This post covers a few sites – The Viaduct, Jetty, and Dump, all of Victorian origin, in use by the Salvation Army (possibly except the dump). The Salvation Army Jetty was used in the early 1900s to load off and on goods, mainly bricks, made at the Salvation Army brickworks located at the bottom of Chapel Lane. The bricks were then taken by train over to the jetty, at the very lower seawall which also exists today, going over the main railway which is the current one in-use today, by a railway leading south which avoided the main railway by going over a viaduct which also remains today, although its top is now gone, just leaving the two supports either side of the railway in existence. This article on Hadleigh’s community archive can be read here: http://www.hadleighhistory.org.uk/page_id__130_path__0p3p.aspx.
In the Victorian era, the land between the train-track and the seawall used to be a Victorian dump. We visited and found hundreds of shards of most-likely Victorian pottery in the churned earth. When walls on Canvey were built up, the Benfleet/Hadleigh ones here were too, and the dump was flattened. This is the first heard of the dump, although confirmed by Martin Lepley (thanks for the information), who went digging there in the 70s with a relative into this field.