Offset prop shaft

[Ampen Spekersohn]

1 hour ago, dmr said:

Hot Press ???? Have only ever heard that term from an Irish lady, usually called airing cupboards. 

Ah yes, a remnant of living in Eire for a while. Doesn't that sound so much nicer than 'airing cupboard'? Also, it has less syllables, so it's easier to say, lol. (The term 'press' originates from the C17th, meaning a cabinet or cupboard, usually for linen.)

It seems that the critical thing here, is to ensure I install the engine far enough forward in the boat. It's the one thing which really can't be moved! I can always make use of a little more room in the back cabin, but if it's too tight, it's going to cause big issues.

9 hours ago, bizzard said:

Amongst many other useful uses that I can think of for the cranked propshaft, this particular one will save you a lot of labour and you'll keep lovely and clean too. An elongated slot will need sawing out in your cabin roof. A flexible rubber seal around the slot and connecting rod will stop the rain gettin in.

:D:D:D:D

I had started to think that rotary action of the crankshaft could be applied to drive a power windlass. How helpful would that be at Hatton?

[Ampen Spekersohn]

1 hour ago, MoominPapa said:

Reading your later post, I see that you're planing exactly what we have - a lengthwise permanent double bed rather than a BMC. The photo below shows the general arrangement. The end of the bed is at the bottom of the frame. The floor to the left of the bed and at the end of the bed on the left is at the same height as the floor elsewhere in the boat. The small step in front the drawers on the right is precisely high enough to allow the propshaft to sit underneath,  running parallel to the floor. The next step (with rectangular mat) has the bearing and UJ underneath and is high enough to allow the shaft to rise to the level of  the final propshaft. Under the bed the shaft runs in box about 10cm wide by 10cm high.

MP, that looks really interesting. I'd love to see any additional photos you may have. My original idea was to have the double bed right up the pointy end, but this also works. It also overcomes the strict limit of length with a cross-bed.

Gawd, my drawing is going to have so many rubbings-out, I'll have worn through the paper, lol! Good job I'm not cutting timber yet.

[MoominPapa]

10 minutes ago, Ampen Spekersohn said:

MP, that looks really interesting. I'd love to see any additional photos you may have. My original idea was to have the double bed right up the pointy end, but this also works. It also overcomes the strict limit of length with a cross-bed.

Gawd, my drawing is going to have so many rubbings-out, I'll have worn through the paper, lol! Good job I'm not cutting timber yet.

Me and the camera are both on the boat, so you can have as many photos as you like. Probably best to PM me an email address, rather than clutter up the forum with many pictures of the Moomin bedroom.

 

Cheers,

 

MP.

 

[MtB]

8 hours ago, Ampen Spekersohn said:

My main reason for adopting a reverse layout was to have a lengthwise 4' 6" double bed, permanently made up. I just find that after a hard days boating, it's nice not to also have to build your bed! A permanent bed also gives the opportunity to have a decent quality domestic mattress and to use an ottoman mechanism to raise the base to expose under-bed storage, as per photo. The hull will be Birmingham Square, which will gain that bit of extra width at floor level to allow passage past the bed.

A BMC bed really requires a sectional mattress, not so comfortable IMO and effectively blocks the route through the boat when made up. It also means that the person sleeping nearest the stern would struggle with night-time visits to the loo. That might need another small design feature adding.

However... I take your point. I have previously refitted an extended back cabin in a butty and agree it is possible to make use of every cubic inch. If I adopted the BMC as the main sleeping area, it would free up more 'square space' (as opposed to space constrained by swims, tumblehome, etc) further down the boat.

I will re-visit my drawings and look seriously at changing it all round. At the moment, it's only lines on paper, so easily altered!

 

 

I thought you wanted a JP3, not a BMC?

Still not sure how you sleep in the engine. I'm wondering if you actually mean "back cabin". 

[Ampen Spekersohn]

You're kidding? You mean there is actually an engine called a BMC? As well as Lister and Gardner and Russell Newbery?

[cuthound]

9 hours ago, Ampen Spekersohn said:

Ah yes, a remnant of living in Eire for a while. Doesn't that sound so much nicer than 'airing cupboard'? Also, it has less syllables, so it's easier to say, lol. (The term 'press' originates from the C17th, meaning a cabinet or cupboard, usually for linen.)

And there was me thinking you were going to install an electric trouser press on your boat. All I could think of was "Why? "

[MtB]

9 hours ago, Ampen Spekersohn said:

You're kidding? You mean there is actually an engine called a BMC? As well as Lister and Gardner and Russell Newbery?

 

There sure is!

 

[Ampen Spekersohn]

Maybe they named it after Boatman's Cabin?

[MtB]

6 minutes ago, Ampen Spekersohn said:

Maybe they named it after Boatman's Cabin?

 

The term "boatman's cabin" is tautology and an invention of the estate agents who seem to populate brokers selling boats these days.

It is a "back cabin" really, on an ex-working boat. Who else would it have been for? 

Or if one is being really picky, just "the cabin" suffices!

[Ampen Spekersohn]

23 minutes ago, Mike the Boilerman said:

 

The term "boatman's cabin" is tautology and an invention of the estate agents who seem to populate brokers selling boats these days.

It is a "back cabin" really, on an ex-working boat. Who else would it have been for? 

Or if one is being really picky, just "the cabin" suffices!

Although not just an invention of boat estate agents... Chapter heading from Graham Booth's Narrow Boat Builders Book!

[WotEver]

Wasn't it sometimes referred to as the bed 'ole? Or was that summat else?

[MtB]

9 minutes ago, Ampen Spekersohn said:

Although not just an invention of boat estate agents... Chapter heading from Graham Booth's Narrow Boat Builders Book!

 

Oh so THAT'S where it comes from then. Graham has a lot to answer for!!!!!!!!!!!!!!!!!!!!

[Ampen Spekersohn]

Here is a photo of the boat which started my whole line of thinking about having the galley located where the back cabin is normally situated. However, as you can see, a cooker is about 3' high, so this illustrates the lack of headroom! Interesting to note where they have managed to locate the cooker, in spite of the swim. Shame I couldn't find this when I placed the OP.

The second two pictures show another boat with a rear galley, but I think this may have been a semi-trad or cruiser stern - hence no problem with the prop shaft and more headroom.

 

[MtB]

That first photo must be in a boat with a horribly short swim, which will probably lead to awful handling.

It might possibly be in a 'cutwater' format hull, like this:

 

[cuthound]

I dont like the steps in the second picture. It doesnt save any wood, but guarantees anyone starting their descent on the wrong foot a nasty fall.

[Ampen Spekersohn]

Could be. I think that's actually called a slipper stern, but either way, the handling is generally regarded as poor. Apparently OK for rivers, but not canals. My hull will have a S-shape swim of 12' minimum.

[Ampen Spekersohn]

6 minutes ago, cuthound said:

I dont like the steps in the second picture. It doesnt save any wood, but guarantees anyone starting their descent on the wrong foot a nasty fall.

I agree. They're also a waste of space. Solid steps may take more room but can be boxed in to give useful storage.

[WotEver]

Just now, Ampen Spekersohn said:

I agree. They're also a waste of space. Solid steps may take more room but can be boxed in to give useful storage.

Or have shorter treads to make it more ladder-ish if you really don't have the space. 

[MtB]

8 minutes ago, Ampen Spekersohn said:

Could be. I think that's actually called a slipper stern, but either way, the handling is generally regarded as poor. Apparently OK for rivers, but not canals. My hull will have a S-shape swim of 12' minimum.

 

We've had this debate before. 'Slipper stern' is a misnomer. This is slipper stern:

 

[Ampen Spekersohn]

Happy to stand corrected. I picked this up from http://www.xrandd.co.uk/ ~ Slipper Stern. Looks like they may be using the term incorrectly!

Nice launch, btw!

Edited September 10, 2017 by Ampen Spekersohn

[WotEver]

46 minutes ago, Ampen Spekersohn said:

Nice launch, btw!

[Ampen Spekersohn]

22 hours ago, MoominPapa said:

Do they geometry before assuming that the propshaft will be at an acute angle. Clearly it depends on the dimensions of the steps and the length of the counter, but on Melaleuca, the angle is probably less than 10 degrees. Indeed it was only when I had to remove the bottom step for another reason several years into my ownership that I realised there was a UJ and a bearing under there, and that I was the proud owner of a kinked propshaft.

I have emailed Wilsons Drive Shafts to get a price for the whole thing

[MtB]

Not sure if anyone earlier in the thread suggested a hydraulic drive would be the best way to avoid having a propshaft at all, and get the floor down low. 

Anglian Diesels dominate the market in hydraulic drive systems. Very helpful and knowledgeable bunch.

[WotEver]

Just now, Mike the Boilerman said:

Not sure if anyone earlier in the thread suggested a hydraulic drive would be the best way to avoid having a propshaft at all, and get the floor down low. 

Anglian Diesels dominate the market in hydraulic drive systems. Very helpful and knowledgeable bunch.

It was mentioned as potentially being too inefficient but that's been questioned and OP said they would consider it again. 

[Ampen Spekersohn]

4 minutes ago, Mike the Boilerman said:

Not sure if anyone earlier in the thread suggested a hydraulic drive would be the best way to avoid having a propshaft at all, and get the floor down low. 

Anglian Diesels dominate the market in hydraulic drive systems. Very helpful and knowledgeable bunch.

Yes, thanks, I have emailed ARS Anglian to ask for pricing. I suspect it will be relatively expensive and rather more complex.