Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/343

 APRIL 19, 1872. and American bridges, and compared the cost and methods of building bridges in the two countries. It isnow generally acknowledged that the “truss” is the form which admits of the greatest economy in the use of material; and yet there are some engineers who cling tenaciously to the old plate or box girder. A few years since an engineer of wide reputation and large experience condemned a truss bridge, giving as a reason that the peculiar construction would cause the iron to crystallise from the trotting of horses over it. ‘The bridge was consequently built as a plate girder, and the cost was more than fifty per cent. greater than it would have been for a truss bridge. The days of tubulars, girders, etc., have substan- tially passed away ; there will be no more Britannia or Victoria bridges ; they stand as vast monuments of indomitable will and energy. -All honour is due to Stephenson for building the bridge over the Menai Straits; considering the then limited knowledge of the use of iron in bridge building, it is a monument worthy to make his name famous for ages to come. Brunel has done eyen more; the Saltash is a con- ception more gigantic, and as much a flight of genius —a work which will remain when the other is de- stroyed by time. Truss and lattice bridges now predominate, the latter being but a form of the first. The bridges of Europe are secured together by al- most innumerable rivets; the various parts being usually composed of plate and angle iron riveted into box and other forms best calculated to resist the storms to which they may be subjected. The building of parts in this manner requires much care and is very expensive. The rivet holes deduct a considerable amount from the strength without re- ducing the weight. A strut or tie composed of several pieces riveted together has not an effective strength proportioned to its section, for it is impossible to bring the dif- ferent pieces to an equal strain at the same time. The engineer has here to make an allowance which isa very variable quantity. The ties and struts are rigidly connected with the chords. Whenever a load comes upon a bridge, there must be some deflection ; this causes a distortion of the form of each panel, and as the ties and struts are rigidly connected to the upper and lower members, a powerful leverage to bend them is the result, and there isat the same time an increased strain upon the rivets. In the crossing of arailway train or other partial load, the counters, necessarily, not being in readiness to receive their proper strains at the proper moment, allow an undulation which materially increases the bending strains upon the tiesand struts. This occurs every time a train or locomotive crosses the bridge. The trusses used in American and European bridges are very similar, the essential difference being in details of construction, which in the European bridge are very expensive, as so much hand labour and fitting is required. A large amount of material is used which is mere dead weight, being of no use in sustaining theload or itself. The action of sucha bridge is necessarily unsatisfactory from the fact that certain portions receive strains in practice which are not legitimate, and consequently must tend to shorten its life. The following data were collected in Europe by Mr. Dayid Busk. The viaduct of Fribourg, on the Orleans railroad in France, is composed of eizht spans of 160ft each, and has a height of 250ft. above mean low water of the Sarine. The piers haye a masonry foundation 89ft. high, with a metallic superstructure of 142ft. The total length of the viaduct is 1299-88ft. and cost, above the masonry, 366,000 dollars in gold, or 282 dollars per lineal foot. ‘The figures for three other viaducts on the Orleans railroad are as follows :— THE VIADUCT OF THE BOUBLE. 6 spans of 164ft. each, total length...... 984 ft. Height above masonry, average .. 138-76ft. Gastspenlaneal foot js.o.+.casse-c--<--cccene 167dols, THE VIADUCT OF BELLOU. 3 spans, average length 140ft., total...... 420ft. Height above masonry ........0ccsse0e---6 137°76ft. Cost per litteal F60b)) Ss..scec..cc-eccessece. 128dols. THE VIADUCT OF NEUVILLE. 2 spans of 161-13ft. each, totallength.., 322°26ft. Height above masonry ...........06. eeacae 136°18ft. Cost per lineal foot ..... 112dols. MUS Aineesdccvec es eacmecseetese Ke 7708ft. Cost per lineal foot.............00. ee. 108dols. The American Truss Bridge, instead of being bound together is one solid mass, is composed of various members, each independent of its neighbour, so far jour. THE BUILDING NEWS. cation, well illustrated by photographs projected | as its own work is concerned, each having a specific upon ascreen by the calcium light, on European | and defined duty to perform, and proportioned ac- cordingly. By no change of temperature, or variety of load in amount or position, can any but legitimate strains be imposed upon-any part. The joints are made with pin connections, so that a deflection can bring no twisting or bending strain upon any of the parts—and though the form of each panel be very much distorted by an approximation to the breaking load, no excess over the proper strain can be brought to bear on the bridge. Each part is known to receive its proper strain at the proper time, as they are made adjustable in all directions, and by this means the vibration and undulation are reduced to a minimum. American bridges have astonished the world that such light structures should haye so little deflection and undulation. American bridges are cheap to build. Most of the work is done by machinery instead of hand labour, and but little skilled labour is required. Work done by machinery does not cost one half as much per pound as work done by hand. Consider- able expense is also saved in handling and erection. It is sometimes necessary to erect bridges over streams which are liable to rise suddenly and sweep away the temporary works. In such a case, the loss would be incalculable in time and money, if the bridge should be carried away. Our bridges—built as they are in parts which are seldom too heavy for two or three men to handle— can be erected in a very short time. A 200ft. span could be swung clear of the staging in three or four days, while the plate girder, lattice, or European truss would require as many weeks. The average cost of railroad bridges in America is about one half as much in currency as European bridges cost in gold. —_—____ COMPETITIONS. ABERYSTWyTH ScHoot Boarp.—The following architects were a short time ago invited to send compe- titive designs for the new schools at Aberystwyth, providing accommodation for 600 children. Mr. J. P. Seddon, London; Messrs. George Jones & Son, Aberystwyth; Mr. R. Owens, Liverpool; Mr. Sher- win, Manchester; and Messrs. Szlumper & Ald- winckle, 11, Philpot-lane, London, E.C. The Board have selected the designs submitted by the last named gentlemen, and the buildings will be com- menced at once. Derwseury.—On Tuesday evening the Dewsbury School Board met to consider a recommendation made by a special committee to examine the plans sent in by competing architects for the three School Board schools intended to be erected at Dewsbury Moor, Boothroyd, and Springfield. The committee recom- mended three, under the mottoes respectively of “Knowledge is power,” ‘Ad valorem,” and “En plein ” This recommendation was unanimously ac- cepted, and on the accompanying envelopes being opened it was found that they were from Messrs, Holtom & Connon, architects, of Dewsbury.
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CHIPS. Two elections to the Metropolitan Board of Works took place last week—viz., one for the Limehouse district, in place of Mr. Dixon, resigned, and one for the Shoreditch district, in place of Mr. Dodd, re- signed. Mr. Rooke was elected for Shoreditch and Mr. Nathan for Limehouse. The Thames Embankment Bill is not to be read a second time before the 7th of May. A new Church of England School, to accommo- date 135 boys and infants, was opened at Stalbridge, Dorsetshire, on the 5th inst. The school has been built Mr. Lionel Parsons, of Stalbridge (who also furnished the plans), the amount of the contract being £501. The material used is native stone, with Doult- ing stone dressings. On Friday, the 26th inst., Robert Stansfeld, Esq., the Goyernment inspector, will, by direction of the Local Government Board, hold another inquiry at the Ryde Town Hall as to the propriety of the pro- posed alterations of the Ryde (Isle of Wight) Im- provement Act, and of the purchase of the gasworks, On the evening of Wednesday week the streets of Manchester were without lamp-light up to eight o'clock, owing to a strike of the lamplighters for in- crease of wages. The difficulty was arranged, and most of the lights were lit by nine o’clock. The chimney of a mill at Brunswick, in Maine, has been moved 20ft., to allow of enlargement of the mill. The chimney was 70ft. high, and nearly &ft. Square atthe base, and it was put upon greased planks and made to slide to the proper place, where it was got to work in eight hours. On Saturday, the 13th inst., the memorial stone of a Wesleyan School Chapel was laid in Bolton. Mr. Thomas Ormerod is the architect. 323 DHuilding Intelligence, —— CHURCHES AND CHAPELS. ArnsTabLe.—The rebuilding of the church at Ainstable is completed. The architect was Mr. G. Watson, of Penrith, and the style adopted by him is Early English. There is a tower 64ft. in height, the lower stage of which forms an open porch. The roof is open-timbered, ceiled to the diagonals above the rafters. The chancel is completely fitted with oak, left unstained, and simply rubbed with oil. A short south transept forms an organ-cham- ber, and affords accommodation for school children. There is accommodation provided for 211 persons, and the cost has been about £1,400. AmersiAm.—The restoration of the parish Church of §. Mary, Amersham, is completed. A new chancel aisle has been added, The church is supposed to be built on a Norman foundation, as fragments of late Norman work have been found, The style of architecture is of the Perpendicular character ; the greater part is fourteenth century work, but the piers, arches, &c., date from a period a cen- tury earlier. The east window has been raised nearly 4ft. and deepened about 2ft., and the floor of the sanctuary has been raised about 18in. The chancel arch and roof haye been raised, and the plaster ceiling replaced by a wooden groined roof. The organ has been remoyed from the old west gallery, and placed in the chancel aisle, and the choir are seated in the chancel, All the galleries have been taken away, and the plaster removed from the roof of nave, transepts, and aisles; the old prin- cipals are left, and the ancient boarding under the rafters shown; the decayed corbels have been renewed and carved. Two stilted arches of peculiar shape were accidentally discovered and opened out. Mr. I. Preedy, of London, was the architect, and Mr. Cooper, of Aylesbury, the contractor. HoyxsnAy.—On the 5th inst., a new mission chapel at Hinkshay was opened. Tite building is Early English in style, the materials used being red brick, with blue brick bands and dressings of Grins- hillstone. The plan consistsof anave 35ft. by 20ft., affording accommodation for about 130 persons. The north and south fronts are divided by buttresses into three bays, each bay having a two-light window with arched stone heads. Theentrance porch is on the north side, and the west gable is surmounted by a bell-turret. All the internal fittings are of deal, varnished. The roof is ceiled at a level with the purlins. The design is by Mr. S. Bidlake, architect, of Wolverhampton, under whose superin- tendence the work has been carried out by the con- tractor, Mr. Rushton, of Dawley. INCORPORATED Socrery ror PRoMOTING THE ENLARGEMENT, BuImLpING, AND REPAIRING OF CuuRcHES AND CHApELS.—This society held its usual monthly meeting on Monday at the society’s house, 7, Whitehall. Grants of money were made in aid of the following objects—yviz., building a new church at Gateshead S$. Paul’s, Durham; enlarging, or otherwise increasing the accommodation in the churches at Cheddar, near Weston-super-Mare ; Cheyington, near Acklington, Northants; Elmswell, near Bury 8. Edmund’s; Llanbadock, near Usk, Monmouth ; Llanfair-Dyffryn-Clwyd, near Ruthin ; Steeple-Ashton, near Trowbridge; Tythegstone, near Bridgend, Glamorgan; and Walton-on-the-Naze, near Colchester. Under urgent circumstances the grants formerly made towards building the churches at Battersea Park, §. Saviour’s, Surrey ; and North Woolwich, Essex ; and towards enlarging the church at Dresden, near Stoke-on-Trent, were each increased. Grants were also made from the School-Church and Mission House Fund towards building, &c., mission churches at Fleur-de-Lis, in the parish of Mynyd- dislwyn, near Newport, Monmouth; and Amlwich Port, Anglesey. The society also accepted the trust of a sum of money as a repair fund for the church of S. Michael and All Angels, Paddington. Norruampron.—Mr. J. Warner has nearly com- pleted the Convent of Notre Dame, at Northamp- ton. The style adopted by the architect, Mr. W. Hull, is Gothic, very plainly treated. The mate- rial is white brick, with dressings of Bath stone. On the ground floor a suite of large class-rooms occupy the front of the building. There is also the children’s refectory, six music apartments, and two reception-rooms. The corridors on the ground floor are paved with Minton’s tiles. The total cost will, it is estimated, be about £5,500. Oswestry.—lt is intended to restore the parisk church of Oswestry. Mr. Street’s report of the ne- cessary alterations gives the following items:— Nave—New roof, £1,815; new columns, arches, &c., £1,200; new oak seats, £1,275; new vestry, £250 >