Deck stepped masts

pjcam

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Can any of you more experienced sailors please help with my query. I have seen a steel hulled and decked 40ft ketch built by a professional yard which is described as a world cruiser. I am very keen on it. However it has deck stepped masts which appear to be very robust but I am cautious as to their seaworthiness in relation to an Atlantic crossing and possibly further. Can anyone give me some guidance from their own experience. Thanks in advance.

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AndrewB

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How is this mast supported underneath?

The usual is for it to be strutted through the cabin down down to the keel, the internal steel strut bolted through or otherwise fixed direct to the external mast tabernacle. From my experience, that is effective on a steel boat, certainly quite adequate for tradewind cruising. The rigging and chainplates are a more common cause of mast problems. Check the strut looks sufficiently strong and shows no sign of bowing.

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Talbot

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most cats are deck stepped (for the obvious reason), however the reinforceing needs to be adequate, but if you are intending long distance, why not have a surveyor check to make sure boat is adequate for intended use.

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AndrewB

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ps ...

Sorry, missed that this is a ketch. My above applies to the mainmast, the mizzen might not need quite such solid reinforcing, depending on size.

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MainlySteam

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Deck stepped masts are the norm on modern vessels of that size.

They are also usually not positively fixed into the mast step on the deck, being just located in it by the compression of the rigging. The deck under the step should be adequately strong and for the mainmast that will normally mean being directly over a column support running from keel to the underside of the deck - in a steel vessel, often an RHS welded in. The mizzen should also be over some deck structure sufficient to take the lesser compression loads from that mast.

John

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ChrisE

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I'd agree with the above, we own a Rival 38 which is deck stepped and these go all over the place, including transat with us. We had a forestay snap mid Atlantic and the mast had no difficulties staying up on an inner forestay.

From our experience we had to get some reinforcing work done on the base of the mast because of corrosion seeping up from the step but this was on a well used craft that had seen 15 years of chartering.

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charles_reed

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Deck stepped masts are far more common, especially in newer boats than keel-stepped masts.
In fact the majority of tough world-cruisers have them in preference to keel-stepped masts.

The answer, however, risks being simplistic, because there are far more considerations to be taken into account.

With conventional bermuda rigs a keel-stepped mast only becomes essential with a fractional rig which employs mast bend for mainsail shape-control. Most people would agree that this is great for round-the-can racing, but the rig inherently stresses the mast unfairly and has a considerable chance of fatigue failure mode.

Providing the mast has a sound compression support from step to floors, a stiff, straight mast with masthead rig and adequate intermediate staying to prevent the mast getting out of simple compression loading the pin joint at coachroof level is no disadvantage.
It does eliminate the inevitable leaks you get round a through-deck mast, the intricacies of demounting and remounting the mast; but at the cost of far less ability to alter lee/weather helm, straighten the forestay, reduce heeling moments and pull forward the centre of effort.

With cat, and junk rigs a keel-stepped mast is essential and it's desirable on a gaff or wishbone rig.
However on a lateen rig the pin-joint is essential for working the rig properly.

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roly_voya

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Since you mention sea worthyness as a question on a deck steped mast I suggest a piont in there favour is that if you ever do loose the mast you are not left with a hole in the boat and have a strong base to support a jury rig so it could be an advantage

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snowleopard

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there is nothing inherently unseamanlike about a deck-stepped mast provided the under deck support is adequate.

a deck stepped mast needs a thicker cross section as some of the stiffening is lost. designers allow for this.

the big benefit of a deck step is in hull integrity - you don't have potential of leaks at the partners and don't have a gaping hole if dismasted.

go for it.

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