Sweeps

Roger Taylor has kindly supplied details of his motive power arrangement on Mingming. He writes:

"For operating each sweep I devised a system using a stainless steel thole
pin and rope grommet. This is more powerful than rowlocks, and keeps the
sweeps in place. I will operate them standing and leaning forward on the
sweeps, fisherman style. The sweeps therefore bear against the rope
grommets, rather than the thole pin, giving a softer ride and less wear on
the leathers. The sweeps themselves are 10' ash, an unmatched pair that I
bought cheap, altered to match and renovated. They also give me more strong
timber on board should I need to rig a jury anything."

A pair of oars on a boat the size of a Corribee makes a lot of sense - no engine means no fuel to carry, no noise or pollution and no running costs. Rowing was the traditional way of manouvering even large vessels in harbours and anchorages. Thole pins are a lot simpler than rowlocks; less likely to be lost overboard and it is easy to jury-rig a replacement.

On a bermudan rigged Corribee, rather than a junk rigged Corribee or Coromandel, the sheet winches pose a small problem - the thole pins would have to be mounted further forward on top of the cockpit coamings. It might be possible to fabricate a fitting that allows some sort of rowlock to be mounted on top of the winch itself. The fitting itself has to be strong as it is the point at which the power is transferred from the oarsman to the vessel. Roger has used three bolts (probably 10mm dia stainless steel) fitted through the grp moulding.

Sweeps (the word tends to be used interchangeably with 'oars', though generally indicates a longer length than would be used for a dinghy) are usually made of spruce, a resilient and light softwood, but ash is a good alternative as it is very tough and springy. The disadvantage of ash is its' weight. Many ash sweeps are counterbalanced by boring a long hole in the loom (the handle end) and filling it with molten lead. The hole is then plugged with a wooden bung. A properly balanced oar should balance at the fulcrum.

Close-up of stainless steel thole pin and rope grommet:

Thole pin arrangement

Fixing arrangement for the thole pin:

port hand oar in thole pin

Pressure on the sweep is taken by the rope grommet rather than the pin itself, spreading the load and reducing wear on the leather:

oar leather

www.corribee.org - mast beam