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Self Tensioning Drum - Technical Spec in PDF

The RMG self tensioning drums allow for the elimination of tensioning devices in the sheeting system such as shock cord, rubber band material, hat elastic, springs etc. The spring loaded return spool in these drums takes up any slack and maintains a positive tension in the sheeting system. This even applies to the spiral drum 45zs4st. Till now, spirals needed to be used with a single line off the drum and a long length of elastic material attached to a fixed point on the boat to maintain tension. Now the 45zs4st spiral can be used just like the standard double drums and the endless loop sheeting system.

32 mm and 42 mm ST Drums are available in Left and Right hand versions. The direction of the winch when sheeting OUT determines which ST drum to use. When the winch drum turns clockwise (viewed from top of drum) to sheet OUT, the Right hand ST drum should be specified. When the winch turns anticlockwise to sheet OUT the Left hand version should be specified.


Main Points

  • Ideal sheet line material is 36 kg Spectra or smaller.
  • Maximum recommended line size is 36 kg. Dacron.
  • Sail load must be taken by the fixed spool.
  • The return spool is only to be used to give tension to the line coming off the fixed spool.
  • 42stR/L and 32stR/L drums must always have some free travel left. The spring must never become bound.
  • 45zs4st drum must have 1 turn of return spool travel left when at close hauled to prevent spring binding.
  • At least 1 turn of sheet line should remain on each spool at any time.
  • Always use the supplied retaining washer or appropriate drum thumb screw to retain the drum.
  • Ensure that there is always tension on the fixed spool line over the entire travel range.
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