Running backstays - required or not?

Relax

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I have a cutter rigged Dockrell 37 - which has no running backstays. The rig is masthead with in-line spreaders and fore and aft lowers. The cutter stay comes in to the mast between the spreaders and the masthead.

The question is - do I need running backstays?

On the one hand you could say that the thing (the mast) has stayed up since 1986 (and I have just replaced all the staanding rigging) with no obvious sign of stress - but on the other hand I have no idea what if any blows the boat has been through. The most wind I have seen over the deck is 35-40 knots - if I need to sail in say 40+ knots with only the staysail and double reefed main will the mast fall down after a few hours?

(I do have a photo - but as a technoprole can't seem to get it to appear here)
 

Jassira

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Hi.
I have a cutter rig with runners, and double spreaders, the inner forestay (staysail stay) attaches at the upper spreaders with the main purpose of the backstays being to tension the inner forestay/staysail luff, although it must also play a part in overall structure of the rig.

My storm jib also sets on the inner forestay and I take comfort from the thought that in conditions that would require the storm jib, the main would be deep reefed and I could set both running back stays.

I guess more stays is better than less stays, but only to a point and the designer presumably didn't think they were needed (and seems to have been proved right), also don't underestimate the cost of retro fitting.

Pardon my ramblings, not much of an answer really
 

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Are you saying that there is no backstay?
If there is a backstay are you asking if you need checkstays for heavy weather?
 

Relax

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There is indeed a backstay - I was asking if the forum considered there should be running backstays to oppose the inner forestay which has no aft restraint - this could potentially cause the mast to pump were the staysail to be heavily loaded. The inner forestay meets the mast between the spreaders and the masthead.
 

FWB

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You are referring to checkstays. I would have thought it unlikely that you would need them. Usually found on fractional rigs in racing type boats.
 

prv

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You are referring to checkstays.

Also known as running backstays.

Usually found on fractional rigs in racing type boats

It sounds like when the OP has just his staysail set, his mast is effectively fractional rigged. Lots of boats have runners to oppose the load of this kind of inner stay. I think it would take a skilled rigger to know if they're needed in this specific case, though. And the mast hasn't fallen down yet, which kind of suggests they're not.

Pete
 

merlin3688

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If the inner forestay fitting is half way between the spreaders and the top of the mast then either runners or jumpers should be fitted. Rule of thumb is the inner forestay needs to be within about a metre of the top of the mast to do away with the runners, you probably would only use them in a blow but I believe they should be fitted. Jumpers are sometimes a better option, once set up on the mast they do not need adjusting where by runners can be a pain!
Hope this help.
 

FWB

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Also known as running backstays.
Pete

No. Running backstays are fitted when the boom is too long or the roach of the mainsail precludes a backstay unless a bumpkin is added.
The OP is referring to checkstays, since he already has a backstay.
 

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Already discussed here:-

http://www.ybw.com/forums/showthread.php?129175-When-to-use-running-checkstays

(did'nt see this when I did a search)

By consensus I think we are talking of running backstays - either way the point is understood I think?

Its something I would rather not do to be honest - but I live in fear of the mast clattering down round my ears.

As said above it hasn't happened yet - on the plus side the rig is modest (which you do notice when its NOT windy) and the mast has a fairly substantial section.

Just trying to see if anyone has been in a similar quandary before - I can only ask!
 

FWB

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You are not talking about running backstays. You already have a backstay on your boat.

Here I am tacking my boat with running backstays. See how I release the starboard stay and then fix the port stay.

http://youtu.be/r692iN6-AEM
 
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Jassira

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You are not talking about running backstays. You already have a backstay on your boat.

Here I am tacking my boat with running backstays. See how I release the starboard stay and then fix the port stay.

http://youtu.be/r692iN6-AEM

imagine you moved the base of the forestay on a fractional rigged boat, inboard by a metre or 3, then fitted a new forestay from the bow to the top of the mast....hey presto, you have a cutter, complete with running back stays
 
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FWB

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imagine you moved the base of your forestay inboard by a metre or 3, then fitted a new forestay from the bow to the top of the mast....hey presto, you have a cutter, complete with running back stays

It's a gaff cutter in the video.
 

Boo2

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The question is - do I need running backstays?
The rig was designed without running backstays so the answer is clearly "no". The D37 was designed as a cruising boat not a racer so it's extremely unlikely running backstays would enter into it and also pretty certain that they have been designed for the mast to stay up in 40 kt of wind.

I think you're worrying unnecessarily.

Boo2
 

grumpygit

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The rig was designed without running backstays so the answer is clearly "no". The D37 was designed as a cruising boat not a racer so it's extremely unlikely running backstays would enter into it and also pretty certain that they have been designed for the mast to stay up in 40 kt of wind.

I think you're worrying unnecessarily.

Boo2

I would say as a general rule of thumb that a cutter rig would have running back stays or a bumkin. We have running back stays and it definitely isn't a racing yacht.
I think it would take an experienced rigger to advise on your rig/mast.
 

Relax

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The rig was designed without running backstays so the answer is clearly "no". The D37 was designed as a cruising boat not a racer so it's extremely unlikely running backstays would enter into it and also pretty certain that they have been designed for the mast to stay up in 40 kt of wind.

I think you're worrying unnecessarily.

Boo2

That would be logical and you may well be right - but I do have some doubts as to the amount of "design" that has actually gone into the rig. The boat is a stretched version of the S&S Deb 33 - Dockrell bought the moulds. The stern areas have been lengthened and the mast moved aft - you can actually see the original mast location in the deck moulding.

The mast section is relatively substantial for the height (same section as that on an Ovni 39' nearby - with double spreaders) and the rig modest so the loads are not huge. It does not however sail at all well without the staysail - that goes up first and down last.

(Maybe I should stop reading "Heavy Weather Sailing"........)
 

pohopetch

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You are not talking about running backstays. You already have a backstay on your boat.

Here I am tacking my boat with running backstays. See how I release the starboard stay and then fix the port stay.

http://youtu.be/r692iN6-AEM

Many racing boats have a fixed backstay, running backstays and check stays. They all do different things and you can have all three or just one or two - no hard and fast rules Dylan! Runners generally tension the forestay or an inner forestay on a cutter and attach either at the top spreaders for a two spreader rig, or at about 7/8th on a fractional rig. Checkstays are usually there to control mast bend and are attached around 1/2 way up the mast.
 

William_H

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Regardless of what they are called running backstays are not appropriate on a cruising boat. They are generally set up to tension the forestay or inner forestay to take sag out. Not often to actually keep the mast up.
I can understand the OP concern about a forestay (inner) which has a sail attached which is anchored mid way between top of mast with outer forestay and backstay plus cap shrouds and the spreader mid mast point supported by inner sidestays either just aft or fore and aft.
The present arrangement is relying on the stiffness of the mast a function of the fore and aft dimension of the mast to resist bending foreward or sideways under load of the inner forestay. I have no idea if it is adequate or not. It may be, but not ideal design.

However if you are concerned apart from running back stays which are horrible for min crew cruising. You could fit jumper struts.
Here 2 short spreaders are mounted angled forward just above the inner forestay attachment. Stay wires run from the top of the mast to the spreader base (mid mast). The tips of the small spreaders (jumper struts can be joined by wire to stabilise them)
As the stay wires to the jumper struts are tensioned the jumper struts push the point of inner forestay attachment aft so counteracting the pull of the inner forestay. They also make the mast more rigid sideways at that point.
Another option is to add more inner sidestays from the mast at the inner forestay down to chain plates set aft of the mast. The distance aft of abeam the mast will dictate how much pull aft at the top of the inner forestay. Unfortunately the distance aft of abeam the mast if excessive will cause chafe to the mainsail when running boom right out. All fractional rig boats put up with this drawback. On your boat a distance of about 2ft might seem right. If you have inner sidestays mounted aft of the mast then you could use those chain plates if not it is fairly easy to fit chain plates and reinforcing. This latter option will give more support to the mast generally and may even be enough to save the mast if any other rigging wire lets go.
I think I would go for the jumper strut myself. I did make one for my fractional rig to limit mast bend and tension forestay. The jumper struts were about 40 cms log angled at 90 degrees to one another. Made of ss 10mm tubing but that was for a 27ft mast the stay wires for the jumper strut went from spreader base to mast top. It certainly straightened the mast. I have a new mast now so not needed. For you I would think struts 60cms long of ali or ss tubing about 25mm diameter welded to a base that curves around the front of the mast. good luck olewill
 
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