new owner needs answers

learywr · Oct 26, 2009

The hull speed of any dispalcement boat is:

Hull Speed=1.34 * (Sq root of LWL)

So a Catalina 30 with a 25' LWL is 6.7

Yes I sail with prop in reverse ... but have heard the Huth Transmission it does not matter.

Table up.

Walter

Stu Jackson · Oct 26, 2009

learywr5093 said:
Yes I sail with prop in reverse ... but have heard the Huth Transmission it does not matter.

That is simply not true and unfair to the respondent to pass on unless you're sure. "...but have heard..." is a dangerous way to answer questions. You might want to reconsider that approach in the future; like "I don't know, so I won't pass on rumors." The reason I seem a tad upset about this is that mpgofast's transmission is on the line here.

And it's HuRth.

Here's the real answer: http://www.c34.org/faq-pages/faq-transmission-position-sailing.html

And we don't know if he has a "standard" M25 with a Hurth, either.

It is the transmission, not the engine, that determines the answer to the question.

mpgofast , you should get to know the folks at the C30 Association website.

Bob4203 · Oct 28, 2009

I will speak strictly from my recent experience. I have the Universal M-18; however, I do not know if the Hurth transmission with my engine is the same for the larger M-25. Several weeks ago under sail we were hauling (I do not have a knot meter), and for the first time we heard the two bladed prop rotating under the boat. I started a thread asking if sailing with the tranny in neutral was preferred. With all my inboard vessels over the years I have not once ever heard a prop rotation in neutral!

The response was simply, "put the gear in reverse", demonstrated by presentation of transmission decals indicating such. Makes sense, but I always thought stresses on the prop, shaft and coupling might cause some gearing stresses. The next time out we did put the transmission in reverse and sailed all day, but not quite as fast as before.

At the end of the day with the sun setting I went through normal start up procedures, but the engine would not turnover. The starter was trying to turn but no engine turnover, just click, click. As it turned out I actually was between neutral and reverse! I had the good sense to get down below, feel the gear linkage and adjust to neutral. The engine then starter to our relief. So, in my case did placing the tranny in reverse change have a slight impact on the linkage and jam the reverse gear? I am sure this is extremely rare and unique as I never hear of issue with the transmission under sail.

My gut tells me, going downstream with an upstream prop just seems to darn weird! I think for better peace of mind I might keep it at neutral for now. If I seem to be too carried away, please chime in.

Bob
"88 Mark II
Breezin II

Stu Jackson · Oct 28, 2009

Bob, we've been sailing for 12 years now with our transmission in reverse when sailing. When we forget to slip it into reverse from neutral after we stop the engine, we almost always hear the whine from the prop turning the shaft. Could be our high winds get us up and sailing fast more often than not.

We have a bucket of a prop: 3 blade. We have never had your issue. I recommend checking your cable to see if it is OK at the transmission end and in the binnacle. It could well be that you have some play, but I doubt that the reverse position while sailing did that to you. You could well have not really fully engaged the reverse position that one time. After all, the instructions do say "change gears firmly." Go down below with someone "upstairs" and make sure the shifter fully throws the transmission lever on the transmission completely and properly.

The Hurth manual says neutral or reverse. It ain't worth discussing which one is better, that's been beaten to death. I use reverse to extend the life of my cutlass bearing.

Bob4203 · Oct 29, 2009

Thanks Stu. Sailing San Francisco Bay is light years ahead of my Lake Lanier sailing. I sailed a Herrshoff 28 in the bay back in the 60's and loved it! I will take your advice and make any necessary adjustments to the linkage. I will assume Hurth made their calculations on affects of forces and resistance on reverse gear as in locking into reverse when sailing at optimal hull speeds. Initially one would view this as parking your heavy SUV on a hill without the brake on, with stresses on the transmission that could have a long term affect. In balance however, saving wear on the cutlass bearing is a strong arguement. We'll give it another shot...........

Bob

learywr · Oct 30, 2009

Stu,

Thanks for catching my spelling error....yes I did mean Hurth not Huth. I am not perfect.

I also thought it was clear when I said "I have heard" means "I have heard" and is not meant to be gospel.

I did check out the link you sent on the subject, and unless I am reading it wrong, I was correct. Keep transmission in reverse or neutral. Which confirms my "I have heard" statement.

I have only had my Catalina 30 for 2 years, sailing for 9, so I am no expert, and I gain lots of knowledge on these lists. I was only trying give back some of the knowledge I have picked up over the years to a new sailor.

I hope I just caught you on a bad day when you responded to my reply. If not ... let me know, as I will refrain from posting on this list. I don't wish to get anyone that upset over an email comment or spelling error.

Walter

Stu Jackson · Oct 30, 2009

Spelling does count, but

learywr5093 said:
...and unless I am reading it wrong, I was correct. Keep transmission in reverse or neutral. Which confirms my "I have heard" statement.

Walter, what you said in your first post was this: "...but have heard the Huth Transmission it does not matter."

Please help me understand how "it does not matter"agrees with only reverse or neutral.

I only added the spelling thing so people would not misunderstand or confuse transmission manufacturers, not to pick on you.

I couldn't agree with you more in "trying give back some of the knowledge I have picked up over the years ."

But I am very careful to refrain from using the phrase "I have heard" because it lacks the specificity needed to answer questions. I try to apply what I personally know to be true. The answers I provide are based on my personal experience, acknowledged texts on the subjects and people I trust, like, for instance Maine Sail and others on this and other 'boards. A perfect example is the link I provided about the transmission position while sailing. How much more specific can we get than referring to the manufacturer's own tag or manual? I use links a lot.

Much of what we hear here includes "...have heards..." from dockmates who may or may not have a clue about what they're talking about. This is NOT you, Walter, it is just my experience with these message boards that the people asking the questions usually use that particular phrase, not those of us answering them. If you review what most of us would consider to be the "quality" answers you'll find specific recommendations, options and/or links. If answers include "...have heards..." I personally tend to minimize their validity.

So keep comin' back and sharing what you know, that's what this is all about. I apologize for offending you as I seem to have done and will try harder in the future to stay on point. I'll share your thin skin with my bad days.

Stu Jackson · Oct 30, 2009

Bob, a new "find"

Also included in the other transmission question today: http://www.c34.org/wiki/images/9/9f/TransmissionCable.pdf

Bob4203 · Nov 2, 2009

Sweeeeeeeet! This one goes into the "Operations Binder".

Thanks Stu.........

Bob

Stu Jackson · Nov 2, 2009

Bob4203 said:
...the "Operations Binder".

Bob, good idea, we have one on board, too. Got so thick I had to separate out the navigation material from the "fixits" material!

We've recently rearranged the technical material on our C34 website. Formerly chronological material has now been also placed in a Table of Contents format in our interactive wiki. Check out the engine section, for starters, NPI, and also the rest of the data, for those with M25 series engines.

http://www.c34.org/wiki/index.php?title=Diesel_Engine