From the article, "Wider and Deeper Clyde" in The Glasgow Herald on this day in 1936:
WORK CARRIED OUT FOR R.M.S. QUEEN MARY
RIVER DEVELOPMENT REVIEWED
Many permanent improvements in the navigable channel of the Clyde were carried out in order to facilitate the launching of the Cunard White Star liner Queen Mary, and a comprehensive account of the river work entailed was given last night by Mr. A. C. Gardner, engineer to the Clyde Navigation Trust, in a paper read in Glasgow at a meeting of the Institution of Engineers and Shipbuilders in Scotland.
Mr. Gardner's subject was "River Work for the Queen Mary," and he described in detail the various ancillary works rendered necessary by the general scheme of river improvement for the Queen Mary, and he stated that they were carried out in the following order:--(1) The widening of the river opposite to Messrs John Brown and Co.'s shipyard and at the entrance to the river Cart;(2) The deep dredging across the river on the line of the launch;(3) The deepening of the fitting-out basin for the reception of the ship after the launch;(4) The placing of the protective barrage and boom at the stern of the ship while fitting out; and(5) The widening of the river at Dalmuir.Outlining the work in connection with the protective barrage placed round the stern of the vessel while she was being fitted out, Mr. Gardner stated that the scheme was devised in conjunction with the builders, and ultimately took the form of a number of steel frames or towers with broad concrete bases placed side by side in three continuous lines, from which were suspended overlapping steel plates of the full height of the towers,and extending as a continuous screen around the stern of the ship.Before the launch of the vessel the whole of the area at the entrance to the basin on which the towers would rest had been carefully dredged to as uniform a level as possible. After the launch, and when the vessel had been moored in the fitting-out berth, heavy sand was deposited from hoppers where necessary...as the time for her departure approached the need for a close and accurate survey of the whole of the river channel became increasingly important. Areas where the presence of loose boulders was suspected had to be swept and afterwards examined by diving bell...Mr. Gardner stated that from first to last nearly 5,000,000 tons of material were removed from the river and deposited at sea as the result of various operations connected with the Queen Mary alone.