Website Banner. John Monash: Engineering enterprise prior to World War 1.

[Main Index.] [Wall Structures Index] [People Index.] [Abbreviations.] [Units & Currency.] [Glossary.]

Miscellaneous Wall Structures.

JM's Swimming Pools.

St Peter's College Baths, Adelaide.

Photo of the baths just after completion with surrounds unfinished. There is some water in the bottom.

Photo:. University of Melbourne Archives, Reinforced Concrete & Monier Pipe Construction Co. Collection, BWP/23772.

Another historic image of the baths may be found in the University of Melbourne Archives Image Collection UMAIC. Search under Record ID for UMA/I/6227. Any enquiries to UMA regarding this image should quote Location Number BWP/23771.

The earliest RCMPC swimming pool of which we have found evidence was built for St Peter's College in Adelaide. A drawing in the J Thomas Collection initialled "JM 19/9/06" [19 Sept 1906] appears to be the pencil original. This date was prior to the installation of W W Harvey in Adelaide as Resident Engineer for the South Australian Reinforced Concrete Co, so Monash would have been personally responsible. The bath was 80 × 30 feet in plan, and the depth varied from 5 feet to 9 feet. The walls projected 4 feet above natural surface and were surrounded by earth embankments to provide a grassed surface 9 feet wide around the edge of the pool.

For notes on technical issues, see below.

There are few mentions of this project in RCMPC records, but there is a report that work was progressing well in January 1907. The pool must have performed satisfactorily, at least in its early years, because JM cited it in November 1909 when promoting the use of reinforced concrete for baths at Bacchus Marsh in Victoria.

[Top.]

Fitzroy Baths.

A historic image of these baths may be found in the University of Melbourne Archives Image Collection UMAIC. Search under Record ID for UMA/I/6509. Any enquiries to UMA regarding this image should quote Location Number BWP/24361. Another image, showing a smaller pool and changing sheds has Location Number GPNB/1159.

Monash must have learned of a proposal to build baths for the City of Fitzroy, a suburb of Melbourne, towards the end of 1906. Two pools were intended, a large one for men and a smaller one for women. RCMPC's records contain a plan of the site dated January 1907 and a note that the City Engineer, A Batson, had been allocated £1500 for the job. Monash seems then to have developed his design and specification in several stages in consultation with Batson. JM's assistant S J Lindsay checked his arithmetic and prepared drawings. By March, Monash had arrived at estimates of £1480 for the large pool and £480 for the small one, both figures including a 40 per cent margin.

In mid-April, the press announced that Fitzroy was to have new Baths, but further delay occurred. In September, Monash compiled a list of "some of the Largest Bath Installations in the World in R.C." presumably in the hope of convincing the Council and its Engineer to adopt reinforced concrete. Examples included Gebweiler, Lorraine (1899) and three localities in Alsatia: Morkirch(1901); Colmar (1904); and Strassbourg (1903); also "Starnberg, Wiesbaden, the Royal Military Academy Vienna, Stockholm, etc". By this stage, Monash's prices were £1679 and £583 for the men's and women's baths respectively. This was after calculating the likely total price for a competing tender with brick walls as £2000, allowing for a backing of puddle clay.

More delays occurred. By 18 February 1908, JM was aware of a competing tender from Reid Bros & Russell and had a copy of their specification which incorporated expanded metal reinforcement and proprietary Kahn bars. He was also aware that Batson was willing to accept an unreinforced concrete floor in conjunction with brick walls. He therefore decided to pull his own price back a little and offer a price for reinforced walls with unreinforced floor. His notes read:

Bedrock for brick2263
Bedrock for exp. metal2533
fair cost for Monier1685
our former tenders2262
proportional margin577
proposed present margin450
Therefore our tender£2135
Our advantage over brick£127
Our advantage over Exp. Metal  £398

In his covering letter, Monash emphasised that his reinforcing system [under the Monier brand and patent] was scientific compared with Expanded Metal. He strongly advised Batson against the use of an unreinforced floor.

RCMPC's tender of £2135 for the swimming basins, only, was accepted on 3 March 1908 along with an indemnity against unsatisfactory performance. The contract for the associated offices and boundary walls was awarded to H Henningsen. RCMPC's first requisition for materials was issued on 13 April. Monash sub-contracted the pipework to Frederick Atherton and the excavation to Heron & Parker.

Cross-section through one wall and part of the floor of the pool.The definitive drawing was issued on 21st. The wall had no counterforts, but was equipped with a horizontal rib or fin projecting from its back. In the working drawing this is shown at varying heights, level with natural ground surface and presumably cast upon it. Monash explained, in a memorandum for Works Manager Alex Lynch, that "The stability of the design against being pressed in by the earth, depends upon the "fin" which projects all round 21" back from water face of wall." This could be placed at any height where it had a good foundation. "The floor has no work to do except watertightness."

For more on technical issues, see below.

On 30 September 1908, JM declared the work "substantially complete", but Batson resisted claims for further progress payments until the baths had been filled and tested. After filling, he complained that there was evidence of leakage. Monash was not convinced, but agreed with Batson that their respective foremen should sort things out. By June 1909, Lynch was able to report that all defects had been rectified and in July, JM noted that the Fitzroy accounts were "fully squared up".

[Top.]

Croydon Swimming Basin.

RCMPC built a swimming pool, also referred to as a "basin", in Croydon in March-April 1914. It seems to have consisted merely of a concrete lining 3 inches thick with sides sloping at 60 degrees to the horizontal. A drawing shows outer plan dimensions of 39 × 21 feet, and depth varying from 3'-6" to a maximum of 5'-6". There were narrow steps at each end following the slope of the sides. RCMPC's account, for £107-13-0 was sent to J P Jones MLC, of 'Ruskin Park', Croydon.

[Top.]

Some unsuccessful projects including Essendon.

The pools at St Peter's College and Fitzroy seem to be the only examples of their type built by RCMPC. Monash quoted roughly £400 to £450 to architects J J & Clarke for a similar bath at Horsham, but without result. He also made unsuccessful proposals for baths at North Melbourne (August 1909) and the Shire of Bacchus Marsh (November 1911).

In the second half of 1911 JM's friend W Murray Pullar, Engineer for the City of Essendon, contacted him to ask the cost of the Fitzroy pools. Pullar had £2500 available to spend on a pool, buildings and other ancillary works. He was proposing a basin 150 by 60 feet in plan and somewhat deeper than at Fitzroy. Nothing transpired until June 1913, when Pullar spent an evening with Monash and produced a drawing "upon which he had delineated an outline plan of the proposed baths with sundry vertical sections, which were a bare and incomplete copy of the design of the Fitzroy Baths". He invited JM to draw up a specification for a pool of reduced size, 115 × 60 feet in plan, with a depth ranging from 9 feet to 3 feet 6 inches.

After some delay due to illness, Monash obliged with a draft. Again, the question of intellectual property reared its head. JM noted: "I think in fairness to me your drawing shown to tenderers should not even remotely suggest the type of Cantilever wall used by me at Fitzroy. This is the crux of the whole matter and any tenderer grasping the idea of it might get a design on my lines and do as well as I. I therefore urge you to show only the outline of the walls …" Further, Monash had made the specification "very stiff", to ensure that inexperienced tenderers would do a good job. As, on the contrary, JM would give Pullar "a thoroughly sound, guaranteed job", he hoped there would not not be "some silly inspector to worry us about subordinate details, simply because they have been specified".

The specification contains the phrase "Retaining wall to be designed with sufficient thickness and a sufficient width of base plate, and sufficient degree of strutting with close spaced counterforts or otherwise, as to ensure that the walls will be absolutely watertight and absolutely stable both under the pressure of the full head of earth filling, when the bath is empty, and under the full head of water when the bath is full".

Pullar's response was that he had not intended JM to go to so much trouble, but the completeness of the specification meant he could call tenders expeditiously. There is no indication in RCMPC's records that the firm obtained the Essendon contract, despite JM's efforts.

In February 1914, Monash tendered very cautiously for baths in the City of Brunswick, a centre of brick-making. It seems that the City Engineer had prepared his own reinforced concrete design. RCMPC submitted a tender on that basis, but also offered a modified design in accordance with their practice at Fitzroy. Again, its exact nature was not revealed. Monash's covering letter stated: "should our tender be accepted, we will be pleased to submit details of our design to you, and will, of course, accept full responsibility in regard to same". However, at the end of the month the Council announced that all quotations were too high, and that fresh tenders would be invited.

In July 1914, W H Melville, barrister and solicitor, enquired about the cost of a pool for Hamilton. JM quoted a price range for a pool the same size as the women's pool at Fitzroy, depending on the "finish and elaboration" required. He assured Melville that it should pay as a commercial proposition whatever the entry fee, but advised him to get a local engineer or architect to work out an overall scheme so that RCMPC could then give a definite costing for the basin alone.

Discussions initiated in October 1912 concerning baths for Warragul resulted in a submission in June 1915 which missed the deadline for closing of tenders.

The early promise of a new line of business offered by the swimming pools at St Peter's College and Fitzroy thus seems to have come to nothing.

[Top.]

Monash's Retaining Walls.

Old and new compared.

Comparison of mass concrete and counterfort reinforced concrete retaining walls, as in main article on Preston No.2 Reservoir.

Above left: the traditional gravity retaining wall (stone, brick, unreinforced concrete). Above right: a modern reinforced concrete retaining wall.

Preston No.2 Reservoir.

The most important of Monash's free-standing retaining walls (sketch above, right) were those of the Preston No.2 Reservoir. Design commenced in January 1908 and construction of the walls themselves began in August. Slight tilting - to a degree that would not now be considered unusual - became evident in October as earth embankments were built up behind the walls. The reservoir was filled for the first time in April-May 1909 for testing. The client, the Melbourne & Metropolitan Board of Works, was concerned about the stability of portions of the walls, and loss of water through the walls and floor; but Monash believed that the MMBW's expectations were unreasonable. A detailed account of the construction of the reservoir, and subsequent disputation over contractual and technical matters is provided elsewhere in this website. [Preston No.2 Reservoir].

[Top.]

Lovely Banks Reservoir Project.

The MMBW's discontent with Preston No.2 Reservoir did not prevent Monash from preparing a similar design for a smaller reservoir at Lovely Banks, north of Geelong, starting at the end of May 1909. The prospective client was the Geelong Water Works Trust. JM had known the Trust's Engineer, J S Sharland, since at least 1901 and they were on friendly terms.

The calculations are interesting, because they show Monash dusting off his higher mathematics. Given that the reservoir had to hold 7 million gallons of water, he attempted to use differential calculus to find the optimum ratio of wall height to plan area to give minimum cost. He finally arrived at £5605 for a retaining wall with counterforts and £4400 for a plain cantilever wall with no counterforts. Both schemes included a reinforced concrete floor and were square in plan. They lacked the outer earth embankment which at Preston No.2 helped the walls resist the outward pressure of the water.

With these proposals, JM visited the Sharlands and inspected the site. He borrowed Sharland's field book showing spot levels over the site, and asked him to sink trial pits to check the nature of the soil. This was a covering several feet deep over rock. Later, he sent Sharland a gift of a circular slide-rule. He encouraged Sharland to persevere in its use because, once he became familiar with it, he would find it provided "an immense saving of time and mental energy". While continuing to develop his design for the wall, JM worked out a cubic equation for cost to optimise the ratio of plan diameter to height of wall, solving it by trial-and-error.

Further calculations showed that it would be cost-effective to excavate the soil from the base of the reservoir and bank it up behind the walls to provide support. This allowed him to reduce the thickness of the wall and its footing, and also the amount of reinforcement. He wrote to Sharland: "Since my conversation with you on 3rd instant, I have completed all design calculations and preliminary estimates … I have devoted lengthy consideration to your proposal to dispense with a solid concrete floor over the whole basin, and have come to the conclusion that this is quite feasible, in view of the nature of the ground." The plan now was to strip the topsoil to bare rock and fill any cracks in the rock with concrete. This would reduce the total cost of the scheme to £5000 of which £500 was allowed for filling cracks and for appurtenant works. JM added: "The following particulars of the principal features of the design are submitted to you confidentially, and on the understanding that they will not be used in any competing mass concrete design that you may be called upon to prepare".

The wall appears to have no counterforts. It is relatively thick at the base and tapers to a minimum just over half-way up, the rest being of constant thickness. At the location illustrated, earth is banked up behind to wall to about half its height.Monash described the proposed wall as an inverted T, but the heel was so short and the toe so long, that it looks more like an L. The base was to be 13'-4" wide, where the wall was 15'-6" high, and reduce to 5 feet wide where the height was 6 feet. Monash noted: "The soil taken from inside of reservoir floor will be used to make an earthern escarpment or embankment around reservoir wall, having a top berm level of 262.50 and a width of 30 ft." If Sharland approved of these details, JM would "proceed expeditiously" with contract drawings and specifications. He asked: "Will you now kindly say whether above particulars have your approval, so that contract drawings and specification can be expeditiously gone on with. As there is a good deal of work in these, I want to be sure before hand that they are on lines which you will approve."

In a memorandum dated March 1910, prior to leaving on his world tour, JM noted: "Mr. Sharland gave me a definite undertaking that if this job matured during the time that I was away, he would afford us a definite opportunity of submitting an alt. tender for same." However, in June, Gibson wrote to him (overseas) saying: "Sharland has finally backed out of your design for the Lovely Banks reservoir, says he must do it in earthwork, but promised us some work in the shape of a reinforced concrete cover thereon".

[Top.]

Adelaide Gas Works Coal Store (Project).

At the end of December 1909 the Adelaide Gas Works asked SARC for a price for a length of retaining wall for their Coal Store, 400 feet long and about 15 feet high. This was just as W W Harvey was due to hand over his duties as Resident Engineer to H G Jenkinson. The existing wall consisted of a few feet of masonry topped by galvanised iron sheeting, and ran alongside a footpath. A reinforced concrete retaining wall would make it possible to build up coal against the wall, and greatly increase the usuable capacity of the store.

The base slab does not project beyond the face of the wall, so as not to encroach on the footpath. The cross-section is therefore L-shaped. The counterfort is a right-angled triangle.Under pressure from the gas company, Jenkinson prepared a hurried design and estimate, and sent them to Monash on Friday 7 January 1910, asking if JM could review them before leaving on the Monday for Seymour (where he was to conduct military manoeuvres in front of Field Marshall Lord Kitchener). Monash's return letter explains that Jenkinson's documents had arrived at the Melbourne office at 12.15 p.m. on the Saturday and it had been "pure chance" that JM had dropped in. He had been able to take some material home, but was obliged to assess the proposal "without any assistance and without access to any reference papers or precedents". He added: "In future, wire warning in such a case".

Nevertheless, Monash gave the design a detailed review, presumably in the midst of his preparations for the military Camp. He was concerned that the base slab did not project in front of the wall. He explained: "The fundamental difficulties about a design which has no toe … are: (a) that the joint between base plate and wall plate will be a rather tricky one to carry out, (b) the intense pressure on base near face of wall, acting on clay, will induce tilting, like at Preston. Even 12" or 18" of a toe in front of wall will help greatly to increase stability and reduce maximum base pressure. I cannot believe that encroachment upon the footpath for 1 ft or 2 ft for a footing can matter. Most buildings have their footings sticking out in this way. The footpath will be torn to pieces in any case." However: "In other respects your design, so far as I have had time to check it, seems all right".

The comments on Jenkinson's cost estimates were even more detailed:

"This is a broken up, intricate, and complex job. While your concrete cost of 1/3 per cubic foot is high, I do not think your labor cost of 1/3 per c.f. is high enough - 9d. per c.f. for steel is about right; but you have allowed nothing for timber cut to waste, plant, &c. I consider that allowing on fair lines for all these matters, the reinforced concrete will cost you net, in Adelaide, fully 3/6 per c.f. Most of our Adelaide wall work has in the past cost nearly 4/- per c.f. The only extraneous work you have allowed for is Excavation, and £5 for 'pulling down'. Who supports existing roof? Who dismantles existing G.I. [galvanised iron] fence and posts? Who fences off footpath and provides hoardings, lights and watching? Rendering ought to be done easily for 2/6 per cubic yard net cost by day labor. Your result of £1177 for a 400 ft wall, 17 ft high, is under £3 per ft. I think it is worth every penny of £3-10-0 per foot to cover all margins. A complicated job like this is not worth having except at a good margin. We should, on a gross expenditure of £1000, clear at least £250, which is only 20% on sale price. Without attempting to re-compute figures in detail, I think something on following lines would better meet the case:
236 ft of wall max 16 ft high @ £3/5/- = £767
160 ft of wall max 20 ft high @ £3/10/0 = £560
External rendering to both £97
E end Wall 74 ft @ £5 = £370
rendering ditto £28
W end wall 46 ft @ £4 = £184
rendering ditto £15.
Above figures are subject to preceding remarks as to proper provision for all extraneous work &c to be done by us. We will probably have to compete against mass brickwork. The trouble in such a case is that the alternative design will probably not have anything like our factor of stability. Also it will take up more storage space than our wall."

On 12th January, SARC quoted the Gas Company £1321 plus £97 if rendered, for 400 feet of wall along the north side of their coal shed, including the gate, and demolition of the outside brick wall along First Street. For 75 ft of wall along the east end of the coal shed the quote was £394 plus £28 for render. The Gas Company advised that the cost was too high and they were looking for an alternative.

[Top.]

Geological Museum Retaining Wall.

Comparison of cross-sections of the PWD wall and the RCMPC wall. The PWD version has no counterforts and has the appearance of a gravity wall whose upper portion has been pared down.This wall supported a concourse in front of the Geological Museum. It was designed by P T Fairway in May 1910, while Monash was overseas on his world tour. The Department of Public Works had prepared a conservative design with massive thickening at the joint between wall and base slab. Fairway's computations indicated that a counterfort wall would be cheaper. He told H J Kerr, Acting District Architect for the PWD: "We have estimated on a somewhat modified design from that shown on your drawings, but have maintained the same depth, height, and outside dimensions and details, and we will guarantee the stability of such modified design in every way".

Fairway noted: "Except for amendments obviously necessary for the carrying out of proposed design, the [PWD's] Specification (original) is quite satisfactory to us". The specification is of historical interest because it was written before engineers began to exercise close control over water/cement ratio and workability to ensure the strength of concrete. It reads in part: "The concrete to be only sufficiently fluid to run freely into place but not too fluid and to be well tamped into corners and around reinforcement".

Construction of the wall was complete by September, when the final account was submitted. In a list of profit and loss on works in hand and completed during Monash's absence, Fairway recorded receipts on this project as £224. With a cost of £136, this gave a gross profit of £88.

[Top.]

District Exhibits Building Retaining Wall.

This is another case of a retaining wall associated with a building. The specification states that the work was to be done in extending the District Exhibits Building at the Show Grounds. "The work includes the cutting away and removal of the embankment under the concrete Stand behind the District Exhibits Building, and erecting reinforced concrete retaining wall to support the embankment. The floor to be made up to level of District Exhibits Building and asphalted. The space between top of stand and top of District Exhibits Building to be covered in with glass. The two ends of the stand also to be covered in. Afterwards the ceiling of the Grand Stand to be lined with iron."

Fairway's computations, in May 1913, include an estimate for the cost of building the wall "as per architect's design". (The architects were Billing Peck & Kemter.) The price for his own design came in cheaper, at £399, and with the architects' approval, was accepted by Master Builder R L Phillips. The wall ran on three sides of the Stand, varying in height from 14 feet to 10 feet. PTF noted: "Use counterfort system for 60 feet and vertical cantilever for 90 feet". Drawings were prepared by C W N Sexton. The first requisition for materials was issued on 24 June 1913.

[Top.]

Esquisses for retaining walls at Oakleigh and Nhill.

In October 1911 a rough estimate was prepared for a Reservoir at Oakleigh for the MMBW. It is described in the RCMPC file as "very similar to Preston but smaller - 10,000,000 galls". The MMBW had prepared a conventional design with gravity retaining walls and presumably stuck to its conservative principles, as there is no indication that RCMPC won the contract.

Some time prior to October 1913, Monash was visited by A F Magill, of the Nhill Water Works Trust, and the Shire President to enquire about storages for the remodelled water supply for the town. On Monash's behalf, assistant engineer J A Laing looked at options for either 1 million, 2 million, or 3 million gallon reservoirs. RCMPC's scheme would once again be based on the Preston No.2 model. This proposal also remained in RCMPC's 'Quotation File' and there is no evidence of any outcome.

[Top.]

Other Retaining Wall Projects.

Many other free-standing retaining walls were incorporated in RCMPC projects. Proposals for a winery at Mildura, for the approaches to a proposed bridge in Adelaide, and for works at Corowa racecourse are some examples. Many retaining walls were built as abutments to bridges.

The walls of many building basements had the function of holding back earth, and were referred to by RCMPC as "basement retaining walls", but have not been included here as they relied on the building structure for support along the sides and top.

[Top.]

Notes on the Engineering of the Swimming Pools.

Cross-section through one wall and part of the floor of the pool. Refer to text below.The structural system used at St Peter's and Fitzroy, as shown in the drawings, is intriguing. There is no evidence of counterforts, which is understandable for relatively low walls. Instead there is a horizontal rib attached to the back of the wall, level with the natural surface. As there are no notes or computations remaining in the relevant files, it is difficult to imagine just how the fin was supposed to work. It is far too small to act as a horizontal beam spanning the whole length or width of the pool. However, in a memorandum to Works Manager Alex Lynch, Monash made it plain that he saw the horizontal rib as essential to the structural action of the wall. (Later, he was concerned that the idea might fall into the hands of competitors.) He also stated that the job of the floor was simply to act as a watertight barrier.

While it is tempting to draw conclusions about structural action from the sketchy indication of reinforcement on the drawings, we must remember that Monash was concerned to protect his intellectual property. The cross-sections for St Peter's and Fitzroy suggest that the portion of wall projecting above natural surface - together with the rib - was seen as forming an L-shaped retaining wall, with the rib acting as its 'heel' (see my diagram herewith). The idea might have been that when the pool was empty, the weight of earth pushing down on the rib would resist the tendency for horizontal earth pressure to overturn the L, anticlockwise, into the void. The connection between the bottom of the wall and the floor shows little strength. At St Peter's, the portion of wall below the rib has vertical reinforcement only on the water face, suggesting that this portion was imagined to span vertically between the rib and the floor of the pool.

The walls at Fitzroy show a horizontally cantilevering slab attached to the top, like a second, upper, rib. Presumably its only purpose was to provide a narrow band of hard standing around the edge of the pool.

The proposal for the Essendon pool shows a more conventional retaining wall with a cross-section in the form of an inverted T. Some reinforcement is shown running across the joint between toe and floor slab to provide dowel action.

[Top.]