KELBURN VIADUCT

Evening Post, Volume CVII, Issue 32, 8 February 1929, Page 11

KELBURN VIADUCT

A NEW STRUCTURE

URGENT

ENGINEER'S REPORT

Reporting to the City Council last niglit on tlio prneticability-of the existing Kolburn viaduct being ■reconstructed and adapted to moot fho requirements of vehicular and pedestrian traffic, the City Engineer (Mr. G. A. Hurt) stated that in August, 1027, tho stresses of the whole of .the members of the bridge were carefully investigated, and it was decided that the speed oi' vehicles over the viaduct should bo restricted to not exceeding eight miles per hour, and that the maximum weight of any vehicle and load allowed over it should not exceed eight tons. On Ist November last year v serious slip occurred in tho bank on tho Keiburn side of the viaduct, between Upland road and Glcninore street, which exposed tho base of the concrete abutment at the Keiburn end and the foundations:; of tho trestles. As a result it was necessary to close the viaduct for a time, and to effect temporary reconstruction, reducing the width available for vehicles to 13 feet at the Keiburn end for 14 yards. "To restore the Keiburn end of the bridge to its original width would necessitate underpinning tho foundations and taking them down practically to the level of Glenmore street and throwing the abutment well back into Upland road. This would mean closing the bridge for traffic for an extended period. The slip shows that the bank will deteriorate in stability tho longer it is exposed to the elements. Tho design of the bridge is not adapted towards an adequate reconstruction _ at tho Keiburn end as a permanent job. The bridge' has arrived' at the stage when stops should be taken to dispense with it, and a new bridge on an independent lino substituted for it before the time arrives in which tho present bridge and its founfAions become dangerous for traffic. ,Xt cannot be guaranteed that tho foundations of tbo present bridgo might not be weakened by (farther slips, but there- is no indieafeon of them at tho present time, nor ftlo I think it will take place within the next two or throe years, which will allow ample- time for the erection of a new bridge, a course I recommend with confidence as prudent and. necessary. "The new bridgo can bo constructed in a straight lino well adapted for curving into Upland road on tho one end, and Glcnmorc street at tho other. The total length of tho new bridgo between abutments would be about 230 feet, which is only 15 feet longer than the present one. At the Glenmoro street end tho bridgo would come in midway between the present bridgo and the motor repair store. At the Upland road end the centre line of tho new bridge would be about 140 feet to tho north of the centre line of tho existing bridge. The new bridge would be 22 feet carriage-way-width between kerbs, with a 6 feet wide footpath on each side, tho footpaths boing cantilovcred over the main girders, the total width of the bridgo between parapets being 34 foot. The bridge would consist of three spans of about 77 feet each, and owing to tho amplo headroom availablo, tho site lends itself to an economical plan and an effective design for carrying the maximum weights of any kind of vehicular traffic, which modern loads require to make provision for. Very little property would havo to bo acquired. Tho new bridgo could bo constructed and opened for traffic before it is noecssary 1 to closo tho existing bridge. I estimate- the cost of the new bridge, with an iillowanco Cor the acquisition of tho small amount of property required, to bo £29,000."