(11) As the Corporation may elect, the person whose tender is accepted will be required to either provide approved sureties for the due performance of this Contract, or to deposit an amount to be assessed by the Corporation, and no interest will be allowed on such deposit.

(12) The Contractor shall not assign or sub-let this Contract, or any benefit or interest thereunder, or make any sub-contract with any other person or persons without the consent in writing of the Corporation.

(13) If any disputes or differences arise during the continuance of this Contract, or afterwards, respecting the true intent of this Specification, the same shall be referred to the City Engineer, whose decision shall be final and binding upon all parties concerned. (14) The Corporation do not bind themselves to accept the lowest or any tender, or to defray any expenses in connection with tendering.

(15) The Corporation do not bind themselves to receive the quantities set forth in this Tender as their probable requirements, but reserve to themselves the right to order such quantities as they may from time to time require, whether the same shall be more or less than the quantities stated, and to accept the tender of any Contractor for any portion of the quantities set forth in this Tender.

(16) The Contractor shall, if so required, also supply other Departments of the Corporation on the official Order of the Head of a Department, with any of the Articles enumerated, at the prices affixed thereto, and on the above conditions; in which case the words "City Engineer" shall be held to refer to the Head of such Department. JOHN A. BRODIE, M. Inst. C. E.,

Municipal Offices,
Liverpool.

City Engineer.

CORPORATION OF BIRMINGHAM, ENGLAND

City Surveyor's Office

SPECIFICATION

Of Materials to be supplied and Works to be performed in laying and maintaining certain Wood and Granite Pavements in Pickford Street, Berkley Street, Holt Street, Sampson Road North, Lionel Street, Barford Street and Heath Mill Lane, as shown upon the Contract Drawings, or upon any further Drawings that may be supplied or approved by the City Surveyor.

Scope of Contract

1. The Contract comprises excavation of macadam roads to such depths as may be required, and the carting away of all materials excavated to tips to be provided by the Contractor, and carting of old paving setts to Corporation Depots; the laying of Portland cement foundations and the floating or rendering of same where wood pavement is to be laid; the loading up and carting of the granite setts and wood blocks (which will be provided by the Corporation) and laying of same, grouting, covering up and all matters incidental to the completion of the pavements; readjusting the levels of manhole and lamp-hole covers, gullies, gas and water boxes and other obstructions in the street services (but not kerb-stones and channel stones, which will be laid or adjusted by the Corporation), the safe maintenance of the vehicular and pedestrian traffic and the provision of access to premises and streets affected. It also includes the maintenance of the whole of the works for a period of six months after completion and other matters referred to in the General Conditions.

Storing Materials

2. The Corporation will give every facility to the Contractor in carrying out the work, but it is distinctly understood that the streets must not be used as a store-yard for material, and only such quantities will be allowed in the streets as are required for the immediate carrying on of the work.

Matters of Urgency

3. In the event of accident or any other occurrence which requires immediate repair and attention taking place when the Contractor is not on the spot to execute, or if he neglects or refuses to execute, the necessary works, the Corporation may proceed immediately (without giving further notice to the Contractor) to make the necessary repairs or give the necessary attention by themselves or their servants, and shall be at liberty to recover the cost of such works from the Contractor.

Maintenance

4. The Contractor, notwithstanding any act, matter or thing done, permitted or suffered in pursuance of the use of the works or during the continuance of such use shall be responsible for and at its expense effectually maintain and uphold in good, substantial, sound, perfect and usable condition, all and every part of the works; including where wood pavement is laid, the expansion joint alongside the kerb and the kerb at the right height and in alignment, for a period of six calendar months after the works referred to in any order to commence that may have been given and shall have been completed to the satisfaction of the City Surveyor; and he shall be liable for and shall pay and make good to the Corporation or other person or parties (being legally entitled thereto) all losses, damages, costs and expenses they or any of them may be liable to by reason or in consequence of the operations or the failure of the works during the time the Contractor is responsible therefor, and shall keep the Corporation indemnified from all actions, suits, claims and demands whatsoever by reason or on account thereof, and the Corporation may deduct the amount of such losses, damages, costs or expenses from any moneys due to the Contractor.

Portland Cement

5. The whole of the cement shall be the very best quality Portland cement. When freshly burnt and ground it shall have a specific gravity (as determined in a Keate's bottle or Mann's gravimeter) not less than 3.12, such test being made upon a cool sample.

The cement must be made entirely from well-burnt clinker, and ground to such a degree of fineness that the whole will pass through a sieve made from wire 0.007 inch in diameter, having 2,500 meshes per square inch. Samples taken from the bulk and tested on the Corporation's "Goreham Flourometer," working under a pressure about equal to that of 1.7 inch of water, shall show a result of not less than 45 per cent. of flour.

The cement shall be reliable, sound and cool; pats of neat cement gauged with the minimum, but not exceeding 25 per cent. of water, shall be subjected to the following tests, to be made by the City Surveyor:

(a) Two pats of a circular shape, with thin edges, mixed neat on glass, one of which is placed immediately under water and one in the air, shall show no signs of "blowing," cracks, tendency to curl off the glass or any other signs of unsoundness.

(b) A pat of neat cement shall be kept in moist air for 24 hours, then immersed in cool water and raised slowly to boiling heat, and being maintained at this temperature for three hours it shall show no signs of warping or radical cracking, or any other signs of unsoundness.

(c) A pat placed on glass shall not commence to set before the lapse of eight minutes from the time of mixing, or take longer than two hours to set hard. And in no case shall the pat bear the weight of a "needle" (having a 1/16 inch square point and a weight of 21⁄2 pounds) in less than one hour.

(d) Briquettes made of neat cement, mixed with not more than 25 per cent. by weight of water, and placed under water 24 hours after gauging, shall resist without breaking an average tensile strain of not less than 250 pounds to the square inch at the expiration of three days from gauging; those tested at the expiration of seven days from gauging to show an increase of at least 33 per cent. over the strength of those tested at three days, but to carry a minimum strain equal to 400 pounds to the square inch; and those tested at the expiration of 14 days from gauging shall show a tensile strength of 500 pounds to the square inch before breaking.

(e) The cement, when tested with sand in the proportion of three parts by weight of dry standard Leighton Buzzard sand to one part of cement, treated as above, shall carry an average tensile strain of not less than 100 pounds per square inch after seven days, 150 pounds after fourteen days and 225 pounds after 28 days from the time of gauging. Increase of test at 28 days to exceed test at seven days by not less than 20 per cent. All briquettes to be made in moulds and tested in a machine approved by the City Surveyor. The strain is to be applied in all cases at the rate of 400 pounds per minute.

The results of these tests to be conclusive, and any cement not passing any or all of such tests will be rejected, and must be removed at once by the Contractor on receipt of notice so to do.

Adulteration

Either the Contractor, the Managing Director or the Manager of the Works supplying the cement, or all these persons, shall make a statutory declaration that the cement supplied for use on the works is free from any admixture of underburnt clinker, Kentish rag, slag, gypsum or any other adulterant whatever.

Cement to be in Store Twenty-one days

6. The Contractor shall provide one or more dry weather-proof sheds or bins capable of being closed under seal on or near the works. All the cement brought on the works shall first be deposited, in bulk or in bags as the City Surveyor may direct, in one or other of the sheds. The sample for testing shall then be taken and the shed or bin sealed up in the presence of the City Surveyor or his representative. The seal shall not be broken until the Contractor has been informed that the cement has passed the tests specified, and then only after at least 21 days have elapsed from the time of depositing the cement in the shed or bin; and in the presence of the City Surveyor or his representative.

Ballast

7. The ballast for the concrete to be clean, non-porous blast furnace slag, broken to such a size as to pass through a 2-inch ring in all directions, and shall be retained on a -inch screen, and shall have such an admixture of sand therewith as shall be sufficient to fill up the interstices of the stones.

Sand

8. The sand used upon the works (except that for the bedding and covering up of the granite paving, which shall be approved clean local sand) shall be sharp and clean, and equal in quality to that obtained from Leighton Buzzard, and to the sample in the City Surveyor's office, and shall be washed before using.

Granite Chippings

9. All granite chippings shall be clean broken stone from the Hartshill Quarries; that for top dressing the wood paving blocks to be 3-inch, free from dust. The granite chippings for the rendering shall be of such sizes as to pass through a 1-inch mesh, shall be washed and free from dust, but shall contain the coarse grit. All chippings used with cement shall be washed until a sample shaken up with water in a test tube shows no signs of clay, nor any appreciable matter that does not quickly settle.

Excavation, Etc.

10. Excavate to the depths shown upon the drawings below the intended upper surface of the wood or granite paving, etc., and grade the bottom to correspond with the finished surface of the roadway. Cart all gutter stones and setts around manholes, etc., to the Corporation depots at Holliday Street or Lancaster Street, or other depot, as may be directed, and cart away all other materials excavated or removed to tips to be provided by the Contractor. Should an error be made in excavating below the required depths, the Contractor will not be allowed to fill in with excavated material, but must fill up with

concrete at his own cost. If, in the opinion of the City Surveyor, it is necessary to excavate to a greater depth than that shown on the Drawings, and to put in extra concrete, such work shall be dealt with as a variation from the Contract. Whenever necessary, the bottom of the excavation shall be watered and thoroughly punned or rolled, and every precaution taken to ensure that it is thoroughly consolidated before the concrete is laid.

Raise or lower the various manhole covers, boxes, gratings, etc., to the heights required for the finished pavements.

Concrete

11. The 7 to 1 concrete shall be composed of one part of Portland cement to seven parts of clean ballast, and the necessary amount of sand, as described in Clause 32, to fill all interstices.

(NOTE.-Three cwts. of Portland cement shall be used to each cube yard of aggregate.)

Mixing Concrete

The cement and ballast to be well turned over and intermixed at least three times dry, the water in minimum quantity to be added through the rose of a watering can, and the materials then thoroughly turned over again three times. The concrete to be put in in layers, and well rammed and consolidated, and levelled to a true surface of a uniform thickness of 7 inches throughout, and where required to screeds, which the Contractor shall provide and set in the concrete to the true curvature of the finished paving surface; where wood paving is to be laid, the surface of the concrete, however, is to be 14 inch below the top of the screeds, in order to allow for the floating or rendering. All materials for concrete or floating shall be measured in proper gauge boxes, and the mixing carried out on stages and bankers as may be directed.

There shall always be at least two men employed in ramming the concrete to every man employed in shovelling off the bankers. The concrete shall be set before the rendering is put in. The Contractor shall remove any concrete or rendering that may be damaged by frost or heavy rains, and replace the same with freshly made concrete or rendering as the case may be, and shall cover up the work whenever necessary to protect it from the weather. No concrete or rendering under any circumstances is to be mixed during frosty weather.

Rendering and Floating

12. After the concrete has been laid to the correct levels and to the curvature shown on the Drawing, and has sufficiently set, in the case of wood paving, it shall be rendered over to a depth of 14 inch with rendering and floated, and set with a steel trowel to a fine surface to the screed fixed to the curvature shown on the Drawing; the screeds to be subsequently removed when the rendering is hard, and the cavities caused by their removal to be neatly filled in and finished off with the steel trowel to a fine surface. The surface of the rendering to be thoroughly beaten up, so that the superfluous water is worked out, and the rendering freed from air. The rendering to be composed of two parts of Portland cement to five parts of the Hartshill granite chippings, well turned over and intermixed three times dry and three times after the water has been added. It shall be mixed in small quantities, and with as little water added through the rose of a watering can, as will enable it to be efficiently used. The Hartshill granite chippings for the rendering shall be of such size as to pass through a 4-inch mesh, shall be washed and free from dust, but shall contain the coarse grit.

Carting Setts and Paving Blocks

13. The wood blocks and granite setts will be provided by the Corporation and delivered to the Contractor at the Corporation Wharves in Lancaster Street or Holliday Street; or at some other wharf or depot whose distance from the work does not exceed a distance of 1 miles from the works where they are to be used. The blocks or setts shall be loaded up by the Contractor, carted to the site and stacked alongside the carriageway as required for laying. From the delivery at the wharf or depot, they will be in the custody of the Contractor, and he will be held responsible for any that may be lost, stolen or damaged.

Granite Paving

14. The granite paving will be 4 inches and 5 inches deep, to be laid with a cross-fall of 1 in 45 from crown of road to channel, and in straight diagonal courses, meeting in the centre at an angle of 90 degrees, with the apex pointing downhill, and at an angle of 45 degrees with the channel where the kerbs are parallel. The sett at each end of the diagonal courses to be not less than 6 inches long, and cut to an angle to suit the longitudinal course. Before heading up for the paviors to lay, the setts shall be properly gauged by experienced men and laid in batches, those of similar and uniform width and depth being kept together. They shall be laid in courses of uniform width, with the closest possible joints not exceeding inch in width, all heading joints being square with line of the course.

Provide for cutting setts for splayed courses next channel out of 4 inch by 5 inch setts not less than 6 inches long, to be provided by the Corporation for this purpose.

The setts shall be laid upon a bedding of approved clean local sand of a thickness not exceeding 1 inch. This bedding to be damped with a spray of water immediately in front of the paviors.

The paving to be well rammed and back rammed, and grouted with Portland cement grout, consisting of 5 parts of Leighton Buzzard sand to 2 parts of cement; the grout to be well swept into all the joints, and to finish flush with the top of the the setts. The finished paving is to form a regular smooth surface throughout. The paving so completed shall be protected from street traffic, and immediately before it is opened for traffic as provided in Clause 17, it shall be well covered with a layer of clean sand.

No granite shall be laid until the concrete has been laid ten days, or such longer period as may be required to ensure it being thoroughly set.

Wood Paving

15. The wood blocks will be prismatic oak, 4 inches deep, to be laid in straight and regular courses, separated by creosoted strips 1/10 inch thick, which will be provided by the Corporation, properly bonded, and in close contact with each other, no closer to be less than 3 inches in length. The grain to be vertical, and the blocks to be laid in courses, square transversely with the line of road, with the exception of three courses which are to form the channel on each side of the road, and which will run longitudinally. These longitudinal courses will not be laid with strips.

In laying the channel courses, one side and one end of each block shall be dipped (to within about inch of the bottom) into a vessel containing a boiling mixture of pitch and creosote oil, immediately before they are laid. The blocks in the body of the road will not be dipped before laying.

Form an expansion joint, 1 inch wide on each side of the road, alongside the kerb. During the laying of the paving this joint is to be kept open by battens the full depth of the blocks and the stipulated width of the joints. After the paving is laid (or partially laid, as directed) these battens to be removed, and the joint run in to a depth of 1 inch with boiling pitch grout; the remaining depth of the joint to be filled with puddled clay.

Provide for maintenance of this expansion joint and taking up and relaying of longitudinal courses and trimming ends of transverse courses, and of making good expansion joint with pitch and clay in manner specified in the event of expansion taking place in wood pavement.

When about 10 yards of the paving has been laid, all joints to be flushed up solid to the top of the blocks with a boiling mixture of best medium soft pitch and creosote oil in such proportions as to give a firm but ductile mixture.

Time for Floating to Set Before Paving

In no case must wood blocks be laid when either they or the floating are wet or dirty. The floating must have set hard, and to ensure this an interval of at least one week must elapse between the laying of the floating and the block laying.