The Trow Rock Floating Platform was also known as the Clarke Maxim Disappearing Platform for barbette mountings. The Clarke-Maxim mounting first appeared in 1885. The trial for this new maxim mounting took place one and half miles south of the mouth of the tyne at Trow Rock (NZ385667), hence its name.
The Durham Artillery Volunteers had three obsolete 32pr guns mounted there for practice. Also a small magazine for which they paid a nominal annual sum to the Tyne Improvement Commissioners who owned the site. In 1885 they were asked to lease/lend the site to the War Office. It was leased for a year and in May 1886 the pit was excavated to a depth of fourteen feet for the mounting. In October 1886 Maxims agreed to construct the emplacement at their own expense and to have it ready for trial within four months. It was not ready until December 1886 and the trials took place in December 1887 with the 6inch B.L. Mk IV gun.
The Elswick mounting at Shoeburyness proved to be more successful and was adopted for service. The Clarke-Maxim mounting was declared ‘unlikley to be of any value and no more should be constructed’. The lease of the land was terminated in 1894; the machinery was removed and the emplacement filled. The site reverted to its use for volunteer practice.
The site was listed as a Grade II Listed Building in 1986. The listing says:
Casing of Clarke Maxim Disappearing Platform, for 6-inch breech-loading gun. 1887 for the Inspector General of Fortifications, for experimental trial purposes. Mass concrete. Cylindrical shape of approx. 21 feet internal diameter with west extension for approach tunnel. Rough-shuttered exterior. Interior shows runners for steel floating platform (now removed) and entrance to tunnel. Structure is sunk deeply into the ground to accommodate the water upon which the platform rose and fell, actuated by air pressure pumps, and is now largely filled with earth.
Historical note: Trials of platform took place on 15th and 16th December 1887. It was found that the raising and lowering of the platform was too slow and the system was abandoned in favour of the quicker and cheaper Elswick hydro-pneumatic mounting.
Of historical interest as a relic of late C19 artillery development experiments.
In 1988 a replica gun and mounting was placed on the site. In 2019 plans to develop the site as part of South Tyneside’s coastal landmark £2.9m Tyne-to-Tees waterfront regeneration and education programme were dropped.
Channel 4's 'Great British Dig' programme explored the site in March 2021.
The platform survives, but filled.