THIS week in Down Memory Lane I recall the sad death 175 years ago of a sapper (Royal Engineer) off Tilbury Fort in 1838.

In May 1837 a mid-stream collision in the river caused the sinking of the Brig William (formerly the Desperate Man of War Brig) with a cargo of 233 tonnes of coal and 40 tonnes of other items.

The wreck was causing a navigation nuisance as it lay in the part of the river most used by vessels.

Initially, a contractor attempted to refloat the brig with air cylinders and other lifting gear, but failed.

The Royal Engineer Colonel Charles William Pasley took over the demolition using the latest diving helmets and traditional diving bells to allow the sappers to place explosive charges around the sunken wreck.

On May 21, 1838, Corporal Henry Mitchell, aged 32, who had some experience with diving helmets, entered the wreck and after coming up once and indicating all was well he re-submerged, but never returned.

After some delay, a diving bell was sent down with novice divers and his body was recovered.

Later huge black powder charges were set off to destroy the wreck and Col Pasley was presented with the freedom of the city of London for his services in removing the sunken vessel.

The body of Corp Mitchell was buried at St James Church, in West Tilbury.