Meeting of April 11, 1837

Mr. Brunel gave an account of the Thames Tunnel. Having described the nature and difficulties of the undertaking, and the previous attempts which had been made by others to effect a similar work, he explained, by reference to sections, the nature of the strata below the river. He had adopted the rectangular form of the present excavation, because the work would set better than if it had been of any other form, and it also had a better sustaining surface. The necessity of supporting the ground, and of having a sufficient shelter, had led to the adoption of the shield, respecting which so much had been said. The construction of this would be most easily understood, by conceiving twelve books set side by side on their ends. These would represent the parallel frames which, standing side by side, but not in immediate contact, filled up the excavation. Each frame was divided into three boxes or cells, placed one above the other, the adjustment of the floors of which, and other details, were minutely described by Mr. Brunel.

By Richard Beamish, M. Inst. C.E.

April 4, 1837

The paper states that several attempts had been made in former years to effect a communication betwixt the opposite shores of the Thames by means of a tunnel, all of which, however, failed. In 1798, Dodd proposed a tunnel at Gravesend; in 1804, Chapman projected one at Rotherhithe; and in 1807, Vazie commenced the construction of a shaft, II feet diameter, at a distance of 315 feet from the river. With Vazie was associated Trevethick, a man of great practical knowledge as a miner, and by indefatigable labor, a drift-way 5 feet in height, 2 feet 6 inches in breadth at the top, and 3 feet at the bottom, was carried 1046 feet under the river. In the spring of 1808, having first ascended from under a rocky stratum, though with a depth of at least 25 feet betwixt them and the bed of the river, the Thames broke in upon them, and not a single brick having been laid, the work was irretrievably lost.

The Thames Tunnel has almost ceased to be a wonder; but the conduct of the younger Brunel on the two occasions referred to below can never lose its claim to admiration. The extract is from an article on the tunnel in the Courier & Enquirer, of Saturday : –

The tunnel has been twice inundated, the first time it occurred, the disorder and fright it caused among the workmen was extreme. Neither Mr. Brunel nor his son were there, but one of the superintending engineers, of the name of Griffiths, preserved his presence of mind, rallied the men, and conducted them in safety to the opening before the water had gained the summit of the arch. In a few minutes afterwards, it was filled.