mast pumping cat 30

[tom]

HELP,I've got a 1984 cat 30 everytime I get a moderate breez from any quarter while tied at the dock the mast pumps and shudders and can be felt through the whole boat. It also causes the internal halyards to slap hard enough so you can't hear yourself think. has anyone else had this problem? Also I'm looking for a way to insulate the ice box better then the factory has done as my fridge is running a bit too much. Tom

 

[Mike Turner]

Try tightening backstay

I've noticed my mast pumping too -- I found that tightening the backstay seemed to help. I'll be interested to read other suggestions on this problem.Mike TurnerS/V Amity

 

[gary jensen]

mast pumping correction

Mast pumping is caused by "vorcies" EG: wind that is disturbed by going around the mast. The disturbance (mast pumping) can be nulified by twisting a halyard around the mast several times. Good luck in doing it.

 

[Dean Bachelor]

Mine too

My 85 c30 does it real often too.I never knew what caused it, I thought itwas water past the rudder,or as a resultof steady pull on the dock lines on one windward side.The other response said wrap a halyard,do you winch it real tight? Looking forward to other responses.Thanks Dean

 

[Michael McCann]

Mast Pumping

My 1986 C25 tall rig would pump at the dock, or at anchor. I tried all sorts of adjustments, but never cured the problem. My current boat, a 1993 C36 also pumps in a breeze. I can't tighten the back stay any tighter ( I keep a fairly tight forestay ). I have a friend with a C42, and his mast pumps also. A friend with a Caliber 40 does not have this problem, but his mast has a lot of things attached ( inner forestay, mid shrouds to support the staysail stay, halyards, topping lift, radar, etc! ), while mine is fairly clean. I haven't heard if other boats have this problem, but I know Catalina's always have.

 

[Don]

mast pumping

Why I was living aboard I used the mast pumping as my middle of the night weather report. All I ever had to do was pull tje backstay real tight and it would stop. I like the idea of wrapping the mast with a halyard - would have saved me a lot of trips on deck in the middle of the night.

 

[John V.]

Wondering...

Is your mast rigged so that it is pre-bent? I think its very important to have a bend built in to the mast, i.e., under no-load conditons, adn that this will also prevent mast pumping.