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Sketch by JM. Reinforced Concrete & Monier Pipe Co. Collection, University of Melbourne Archives.
This project is one of Monash's attempts to develop business in Western Australia while he was based there assisting Baxter & Saddler in a lengthy arbitration concerning one of their contracts. It is significant because it shows him performing computations for Monier arches as early as July 1898. (J T N Anderson had established links with Carter Gummow & Co in September 1897. Monash had visited CG&Co's works in Sydney in March 1898 and again in May-June, spending time with Baltzer.) It is also of interest because it includes the only case we have sighted in which M&A made a considered proposal to use tied-arch construction.
The scheme appears to have come entirely from JM - there is no sign of support from, or involvement of, government officials. He proposed that overbridges be built to carry Melbourne Road and William St over the main railway lines. Further overbridges for Mackie, Lord and Sampson Streets and Glaisebrook Road would have involved lowering of the tracks. He costed the entire project at £120,000.
Almost all the other projects were for bridges over waterways where ties would have presented an obstruction to floating debris in time of flood. However, M&A did mention a tie as a possibility for the Grant Street Bridge in Ballarat (see timeline entry 1899/07/10).
JM seems to have chosen the William Street bridge as a typical case for more detailed investigation. The railtracks were to be crossed by a number of spans making a total length of at least 330 feet (101m). Providing supports without interfering with the tracks was a problem. JM made a note to ask the Railways Department whether they would be willing to relocate the tracks and whether they would reorganise the running of trains during construction to permit possession of part of the ground by the contractor. A further problem was that the length of the approach embankments would be limited by the surrounding streets and properties. A steep grade would present difficulties to heavy goods vehicles. It was therefore important to keep the road level over the bridge to a minimum, but still provide the required clearance for trains beneath. To meet these requirements, JM proposed a number of solutions. In the sketch above, the piers are arranged to include two tracks within each of the left-hand spans. This implied clear spans of the order of 128 feet compared with 95 feet for the Anderson Street (Morell) bridge. In a rough estimate with undimensioned sketches showing an open-spandrel arch, the figures suggest a scheme for four spans of about 80 feet, costed at £5152. The most intriguing is a scheme entitled "22 foot Monier Arches and Tie Rods". JM must have been driven to this solution by the need to keep the height of construction to a minimum. He estimated that 22 such spans would cost £2400 compared with £5500 for a competing alternative of steel troughing filled with mass concrete. The drawing (below) shows the tie rods attached to an iron or steel I-beam with the end of the arch resting against the web and bottom flange somewhat after the fashion of the jack arches in a 19th Century industrial floor. The width of the arch was about 48 feet (to provide a 30-foot roadway and two footpaths of 8'-6"). Over this width, JM proposed to use 22 rods of 1.5" diameter (38 mm).
JM prepared a typewritten submission, arguing the case for the scheme and defending the steep grade of the approaches to the William Street bridge on the grounds that heavy freight would soon be carried from "Port to Perth" by water. However, there is no evidence in the file that the proposal was ever formally submitted.
JM made these notes and computations about 28th and 29th July 1898. The following edited extracts will not interest all readers, but are included for those who might like to get an idea of JM's approach to preparing a proposal for a major civil engineering project. [Skip Notes & Calcs.]
"Matters for Inquiry."
Public Works Department, Inspector of Engineering Surveys, Old St George's Hall.
Steam Roller 15 tons
10' × 6' base
113 lbs per sq ft.
Monash's sketches. 1. Half-width of a pier. 2. Side view of a pier. (Scales differ.) Reinforced Concrete & Monier Pipe Construction Co. Collection, University of Melbourne Archives.
Area of footing 49 × 6 = 294 square feet
Area of top 46 × 3 = 138
Footing: 49' × 6' × 1'= 294 cubic feet
Body: 48' × (3' + 5.5') × 15' / 2 = 3060 c.f.
3354 c.f. = 125 cubic yards
If concrete cost = say £3 per c.y. = £375
If masonry cost = say £3/10/- = £437-10-0
[Here JM has a sketch and rough estimate for the long-span alternative. The sketch appears at the head of this section. A note above the sketch shows that the projected total width is 47 feet between parapets, with two paths of 8'-6" each and a roadway of 30 ft.]
Cost of bridge alone: £9,000
Cost including approaches: £12,000
Rough estimate - Cost price.
|7' × 2.5' × 48'||= 840 c.f.|
|11' × 4.5' × 48'||= 2376 c.f.|
|3216 c.f.||= 120 c.y.|
|[Pier] Concrete @ 2/-/-||= £240|
|Monier Compo 45' × 47' × 0.8' = 1692 c.f. = 63 c.y. @ 2/10/-||= £158|
|Monier Lattice 45' × 47' × 1 lb = 1 ton||= £15|
|Monier Centres say||£87|
|Monier Royalty 10% on cost||£26|
|4 × 15' × 2.0 × 2 = 240 c.f.|
|2 × 3 × 4 × 2 = 48 c.f.|
|288 c.f. = 11 c.y. @ £2||= £22|
|Parapets: 2 × 42 × 5 × 1 = 420 c.f. = 16 c.y. @ 2/10/0||= £40|
|Filling with sand 200 c.y. @ 1/6||= £15|
|Road Metal: 14 l.y. × 10 × ¼ = 35 c.y. @ 8/-||= £14|
|Tar paving: 2 × 14 × 2 = 56 s.y. @ 3/-||= £8|
|Kerbing: 2 × 42 = 84 l.f. @ 1/1 [?]||= £5|
|Channeling: 2 × 14 × 1 = 28 s.y. @ 5/-||= £7|
|Total for one span:||£647|
Cost of eight such spans: £5200
JM then considers using tied arches of 22 feet span, in which the outward thrust of each arch would be resisted by tie rods spanning between the ends. He calculates the force that would develop in the ties and decides he would require 22 rods of 1½ inch diameter. (Details appeared on p.9 of our Dossier published in 2000.)
|Monier Compo: 23' × 0.8 × 48' = 883 c.f. = 33 c.y.||= £85|
|Monier Lattice 23' × 48' × 1 lb = ½ ton||= 10|
15 such spans @ £160 = £2,400
JM then makes a rough estimate of the cost of a then conventional form of construction in which iron or steel trough decking was used to span the gap and filled with a layer of concrete. The latter provided extra strength and stiffness, and formed the roadway.
against £4,500 for troughing and £1,000 for concrete = £5,500
Here JM sketches his proposals for anchoring the tie rods, at each end, to a rolled steel joist running across the width of the bridge and taking the thrust from the arch.
The formal (typewritten) proposal summarised the cost of the entire system of bridges as:
|Subway at West Perth Rly Stn:||£5,000|
|Overbridge for Melbourne Rd:||£15,000|
|Overbridge for William St:||£20,000|
|Mackie St, Lord St, Sampson St, Glaisebrook Rd||£80,000|
"Mackie St, Lord St, Sampson St, Glaisebrook Rd" may have been a group of overbridge projects that involved lowering the railway tracks.
Image: J. Thomas Collection.
This design illustrates JTNA's efforts to reduce the cost of Monier arch bridges to a level acceptable to frugal municipalities by employing composite construction. M&A's tender for Monier construction with conventional spandrel walls and earth fill had been reduced to some £4,300 during negotiations. (The exact price would depend on provisions for temporary access during construction.) In the second half of January 1899 JTNA, in some desperation, hurriedly produced the composite version to achieve a further reduction. Initially he proposed that a timber trestle viaduct be substituted for one of the Monier side spans and part of one approach embankment, and that the upper structure of the remainder of the bridge consist of steel members supporting a timber deck. However, after detailed investigation he found he could retain all three arches and provide them with a steel upper structure and timber deck at a saving of £700. It seems he foresaw the replacement of the steel and timber by conventional spandrel walls and earth fill at some time in the future. JTNA was not enthusiastic about this proposal. Having gained some impression of his personality from the M&A records, I suspect he had his tongue in his cheek and was hoping to shame the Councillors into opting for the more solid form of construction. The proposal had a very short life, as the two Councils concerned accepted the tender for the conventional version on 31 January.
1899/01/18: M&A to Morris [Secretary and Engineer for the Shire of Bannockburn and Secretary of the Joint Committee formed by the Shires of Bannockburn and Corio to oversee the contract.] We are prepared to submit a plan and specifications for a further modification of the bridge, saving approximately £700. "These proposals will retain the present central span, and 18 ft roadway, but will vary the character of the approaches and side spans." Strength and waterway will not be affected.
1899/01/20: JTNA to Morris. M&A are getting plans and specifications ready so that JTNA can explain to Council how to save £700. The chief item is replacing one of the approach spans (58'-6") and the earthen approaches by a length of 110 ft of timber bridge. The proposal retains the centre span and one side span, i.e. 80% of the proposed bridge "thus giving by far the most important part of the bridge as a permanent structure to posterity, and only bequeathing a viaduct on dry ground and of trifling height to be replaced hereafter." Subsequent substitution of a Monier arch could be done for less than £1000. It is important that the foundations be got in before winter, so please put these proposals to the PWD as soon as possible.
1899/01/21: JTNA and A G Timmins work all day on the new proposal.
1899/01/21: JTNA submits the specification and drawing for the open-spandrel bridge.
UNDATED: Drawing. Pencil on cartridge paper. "Proposed Fyansford Bridge." This shows a centre span of 100 ft clear, a rise of 26.8 ft (scaled), and two end spans 59'-6" clear with a rise of 22.8 ft (scaled). The spandrels and fill have been replaced by a steel superstructure supporting a deck of timber planks on rolled steel joists. At one end the earth embankment has been largely replaced by a bridge of 44 ft span with RSJs carrying a timber deck. CRB No. 19916. [The drawing we sighted is in the John Thomas Collection. Some years ago Peter Alsop sighted what must have been another copy of this drawing, carrying the date 23 January 1899. (Alsop, P. F. B. A History of the Reinforced Concrete Arch Bridge over the Moorabool River at Fyansford. Amended version, 1982. First delivered as a lecture, October 1971.)]
1899/01/23: JTNA to Morris, with two attachments. "I have carefully redesigned this bridge to offer the saving of £700 I promised. I am very pleased indeed to say that I have been able to save almost this sum without using any wooden girders or trestles or joists whatever. I have done this by the use of open spandrils, spanned by rolled steel joists (acid process). This method gives you the advantage of masonry in all the more expensive portions of the bridge while all the cheaper and more accessible portions of a steel bridge are used. The superstructure will be therefore carried out in general accordance with the terms specified by Mr Campbell for his steel bridge
" Steel rates are at cost to ensure adoption versus wood. The only other item not covered by prices already tendered is the timber deck and handrailing.
The first attachment is a tender for £3656.
The second sets out the tender schedule.
1899/01/24: JTNA to Taylor [Manager of the Fyansford cement works and a supporter of M&A's tender.] re dates of closure of the old bridge. JTNA's new [light-weight] scheme would allow the old bridge to remain open longer, because the existing abutments would not be destroyed. However, JTNA is glad to hear there is a chance that the full scheme will go ahead "since it is every way far better for the district to have £1000 spent there than go outside for iron and wood "
Image: J. Thomas Collection.
This proposal was for a composite structure consisting of a Monier arch ring and a timber superstructure. The conventional timber road deck was to be carried on trestles consisting of a pair of columns with a single diagonal brace. The idea was adopted partly because Jamieson lay in hilly country far from the nearest railway station, making transport of cement a problem; and partly because it was a centre for the forestry industry, making it financially and politically difficult to win the contract in competition with the timber truss bridge proposed by the Shire Engineer, G. M. Scott. The site was on the road from Jamieson to Wood's Point where it crosses the Goulburn River, about seven kilometres from Jamieson. At one stage, JTNA proposed an arch of 100 feet span and 16 feet rise. This would have obviated the need for substantial ashlar-faced abutments shown on Scott's proposal, in which the truss had a span of only 80 feet. However, in the tender, the arch span was cut back to equal that of the truss. The proposed arch had a width of only 12 feet. Calculations for quantities were first based on an average thickness of 18 inches, but this was later reduced to 14. Reinforcement was to be the conventional 3/8" diameter bars in the longitudinal direction and ¼" laterally, both spaced at 3 inches. Following their experience at Fyansford, M&A were careful to note in their draft specification that excavation was "to be taken down to, and a little way into solid rock, which is assumed, as stated in the Shire Specification, to be at a depth of 6'-6"." Any depth of excavation below this was to be treated as an extra.
1899/05/09: M&A to G. M. Scott, Engineer, Shire of Howqua, Shire Hall, Jamieson. M&A have been informed by Catani that Scott proposes a bridge which might be suitable for Monier. They enclose a pamphlet and cite the Anderson St Bridge, Melbourne, as an example.
1899/05/09: JTNA to Scott. (Private) If you want to go for the Water Supply exam you better start reading now. Re the bridge: M&A are building spans from 67 ft to 108 ft and the PWD is "well pleased". Catani has told them that Scott wants a bridge of 70 or 80 ft span. "Our construction under favourable conditions is about as cheap as wood, and is more durable than iron." If Council is interested, JTNA will come up to view the site and give a reliable estimate. He is coming to the Woods Point Road so he will be at the boundary with the Howqua Shire. Is the bridge site anywhere near that? [JTNA, who owned a property in Narbethong, was acting as consultant engineer to the Shire of Healesville on a part-time basis.]
1899/05/16: M&A to Scott. Thanks for your prompt reply. Please send data as per the accompanying list of questions.
1899/05/24: Drawing. Sketch elevation by Scott, showing his proposed timber truss bridge of 80 feet span.
1899/05/24: Scott to M&A. "Sir, Herewith data re Monier bridge. The roadway leading to bridge is at present almost level but a grade to top of arch of 1 in 12 would not be too severe. As this shire will probably interview the Minister for Public Works re a grant for this bridge early next week it might be to your advantage to wire an approximate estimate of cost of Monier bridge not later than next Saturday. I may say there is a quantity of timber growing in the locality of bridge which would come in for centering."
No date: Initial sketches, quantities and costs for the composite Monier-timber design.
No date: Outline specification headed: "Bridge over the Goulburn near Jamieson. Monier Arch & Timber Superstructure".
1899/05/27: M&A to Scott, confirming their wire quoting £1000 for the bridge complete. This might reduce if good material is available locally. On the other hand, the abutments cost about one third of the total, so if the rock is any deeper than indicated, the price will go up. The span is to be 80 feet and the rise 16 feet. Thus the road level is about 3ft higher than Scott has shown it. The approach gradient is about 1 in 15 and the springings are 7ft above the summer level of the river.
1900/02/09: The Argus. Shire of Howqua calls tenders for the bridge.
1900/02/12: Calculations for the timber superstructure, indicating an arch of 100 ft span and 16 ft rise.
1900/02/14: Final quantities and estimate by M&A showing a cost price of £802.
1900/02/15: Drawing and Specification. "Proposed Monier Bridge near Jamieson".
1900/02/15: M&A to Secretary, Shire of Howqua. "Truss bridge over the Goulburn near Jamieson. As an alternative to the tenders which have been called for the above work, we have the honor to submit our tender for carrying out the work upon the Monier System, of which we are the representatives in Victoria. Our action in submitting an alternative tender has been suggested by, and is approved of by the officers of the Public Works Department, to whom no doubt the whole of the tenders will be submitted. The advantages of the Monier System for bridges are now well understood in Victoria, so that we need not dwell upon them any further beyond mentioning that already 8 arches have been constructed in this colony, and others are under consideration. We accompany this tender with a blueprint drawing, being an outline design of the type of bridge which we propose, and it is only necessary for us to call attention to the opportunity which the arch type of bridge offers for improvements in the design.
A. The total waterway is larger than in the timber truss type.
B. The total deadway above highest flood mark is greater.
C. Concrete abutments and wingwalls, which supersede the drystone pitching proposed by you, afford a much greater protection against scour.
D. The whole of the work below the level of highest flood mark is of an absolutely permanent character, requiring no maintenance whatever, and the first expense is the only expense.
E. The superstructure and roadway, which is chiefly of timber is entirely above the level of the highest floods, and therefore its life is much greater. The whole cost of entirely renewing the timber superstructure in the remote future would not exceed £100, whereas in the case of a timber bridge, practically the whole bridge would be subject to gradual decay.
F. The arch type submitted embodies some measure of architectural beauty, and would be an ornament to the District.
G. We anticipate that the capital cost of the bridge proposed by us will be very little, if at all higher than that of a perishable timber design.
Our price for the whole of the work as illustrated and described by us is NINE HUNDRED & FIFTY-EIGHT POUNDS (£958)."
1900/02/15: M&A to Sec., Shire of Howqua. "We enclose herewith Bank Cheque payable to the President of the Shire, to the value of £48 being 5% on our tender. We also enclose an outline specification, which, in the event of our tender being accepted, can be expanded to meet the requirements of the PWD."
The specification includes:
Excavation. "To be taken down to, and a little way into solid rock, which is assumed, as stated in the Shire Specification, to be at a depth of 6'-6". Any depth of excavation below this to be treated as an extra."
Concrete Foundations and Abutments. All concrete over 3 ft thick is to be rubble concrete 8½ to 1, with not more than 20 per cent displacers. Concrete to have 3¼ c.ft. of cement (test 400 lbs) to every finished yard of concrete.
Wingwalls. Concrete less than 3 ft thick to be 7 to 1, with 4 c.ft. of cement per yard.
Monier Arch. Compo to be 3 sand to 1 cement (test 400 lb) with grid 3/8" and ¼" at 3" grid [sic] both ways. Cover 1" from soffit. Arch to be kept wet for one week and centres not to be removed before 2 weeks.
Timber. Messmate or Stringybark. "All work to be in best style of ship's carpentering."
Test. "Bridge to be capable of standing any test that may be applied to it up to 10 tons, without any permanent disfigurement whatever."
1900/02/19: M&A to GF&Co. Re Jamieson, M&A have designed a timber superstructure. "We have done this as an experiment to compete with an 80 ft timber truss in a timber district, access for cement being specially difficult. If we come anywhere near the timber cost, we shall address you at length and in detail for advice in developing a scheme for composite Monier and timber bridges, to compete outright with timber designs as to first cost."
1900/02/20: Shire of Howqua to M&A. The lowest timber tender was £715. Council have only £600 available and hope the PWD will advance the extra £358 to permit adoption of the Monier design. Council suggest M&A bring their system "under notice" to the PWD.
1900/02/22: M&A to McKenzie, MLA. [Member of the Legislative Assembly.] The Government has given only £600 for the "Sangers" Bridge at Jamieson. All tenders exceed this, M&A's being £358 higher than the grant. M&A would like to meet McKenzie to argue for an extra grant "to give your constituents a really good bridge".
1900/02/22: GF&Co to M&A, offering to give "our best advice" re Jamieson.
1900/02/23: M&A to T. Hill, Shire Secretary. Thank you for return of the deposit on Sangers. We hear you will be calling tenders soon for a 120ft span bridge. Could Mr Scott send particulars?
1900/02/15 M&A to Sec., Shire of Howqua. "We enclose herewith Bank Cheque payable to the President of the Shire, to the value of £48 being 5% on our tender. We also enclose an outline specification, which, in the event of our tender being accepted, can be expanded to meet the requirements of the PWD." The specification includes: Excavation. "To be taken down to, and a little way into solid rock, which is assumed, as stated in the Shire Specification, to be at a depth of 6'-6". Any depth of excavation below this to be treated as an extra." Concrete Foundations and Abutments. All concrete over 3 ft thick is to be rubble concrete 8½ to 1, with not more than 20% displacers. Concrete to have 3¼ c.ft. of cement (test 400 lbs) to every finished yard of concrete. Wingwalls. Concrete less than 3 ft thick to be 7 to 1, with 4 c.ft. of cement per yard. Monier Arch. Compo to be 3 sand to 1 cement (test 400 lb) with grid 3/8" and ¼" at 3" grid [sic] both ways. Cover 1" from soffit. Arch to be kept wet for one week and centres not to be removed before 2 weeks. Timber. Messmate or Stringybark. "All work to be in best style of ship's carpentering." Test. "Bridge to be capable of standing any test that may be applied to it up to 10 tons, without any permanent disfigurement whatever."
No further corespondence on file.
Image: Reinforced Concrete & Monier Pipe Construction Co. Collection, University of Melbourne Archives.
Note: M&A's drawing for this bridge is entitled "Proposed Bridge over Werribee River". Correspondence refers to the "Bacchus Marsh Bridge". However a later, T-girder bridge, built in 1915 over Pyrite Creek was sometimes referred to as the "Bacchus Marsh Bridge".
This project was initiated by the proprietor of the local newspaper, Christopher Crisp, who noted that the township of Bacchus Marsh had polarised into a "West-End" and an "East-End" and that the latter was stagnating, partly because of its distance from the existing bridge over the Werribee River. He thought this could be remedied by providing another bridge at the East end of town, and apparently thought the Monier system might offer an economical way of obtaining a substantial structure. In response, M&A designed a handsome arch whose architectural treatment seems to have been inspired by the Anderson Street Bridge (later named Morell) in Melbourne.
1899/07/15: Bacchus Marsh Express. The lack of progress in getting a bridge over the Werribee at Fisken St is attributed to opposition on the part of the "West Enders". A new bridge would prevent the East End "lapsing into the background more than it has done". Also it would be more convenient to the railway station. The author suggests a Monier bridge, saying there are eight such in the colony already.
1899/07/24: Crisp to M&A. He is trying to get a Monier arch over the Werribee River in the township. He suggests a width of 11 feet and a span of 70 feet (or 100 ft if JM wants to keep the abutments in the dry). If M&A give Crisp an idea of the cost he will then go to Albert Miller and see what aid he would give to the work, by loan of otherwise. Then he would bring the matter before the Shire Council. Or: "If you would like to take the matter up by communicating with Mr Miller and the Council yourself I shall be glad to leave the whole affair in your hands." If M&A come up by early morning train they can see the site and Mr D. A. Little, Shire Engineer and get away to Melbourne by midday train. Then see Miller before or after the visit.
Note: we have not identified Mr Miller. The MPs at the time were Thomas Brunton, Donald Melville and Sir Rupert Clarke (MLCs); S. T. Staughton and J. P. Chirnside (MLAs).
1899/07/25: M&A's initial estimate of £984 for an arch of 100 feet span, with a rise of 12 feet 71/2 inches (the same dimensions as for the centre span of the Fyansford Bridge) and a gross width of 15 feet.
1899/07/26: Drawing. "Proposed Bridge over Werribee River." Half elevation, half longitudinal section. Initialled by A G Timmins.
1899/07/26: M&A to Crisp. We need to examine the site before giving a quote. Can you arrange to meet JTNA and Mr Little? A very rough estimate would be £1000.
1899/07/27: Crisp to M&A. Thanks for your trouble which was more than is needed at this stage.
1899/07/29: Little (Shire Secretary and Engineer, etc) to M&A, enclosing a cross-section of the Werribee River at the site. The cross-section shows one bank as "alluvial liable to scour". The other bank is marked "clay" up to mid height, and "alluvial" above this.
There is some doubt about the month in the date of this letter.
1899/07/30: Second estimate, for a bridge of 75 feet span: £1111-17-0d. This allows for piles for both foundations.
1899/08/01: M&A to Little. Please complete the data form. There is no point in our coming out unless the project is fairly certain.
The "data form" was a proforma M&A sent to prospective client engineers asking for details of site conditions.
1899/08/02: Little to M&A. (Confidential.) Re yours of yesterday, there is very little hope. "Mr Crisp of course is a strong advocate for the bridge but I doubt if it will ever get further. Your estimate of £1000 is near enough. £200 either way will not drop[?] it. In any case you will hear much more about it before you are asked for an official estimate. I will mention at the next Council meeting that a bridge can be put up for about £1000 and there I think the matter will rest for some time at any rate. If however favourable developments should occur I will communicate with you."
1899/08/09: Crisp to M&A. Thanks for all your trouble. I will let you know what developments occur. "P.S. The Monier being special, warrants special action, apart from ordinary routine of initiative +c."
1899/08/09: M&A to Crisp. We much prefer the initiative to come from local people, while we merely hold ourselves in readiness, so please keep agitating.