Reinforcing Pushpit/Pullpit (?) to hold heavier Outboard

[taikohax]

Firstly - apologies if i've got this in the wrong section.

I own a Beneteau Oceanis 45 (yes I know, boo hiss etc ) and the rear pushpit (pullpit? sorry, not sure the correct name) which holds the outboard is only rated to approx 25kg.
The outboard i'm going to put there is approx 40kg.
Knowing that Beneteau "build to a price point" that leaves me with the following challenges to overcome :

1. Strengthening the rail base for the downward force presented by the additional weight against the deck
2. Strengthening the underside of the deck (where there are petit washers) for any force going 'upwards'
3. Making it as easy as possible to lift the engine too/from its mounting point without falling in the water or sacrifing it to the sea.

After waiting (and chasing) for a quote from my local workshops for well over a month* i've decided to start working out how to do it myself (or at least mitigate some of the cost).

* side note - i'm new to boating, have only had the boat for 4-5 months, but i've been baffled at how little the marine industry seems to want to make money or engage with customers (and when it does it adds a 200% premium on top) - everything's been "eventually get around to it" or "oh, you mean you ACTUALLY want a quote and for us to DO the work?". Possibly (likely!) a naive comment but I can see why so many people go "bugger it, i'll do it myself". Maybe i've just been unlucky (that being said, the guy who fitted our heater was solid gold so i'm likely just being grumpy).

Anyhow. I'm writing this to hopefully pick some brains to see if you think the approach i'm proposing below is sensible (and if you have any advice you can add) - namely :

1. Unscrew the rails, slide a slightly wider stainless steel 'washer' in-between the existing pushpit and the deck to spread the load downwards (is there a way of mitigating 'cracks?' is there a durable rubber or plastic washer you'd recommend I put in-between?
2. underneath the deck, add a wood (not sure if I need a specific type - open to recommendations) board to spread the load upwards and ideally a wider SS washer.
3. Mount an outboard hoist/davit (similar to the ones F4 and others sell) - ideally also bolted to the rail to give it some extra stability for lateral movements

I'm reasonably 'handy' however this is my first boat and i'm conscious there's a wealth of experience I lack and i'd rather avoid stupid mistakes since my knowledge of the boat 'structure/composition' is limited. At the same time, I have limited free time (still working heavy hours unfortunately) so where I can buy 'off the shelf' at a reasonable price i'd certainly like to do so - since i'd rather be using the boat where I can!

I've attached some pics below (and added a link as the pictures didn't appear in preview) to give context - all advice and experience welcome

https://photos.app.goo.gl/h0wR7JIEqXy4rj632

 

[simonfraser]

Push - that’s what you’d do to get the boat going, so its at the stern
Pull - that’s where you’d pull to get it to forward, sot its at the bow

 

[taikohax]

Thanks - that makes total sense!

 

[neil_s]

I think you've got the right idea. I think the additional loading will be similar in all planes so I would suggest similar stainless steel spreader pads both above and below the deck. I found with my own push/pull pit that bedding the spreader pads in Sikaflex or similar makes a really strong job - and it doesn't leak! You might need to reinforce the stainless steel pushpit structure too - how about using some eyebolts to secure the pushpit feet and use the eyes to fit bracing wires with turnbuckles?

 

[macd]

Simon's suggestion's a useful mnemonic, if you need one.

It is of course 'pulpit' rather than 'pullpit', which historically referred to a platform and at some stage came also to mean a platform (and then a guard rail) at the bow of a boat. Think of those two doomed lovers in 'Titanic'. Or clerics inflicting sermons.

For exactly the rational Simon described, 'pushpit' is no more than a witty play on the sound of 'pulpit' for a guardrail at t'other end of a boat, which just happened to catch on. It's probably quite a bit younger than I am. Before its adoption, it was usually called a stern or taff rail.

Getting back to the point, piddly little washers have no business holding down a pushpit, whether it supports an outboard or not. At the very least, it needs big fat penny washers and backing pads, but preferably suitable plates.

 

[Plum]

I'm writing this to hopefully pick some brains

I agree with the other comments about larger and thicker washers/plates under the nuts. It is not the downward loading you need to worry about, its the loading of the pushpit in the horizontal plane causing bending loads at the base of each pushpit upright. You need to brace the top. In the picture of the arrangement with an outboard davit there appears to be a brace from near the outboard coming down and forward. Even better would be to fix a tubular brace between the top two corners (near the loops for the top guard rail/wires) so the top of the pushput forms a triangle then this would allow the davit upright to be fitted to the pushpit too without additional bracing for that.

Www.solocoastalsailing.co.uk

 

[pvb]

I don't think you need to mess about with washers under the pushpit feet, the existing arrangements are fine. However, you may need to add a diagonal brace to support the top rail of the pushpit. Before you do that, try the 40kg outboard on the bracket and see how wobbly it is. If you need to add a brace, Scanstrut do some very neat deck fixings.

Your photo shows some other bits of structure attached to the pushpit rails, is this a bimini or similar?

 

[Daydream believer]

Those 2 pictures are not of the same pushpit configuration!!!
But that aside I note that on my own boat the studs at the base of the 25mm stanchions are only 6mm. If yours are the same i would suggest that these are the weak points. Any side loads or " wobbling" back & forth will eventually cause them to shear.

 

[Resolution]

Slight drift, but what would be the force exerted on the pushpit by a typical heavy crew climbing up over the transom or in at the side? Where does this 25 kg rating come from?

 

[taikohax]

Some excellent input (much thanks).

So it sounds like :

Rotational or Lateral movement is a concern when it comes to that kind of weight (makes sense) so my options are likely :

1. Brace it somehow (wires or triangular brace)
2. Build a new one out of thicker guage i guess

And my above idea is sound (to a greater or lesser degree) but it sounds like plywood is less useful than some stainless (which is a shame as plywood is within my abilities to hack apart).

pvb - yep, that's part of the bimini (a veritable wobble fest that is!)

Daydream - not sure what you mean about the two pictures - of the three one is labelled 'not my boat' and the other two are of the same configuration just from slightly different angles (I should know as I took the pics)

 

[taikohax]

Resolution - the 25kg is from the Beneteau Oceanis 45 Owners Manual - I expect (I'd hope!) there's some leeway in that of course

 

[Daydream believer]

Daydream - not sure what you mean about the two pictures - of the three one is labelled 'not my boat' and the other two are of the same configuration just from slightly different angles (I should know as I took the pics)

Apologies - cannot read !!!!!!!

 

[Plum]

Some excellent input (much thanks).

So it sounds like :

Rotational or Lateral movement is a concern when it comes to that kind of weight (makes sense) so my options are likely :

1. Brace it somehow (wires or triangular brace)
2. Build a new one out of thicker guage i guess

And my above idea is sound (to a greater or lesser degree) but it sounds like plywood is less useful than some stainless (which is a shame as plywood is within my abilities to hack apart).

pvb - yep, that's part of the bimini (a veritable wobble fest that is!)

Daydream - not sure what you mean about the two pictures - of the three one is labelled 'not my boat' and the other two are of the same configuration just from slightly different angles (I should know as I took the pics)

The diagonal brace needs to be a strut, not a wire tie. Hopefully you can find a piece of stainless tube the same spec as the pushpit and use some clamp-on connectors so should be well within a DIY project.

No need for thicker wall tube. I bet the existing structure will take two people standing on it. Making the tubes stiffer without the diagonal brace will just put more stress on the deck fixings.

Www.solocoastalsailing.co.uk

 

[greeny]

I did the same on my Beneteau albeit a smaller one (323). I added a brace down to the boarding platform deck but I don't think you have that option as yours is a drop down platform I think. The brace also added an extra hand rail for boarding from the dinghy. Can you add a bracket onto your transom and brace to that? You don't need too much of an angle to give the extra support needed. As for the original pushpit mounting, I just left them alone and they've been fine. No sign of any stress crazing on the gelcoat or any cracks.