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Water supply reservoirs: water towers

On this page:
[Mildura.] [Tatura.] [Rochester.] [Echuca.] [Tongala.]

Mildura Water Tower

1. 2.

1. University of Melbourne Archives image NN/764.
2. Geoff Taplin, c.1997.

Location: Madden Avenue, Mildura (-34.18546, 142.16398). Fate: Extant. Firm: RCMPC. Designer: John Monash. Assistant Designer: J. A. Laing? Draughtsman: J. A. Laing. Client: First Mildura Irrigation Trust (Urban Section). Client's Engineer: C. J. Grant. Client's Consultant: A. G. M. Michell. Initial Design: January 1911. Major Design: February 1911. Modified Design: July 1911. Construction: October 1911 to March 1912.


Grant first approached RCMPC in September 1909, asking for a quote for a 100,000 gallon tank with its floor some 60 or 65 feet (18.3 or 19.8m) above ground. Shortly after, he may have enquired whether a 'standpipe' would be suitable, for Monash replied: "If the water in the lower 60 ft be not actually required, it would be much cheaper to build a tank of the required net storage of 100,000 gallons, elevated upon a substructure of reinforced concrete columns braced together. We have already built a number of such structures, but upon a somewhat smaller scale, one at Dudley St, Melbourne for the Railway Dept. It would be wasteful to make this structure a Water Tower holding water from the ground upwards as the shell tension for so great a height would be considerable." A tank "of plain design" would cost £1250 to £1400 fully equipped and "would of course require no future maintenance whatsoever". Monash evaded Grant's request for a fully detailed design.

There was a delay until early 1911 before tenders were called. Grant advised Monash that a drain should be provided near the foundations to carry away leakage, and suggested the tank be 37 ft in diameter and 16 feet deep. Monash replied that such a wide shallow tank, with large floor spans, would be uneconomic; and Grant would be advised to leave the design to him. Detailed computations were made by Laing or Fairway. A sketch of a water tower from Emperger's 'Handbuch' suggests that this may have influenced design. The supporting structure was a circle of columns enveloped by a thin cylindrical wall of reinforced concrete, to which they were attached.

In February 1911, Monash produced the computations for the tender design. He investigated the possibility of a strip footing for the wall of the shaft but adopted a full circular raft 30 feet (9.14m) in diameter. Tenders were called in mid-March, the documents being available for inspection at the office of A. G. M. Michell. An undated specification exists marked "Compiled with Mr Grant", suggesting that Monash as usual advised on its formulation. Michell made minor amendments which resulted in a slight rise in the tender price to £1784-13-0 and this was submitted on 12 May. Unofficial approval was communicated when the Secretary of the Irrigation Trust wrote to say that the river was low and they were taking the opportunity to win sand. How much would RCMPC need?

Michell's proof-engineering of the RCMPC design, with resulting discussions and negotiations, lasted until the end of July. Monash agreed to increase the thickness of the tank floor from 9" to 12" and that of the foundation plate from 18" to 33" - also to provide a conical base to the central column where it rested on the foundation plate. Later amendments included a flaring of the walls to 12" where they met the foundations, increased reinforcement in the foundations, and an increase in the strength of the concrete. In mid-July the Trust wrote to ask about progress and Monash replied he was "very much upset at the long delay which has taken place in the Dept in dealing with our tender". The men and materials held in readiness for the job had been dispersed to other jobs and it would take two or three weeks after signing to reassemble them.

Lynch went to Mildura in mid-October to get foreman Giggins started on construction. The job was marked by the somewhat eccentric behaviour of those involved. The Clerk of Works, P. J. McGrath, evidently felt he had a special relationship with Monash and sent chatty letters reaffirming a promise to smooth RCMPC's path, commenting on the running of the job, and praising Giggins's capabilities as foreman. Monash seems to have been sufficiently cool in his responses for McGrath to change the ending of his letters from "Yours affectionately" to "Yours respectfully". Giggins seems to have been somewhat overcome by the responsibility for such a large project, at a time when there was an acute shortage of skilled labour. He twice left the job and returned to Melbourne. When Monash received a telegram from someone announcing that work had again been halted, he wrote to Giggins:

"Of course you will understand that so long as you are in charge on our behalf as Foreman, your authority will be fully upheld, and we will not be tempted to go behind your back at the instigation of any other person. In view of the fact however that we are prepared to be loyal to you, we expect you to be equally loyal to us, and if for any reason whatever, whether justifiable or not, you find it necessary to stop the work or threaten to leave it, we would of course expect you to give us immediate notice, so that our valuable interests should receive no injury … I would impress you strongly with the fact that we have reposed full confidence in you to see this job through and to protect our interests in every way, and I trust that from now on you will see that we have no cause to feel any uncertainty or doubt as to the wisdom of our choice in entrusting you with so large and important a piece of work."

Eventually Lynch was sent up to investigate and reported that the progress and quality of the work was good, as was Giggins's relationship with the locals. In fact, he was somewhat too popular and his salary was not large enough to meet his "social expenditure". As the tower neared completion at the end of February 1912, a crowd climbed to the top to look at the view, eliciting a response from the police. Monash checked with Major Brown, Secretary of the Trust and presumably a colleague in the militia, to ask whether any of the RCMPC men were involved. Brown replied that Giggins and another man had been, but the crowd had done no harm and the police action had caused more excitement than if they had been left alone.

Despite pressure from Brown, Monash delayed plastering until after the summer, on the grounds that conditions were not favourable. A severe shortage of plasterers might have been a factor in this. From late April to mid-June, R. Coghlan seems to have taken over as foreman. RCMPC presented its final account on 7 June for the contract amount, without extras. At the end of July, Lynch reported there was then no serious leakage, but correspondence on leakage problems and attempts to fix them continued until the end of December. In October the loss was calculated at 4.5 gallons (20 litres) per day. In January 1913 a new Trust Secretary, W. Burrows, took over from Brown. The correspondence on leaks developed new life, but Lynch, once more sent to investigate, reported the tank was in good order; the leaks were not serious; the Trust was not worried; and Burrows was simply "showing off". However, the latter sent drawings and photographs of leaks and persisted in his attempts to have them remedied. As late as August 1915, Gibson wrote to Monash (at Gallipoli) "we have been at our wits end to get over the trouble". Hope was now placed in an asphalt-based compound which might seal the cracks while coping with movement due to temperature change and moisture content.

Technical Description (based on drawings)

Capacity: 100,000 gallons (455,000 litres). Tank: mean internal diameter 29 ft (8.84m); depth 25'-5" (7.75m); wall thickness 3" (76mm) at top (with stiffening ring), 8" (203mm) at bottom (with thickened portion). Concrete roof supported on three parallel beams. Tank floor: basically 12" (305mm) deep, thickened near supports and thinned at cantilevered periphery. Cylindrical shaft 57'-6" (17.5m) high and 21'-4" (6.50m) internal diameter, with generally wall 7" (178mm) thick. Central column of Monier pipes of 2'-10" (864mm) outside diameter, filled with concrete and eight 5/8" (16mm) bars. Circular foundation raft 18" (457mm) thick.

Historic images of the Mildura reservoir held by University of Melbourne Archives have Location Numbers from NN/761 to NN/766.


Tatura Water Tower

1. 2.

Photos above, c.2000: 1. Exterior. 2. Interior, beneath floor of tank.

Location: Murchison-Tatura Road, Tatura (-36.44296, 145.2224). Fate: Extant (2000). Firm: RCMPC. Designer: John Monash. Assistant Designer: J. A. Laing. Client: Tatura Waterworks Trust. Client's Engineer: A. E. Castles. Initial Design: May 1911. Definitive Design: September 1911. Construction: September 1911 to April 1912.


This project marks the start of a fruitful professional relationship between RCMPC and A. E. Castles. On 9 May 1911, Monash received a list of forthcoming projects administered by Castles and made notes on the latter's design in steel for a tank at Tatura. Tenders, called on 11th, already included a specification for reinforced concrete. Monash prepared a design and estimate, directed Laing to acquire the specifications and check his calculations, and then apparently sent a simple quote of £1443. (The specification generally called for a tank of not less than 65,000 gallons capacity, 65 ft above ground, with the capability to be extended to 80,000 gallons.) Castles wrote in June to say the tender had been referred to him and asked for drawings. This inspired more computations (by Laing?) plus a detailed drawing, which was sent to Castles on 9 June.

At the start of July, Castles wrote to ask for a copy of the computations, which he had to submit to the State Rivers & Water Supply Commission. There is a copy on letterpress tissue preserved in the file, but it seems doubtful if it was sent to Castles, as Monash was cautious of allowing other engineers to know his methods. He wrote to say the matter was "cumbersome", so he had gone directly to Thomas Murray at the SRWSC to show him the drawing and discuss the design. Murray had been happy with it, apart from some "trifling" matters concerning thicknesses. These proved to be an increase in the floor of the tank from 8" to 9" (203 to 229mm), an increase in the thickness of its wall at the top from 3" to 4" (76 to 102mm), and a 6" (152mm) chamfer between the foundation and the wall of the shaft. Monash also supplied Murray with complete details of the reinforcement. This was normally left off tender drawings for commercial secrecy.

Asked about the cost of an immediate increase to 80,000 gallons, Monash replied that it would be £116 on top of the £1443 already quoted. (The latter figure included a "margin" covering contingencies and profit of £400.) Final acceptance of the 65,000 gallon scheme was notified on 16 August and RCMPC prepared a drawing of metalwork details. On 14 September, Castles wrote to say that the Trust had decided after all that it wanted an 80,000-gallon tank. Monash pointed out the inconvenience of altering designs and drawings, but decided that, as the SRWSC was likely to approve the increase, he would push on with construction, which commenced on 27th under J. H. Barratt as foreman. There was some sparring over the fineness of the sand being used - RCMPC attempted to obtain coarser material from Shepparton - and the usual difference of opinion over the exact meaning of the specified mix proportions. Castles ordered a halt to work, claiming a portion of the shaft had been built in concrete weaker than specified. Monash responded with a combination of technical argument and umbrage - "personally I do not like to talk fight [but] this is the first occasion in our experience, extending over many years, where it has been suggested that we have attempted to perform work at a standard below that specified". Castles was convinced and soon permitted work to resume.

On 8 March 1912, Monash wrote to tell Castles the tank was complete, and filling could commence. He warned that it should not be expected to be watertight at the outset, but that the leaks would take up within three weeks or so, and "in course of time" the outside of the tank would become quite dry. Gradual infiltration of water through the concrete was the best means of achieving watertightness. When plastering was complete, Lynch went up to finalise matters and reported that Castles was "inclined to take a rather stiff attitude" towards leaks, but had agreed amicably on finishing up of work. Unfortunately, it proved that construction joints in the tank floor, which occur when fresh concrete is laid against set concrete following an interruption to work, had not been well made and were leaking badly. The Trust retained the last £30 of the contract payment. The leaking water flowed down the shaft and out of the door at the bottom. In October 1914, Lynch reported that the rate had decreased to about half a gallon (2.3 litres) per hour with the tank full. Attempts to seal the cracks failed because they opened and closed with changes in temperature and in the pressure of water in the tank. It was finally agreed to grade the upper floor (diaphragm) beneath the tank to lead the leaking water to a sump and an outlet pipe.

Despite these problem, Castles must have considered the project successful in general terms, because he placed orders for further similar structures at Tongala, Rochester and Echuca.

Technical Description (based on drawings)

Tank: capacity 80,000 gallons (364,000 litres); mean internal diameter 26 ft (7.92m); depth 24'-6¾" (7.49m); wall thickness at top 4" (102mm), at bottom 7½" (191mm); floor thickness 9" (229mm). Shaft 21 ft (6.40m) outside diameter, 67'-8" (20.6m) high; wall thickness 6" (152mm). Two intermediate floors (diaphragms) 4½" (114mm) thick. Floor near ground level 3" (76mm) thick on fill. Central column: Monier pipes 2'-10" (864mm) outside diameter, filled with concrete and eight 5/8" (16mm) bars. Base slab 26 ft (7.92m) diameter, 12" (305mm) thick.

Historic images of the Tatura reservoir are held by the University of Melbourne Archives with Location Numbers from BWP/23888 to /23892, NN/770, and NN/702.


Rochester Water Tower

Photo c.2000. (Original tank replaced in fibreglass.)

Location: Campaspe St, Rochester (-36.36194, 144.70315). Fate: Tank replaced, supporting structure original. Firm: RCMPC. Designer: John Monash. Assistant Designer: J. A. Laing. Client: Rochester Waterworks Trust. Client's Engineer: A. E. Castles. Initial Design: February 1914. Definitive Design: March 1914. Construction: April to October 1914.


Castles approached Monash about the Rochester tank in March 1912, and then again in August. In October, he wrote that the project was hanging fire because of a problem with the Electric Power Company regarding the cost of pumping. In January 1914, Monash delegated Fairway to prepare a tender for Rochester, using the Mildura tank as a guide, but allowing for the fact that Mildura had a roof and was further away. He told his assistant: "… the floor could, with very small expense, be made 2" or 3" thicker all over, to ensure greater watertightness - and allow specially for rich rendering inside, to avoid or reduce leakage trouble - also more circumferential steel in floor … Our margin ought to be substantial as we have plenty of work in hand and offering, and ours is a cheap type." Monash's own calculations include a study of the effect of varying the diameter of the base slab. He chose 34 feet to limit the soil pressure on the downwind edge to 3100 pounds per square foot (148 kPa). The tender price, submitted on 20 February, was £2142, including a margin of £500.

A week later, Castles wrote asking for full details. Monash replied that he assumed this meant that RCMPC had got the contract, so he had started preparing working drawings. (The general drawing had been completed only the previous week.) He told Castles of his measures to improve watertightness "in view of our experience at Tatura". The reinforcement in the floor would be arranged differently "so as to take up any secondary or thermal stresses and so prevent any tendency to radial cracking". In addition, the method of making "vertical joints which occur at the beginning and end of each day's work" would be improved, "the trouble at Tatura being entirely on these points". The interior of the tank would be rendered in cement "brought to a glass surface." More detailed calculations were then prepared (probably by Laing) fixing the thicknesses of the tank shell, the reinforcement at various depths, etc. A copy of the working drawings was sent to Castles.

The Trust accepted the tender, but Castles and the SRWSC disagreed with RCMPC's calculations and demanded the diameter of the base be increased to 36 feet and the part that projected beyond the shaft be thickened. Monash was not convinced and wrote to Castles: "Pursuant upon your several interviews with us on the 23rd and 24th inst, we have again gone carefully into the question of the computed strengths of the tank. We feel bound to say that the result of this investigation again satisfies us that the proportions proposed in the drawings submitted with our tender satisfactorily fulfil the conditions imposed. At the same time … we are most desirous to meet the views of yourself and the Department and now forward herewith a diagram which embodies the following alterations …"

Laing, too, was unconvinced and wrote a memo to Monash pointing out that the changes involved an additional 13 cubic yards of concrete and asking: "Is it worth while sending any computations to show that this design is alright? JAL". Monash replied with a simple: "No. JM". Further extremely polite exchanges occurred in which both sides insisted they were correct, but Monash finally agreed to comply with Castles' demands.

Castles' reply included: "I cannot agree with your contention that the original design for the foundation is in accordance with the requirements of the specification, as without taking wind load into consideration, the dead load on the foundation bed is at least 1000 tons = 36 ft diameter. I am sending you under separate cover my calculations which were submitted to the Dept with the original design and tender and these show clearly how the weight is arrived at and etc …" He asked Monash for yet further changes and asked him to keep the price down.

Monash replied that RCMPC had again looked carefully into the question of the design of the foundations, and had scrutinised Castles's figures. "There are several aspects which we could point out to you, which would mitigate the severe conditions assumed in your calculations, if we could talk over the matter face to face, but it is very difficult to convey our views to you in writing." However: "We are so much in sympathy with your views to make sure of these foundations that we are desirous of meeting you as far as we can afford to do." Therefore RCMPC would widen the foundations to 36 feet with consequential alterations to reinforcement and would not charge extra, but any further strengthening will have to be at £3 per cubic yard. Monash noted this complied with what Castles evidently thought had been agreed in Melbourne, but it "does not entirely agree with our recollection of the meeting".

Castles accepted the negotiated tender on 4 April 1914, the price being £2300, and work started at the end of the month under foreman A. E. Lynch (son of Alex Lynch). Monash was again concerned with commercial secrecy. He asked Castles that the drawings be kept out of "unauthorised hands" as "our designs are our sole stock in trade on which we depend for our living, and we have a great many would-be competitors who will stop short of very little to secure information about our methods and designs, and who would … attempt to compete with us by making use of our own ideas, which have cost us much money and years of labor to develop." Arrangements were made for the Clerk of Works to consult the foreman's set of drawings rather than have one of his own. No-one else was to see them, especially "a man named Taylor who is building a bank nearby and tendered for the tank", as he would be "keen to … gain hints for possible future work of this kind".

On 6 July 1914, Alex Lynch reported that the tower concrete was complete and work was starting on the formwork for the tank floor. On 12 October, with the tank concrete complete and the inside plastered, he reported that high winds were slowing the plastering of the outside. Late in the month he reported that, after a false start, the tank had been filled to a depth of ten feet and there was no sign of leakage except a little dampness low in the wall. There was no sign of dampness under the floor. On 28th, Monash asked for a progress payment of 75%, pointing out that work was finished and that the small amount of weeping had no significance and would undoubtedly fix itself up. On 11 November, Lynch reported the tank completely full without signs of leakage.

In RCMPC's files there is a draft inscription for a marble commemorative tablet which looks something like this:



The official opening took place in February 1915.

Technical Description (based on drawings).

Capacity 100,000 gallons (455,000 litres). Overall height of structure 112 ft (34.1m). Tank: mean internal diameter 28'-7" (8.71m); depth 25'-6" (7.77m). Wall thicknesses: 3" (76mm) at top (with stiffening ring), 8" (203mm) at bottom with local thickening to 12" (305mm). Tank floor 14" (356mm). Shaft: 84'-1" (25.6m) tall; 21'-4" (6.50m) internal diameter, with wall thickness 6½" (165mm) at top and 8½" (216mm) at bottom. Central column of Monier pipes 2'-10" (864mm) outside diameter, filled with concrete and eight 5/8" (16mm) bars. There is a suspended floor at ground level and three other floors (or diaphragms). Base 36 ft (11.0m) diameter, 15" (381mm) thick.

Many historic images of the Rochester reservoir, under construction and complete, are held in the University of Melbourne Archives with Location Numbers from BWP/23895 to /23905, also BWP/24367 and /24368, and NN/926 to NN/934.


Echuca Water Tower

Photo c.2000.

Location: Intersection of Pakenham St & High St (Northern Hwy), Echuca (-36.12842, 144.7486). Fate: Extant. Fibreglass lining added to tank. Firm: RCMPC. Designer: John Monash. Assistant Designer: J. A. Laing. Client: Echuca Waterworks Trust. Client's Engineer: A. E. Castles. Initial Design: March 1914. Definitive Design: May 1914. Construction: July 1914 to March 1915.


Castles first told Monash of the reservoir planned for Echuca in February 1913, but it was not until a year later that the project got under way. Monash perhaps had other channels of information because he had a general outline drawing prepared in February 1914, a week before Castles wrote to say he would soon be calling tenders. Castles wanted a tank of the same diameter as Rochester, deepened to contain 150,000 rather than 100,000 gallons, even if this was not the economic optimum. A sum of £3000 was available. In sending his tender, Monash felt obliged to explain why a tank with 50% more capacity should cost 50% more than Rochester.

"I am posting today our tender for the Tank at Echuca, and want you to be in touch with one or two aspects of the question which might otherwise escape notice. I have found it very difficult indeed to keep the price below £3000 as I promised you to try to do. When one comes to look at the matter squarely, and, remembering that the tank proper really carries the bulk of the cost, it is not surprising that a tank of 50% more capacity should cost within measurable distance of 50% more as a whole. The tank portion itself works out really at more than 50% of the cost. Added to this there are a number of small matters which all go to enhance the cost, such as increased freight, more money in cast iron pipes and a considerable increase in the rendering, owing to the greater superficial area relatively speaking of the tank. Then also, on this occasion, the whole of the rendering has been included as part of the contract price instead of being stated separately. Now I want particularly to remind you of our last conversation about this matter, during which I pointed out that in order to comply with the special requirements as to level of top and bottom of water, producing a tank deep in proportion to its width, there would certainly be a loss of economy to the extent of one hundred or two hundred pounds, and I will ask you to definitely bear this fact in mind should there be any other tender lower than ours. Upon the whole, I hope you will find the proposition we have submitted one that you can see your way to recommend, having regard to the design itself in contrast with other designs submitted, as I am sure you would not like to be in the position of having to accept a less efficient structure merely because of some small difference in tender price."

Prices came in as follows:

Stone & Siddeley of Geelong   £3600
G. F. Taylor, Geelong£3259

Castles wrote that he had been asked to evaluate the designs and intended to recommend RCMPC's, but requested the details and information necessary for him to investigate the design. Late in May he requested, amongst other modifications, that the central column be increased in diameter from the now standard 34" diameter pipes filled with reinforced concrete, to a circular cross-section of 37" diameter. When Monash demanded an extra £66 for these additions he expressed surprise. Subsequent bargaining resulted in some of the modifications being dropped, and the price rise reduced to £39.

Construction took place under foreman A. E. Lynch. Monash had sailed for Egypt before the tank was finished. In March 1915, Lynch reported to Fairway that there was 34 ft (10.4m) of water in the tank. The final account for £3012 was presented in June 1915. The usual disputes about leakage continued until at least August, when the Trust agreed to make the final payment as long as RCMPC promised to fix the tank if it did not stop leaking during the summer.

Technical Description (based on drawings).

Capacity 150,000 gallons (682,000 litres). Overall height of structure 111 ft (33.8m). Tank: mean internal diameter 28'-7" (8.71m); depth 38' (11.6m). Wall thicknesses: 3" (76mm) at top (with stiffening ring), 8½" (216mm) at bottom with local thickening to 14" (356mm). Tank floor 17" (432mm). Shaft 70'-6" (21.5m) tall, 22'-9" (6.93m) internal diameter, with wall thickness 7½" (191mm) at top and 9" (229mm) at bottom. Central column: circular cross-section 3'-1" (940mm) outside diameter, apparently not made of pipes, with eight ¾" (19mm) bars. There is a suspended floor at ground level and four other floors (or diaphragms). Base: 37-6" (11.4m) diameter, 18" (456mm) thick.

Historic images of the Echuca reservoir, under construction and complete, are held in the University of Melbourne Archives with Location Numbers BWP/23906 to /23914, also NN/991 and NN/992.


Tongala Water Tower

Photo c.2000. The reservoir was extended upwards in the 1920s.

Location: Tongala Road, Tongala (-36.25187, 144.94872). Fate: Extant, extended. Firm: RCMPC. Designer: John Monash. Assistant Designer: J. A. Laing. Client: Tongala Waterworks Trust. Client's Engineer: A. E. Castles. Initial Design: March 1914? Definitive Design: April 1914. Construction: August to October 1914.


Some work was done on this tower in March 1914, but when tenders were called in April, RCMPC decided not to tender "owing to want of time". A few days later, Monash made a one-page estimate and wrote to Castles to ask if he wanted a reinforced concrete tender. In the meantime Laing continued with detailed investigation and design. The Trust was evidently short of money, for the idea was to build a tank capable of holding 10,000 gallons which could be doubled in capacity at some later date. This meant reinforcing the lower part of the tank wall to withstand a head of 18 feet of water, though it would only be subjected to 9 feet in the first part of its life. Monash quoted about £350. At the start of June, Castles informed him the Trust was trying to raise another £100, and asked for a detailed design as soon as possible, as the tank was needed urgently for the coming summer. A reinforcement drawing and specification were duly produced in mid-June. When Castles saw that the wall was to be only 4" thick he was worried that it might not be watertight, but was reassured by Laing. There was some delay in formalising permission for the tank was to be sited on Railway property, and then because the SRWSC was "sitting on the plans". Monash offered to call on Thomas Murray to do what he could to help the matter along. SRWSC approval was given a few days later. In a massive understatement, Monash wrote to Castles: "The impending troubles in Europe may possibly have some effect upon our organisation and work in the near future, but I am hoping that this will not be so …" Construction commenced at the end of August under A. E. Lynch, and was completed late in October. Although Castles complained about the painting of woodwork and a sticking depth gauge, the file contains no complaints regarding leakage.

Technical Description (based on drawings)

Capacity 10,000 gallons (45,500 litres) extendable to 20,000. Tank initially 9'-6" (2.90m) deep, increased to 18'-6" (5.64m) in 1923. Internal diameter 15 ft (4.57m). Wall thicknesses: at top of extension 3" (76mm); at top of original wall 3½"(89mm); at bottom 4" (102mm). Floor 11" (279mm) thick. Shaft 39 ft (11.9m) tall, 10'-8" (3.25m) internal diameter, wall 4" thick. No central column. Two intermediate floors or diaphragms. Base 16 ft (4.88m) diameter, 12" (305mm) thick.

The University of Melbourne Archives holds a photograph taken about 1923-1924 showing the tank after upward extension. The Location Number is BWP/24325. It is an amateur snapshot, with the top of the tank cut off.