|Ballast and buoys|
Gravel for sale
Elizabeth I issued a new charter in 1594, granting Trinity House the sole rights of ballastage in the River Thames. This had previously been the preserve of the Lord High Admirals. This meant that the Corporation could dredge up gravel from the river bed for sale as ballast to unladen sailing ships.
This diagram of the warship HMS Crescent (1784) gives an idea as to how ballast was distributed around a sailing vessel to keep it stable.
At the height of the trade, in 1804, the Corporation employed nearly 250 men in the work of ballasting ships. With the passing of sail in the mid-19th century, ballastage began to die out because steamers used water as ballast.
Keeper of seamarks
The Corporation was allowed to fine anyone up to £100 for removing any of these land-based seamarks without the Trinity House Elders' permission. If the guilty person was not worth that amount, he could be convicted of 'outlawry'.
Until lighthouses became widespread, landmarks were vital navigational aids. This picture shows a mark being erected by Trinity House's Captain Bullock on Goodwin Sands, a notorious stretch of coast in the Thames Estuary.
This image shows the variety of buoys used by Trinity House in the 19th century.
Most buoys have two main colours, black and red, either used plain or with white. There are also green wreck buoys.
Sometimes they have flashing lights or bells that ring with the movement of the waves and serve to warn approaching ships. The buoys vary in size and are usually conical, cylindrical or spherical in shape. These two examples are currently on display at the entrance to the National Maritime Museum.
In this photograph, two Trinity House workers are repairing a buoy that has been winched on board the Trinity House vessel Hanton.
From 1 April 1993, following the Ports Act, the management of lights, buoys and beacons needed for local navigation was transferred from Trinity House to local harbour authorities.