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James Thomson: Pontoon Pioneer

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5 min read
View of Horse Paddock at Woolwich from Cockatoo Island.
In the late 1800s, James Thomson helped install an innovative pontoon dock at Clarke’s Point, Woolwich when the area hosted the Atlas Engineering Company’s shipbuilding yard. In this DigiTale, Harbour Trust volunteer researcher Reto introduces readers to the talented Australian engineer and inventor.

Thomson was originally from East Maitland in the Hunter Valley, where he was born in 1845. His first patented invention, known as ‘Thomson’s Air-pump Valves’, was registered when he was just 33 years old and offered proof of his flair for mechanics. Indeed, his pumps were widely used and provided shipowners with significant savings.  

A giant puzzle

Together with an engineer known as John Edington and a chief draftsman by the name of George McRitchie, Thomson shared in the unique task of assembling and launching a novel hydraulic dock at Woolwich for their employer, the Atlas Engineering Company.

Edington had been sent to England to investigate the most advanced floating docks on the market and purchase one that could be transported back to the colony. On Edington’s return to Sydney, he submitted his report to Atlas and – with the help of Thomson – his recommended decision was adopted.  

When the floating dock arrived, it was said to have resembled a giant puzzle, all in pieces. This was the moment when Thomson’s skills were especially needed. Under his expert supervision, the multi-part pontoon was securely assembled. Pumping machinery was erected in a longitudinal cellular girder or tower and two powerful centrifugal pumps (capable of throwing 2,000 tons of water per hour) were placed near the bottom to discharge underwater. These works took place in surroundings that were described as a ‘large and ugly industrial wasteland’.

Compared with traditional dry docks, the floating pontoon dock was a technological marvel. It enabled works to be quickly and effectively carried out on vessels ‘with the sun shining on the sides and dry air all around, instead of being in a hole’.

A spectacular launch

The floating pontoon dock was publicly launched on 26 May 1888. Two days later, the Sydney Morning Herald ran an article, titled ‘The Atlas Floating Dock’, which described the spectacle:

“An interesting event took place on Saturday morning at the Atlas Engineering Company’s works, Woolwich, it being the launching of the large floating pontoon dock, which has just been constructed at this establishment. This important dock is the largest of its kind in Australia.

The ceremony of launching was performed at 9 o’clock, when Miss Thomson, under directions, severed the connecting rope, and the huge structure having been duly christened by another young lady, ‘Miss Edington’, glided smoothly off the stocks, amid applause from a large concourse of spectators.

The Atlas Engineering Company imported their dock in plates ready for erection and the quality of the work was much admired by engineers visiting the section, which was much appreciated by those who erected it.”

Thomson's later life

Although Atlas went into liquidation in 1893, Thomson – like the innovative pontoon he installed at Woolwich – stayed afloat. Joining the Australasian Steam Navigation Company Ltd, he helped them to develop the very first compound engines in Sydney. The S.S. Florence Irving became the first steamer to be fitted with his engine.

Later, Thomson worked as a consulting engineer for the Newcastle & Hunter River S.S. Company Ltd. At the beginning of the 20th century, he kept diversifying his know-how through innovations for wool presses, elevator machinery and even a special tool for aquifer boring –  readily adopted by American manufacturers, it is still used today. Thomson never gave up his passion for technology and kept working to the day of his passing in 1912, aged 77. 



Thomson never gave up his passion for technology and kept working to the day of his passing.

– Reto

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