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Four bridges in the Shire of Bright
'Wabonga', Quinn's, Freeburgh, Porepunkah

Introduction

In 1913-1914, the Reinforced Concrete & Monier Pipe Construction Co won contracts for four T-girder bridges in the Shire of Bright, a mountainous region, where creeks and rivers were subject to intense floods carrying large amounts of debris, including entire tree trucks. Impact could loosen the joints of timber bridges causing break-up. It could strip the cover from concrete girders and rip out the reinforcement causing collapse. Smaller debris could lock together to form a dam, and the pressure of the pent-up water could destroy or overturn a complete bridge.

To resist these forces, the piers of timber bridges were built with more piles than usual. This made them less competitive with the relatively new reinforced concrete bridges offered by RCMPC. However, while the timber piles penetrated deep into the gravel bed of the rivers, some of the piers of RCMPC's bridges were founded on gravel, because it was deemed uneconomic to take them down to the rock. As a result, they were liable to undermining by scour in heavy floods.

Monash and his assistants were aware of the above dangers. RCMPC had been adopting a trestlework form of pier [example] to save concrete; but there was a danger of debris becoming entangled, so at the 'Wabonga' bridge, built between April and July 1913, they used solid walls aligned in the direction of stream-flow. The bases of these walls were greatly extended in the direction of flow, to increase resistance to overturning. We believe that this bridge lasted until 1997, when it was replaced.

Although Monash was involved in preliminary negotiations for the remaining three bridges in the first half of 1914, tenders were not called until July of that year, by which time he was subject to a heavy business workload and was preparing the Militia for the coming war. Reports from site for these later three bridges commence in November 1914 and the work seems to have been finished in the second half of 1915. In June 1917 they were badly damaged or destroyed by heavy flooding. The design of the bridges had been approved by the engineers of the newly-formed Country Roads Board of Victoria, and it is probably fair to say that a lesson was being learned: that if engineers were to take advantage of the greater durability of reinforced concrete bridges it would be necessary to invest in more expensive foundations taken to rock.

Wabonga Bridge

Wabonga Bridge, completed July 1913. (Photo, 18 December 1914, University of Melbourne Archives, Reinforced Concrete & Monier Pipe Co Collection, BWP-24038.)

Other images related to this bridge held by University of Melbourne Archives are BWP-24033 to 24037. The first two show the site prior to construction, and the others show work on the foundations in June 1913.

Note: we are not sure about the location of this bridge. Wabonga (spelled with an "a") was the name used in the RCMPC project folder and in the local newspaper. However, Wabonga is a remote location and it is difficult to understand why a reinforced concrete bridge would have been built there in 1913. Also, the waterway shown on the drawings is 80 feet (24.4m) wide and the flood plain is over 150 feet (45.7m) wide. It has been suggested by VicRoads that the bridge was at Eurobin and carried Wobonga Lane (spelled with a "o") over the Ovens River. If that is correct, it was replaced in 1977. A sketch of the bridge 'As built' (see below) indicates that it ran in an east-westerly direction.

In September 1912, extensive flooding destroyed many timber bridges in the Bright area, including "the Eurobin Bridge crossing the Ovens River" (Argus 18th, Trove). The RCMPC Wabonga project file contains a letter dated March 1913 from A McKenzie Tyers, the Engineer for the Shire of Bright, saying that the old bridge had been swept away, and explaining that the Shire had only £700 available to build a new one. He suggested that a length of 80 feet over the waterway might be built in reinforced concrete, with timber spans at either end over the flood plain. The deck need be only 7 or 8 feet wide (2.13 or 2.44m). Tyers asked Monash what he could do with the money available.

Monash, or perhaps his assistant Percy Fairway, offered to do better. A drawing was prepared, based on computations by Fairway, entitled "Shire of Bright - Wabonga Bridge". This is dated 29 March and shows a width of 9 feet between handrails, with three spans nominally of 40 feet (12.2m) and a fourth of 30 feet (9.14m). As was RCMPC's custom, it gave no details of reinforcement. It was accompanied by a formal quotation of £694. This was accepted on 2 April, apparently without a tender process. Next day The Argus (p.5) reported: "The Bright Shire Council, at its meeting on Tuesday, authorised the construction of a Monier bridge over the Ovens River at Eurobin, to take the place of one destroyed by the recent floods. The tender was £694. The residents have agreed to build the approaches." And on the day after this, the Alpine Observer reported: "Wabonga Bridge. The Engineer reported that the length of the Wabonga bridge site is more than 150 feet. To withstand floods a large number of piles are necessary, which makes the costs high. Before finally deciding on the timber structure he is getting a price for a Monier bridge which he thinks will be cheaper."

Fairway now did more detailed calculations to finalise the dimensions of concrete and reinforcement, and prepared a working drawing showing full details for use by the foreman in construction. These were then sent to George Kermode at the Public Works Department for approval.

Tyers was now informed that RCMPC had found a better site for the bridge, 30 feet (9.14m) from the old site, where the river could be crossed by four spans of only 30 feet, and where only one of the piers would have to be built in water. He was asked to pressure the Council to approve this change before wet weather set in. There was a delay caused by disagreement between the Chief Engineer of the PWD, Carlo Catani, and Kermode over the design. Catani wanted the land spans shortened and the shear reinforcement increased. Kermode thought them satisfactory as designed. He told RCMPC that he would forget the matter if "corbels" were introduced on the land end of the shore spans. On 22nd April the PWD informed the Shire that it approved the design, subject to these modifications.

RCMPC's foreman "Ben" Bendschneider was put in charge, and his daily reports of operations run from 29 April 1913 to 17 July. Early in May the RCMPC's Works Superintendent, Alex Lynch, reported that the re-siting of the bridge would involve an extra 60 cubic yards (46 cubic metres) of fill. He had told Bendschneider "in the event of any outcry … to say that we would be prepared to fill it up". Lynch also reported that the new site had rock foundations for all piers. A decision was made to widen the deck slightly to provide a distance of 8'-9" (2.67m) between gravel beams, so that a traction engine could pass.

(a) Wabonga Bridge, June 1913. University of Melbourne Archives, Reinforced Concrete & Monier Pipe Co Collection, BWP-24035. (b) Scheme for river pier, taken from the drawing of 9 April 1913. The wall forming the superstructure of the river pier was supported at each end by two cylindrical pillars. Each of these consisted of a large-diameter Monier pipe, stood on end. The lower end was normally furnished with a cast iron cutting-edge. Workers excavated the material from the inside of the cylinder and from under the cutting edge, allowing the cylinder to sink into the river bed. The 'As built' sketch (below) shows the bottom of the excavation "belled out" to provide greater bearing area on the gravel. The excavation and pipe body were then filled with concrete to create a solid pillar. The top of a cylinder may be seen in the photograph (a), to the left of the plank decking. A rudimentary hoist is in position to lift buckets of excavated material out of the pipe.

The decision to re-site the bridge did not go unchallenged. The Alpine Observer for 13 June reported "Good progress is being made with the Wabonga bridge, and the superstructure will be in place in a few days. Cr. Dundas said he had heard that the foundation on one side was not on rock. Engineer said there was no rock there. Cr. Dundas understood that the reason why a Monier bridge was put there was on account of the rock. Engineer said the design he first drew out required a great number of piles so as to get holding ground. The present structure rests on a solid bottom, but it is drift all the same. The drift is solid and the bridge being a heavy one could not be shifted by flood. Cr. Dundas said there was a man prepared to swear that there was no gravel under the foundations. Engineer said he had no doubt that the pier rested on 5 feet of gravel. Cr. H. Wallace enquired who authorised the shifting of the site for the bridge. Engineer said it was practically on the same site. Cr. H. Wallace said the ratepayers were dissatisfied as it would mean an additional cost to them in making the approaches. Engineer differed from them in this matter, as by shifting the bridge to its present site it would avoid the filling of the gulch on one side, and on the other side they had got superior rock foundations."

The sketch below appears to be an 'as built' drawing of the completed bridge. It shows both abutments and Pier 1 founded on rock. Pier 2, the only river pier, is supported by cylinders at each end, sunk into gravel and with a belled footing. Pier 3, on the flood plain, has a wide spread footing built within a sheet-piled caisson and is founded on gravel.

Wabonga Bridge. 'As built' sketch. University of Melbourne Archives, Reinforced Concrete & Monier Pipe Co Collection, File 936. The hand-writing is P T Fairway's.

A new foreman, W A Quinlivan took over briefly on 19 July 1913 to put the finishing touches to the bridge. RCMPC's final account was submitted on 29 July for £712. This total included extras for the modifications demanded by the PWD, but allowed no credit for the re-siting.

Trio of Bright Bridges

RCMPC nomenclature

These bridges were known to Monash and his colleagues as:

Quinn's.Half a mile (804m) from Bright Railway Station, over Morse's Creek at Bright Township, just before Morse's Creek flows into the Ovens River. 66' × 20' (20.1 × 6.1m).
Freeburgh.Over the Ovens River at Freeburgh, on the Bright-Harrietville Road, 6 miles (9.7km) from Bright Railway Station 66' × 16' (20.1 × 4.88m).
Porepunkah.Girder bridge over the Ovens River at Porepunkah, half a mile from Porepunkah Railway station. It carried the road from Myrtleford (now diverted) to join the Buffalo-Bright Road (just before the T-junction) 66' × 20'

The descriptions of their locations has been taken from the RCMPC records. Distances of bridge sites from railway stations was important because of the cost of transporting cement and reinforcement.

Because their design seems to have been carried out by Monash's assistant engineers at a time when he would have been preoccupied with other matters, and construction started in November 1914, just weeks before he sailed for WW1, only a brief account will be given of these bridges.

By August 1913, RCMPC had built two bridges for the Shire of Bright: a Monier arch at Porepunkah, and a narrow four-span girder bridge known as the Wabonga bridge, probably at Eurobin (see above). As the shire considered the construction of three more reinforced concrete bridges, December brought a change of Shire Engineer. McKenzie Tyers, who had held the dual positions of Engineer and Town Clerk, resigned and Herbert Crowther took over. About the same time, the recently-formed Country Roads Board took over responsibility for the bridges from the Public Works Department.

Preliminary quotes put RCMPC in the running, but it was not until 18 July 1914 that formal tenders were called for the three new bridges. Because of the impending war, Monash had the following note written in red ink on the documents: "This tender is conditional upon the preservation of normal trade conditions". A single drawing sufficed to show the working details for all three bridges.

The Shire notified acceptance of the tender on 22 September, at a total price of £2,300 for all three bridges. Further detailed drawings were produced and some modifications made before work started in November 1914. Problems were experienced similar to those at the Wabonga bridge. Alex Lynch went down in a diving suit at the Porepunkah site and drove an iron bar 5 feet (1.52m) into the bed of the river without finding rock. RCMPC was beginning to feel the shortage of good workers as they volunteered for the war. There seems to have been some tension between RCMPC and Crowther. In August 1915, the Alpine Observer reported that the Council would take action, following the Engineer's report. RCMPC's General Manager, John Gibson, wrote to Monash that they were having a lot of trouble up at Bright "with that impossible engineer Crowther". Gibson had been obliged to seek the intervention of the CRB, which had been sympathetic "at least in writing".

No doubt Crowther had been concerned about the foundations. Already, one of the mass concrete abutments at the Porepunkah girder bridge had developed major cracks. One of the bridges had a noticeable sag which was due to the falsework subsiding under the weight of wet concrete, and thus was permanently built in. In September the bridges suffered minor flood damage. In December 1915 the Shire terminated the contracts - a pointless gesture, since the bridges had already been built.

In June 1917 a major flood caused damage to many bridges in the Bright area, including the three under discussion. Freeburgh and Quinn's had to be replaced. The Porepunkah girder bridge lost most of its girders and one abutment. It was rebuilt in 1918 using second-hand wrought iron girders to replace those lost. The central pier and eastern abutment were strengthened and the western abutment was rebuilt.

The information for this paragraph was supplied by Mr Robert J Kaufman and by the National Trust of Australia (Victoria). See also The Argus for 8 June Trove.

Photographs in The University of Melbourne Archives relating to the three later bridges:

Freeburgh:BWP-24144 to 24153.
Porepunkah Girder Bridge:BWP-23965 to 23967 and BWP-24154 to 24166.
Quinn's Bridge:BWP-24141 to 24143.

Some of the above images may be seen in UMA's online catalogue UMAIC by searching under "Record ID" for the following numbers:
Porepunkah Girder Bridge: UMA/I/6413, UMA/I/6415, and UMA/I/6474.
Freeburgh Bridge: UMA/I/6470 to UMA/I/6473.