The SB Kathleen was a spritsail Thames barge built by Glover at Gravesend, Kent, in England in 1901, and registered in Rochester.

She was rerigged by an enthusiast in 1966 and raced again, before meeting her end in Spaarndam in 1986, with spars and fittings being passed on to the Wyvenhoe.

[1] She was launched in 1901 and worked for Daniels Brothers of Whitstable principally as a grain barge.

[4] In the first world war she carried other dry cargoes such as coal, timber and iron pipes.

She continued to do cross channel work until 1920: as a barge she could safely sail over the Goodwin Sands if the leeboards were raised.

[5] On 6 March 1923, she and two other Whitstable barges were taking on cargo in Greenwich when the Cunard steamer, Virgilia (1918–1944) lost control and smashed into them, sinking two of them.

[4][6] The Why Not, had previously survived an incident in 1917 when she has been hit by a 2-seater aircraft from the Royal Flying Corps No.63 Squadron from the airfield at Joyce Green Isolation Hospital, the Kathleen rendered assistance.

The rigging had become a hindrance when loading cargo, so in September she had a leg of mutton, trysail bent to the topmast.

Fred Wraight Jnr left the boat in 1960- she took her last cargo in October 1961, her engine was removed, and she was laid up and decommissioned at Strood on 23 November 1961.

The topsail and a foresail came from Lower Halstow, the mast case came from Pin Mill from the hulk of the Charles Hutton.

[14] The main mast and the standing rigging came from Erith, from the Lady Mary, built in 1900 as an F.T.

She had a new owner, Pat Murphy who invested in a new mainsail and a pair of Kelvin 44 hp diesels.

They were built in bargeyards adjacent to a river or creek on bargeblocks- a series of trestles raised about a metre from the compacted ground, that allowed working access above and below.

At the bow the stempost was raised vertically and at the stern the sternpost, these were made from 6 feet (1.8 m) lengths of 12 by 9 inches (30 by 23 cm) English oak.

The fore and aft deadwood would raise the floors to give shape at the bow and the sweep to the fashion timbers of the transom.

On the Kathleen the keelson was a made of a 49 feet (15 m) steel section, in profile similar to railway line (6 by 11 inches (15 by 28 cm)):[20] it was cheaper but could distort.

The futtocks (side-frames) were dovetailed onto the end of each floor, and every other joint was strengthened with an iron angle plate.

Above it was a 12 by 3 inches (30.5 by 7.6 cm) oak stringer that was bolted to the futtocks and led out to stem and stern post.

The height of the deck was marked on the frames- forming a beam-line, and a beam thickness beneath it, a 15 by 4 inches (38 by 10 cm) oak inwale was bolted to the futtocks.

[22] The inwale formed a ledge on which the 8 by 8 inches (20 by 20 cm) curved beams of the deck, and the carlings rested.

The sailmakers exact formula is a closely guarded secret, and sailormen believe that some dressings are faster than others.