Slag Block Pavements
The slag block are cubes of 61⁄2 inches linear dimensions; 4-inch and -inch stones are used as binder stones. The specifications for course-stone pavements are applied to this pavement generally. Uniform joints of moderate width should be kept between the stones to enable the construction of a proper cementation. The clipping of normal stones is allowed only at crossing, curved curbstones, manholes and sewer basins, etc.
10. Dressed Stone Pavements
So-called bridgestones shall have a facing 5 to 10 inches long, 4 to 6 inches wide, and 4 to 44 inches deep. The upper surface of the concrete foundation shall be 5 inches unde: neath the surface of the finished street. The concrete is mixed according to directions of the engineer, which is usually one volume cement to seven volumes of silica sand which is free from loam (sand from the river Elbe or quarry sand). The concrete shall be mixed with as little water as possible, and shall be tamped well. If broken stone is used, it must be smoothed with a mortar of 1 to 3. The laying of the stones can only be started when, in the judgment of the engineer, the laborers can walk on the concrete without
injuring it. The bridgestones are set with a mortar of 1 cement to 3 sand, which is moistened with water, and in such a way that there will be joints of 1⁄2 inch or less. All joints should be filled carefully with mortar and hammered down to the proper height, so that they are not moved when walked upon.
The joints shall be cleaned with water to get rid of any excess mortar previous to filling the joints with liquid mortar. In case the street has to be opened to traffic immediately, the time being insufficient to insure a proper set of the cement, then asphalt filler should be used.
11. Asphaltic Filler
Course-stone and slag stone pavements are usually, bridgestone pavements occasionally, laid with an asphaltic filler. The specifications hereinafter provided apply to this filler.
12. Road Pavements of Split Stones
In pavements of split stones, gutters the width of two stones and crossings as wide as the sidewalks shall be made of course-stone according to specifications in paragraph No. 8. The pavement made of split stones shall be laid with tight joints according to the direction of the inspector. It is laid into the gravel, rammed three times. The joints shall be filled before each ramming with gravel. After completion of the pavement, all excess of the gravel shall be removed and the pavement shall then be cleaned. During the first four weeks after completion of the pavement, all washed-out gravel should be renewed, and after each renewal the excess of gravel should be removed.
13. Small Paving
Kleinpflaster stones shall have a surface of 5.60 square inches to 10.24 square inches and a height of 2.8 to 3.6 inches. The area of the base has to be at least two-thirds (2/3) of that of the surface and must be parallel to it.
In laying the stones, they are to be assorted so as not to vary more than .4 of an inch in height. In selecting these stones their height should be considered in regard to the top surface of the pavement.
The foundation for the kleinpflaster is to be a stone cushion, rolled in proper manner to the depth of 8 inches. In exceptional cases the foundation shall be a bed of silica or slag concrete. When the kleinpflaster is to be replaced on an earth road, the road surface can be used for the foundation if the surface is in good condition. If otherwise, the surface has to be repaired and properly reinforced. Streets with heavy traffic, if the case demands, are to be provided with a packing of old broken stone; in these cases a cushion of 5 inches is sufficient. Before construction of the foundation or the packing, the ground has to be well rolled. If the ground consists of loam, a layer of sand 6 inches thick is to be put on the ground and rolled down. In streets with a curbstone, and pavements of the full width of the street, gutters are to be made of course-stone in the width of two (2) stones. In case the surface of the street is not to be finished with curbstones, special edge-stone at least 8 inches deep are to be laid, so that the upper surface of these stones is 1⁄2 inch lower than the proposed surface of the pavement. These stone have to have the same grade as the street and have to be carefully braced.
In utilizing the existing road surface as foundation, the surface has to be cleaned of all dirt and dust and smoothed. All existing cavities have to be filled
with good material and be well rammed.
The upper surface of the existing road shall be 34 to 4 inches below the top surface of the street, depending on the size of the stones used. A layer of sand inches deep is at first spread over the road. The stones are then laid in this in polygonal or concentric order, with tight joints. This pavement is then over
spread with a layer of gravel, which is to be brushed well into the joints and rammed once, with a light rammer. All arising irregularities are to be corrected
In construction of a roadway having full width of street or with curbstone, gutters of course-stone in width of two stones are to be constructed.
In case the roadway is not bound by curbstones, it is to be provided with special edge stones 8 inches deep, so that the upper surface of the stones is inch below the surface of the road. To obtain a compact roadway the surface is to be covered during the rolling with road scraping or gravel, and this is to be washed into any joints or grooves. The rolling is to be continued until a compact roadway is obtained. After completion, the road is to be covered with a layer of silica and sand. It is then ready to be opened for traffic.
Roadways are to consist of a pack layer and a covering.
The pack layer is to be constructed from old paving material in such a way that the faces of the stones are close together and in close contact with the foundation. Any openings between them shall be carefully filled with broken stones.
The cover shall have a depth of 5 inches and shall consist of a uniform and hard material (basalt) of about 11⁄2 inches in size.
15. Railroad Area
The rails used in new construction shall be 8 inches high, except when circumstances demand a lower profile. The same profile is, as a rule, used in replacing old rails, except in streets with concrete foundations, where the rails to be used should be 6 inches high to prevent a weakening of the concrete. In curves, reinforced double rails shall be used. Switch and crossover rails shall be of hardened steel and may be made of rail ends. Cross-ties shall be welded, except at curves and connections, where the ties may be connected with ordinary joints.
The railway area in streets of the Alster and Geesch marshes should be provided with concrete foundation 8 inches thick. In other marshy sections the concrete foundations shall be left out on account of the heavy sagging of the streets. The foundation concrete below the 8-inch rail height, where there is asphalt, wood or bridgestone pavement, is increased in depth to the extent to which the rail sets into the concrete, on a foundation base 14 inches wide and sloping at an angle of 45 degrees to the under side of the foundation concrete.
The expense of constructing the concrete foundation in the installation of new railroad lines is to be charged to the railroad company. In repaving streets which are provided with rails on a concrete foundation, the new concrete foundation is furnished by the city. According to an agreement made in 1904 the railroad company shall pay at the rate of about $0.24 for each meter of rail for reinforcing the concrete, made necessary through the change to rails 8 inches high. In case the usual stone block is replaced with those of greater depth, the premium to be paid by the railroad company will be increased to about $1.32 for each meter of rail. The rails are to be imbedded securely in the concrete to a height such as the paving stones allow. The concrete for the foundation is made by mixing one part cement with seven parts sand. Immediately below the rails a layer of 34 to 4 inches of concrete, made of 1 part cement to 3 parts sand, shall be used.
The pavement between the rails and the pavement 12 inches in width on either side of the tracks, maintained by the railroad company, is to be made of the same material as the rest of the street, except that the normal course-stone may be replaced by bridgestones. In case the street is paved with rough stones, a row of course-stone shall be used on each side of the rails.
For all stone pavements, special stones are used alongside of the rails. For rails 8 inches high, stones 64 inches high are in stock at the yard. For rails 6 inches high the stones shall be cut at the base in such a way that the base will not rest on the foot of the rail.
It is the duty of the railroad company to construct proper water drains for the rails in streets with a long grade at proper intervals. The cleaning of the drains is done by the street cleaning department.
The railroad company has to maintain the railroad area and has to take up all necessary work with the engineering staff and stand all costs of repair. The railroad company is not obliged to construct new pavements except if stated so in the charter.
16. Bicycle Paths
In streets of asphalt, wood and course-stone pavements, no special bicycle paths are provided.
In all streets with through traffic paved with rough split stones, a path of course-stone or slag blocks should be laid on both sides of the streets. In streets not paved throughout the whole width, a path of rolled slag and finished off with one row of old course-stone running along the gutter is sufficient. In exceptional cases, the paths running in both directions can be combined on one side. The construction of paths on sidewalks should be avoided if possible, so as not to occasion collisions with pedestrians.
The width of these paths shall be:
(a) On a roadway for one direction about 3 ft.
(b) On a roadway for two directions about 4 ft.
(c) On a sidewalk for one direction, including curbstone, about 34 ft.
The bicycle paths are usually constructed of a strip of slag blocks 24 times the width of the blocks and an edge of old course-stone. The gutter is included in the path. If no gutter exists, a strip of 44 blocks is used. The path is to be laid the same as the course-stone pavement on a silica sand cushion and the joints filled with an asphaltic filler.
The paths on the sidewalks are to be bound by clinkers and provided with signs.
17. The Laying of Sidewalks
For the construction of sidewalks, the earth should be removed to a depth of 4 inches. In that so constructed bed, the material consisting of 34-inch rough and 1⁄2-inch fine furnace slag, 1⁄2-inch earth cover and 1⁄2-inch gravel shall be placed. The material should be tamped and rolled in single layers and repeatedly watered. In general, the specifications for sidewalks shall be carried out.
The stone-plates shall be laid on a sand cushion 3 inches thick, according to the specifications.
Mosaic pavement adjoining the plates is laid only in interest to the watering of trees, and this pavement shall not be filled with mortar. The small stones of 3 inches in length are laid on top of a 3-inch sand layer, rammed, and a binder of sand is used.
Mosaic strips made of stones 14 inches long, used for walks in lawns and promenades, are laid on a 3-inch sand layer, rammed, and bound with a 1 to 8 mortar.
Hamburg, March 14, 1910.
SPERBER, Chief Engineer.
SPECIFICATIONS FOR PAVEMENT FILLING
1. The filler is handed out to the laborers. Laborers are forbidden to take any material on their own account. The amount used for course-stone pavement is about 18.3 lbs. per square yard.