1878 – A title to mine some 4000ha under Sydney Harbour by the Sydney Harbour Colliery Co. is granted to the Sydney and Port Hacking Coal Company.
1890/91 – A test bore is sunk in the Cremorne area by the Sydney and Port Hacking Coal Co with 3m of cindered coal being located at 853m.
1892/93 – A second bore, also at Cremorne, locates a good 3m section of coal at 884m depth.
A request for land at Bradley’s Head for the pit top is rejected after local landowners object. An alternate site is located at Birchgrove, being purchased in 1895 for $15,000.
The site is at the junction of Birchgrove Road and Water Street, adjacent to the Birchgrove Public School, built in 1885.
The site is levelled, a 177m sea wall built and the harbour dredged to a depth of 7.9m at low tide.
1897, Jun – Sinking is commenced on No. 1 or “Birthday Shaft” at 5.5m diameter.
1897, Aug – Sinking is commenced on No. 2 or “Jubilee Shaft” at 5.5m diameter.
1900, Mar – Five men are fatally injured after being tipped out of the sinking bucket, 122m from bottom.
1902, Nov – Both shafts are completed, fully lined with over four million bricks. Coal is located at 878m but the seam is split. A decision to use advancing longwall is made instead of “bord & pillar” because of the depth and the percentage of coal required to remain by the Regulations.
The “Birthday” Shaft is fitted with a 21m high, 81.6 ton steel lattice headframe carrying 2 x 5.5m pulley wheels. At the 21.6m level a horizontal tunnel is driven to the waters edge to facilitate the direct loading of coal. This winding shaft is also the downcast.
The “Jubilee” Shaft is fitted with an ironbark headframe carrying 2 x 4.6m pulley wheels. At the 7.2m level a ventilation drift is driven. This shaft is the upcast for ventilation.
A 58.5m brick chimney is attached to the boiler house for the steam engines.
1902, Jun – The first coal is brought to the surface. Mining heads towards Cremorne.
1908 – Mine workings are under Simmons Point.
1909 – Brief mine shut-down.
1909 – Mine workings are under Goat Island.
1915 – The mine is forced to close due to ventilation and insufficient funds.
1924 – Balmain Colliery reopens under a new company, the workings reaching Balls Head by the end of the twenties.
1928 - Financial difficulties led to an employee cooperative, operating as the Balmain Coal Contracting Company Ltd, taking over the mine.
Conditions underground were atrocious with temperatures reaching 36 deg with extremely high humidity. The geothermic gradient within the Birthday Shaft was found to be 1deg F per 90.7 ft or approximate a 30 deg F increase at the bottom. The mine was never mechanised only picks and shovels with nearly an hour’s walk from the shaft bottom to the face. The coal was hauled by horse drawn skips to pit bottom.
1931, Feb – Sydney Collieries Ltd goes into liquidation and Balmain Colliery ceases production of coal with some 863,600 tonnes having been produced.
1932 – A new company, Natural Gas and Oil Corporation Ltd is formed to drill below the mine workings searching to tap the gas.
1933, Jan – Two men die from severe burns sustained from a gas explosion at the bottom of No. 1 Shaft while excavating prior to setting up a drill rig.
1937 – Drilling reaches 1505m with only a weak flow of gas. Gas production at Balmain Colliery ceases.
1942 – Gas production is revived due to wartime shortages of petrol for motor vehicles, extracting it from the old workings.
1944 – More than 311,500 cu m is produced with Dairy Farmers being a regular customer.
1945 – The shafts were sealed with concrete due to the explosive nature of the gas emerging from the workings. Three men are killed by an explosion during the sealing of the Birthday Shaft, although this shaft is retained to produce limited quantities of gas.
1950 – Gas production ceased.
1950’s – The Natural Gas and Oil Corporation Ltd attempts to revive the gas production from the Birthday Shaft during the oil and gas boom of the 1950’s however the previous explosion has damaged the seal so that air is entering the shaft, mixing with the gas. The site is listed for sale.
The whole site is now considered dangerous and the Mines Department steps in, fencing the site and continues to monitor it for the next 10 years.
1954 – Increasing levels of gas leaking from the shafts triggers the company to flood the mine and seal the workings. 18.2 million litres of fresh water with boiler ash from the Pyrmont Power Station (fly ash from White Bay Power Station) are pumped into the mine.
1955 – The site is sold to Grascos Cooperative Ltd.
1956 – The filling of the Balmain D/C shaft with flyash is nearing completion, with surface structures above the shaft having been demolished. (DoMAR 1956)
1957 – Concrete seals are placed on the shaft heads.
1957 – The sealing process is now considered complete and the site safe. The surface structures are demolished to erect wool stores.
1959 – A gas sample taken from the top of the western shaft and below the concrete floor of the building erected above the shaft reveals no methane.
1971 – Proposals to utilise Balmain Colliery for Liquid Industrial Waste and for the underground storage of natural gas.
1990 – The shafts are exposed during redevelopment work and inspected by officers of the Dept of Mineral Resources. Gas samples are not taken.
1994, Sept 27th – An inspection of the site shows the shaft sites to be covered with compacted sandstone.
Jack Clark, 2002 “People & Places Afloat”
MinFact No. 6 July 1993 – Mineral Resources
Prime Fact 556 (replacing Minfact 38) Feb 2007 – Dept Primary Industries
Hansard Oct 1994
A.R.McCoy, 1952, Speculations on Balmain Colliery, Engineering Faculty Year Book 1951-52
A. C. McDonald, 1958, Balmain Colliery Shafts, Eliminating the Gas and Filling the Shafts.