Josh,
Great! I would be most interested in the displacement of the
hydraulic RAM vs. the Loos gauge tension, since I don't have a working
pressure gauge:
What would be most interesting to me, would be a table like:
Pressure Loos Gauge Displacement of the RAM in inches
pounds pounds inches
0 ??? 0"
500
1000
1500
2000
etc.
. I don't actually have a Loos gauge, either, but am trying to borrow one.
Thanks,
Gary
~~~~~~~_/)~~~~~~
On Fri, Aug 3, 2018 at 10:21 AM, Josh Muckley via CnC-List <
[email protected]> wrote:
> With that info I'll head down to my boat and apply various psi to the
> hydraulics and then measure the tension with my loos gauge.
>
> Josh
>
> On Fri, Aug 3, 2018, 10:17 AM Gary Russell via CnC-List <
> [email protected]> wrote:
>
>> So... I went over to Kaylarah this morning and found the following:
>>
>> The back stay diagonals are 235" long
>> The spread between the attachments is 80"
>> Doing the math, that means if the maximum tension on the vertical rod is
>> 5000 lbs., then the tension on the diagonals is 2537 lbs.
>> From here you can apply any safety factor you like, just maintain the
>> ration of 2537 : 5000.
>> Because the angle between the diagonals is so small (smaller than I
>> thought), it is pretty close to 2:1.
>>
>> Personally, I'm going to try and keep the tension on the diagonals less
>> than 2000 lbs. which keeps the upper rod below 3942 lbs. (Now where did I
>> put that Loos gauge?)
>>
>> Gary
>> S/V Kaylarah
>> '90 C&C 37+
>> East Greenwich, RI, USA
>>
>>
>> ~~~~~~~_/)~~~~~~
>>
>>
>> On Thu, Aug 2, 2018 at 9:00 PM, Gary Russell <[email protected]>
>> wrote:
>>
>>> Actually, if you look closely at the manual, you will notice that
>>> the 4125 lbs. refers to "wire limit", and 5000 lbs. refers to "rod limit".
>>> Since the vertical part of the back stay assembly is rod, I will assume
>>> that the 5000 lbs. refers to the vertical. I will go over to the boat
>>> tomorrow and try to measure the back stay angle, to see which limit gets
>>> exceeded first, the rod or the wire. C&C could have made this a lot
>>> easier. I've got to believe the transom will fail before the wire, yet the
>>> wire is all that is specified.
>>>
>>> Gary
>>>
>>> ~~~~~~~_/)~~~~~~
>>>
>>>
>>> On Thu, Aug 2, 2018 at 8:52 PM, Josh Muckley via CnC-List <
>>> [email protected]> wrote:
>>>
>>>> Absolutely without any doubt in my mind the backstay tension of 4125 is
>>>> to be measured on the mainline. This works in opposition to the head stay
>>>> which is equally sized #12 rod.
>>>>
>>>> Josh
>>>>
>>>> On Thu, Aug 2, 2018, 8:41 PM Gary Russell via CnC-List <
>>>> [email protected]> wrote:
>>>>
>>>>> Hi Josh,
>>>>> Oops! I missed that. I looked in the chapter about rigging and
>>>>> didn't find it there. Silly me! I even searched for the number 4125 and
>>>>> found nothing. I guess the document is an image rather than text. Now the
>>>>> question, is that the tension in the vertical part of the back stay? I
>>>>> guess, the safest assumption is that it is.
>>>>>
>>>>> Gary
>>>>>
>>>>>
>>>>> ~~~~~~~_/)~~~~~~
>>>>>
>>>>>
>>>>> On Thu, Aug 2, 2018 at 8:33 PM, Josh Muckley via CnC-List <
>>>>> [email protected]> wrote:
>>>>>
>>>>>> Page 68 of the manual pdf file which I linked before has the pre-load
>>>>>> and max load limits.
>>>>>>
>>>>>> Again I am corrected in my preconceived notions regarding the
>>>>>> correlation between a hydraulic gauge and the tensile load on the back
>>>>>> stay.
>>>>>>
>>>>>> Josh
>>>>>>
>>>>>> On Thu, Aug 2, 2018, 8:13 PM Gary Russell via CnC-List <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> Hi Josh,
>>>>>>> Where did you find the 4125 or 5000 lb. limit? I don't see
>>>>>>> that in the Owners Manual? Is the 4125 lb. limit for the lower angled
>>>>>>> segments of the the back stay or the upper vertical part. You can't
>>>>>>> simply
>>>>>>> measure the port back stay tension and multiply by two, because of the
>>>>>>> angle between the two. You would have to measure the angle and apply
>>>>>>> some
>>>>>>> trig to get the right value. Mike Cotton's boat was the one I was
>>>>>>> referring to in my email above.
>>>>>>>
>>>>>>> Gary
>>>>>>>
>>>>>>> ~~~~~~~_/)~~~~~~
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Aug 2, 2018 at 6:31 PM, Josh Muckley via CnC-List <
>>>>>>> [email protected]> wrote:
>>>>>>>
>>>>>>>> The manual says limit to 4125lbs and then says absolute max of
>>>>>>>> 5000lbs. https://drive.google.com/file/d/
>>>>>>>> 0B8pEh5lnvP1ySXFBdDhrX0ZaMzNnazViYkZzRVRoODlSSUd3/view?usp=drivesdk
>>>>>>>>
>>>>>>>> I never considered that the hydraulic pressure psi could/would be
>>>>>>>> independent of tensile load. When I had my hydraulic pump rebuilt by
>>>>>>>> Lew
>>>>>>>> Townsend he tried to adjust the relief valve but mine adjustment knob
>>>>>>>> was
>>>>>>>> seized. He gave up and just hydro-tested it anyway. He found that the
>>>>>>>> relief was roughly 3500. I rarely go over 2500. Now that I have to
>>>>>>>> consider the corollary between psi and lbs I'll be pulling out my Loose
>>>>>>>> tension gauge and get back to you. Since it is split I'll remember to
>>>>>>>> add
>>>>>>>> together or double a single.
>>>>>>>>
>>>>>>>> As for the attachment to the transom, I agree it does seem slightly
>>>>>>>> poor engineering. In fact when we were shopping around the first boat
>>>>>>>> looked at wad named Blue Pearl and had been owned by Mike Cotton who
>>>>>>>> was
>>>>>>>> and may still be on this list. It was evident that some past event had
>>>>>>>> caused the port aft attachment to separate the flat horizontal (cap)
>>>>>>>> part
>>>>>>>> of the fiberglass casting from the curved (body) potion. The hydraulic
>>>>>>>> pump was a single piston and pump combo that attached between the port
>>>>>>>> anchor amd the port side of the back stay. Evidently a sheave
>>>>>>>> communicated
>>>>>>>> the tension to the stbd size at the point where the single rod attached
>>>>>>>> from the mast head. It seemed as though maybe the sheave didn't roll
>>>>>>>> smoothly and failed to split the tension evenly between the port and
>>>>>>>> stbd
>>>>>>>> anchor on the transom. That of the fiberglass layup was uneven and the
>>>>>>>> port side was just coincidentally weaker.
>>>>>>>>
>>>>>>>> I was attentive to this weakness when I continued shopping and
>>>>>>>> found Sea Hawk. I discussed the issue with the PO and he showed his
>>>>>>>> engineering answer.
>>>>>>>>
>>>>>>>> https://drive.google.com/folderview?id=0B8pEh5lnvP1ybDFIZ0ZZTU1XdHM
>>>>>>>>
>>>>>>>> I'm not convinced that it is "correct" but it is certainly better
>>>>>>>> than nothing. I had decided years ago that I was going to engineer a
>>>>>>>> reinforcement of my own with some G10 FPR. I still have the G10 but
>>>>>>>> have
>>>>>>>> never acted on the project. My idea was to back the entire corner of
>>>>>>>> the
>>>>>>>> transom with 1/2" G10 FRP by epoxying it in place and then fill the
>>>>>>>> attachment cavity (the bump out) with epoxy. Longer u-bolts and a
>>>>>>>> spade or
>>>>>>>> mortise bit to countersink a flat load bearing "pad" for the washers
>>>>>>>> and
>>>>>>>> nuts to drive against and I would be done.
>>>>>>>>
>>>>>>>> Josh Muckley
>>>>>>>> S/V Sea Hawk
>>>>>>>> 1989 C&C 37+
>>>>>>>> Solomons, MD
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, Aug 2, 2018, 5:53 PM Gary Russell via CnC-List <
>>>>>>>> [email protected]> wrote:
>>>>>>>>
>>>>>>>>> Does anyone know the maximum back stay tension allowed on the
>>>>>>>>> C&C 37+. My problem is the hydraulic back stay adjuster pressure
>>>>>>>>> gauge has
>>>>>>>>> failed and I don't even know what the maximum pressure spec allowed
>>>>>>>>> is,
>>>>>>>>> anyway. I'm concerned that at least one owner has had the attachment
>>>>>>>>> points on the transom fail presumably due to excessive
>>>>>>>>> tension/pressure.
>>>>>>>>> Frankly, the attachment points don't instill a lot of confidence as
>>>>>>>>> there
>>>>>>>>> aren't any backing plate; just a couple of holes drilled in the hull.
>>>>>>>>> I'd
>>>>>>>>> feel more comfortable putting a Loos gauge on the wire and calibrate
>>>>>>>>> the
>>>>>>>>> extension of the back stay adjuster to it. Any thoughts / ideas out
>>>>>>>>> there?
>>>>>>>>>
>>>>>>>>> Live Slow / Sail Fast,
>>>>>>>>> Gary
>>>>>>>>> S/V Kaylarah
>>>>>>>>> '90 C&C 37+
>>>>>>>>> East Greenwich, RI, USA
>>>>>>>>> ~~~~~~~_/)~~~~~~
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>>
>>>>>>>>> Thanks everyone for supporting this list with your contributions.
>>>>>>>>> Each and every one is greatly appreciated. If you want to support
>>>>>>>>> the list
>>>>>>>>> - use PayPal to send contribution -- https://www.paypal.me/
>>>>>>>>> stumurray
>>>>>>>>>
>>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>>
>>>>>>>> Thanks everyone for supporting this list with your contributions.
>>>>>>>> Each and every one is greatly appreciated. If you want to support the
>>>>>>>> list
>>>>>>>> - use PayPal to send contribution -- https://www.paypal.me/
>>>>>>>> stumurray
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>>
>>>>>>> Thanks everyone for supporting this list with your contributions.
>>>>>>> Each and every one is greatly appreciated. If you want to support the
>>>>>>> list
>>>>>>> - use PayPal to send contribution -- https://www.paypal.me/
>>>>>>> stumurray
>>>>>>>
>>>>>>>
>>>>>> _______________________________________________
>>>>>>
>>>>>> Thanks everyone for supporting this list with your contributions.
>>>>>> Each and every one is greatly appreciated. If you want to support the
>>>>>> list
>>>>>> - use PayPal to send contribution -- https://www.paypal.me/
>>>>>> stumurray
>>>>>>
>>>>>>
>>>>>>
>>>>> _______________________________________________
>>>>>
>>>>> Thanks everyone for supporting this list with your contributions.
>>>>> Each and every one is greatly appreciated. If you want to support the
>>>>> list
>>>>> - use PayPal to send contribution -- https://www.paypal.me/stumurray
>>>>>
>>>>>
>>>> _______________________________________________
>>>>
>>>> Thanks everyone for supporting this list with your contributions. Each
>>>> and every one is greatly appreciated. If you want to support the list -
>>>> use PayPal to send contribution -- https://www.paypal.me/stumurray
>>>>
>>>>
>>>>
>>>
>> _______________________________________________
>>
>> Thanks everyone for supporting this list with your contributions. Each
>> and every one is greatly appreciated. If you want to support the list -
>> use PayPal to send contribution -- https://www.paypal.me/stumurray
>>
>>
> _______________________________________________
>
> Thanks everyone for supporting this list with your contributions. Each
> and every one is greatly appreciated. If you want to support the list -
> use PayPal to send contribution -- https://www.paypal.me/stumurray
>
>
>
_______________________________________________
Thanks everyone for supporting this list with your contributions. Each and
every one is greatly appreciated. If you want to support the list - use PayPal
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