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This was a project on which Monash and Anderson worked jointly, with Anderson prominent in the early stage and Monash in the later. The partners' submission was encouraged by Carlo Catani, the government's Engineer for Harbor Works. From Sydney, W J Baltzer provided initial design drawings and computations, which the partners studied and developed. Although Monash & Anderson's price for a Monier reinforced concrete tower was considerably lower than that of their only competitor (for a plain concrete tower), the Chief Engineer responsible for lighthouses chose not to adopt the relatively new form of construction.
Figure: Cut-away elevation with cross-section near base. Extract from the tender drawing. (University of Melbourne Archives, Reinforced Concrete and Monier Pipe Construction Co. Collection.)
As holders of the licence in Victoria for the patented Monier system of reinforced concrete construction, Monash & Anderson were asked in August 1899 to quote for design and construction of a lighthouse for Point Lonsdale, near the entrance to Port Phillip Bay. The request came from Carlo Catani, Engineer for Harbor Works with the Department of Public Works, Victoria, acting on behalf of the Chief Engineer of the Harbours and Rivers Department, a Mr McLean. Catani had experienced the advantages of reinforced concrete in his native Italy, and was keen to see its more widespread use in Victoria. He had already encouraged the application of the 'new' technique to the construction of arch bridges.
M&A had been granted its licence by the Sydney firm of Carter Gummow & Co, which held Australia-wide rights for the Monier system. Part of the agreement was that the Sydney firm would supply expertise as required, mainly through its design engineer, W J Baltzer.
Initially, the hollow cylindrical tower for the lighthouse was required to be 30 feet (9.14 m) high, from ground level to the platform that would support the lantern. Monash & Anderson's preliminary figuring suggested a wall thickness of six inches (152 mm) and a price of approximately £300. They wrote to Gummow: "We think it would be well, if Mr Baltzer could spare the time, to outline a design at once, and send it to us together with the outline of the principal calculations upon which the sizes have been fixed. We can then elaborate the details, when close particulars are made available to us."
The tower was to be built on solid rock and have an internal diameter of 9 feet (2.74 m) or perhaps 9'-6". Wind pressure was to be assumed as 50 pounds per square foot (2.39 kPa). Baltzer was requested to calculate the required wall thicknesses at top and bottom, and "the disposition of the Monier lattices" [i.e the grids of reinforcing rods].
Following the death of Carter, and during the events recorded here, Carter Gummow & Co became briefly F M Gummow & Co, and then Gummow Forrest & Co.
Within a week, Baltzer had responded with a drawing, an explanation of his outline design, and advice on construction.
On 26 February, the Harbors Department announced that it now wanted a tower 70 feet (21.3 m) high, and requested a revised quotation. The internal diameter was to be 9'-6" (2.90 m). Stairs and landings were to be provided, leaving a weight-well three feet (914 mm) in diameter down the middle. The platform for the lantern would have a diameter of 20'-3" (6.17 m), and the lantern itself (to be supplied by Chance Bros of England) would measure 13'-6" (4.11 m) across.
Again, M&A wrote to Gummow, providing these and other details. "Will you be good enough to supply us with a design for such a structure carried out entirely in Monier work? We think it highly desirable that you should supply us with an outline of the calculation of stability, and stating what wind pressure you assume." Because the site was elevated, there would be no need to consider wave pressure.
At this point the correspondence becomes confusing. The details supplied by M&A were headed "Split Point Lighthouse". Split Point is at the town of Airey's Inlet further west along the coast of Victoria. For some weeks after this, letters from both parties include references to the "Split Point / Point Lonsdale Lighthouse", or even the "Split Point Lonsdale Lighthouse". Then they revert to "Point Lonsdale Lighthouse". The present Split Point Lighthouse was built in 1891 (of plain concrete) so it could hardly have been the subject of a call for tenders in 1900. Split Point.
On 8 March, Baltzer sent another drawing and lengthy tabular calculations to M&A. In his scheme, the tower walls were to be reinforced by vertical rolled steel joists (3" × 4", 76 × 102 mm) as well as steel reinforcing rods. Monash studied Baltzer's rough calculations, made a "précis", and then prepared his own more precise version, allowing for variations in tower diameter and wall thickness over the height. In the process he did away with the steel joists, replacing them with additional reinforcing rods. (More details below.)
Early in April 1900 M&A informed Gummow that the Public Works & Harbors Department had definitely decided on Monier construction for the lighthouse. "The Monier design and that only will be gone on with." They were now awaiting accurate details of the lantern from England. Once these arrived, Catani's Department would prepare the working drawings upon which tenders would be called, and Catani had promised to refer to M&A for advice and information on the details.
On 20 July, Monash and Anderson were called to a meeting with Catani. His rough sketches, preserved in the RC&MPC files, suggest they discussed details of the stairs and landings, and of the cantilevered platform to carry the lantern. Then followed a flurry of final computations, including a check on the factor of safety against bodily overturning (three). A hand-written Schedule reveals that the contract included provision of an inspector's office, cast and wrought iron components, external plastering, the internal casing of the tower, speaking tubes, lightning conductors, and windows and ventilators. Cement would be bought from the works at Fyansford, near Geelong, and materials would be delivered from Melbourne by boat to Queenscliff. As was his custom, Monash prepared a document setting out the principles on which his design was based. (See technical section below.)
A "First Rough Estimate" of cost resulted in a figure of £1286-19-6. This included the Monier Royalty for 77 cubic yards of "Compo" @ 8/6 = £32-14-6, payable to Gummow Forrest & Co. The tender price, excluding the fixing of the lantern, was set provisionally at £1900.
On 5 September, Catani wrote to say that he had now received the formal requisition for the lighthouse, and to ask the partners to meet him to arrange final details. Anderson was called unexpectedly to the Charlotte Plains Gold Mine where M&A were constructing an underground pump chamber protected by a Monier vault. He told Monash "This means you will have to go to Catani alone. Of course you know that I am content that you should use a free hand in the Lighthouse matter."
Over the next couple of weeks, the partners were preoccupied with other projects - problems at the Wheeler's Bridge site, the job at Charlotte, and submission of tenders for the eight Monier arch bridges at Bendigo. On 27 September, word came that tenders for the lighthouse were to be called within a month. Monash noted in his diary for that day: "I at office with Vic all evening at Lighthouse". (There is evidence elsewhere in the records that Victoria Monash occasionally helped her husband with bookwork.)
The full working drawing showing the foundation, concrete tower with porch, and details of the metal fittings and platform is intitialled by M&A's draughtsmman, J S Gregory. The cut-away elevation and the cross-section shown above are reproduced from this drawing.
The estimate of cost included £128 for the mass concrete base and £756 for the Monier tower. On top of these and other basic costs, it allowed 4% for contingencies, £130 for supervision over 26 weeks, and £39 for costs in the Melbourne Office. This gave a total of £1270, to which was added £350 for profit, resulting in a price £1620.
M&A did not have the right to prevent general contractors from tendering to build structures using the Monier system, but they did have the right to charge them a royalty. A letter to Neville & Kelly from Geelong sets this at £165 for the lighthouse.
As December progressed, M&A staff copied parts of the government specification for the lighthouse, and Monash prepared an appendix to apply to Monier construction. His diary shows he spent 26th at the office, before taking Vic on a harbour cruise in the evening. On 27th Herman Roth, then a clerk in Monash's office, and presumably sent to witness the opening of tenders, reported that he had heard Catani "gasping at a concrete price of over £2000". However, no immediate decision was taken, and Monash left for a working holiday in Sydney during which he socialised with Gummow and Baltzer, visited GF&Co's works, and made good progress in putting the business relationship on a sound basis.
Early in the New Year, Anderson learned that M&A's tender was the lowest out of three. One of these had been declared informal, and the other was for a plain concrete tower, at £2252. Confident that the contract was won, he made plans to contact Charles Evans, a foreman with marine experience, and sent for a copy of the official Specifications - only to be told that there was still no decision on the type of construction to be adopted.
On 11 January 1901, the Department informed M&A that they had been unsuccessful and returned their deposit. On 12th, the partners learned from the morning newspapers that the tender for plain concrete had been accepted.
M&A's letter to Gummow (probably written by Anderson) stated that they had called on Catani, who had been "very sympathetic though reticent and shame-faced". He would tell them only that the PWD had been acting on behalf of the Harbours and Rivers Department. Its Chief Engineer had at first approved Monier construction, but had finally made an official recommendation that plain concrete be used. Catani's Department had been obliged to accept this decision. The writer explained that it would be "impolitic to make any fuss about this, as it might prejudice us in the future, and we must particularly avoid doing anything to embarrass Mr Catani, as we believe that he did his best in the interests of Monier in the matter throughout". In his reply, Gummow regretted the treatment M&A had received, but agreed it was "best to be philosophic". He expected that Catani would also be annoyed with the way he had been treated.
In the calculations, the tower is treated as a vertical cantilever subjected to gravity and horizontal wind forces. Wind force is calculated as a static pressure on a projected vertical face due to 50 psf. The 70-foot tower is imagined sliced horizontally into seven 10-foot portions. For the base of each portion, the weight above (including lantern) and the bending moment due to wind are listed, together with geometrical properties of the annular concrete cross-section. The stresses on the concrete due to weight and moment are computed and added algebraically. Analysis of the reinforcement is considered quite separately. The cross-sectional area of the rods (varying from 3/8 to 5/8 inch and spaced 3 or 4 per foot of circumference) is imagined spread around the circumference to form an annulus of equal cross-sectional area, and the stresses in it due to weight and moment are calculated ignoring the concrete. The table of final calculations has seven rows of figures (one for each cross-section) and 22 columns. No attempt was made to analyse the cross-section as a cracked section, as is now normal for a reinforced concrete beam or beam-column. The results for the concrete section alone were 141 psi compression and 55 psi tension. For the steel annulus considered equivalent to the reinforcement (neglecting the concrete) the stresses due to moment alone were computed at just over 11,000 psi. No attempt was made to combine these with compressive stress due to weight.
The main points of Monash's "Outline of Design" included: