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History of Monier arch bridges at
Barber's Creek and Wollert.

Barber's Creek Bridge c.1997.
Coordinates: -37.5744, 145.10448
Wollert Bridge c.1997.
Coordinates: -37.5959, 145.05357

For a historic image of Barber's Creek Bridge see:
UMAIC University of Melbourne Archives Image Collection. Search under Record ID for UMA/I/6505. Any enquiries to UMA should refer to Location Number BWP/24355.
There are no contemporary photographs of Wollert Bridge in the RCMPC Collection at UMA.

Note: The nomenclature adopted here for the Barber's Creek and Wollert bridges is that used in the Monash & Anderson archives: the first is named after the creek it spanned, and the second after the local township. In the Monash & Anderson documents the name of the township is spelled "Woolert". The modern spelling (Wollert) has been adopted here.

Introduction.

The planning and construction of these two bridges was distinguished by cordial relations between Monash & Anderson and the Shire Engineer, W. H. Lockwood, who was convinced of the long-term benefits of reinforced concrete. The time span for this project fell within that of the Bendigo Bridges project, where conditions were very different. The construction period for the Barber's Creek and Wollert Bridges overlapped those of the High St, Booth St, Wade St, and Abbott St bridges in Bendigo and the start of construction of the second King's Bridge. The two bridges discussed here seem to have been the particular concern of J. T. N Anderson. He was mainly responsible for the initial negotiations; for liaison with Lockwood; and for visits to site to instruct foremen and supervise critical events. The project also provided an opportunity for Alex Lynch to display his potential as a foreman. He was later to become Works Manager of the Reinforced Concrete & Monier Pipe Construction Company, playing a key role in its development. Another noteworthy feature is that on this occasion Monash & Anderson did not refer for engineering advice to Gummow Forrest & Co., the firm through which they held Victorian rights to the Monier patent.

The Barber's Creek Project.

The replacement of the old Barber's Creek bridge was mooted in the Whittlesea Shire Council in September 1898. As the first Monier arch bridge in Victoria was then still under construction (at Anderson Street over the Yarra) it is not surprising that a concrete bridge was not considered. A contract to build in timber was won by a local man, W. Bruce, who must have underbid because he later asked the Council for an extra £80, and then withdrew from the contract when it was refused. The partners heard of the resulting opportunity through their friend T. B. Muntz who was also a close friend of Bruce. Rough calculations made in March 1900 persuaded Anderson that it was worth visiting the site to investigate further and he arranged to bicycle out, asking Lockwood to have exploratory holes made ready to check soil conditions. Within a few days a drawing had been prepared by A. G. Timmins and a quotation of £400 submitted. However the Councillors decided that, even with a grant of £200 from the Public Works Department, they would have to delay construction until the next financial year.

Thus the decision was not taken until September 1900, when it was made over the objections of Cr Murphy who considered £400 "a terrible lot of money to be expended on a bridge at such a place" and pointed out that "£150 would build a bridge that would last 30 years - and so elaborate a bridge [as the Monier] would preclude local contractors tendering". The terms of the grant required Council to submit the plans to the PWD whose Chief Engineer, Carlo Catani, demanded a number of changes. The spandrel and wing walls (see Sketch) were to be stepped in smaller increments; a "proper specification" was to be prepared; and the spacing of the iron reinforcement was to be stated. Most importantly, Catani demanded that the bridge be raised three feet to clear the level of flood waters indicated on the drawing. This would have increased the cost considerably. Monash volunteered to draft Lockwood's response, arguing successfully that the indicated level had been measured upstream of the bridge site, above a constriction in the waterway, and that the actual flood level at the site was lower than this.

Tenders were called on 6 February 1901, making specific reference to a Monier Bridge. Monash & Anderson arranged that they would tender as main contractors and sublet all work, except the Monier arch proper, to Bruce. They offered a price of £423, of which £286-10-00 was Bruce's portion. The tender being successful, J. S. Gregory completed the drawings and strength calculations for the arch and the centres. When Anderson again visited the site it became evident that payment would be needed for access to private land. In trying to minimise this need Lockwood set out the bridge in a way which would involve the contractors in further unforseen expense. However, Anderson felt it was so important to retain the contract that he proposed to Monash that they and Bruce absorb the extra cost, allowing them to get on with the job "even if we only make travelling expenses". The contract was signed on 9 March 1901.

Bruce was hindered in digging the foundations by the high flow in the creek and distracted for a time by the death of his eldest son. The lime concrete abutments appear to have been completed in mid-May, after which work began on erecting the centering, placing the planks (or 'lagging') to mould the soffit of the arch, and installing the reinforcement grids. At this critical point the King's Bridge at Bendigo collapsed under test. The day after the collapse Monash & Anderson wrote to Bruce, emphasising the importance of providing the falsework with a solid foundation protected against scour, as "any displacement of the centering while the arch is setting would be likely to lead to disastrous results." However, within a few weeks a coronial inquiry had accepted the advice of Professor Kernot of the University of Melbourne that failure of King's Bridge had been due to its extremely high skew. This had resulted in stresses several times higher than those predicted by currently accepted methods of stress analysis. As the Barber's Creek bridge was square to its abutments there was no similar danger there, but it was still commendable of the Councillors and Lockwood to continue with the contract when many of their counterparts in other municipalities were discouraged or confirmed in their opposition to the new system of construction.

In mid-June Councillors decided they would prefer to have the spandrel walls built in brick masonry rather than mass-concrete, possibly for the sake of appearance. Lockwood added that he thought the top two courses of brickwork should be plastered over "to prevent dislodgment of single bricks by boys, &c". The following day, logs carried by flood waters smashed the posts supporting the falsework. Fortunately no damage was done to the formwork or the grid of reinforcing bars and the rest was soon repaired. Lynch arrived on site about the 20th to oversee placing of the concrete. He reported that the creek was already back to normal, but that the lime concrete in the abutments was still soft. Because the volume of concrete in the arch was more than could be placed in one day using the simple methods available, it was to be cast in two parallel strips to ensure integrity of material throughout the length of the bridge. The first strip was cast (or 'turned') on 27 June 1901. As usual, the falsework was built to support only this strip, with the intention of moving it sideways when the concrete had gained sufficient strength to support itself.

Monier arches were built with cement concrete which gains most of its strength within 28 days, and about two-thirds to three-quarters of this within the first 7 days.

However, in this case, further delay was caused by the softness of the abutments. There was a danger that when the falsework was removed, throwing the weight of the arch onto the abutments, they would settle and cause distortion or even cracking of the still immature concrete of the arch. Monash & Anderson blamed the softness of the abutments on the use of excess water in the lime concrete, and claimed that their foreman (presumably meaning Bruce) had warned against it. The implication seems to be that Lockwood had insisted on a high water-content, but he replied "It is well for Mr Bruce to throw the onus on me. I don't wish to impute blame in any way - I want to forward the work all I can and will endeavour to do so."

Transition from Barber's Creek to Wollert.

In a further exhibition of faith in the Monier system, Lockwood informed M&A through Lynch on 30 June that there was an opportunity for a Monier arch near the town of Wollert (then spelled Woolert) in the Shire of Epping, which Lockwood also served as Engineer. The existing bridge had bluestone abutments supporting a timber deck which was becoming unsafe. Lockwood was keen to see a Monier arch substituted for the timber to provide a lasting superstructure. Anderson provided a quotation by simply giving a unit price of £96 for the arch itself and a rate per cubic yard for concrete, and then quoting "reasonable rates" for minor items. Early in July computations were made, a drawing was prepared, and a formal tender submitted for £167-10-00.

On 16 July the second strip of Barber's Creek bridge was turned. In the following weeks the spandrel walls were built, and the earth filling was spread and compacted between them and on the approaches. The Whittlesea Council decided not to make the customary test by traction engine or steam roller before taking possession and making the final progress payment. As Lockwood put it: "they took your word for it that it would stand". However, the cost of a test and shortage of funds must have played a part because Council could not afford to sign the cheque for the final progress payment until the following month. By this time both the Oak St and Booth St bridges at Bendigo had been satisfactorily tested, and traffic was passing safely over the first two strips of the High St bridge.

The Wollert project.

Meanwhile on 13 July the Epping Council had called tenders for Monier and timber alternatives for the Wollert bridge and on 16th accepted Monash & Anderson's offer, rejecting a tender for the timber alternative on the grounds that it was impossibly low and that the "permanence" of reinforced concrete would prove cheaper in the long run. A drawing was prepared by Gregory on 21st and traced on 25th. By 13 August, Lynch had dismantled the old bridge and begun stripping down the bluestone abutments to receive the ends of the arch. It appears that the centres from Barber's Creek were re-used, the spans and rises of the two bridges being almost identical. Work at both sites was delayed by extensive floods in July and August, the latter cutting off Wollert from the town of Epping, were the workers lived. The Wollert arch, being narrower than that at Barber's Creek, was cast in one operation, probably on 7 September. The mason started on the spandrel walls - this time in bluestone to match the abutments - on the 10th. By 26th the walls and filling were complete and people were unofficially crossing the bridge in their traps on the way to "town". Anderson struck one of the centres during a visit on 14 October, but did not have the help or tools necessary to do more. Lynch completed the job in the last week of October. Again there is no mention of a test. It might have helped that the partners had lent Lockwood a copy of Professor Kernot's report, stating the reasons for the collapse of the King's Bridge.

Monash & Anderson publicised the two bridges widely, sending photographs to many municipalities and foreseeing a thriving business in small country bridges of this type. Lockwood was extremely proud of his association with them, supplying Councillors of both municipalities with souvenir photographs. Unfortunately in 1910, when on the point of retirement, he was obliged to return Monash & Anderson's plans for a new reinforced concrete bridge across the Plenty River near the town of Whittlesea, as the Council had insisted that he pare down his own design for a cheaper form of construction. He declared he was ashamed that this would be the last bridge he would build after 40 years of service, but consoled himself with the thought "I am pleased with the two Monier bridges, they will remain after me."

Note: The above account was extracted from our Dossier on the Barber's Creek and Wollert Bridges, and has been lightly edited for presentation here. The Dossier includes details of archival sources, dimensions, a list of personalities, and a "Timeline" in which all relevant correspondence known to our research team was recorded chronologically in precis or verbatim form.