mast lifting system (MLF)




mast almost vertical - click for higher resolution photo
We redesigned and rebuilt MLF. It is now lifted by slider, pulled down by mainsheet tackle while it is supported by couple of support bars. 

Mainsheet tackle is connected between slider and shackle on the mast step. Rope goes back to cockpit to existing winch, which is used to do the hard work. Mast needs to be lifted partly before system can be used but it is within easy reach height from cockpit floor. No babystays etc are needed - support bars provide excellent positioning.

System can be use by single person and lifting can be stopped at any stage. Mast can be even lowered and raised (partially or fully) on water if necessary.


 
Following photos were taken during recent lowering of mast. Comments:

Two crutches are used - none should be needed for most boats. The first one is helping to control  genua roller system with its internal thin wall aluminium tube and it is not needed really. The second one is used to support mast after it is lowered. It is needed because our MLF suport bars do not clear top corners of  stainless steel mast support frame used for transport (design fault of mast support frame used for transport...).

We keep some tension on genua roller system with trailer winch. If plain jib is used or roller system is controlled in a different manner trailer winch is not needed. One possibility is to put a single block on the bow and tension roller system with single line to cockpit (not much force is needed or used). Trailer winch also provides backup mast holding system in the case that something goes wrong with MLF. (I use it for this purpose only once, when MLF rope on winch got tangled and jammed - I used trailer winch to take off tension from MLF block & tackle. )

control of genua system and MLF backup mainsheet is used for MLS block & tackle MLS support bars act between cockpit brackets and mast slider controlled by MLS block & tackle

A few more details (slider is need of adjustment, see the last photo where section which keeps it in track is visibly at angle).

These photos were taken before raising of mast in approx 25kt wind, blowing from side. After mast was fully raised we found out that backstay got tangled and that we have to lower back to approx 45 deg to clear the mess. It took about ten minutes and all contraption was vibrating in gusts but there was never any loss of control or any danger. Not pleasant anyway because breakage of any element of the system would be highly dangerous in such conditions.