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SPECIFICATION FOR LIGHT TRAFFIC

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Carriageway Excavate or fill in the ground, as the case may be, to the requisite level, and remove all surplus material; properly form and trim off the surface, and thoroughly consolidate the same, and then lay a foundation of hand-pitched rock, 10 inches in depth, set on edge in the manner of a rough pavement. Over this a coating of gravel is laid of sufficient thickness to fill in the interstices and to form a smooth surface to the foundation, which must be thoroughly consolidated by rolling with a steam roller before the paving is laid. The paving shall consist of 4 inch by 4 inch granite or syenite cubes, from North Wales, or other approved quarries, laid in regular, straight and properly-bonded courses, with close joints, and to be evenly bedded on a layer of fine gravel } inch in thickness. After the paving is laid the joints shall be filled with clean, hard, dry shingle; the sets shall then be thoroughly rammed and additional shingle added until the joints are perfectly full. The joints shall then be carefully grouted, until completely filled up, with a hot composition, consisting of coal pitch and creosote oil, and, finally, the paving shall be covered with 1 inch of sharp gravel.

The crossings, footways, channels and curbs shall be the same as specified for first-class streets. SPECIFICATION FOR WATER-BOUND MACADAM FOR RESIDENTIAL ROADS

Excavations After excavating the area of carriageway to a depth of 17 inches below the finished surface line, hand pitch the same with hard rock set on edge with the broadest side downwards, 10 inches deep, break off the irregular corners of the stones, and fill in the interstices of the pitching with these fragments as well as with similar rock, broken small. Consolidate the foundation thus formed by passing over it a steam roller until the whole is firm and compact.

Macadam When this is done spread over the surface evenly to a depth of 7 inches, broken screened macadam free from slaty or flat fragments. This macadam to be durable granite or trap rock from the quarries of North Wales, or from other approved quarries having similar class of rock. A layer of 23-inch gauge stones to a depth of 3} inches to be first spread and rolled until solid with a steam roller, then a layer of 2-inch gauge stones, to be finished level, consolidated in a similar manner. Where binding is necessary it should be sparingly used and must consist of granite chippings, preferably of the same rock as the macadam.

Channels Lay channel stones over the hand pitching on each side of the carriageway of granite or syenite, of a quality approved by the City Engineer, in length not less than 3 feet, in depth not less than 7 inches, in width 12 inches. The upper surface, if not natural faced and perfectly true, must be accurately worked out of winding, the bed as far as practicable parallel to the face, the sides and ends truly square, and the joints filled with clean shingle grouted with melted pitch and creosote oil.

Curbs Lay granite or syenite curb-stones of a similar quality to that specified for the channels, straight or circular as required, 5 inches thick at top, 6 inches thick at 5 inches below, and not less than that thickness for the remainder of the depth; to be not less than 12 inches deep, nor less than 3 feet in length; to be carefully dressed on top, 8 inches down the face and 3 inches down the back; the remainder to be hammer-dressed, the heading joints to be squared throughout the entire depth.

Footways Pave the footways with “Best Barns” Lancashire flags or Yorkshire flags of the best quality, not less than 3 inches thick, 2 feet in width, not less than 6 feet superficial area in each flag, which must be solid, free from laminations, windings and hollows on the surface; the joints to be squared the full thickness; the flags to be truly laid on a bed of fine gravel, with close joints flushed with hydraulic lime mortar and in uniform courses, breaking bond; the surface to be flogged off after laying where necessary, but great care to be exercised in bedding the flags, so as to prevent the necessity for the after flogging. Natural asphalte upon concrete, granolithic or other artificial paving may be laid in substitution of flags at the discretion of the City Engineer, and in accordance with his discretion in each case.

Crossings Lay crossings, where required, consisting of three rows of 16 x 8 inch granite of a quality approved by the City Engineer, and in lengths not less than 3 feet, dressed true and out of winding on the face, the sides and joints square and accurately dressed throughout their entire depth; the joints to be filled with clean shingle and grouted with pitch and creosote oil; a V-groove 1 inch wide and inch deep to be cut along the surface of each stone.

SPECIFICATION FOR PITCH MACADAM

Upon a hand-pitched foundation, laid and consolidated in accordance with the Fourth Class Specification (for water-bound macadam) a layer of dry macadam of 24 inch gauge stones, similar in quality to that used for water-bound macadam, shall be spread evenly to a depth of about 3inches (before consolidation). This layer after being rolled with a light steam roller, shall be grouted with a hot mixture of pitch and creosote oil prepared in accordance with the specification below and again rolled while hot until the mass is thoroughly consolidated. A second layer of similar macadam, of 14 inch gauge stone, 3 inches deep, shall then be laid, preferably while the lower layer is still hot. After being rolled dry it shall be grouted in a similar manner with the pitch mixture, and again rolled until the whole is consolidated. The surface shall be finished off with a sprinkling of dry granite chippings. The road shall be laid to an approximate circular camber, with a crossfall from crown to channel of 1 in 48.

SPECIFICATION FOR PITCH GROUTING

The pitch mixture used for grouting shall consist of coal-tar pitch and creosote oil supplied to the specifications given below, and boiled together in a tank in the proportions of approximately 70 gallons of oil to 1 ton of pitch, a temperature of from 250 degrees to 300 degrees F. being attained. The proper consistency shall be obtained by applying the following rough tests:

A small sample of the mixture when cooled in water to 60 degrees F. shall stretch at least three feet without breaking, the threads pulling out very fine. It shall also when doubled into length of about 1 foot bear hitting hard on a hard surface without showing any sign of cracking. After leaving the boiler and immediately before being put on the road, an equal quantity of fine shore sand heated to 400 degrees F. shall be added to the pitch mixture which shall then be kept continually stirred until spread.

SPECIFICATION FOR MATERIALS

Macadam The macadam shall be of durable granite or trap rock from the quarries of North Wales or from other approved quarries having a similar class of rock. It shall be carefully broken into cubical form so as to be capable of passing through the specified gauge in any direction. It shall be cleanly riddled to free it from dust, and all flat, slaty fragments shall be picked out before shipment.

“2}-inch macadam” shall pass through a 24-inch ring and be held by a 2-inch ring.”

“1}-inch macadam shall pass through a 11-inch ring and be held by a 1-inch ring.”

Special Coal-Tar Pitch 1. The pitch shall yield no matter volatile below 270 degrees C. when subjected to dry distillation, and its total volatile organic matter shall not fall below 30 per cent.

2. It shall not contain more than 80 per cent. of its weight of matter insoluble in petroleum spirit of 0.700 specific gravity (boiling) and must be free from extraneous matter, such as sand and grit.

3. It must twist fairly after immersion for two minutes in water at 60 degrees C., but not under 55 degrees C.

Special Creosote Oil 1. The oil supplied shall be obtained exclusively by the distillation of coal-tar, and shall not contain any portion of the distillate obtained below 240 degrees C. None of it shall re-distill below 240 degrees C.

2. The oil as obtained by distillation of coal-tar shall not be treated in any way, either by the addition of any coal-tar product, or by the extraction of any of its constituents, excepting such extraction as may be necessary to comply with clause 3. It shall contain no moisture.

3. It shall contain no solid matter at 15 degrees C. and shall have a specific gravity of not less than 1.075 (taking water as 1.00 at 15 degrees C.).

4. It shall contain not less than 40 per cent. of its constituents that do not distill over below 320 degrees C. and the 60 per cent. which does not distill over below 320 degrees C. shall contain 10 per cent. of tar-acids, to be extracted by soda, specific gravity 1.125 (water 1.00).

SPECIFICATIONS FOR WOOD PAVING

The foundation shall consist of a concrete bed as in the case of set-paved streets, but the surface shall be carefully smoothed to the exact contour, which shall be approximately circular in section with a crossfall from crown to channel of 1 in 48.

The pavement shall consist of blocks of Baltic, Swedish or Canadian Red Pine, thoroughly seasoned, sound throughout and free from sap, shakes, waney edges or large knots. They shall be 9 inches long by 3 inches wide, by 5 inches deep, the depth and width to be absolutely accurate. They shall be impregnated with creosote oil of approved quality to the extent of not less than 8 pounds per cubic foot of timber. They shall be laid on the concrete bed without any intervening layer, in regular, straight and properly-bonded courses with close joints. The channels shall be formed of longitudinal courses of blocks, which shall be hand-dipped end and side in a hot mixture of pitch and creosote oil, and an expansion joint 2 inches wide shall be formed along the curb, and filled with a properly tempered mixture of pitch and creosote oil, or other approved material. The joints of the pavement shall be grouted first with a hot composition of pitch and creosote oil and afterwards with a grouting of cement and sharp sand, and finally covered off with small pea gravel.

SPECIFICATION FOR BACK OR SECONDARY STREETS 9 FEET WIDE OR UPWARDS

Exca tion and foundatio After excavating the area of carriageway to a depth of 17 inches below the finished surface line, hand-pitch the same with hard rock set on edge with the broadest sides downward, 10 inches deep, break off the irregular corners of the stones, and fill in the interstices of the pitching with these fragments as well as with similar rock broken small. Consolidate the foundation thus formed by passing over it a steam roller until the whole is firm and compact.

Paving The paving shall consist of sets of Haslingden grit stone of the best quality, uniformly gauged to a depth of 6 inches, laid in courses 6 inches wide, with a fall towards the centre of 1 in 48. Two courses to be laid longitudinally to form a channel. After the paving is laid, the joints shall be filled with hard, clean, dry shingle; the sets shall then be thoroughly rammed and additional shingle added until the joints are perfectly full. The joints shall then be carefully grouted until completely filled with a hot composition consisting of coal pitch and creosote oil, and, finally, the paving is to be covered with } inch of sharp gravel. Municipal Offices,

Liverpool, September, 1912.

DESCRIPTION OF PENMAENMAWR STONE

(For Street Pavements.)

CHEMICAL ANALYSIS
Silica...
Titanic acid.
Alumina.
Ferrous oxide.
Ferric oxide.
Lime ..
Magnesia.
Potash..
Soda..
Combined water and loss.

56.12

0.71 18,28 2.56 4.57 6.88 4.40 0.70 3.07 2.71

100.00 MINERALOGICAL COMPOSITION (See Proc. Royal Dublin Soc., Vol. X., Part 1, No. 5 and Quarterly Journal Geological

Society, Vol. XXXIII., 1877.) The dominant type of rock is a quartz bronzite or enstatite diabase. It has also been described as an exstatite diorite. In an average sample examined under the microscope "the colored constituents are a very pale brown angite in a fresh condition and a fibrous rhombic pyroxene, probably an enstatite rich in iron. A little biotite is also occasionally present in irregular plates. An opaque black ore, probably magnetite, is present in scattered crystals. The rest of the field is occupied by feldspar and quartz. These hard constituents compose some 70 per cent. of the rock. The feldspars are columnar and lath-shaped, making up an almost continuous field of crystals orientated in every direction. The chief feature of the rock is the uniform distribution and fine state of sub-division of the various constituents, and this accounts for the exceptional durability of the rock under wear." Specific gravity...

2.74 to 2.8

STRENGTH

Crushing Test Dimensions of sample 3 inches x 3 inches x 3 inches. Total crushing stress (on a base of 9 square inches) 476,800 pounds equals 3,406 tons

per square foot.

Attrition Test. (Mr. Lovegrove's experiments.)
Percentage of loss in dust-dry, 3.12; wet, 4.78.
Percentage of chippings. Nil.
The stone was tested as follows:

“A sample weighing 4 pounds and consisting of about 16 stones broken to a 2-inch gauge was placed in a hollow cast-iron cylinder 11 inches in internal diameter and having three 1 inch x 1 inch angle iron ribs bolted lengthwise inside at equal distances apart and parallel to the axis of rotation. The cylinder was rotated at a speed of 20 revolutions per minute for 400 minutes.

For the wet test half a gallon of water was added. In each case the stones, chippings and dust were weighed dry before and after the test.

(See Lovegrove's "Attrition Tests of Roadmaking Stones”; also "Surveyor," Nov. 10th, 1905; and also "Surveyor,” April 15th, 1910, for Mr. Page's tests for water absorption, hardness, toughness and cementing value.)

CITY OF LIVERPOOL GENERAL CONDITIONS AND SPECIFICATIONS TO ACCOMPANY TENDER FOR PAVING SETS

(1) The accompanying Schedule is to be filled up with the total quantities and rate per month of Sets guaranteed for delivery in Liverpool, from the 1st day of April, 1913, to the 31st day of March, 1914, and delivered in accordance with the instructions.

(2) The Sets to be supplied shall be equal in quality as regards toughness and rate of wear under traffic to the samples submitted by the Contractor, and they shall be properly squared. The Sets shall be accurately gauged, and this will be tested by calliper, as is customary in the City Engineer's Department, previous to accepting delivery. The maximum deviation from the specified size of the Sets shall be a 4 inch in depth and breadth respectively. Sets where there is a difference of more than a 1 of an inch between the broad and thin ends will not be accepted.

(2a) Where Sets are ordered to be specially dressed, they shall be equal in quality as regards toughness and rate of wear under traffic to the samples submitted by the Contractor, and they shall be properly squared. The Sets shall be accurately gauged, and this will be tested by calliper, as is customary in the City Engineer's Department, previous to accepting delivery. The deviation from the specified breadth of the Sets in any one cargo shall not exceed a { of an inch between the largest and the smallest Set in that cargo. The depth must not deviate more than } of an inch from the specified size.

(3) The Sets to be supplied under this Specification and Tender must be delivered promptly by the Contractor, on the order of the City Engineer, at the places named in the Schedule, in such quantities, and at such times as shall be stated in the said order.

(4) This Contract shall last for twelve months; but should the supply of materials, according to any order given before the expiration of that time be then incomplete, the Contractor shall still be responsible, and, if the Corporation think fit, shall fully complete such order in compliance with the terms of this Specification.

(5) The Contractor shall furnish to the City Engineer, upon the despatch of each cargo of Sets, an advice note, specifying the quantity, sizes, full description and price of the same, together with the number of the City Engineer's printed order. Under no circumstances will delivery be accepted unless this condition be complied with, and then only for a quantity not exceeding that specified in the official order.

(6) The Contractor shall forward his account to the City Engineer, within one week from date of delivery of each cargo of Sets, accompanied by weighing machine vouchers, duly signed, and setting forth the cart No. and cart owner's name.

(7) Should the Contractor fail to supply any Sets within the time named in the order, or to carry out this Contract to the satisfaction of the City Engineer, and according to the Terms of this Tender and Specification, the Corporation shall be at liberty to order such material from any other person or persons, and may deduct the cost thereof, with any other expenses incurred, from any money that may be or may become due to the Contractor.

(8) Payment shall be made on the certificate of the City Engineer, and within three weeks from the date thereof, for the value of all materials received and approved, provided the requirements of the Department as to advice and weight notes have been complied with; but the City Engineer reserves the right to withhold his certificate should circumstances arise which, in his opinion, would justify such a course. The Contractor to execute an agreement (if called upon to do so) for the due performance and fulfilment of the conditions expressed or implied herein. Until the execution of the said agreement, of which a copy may be seen at the Town Clerk's Office, this Specification and Tender, with the acceptance thereof by the Council, shall be the contract between the parties.

(9) In case Sets from any cargo are found not to fulfil these conditions, or in the City Engineer's opinion to be otherwise defective, the City Engineer shall be empowered to reject the whole of that cargo.

(10) The Sets shall be weighed over a public licensed weighing machine, and if so required, over the nearest available Corporation public licensed weighing machine, the cost of the same to be paid by the Contractor.

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