FORERUNNERS OF THE LIFTING BAG.

A forerunner of the ‘lifting bag’ although it was not recognized as such at the time. Spaldings Bell of 1775, with a top compartment ‘H’, into which air could be admitted by valve ‘A’, or released by the operation of valve ‘G’, hence changing the buoyancy of the device overall. The invention won a 20 guinea award.

An early print showing the manner in which surface vessels were employed to offer ‘tidal lift’ to a wreck, in this case, the Man O’ War Royal George, sunk at Spithead in August 1782, which proved un-successful in this and in many other instances.

The Mary Rose for example, in August 1545, when Venetian salvors, then considered to be the most skilled in the world, employed the Jesus of

Lubeck and the Samson, each of 700 tons, to raise the wreck but failed. This was not surprising since the wreck lay over on her starboard side at an angle of 60º.

The best insight to the development of both buoyancy and diving, which are naturally linked, is to be found in the archives of the British Patents Office, in London. Here are preserved details of all the patents registered since the early 1600’s Many of the early ones are completely lacking any detail of how the device was supposed to work, and indeed, probably many of them never did.

William Kemps’ specifications for a rigid lifting device of 1835, the forerunner of the modern flexible bag.

The Wreck of the Earl Grey in 1847, with lifting caissons attached and inflated, ready for recovery.

The wreck of the Earl Grey, 1847, supported by floatation bags being towed the 20 miles to Burnham, by the steamer Fly.