Off Centre Layouts - a bad thing?

[malcolmd]

Hi this is a classic "does the panel think" question (an allusion which ageing Brits will get)...

I am making a bunch of final decisions on the layout of machinery in the boat I am building (SY-Befur http://sy-befur.co.uk), and as part of this it seems to me that there could well be some benefits (access and maintenance) which could be realised by placing the engine and boiler off the centreline of the hull.

I have to also install some 500kg of ballast into the hull, so this leaves plenty of opportunity to ensure she sits flat in the water if I made this choice. (Although I recognise that dynamic balance might be something sea trials would finally determine (she has sails too).)

I remember Mudlark in the UK had its engine installed to one side and this seemed to work fine - what do you all think?

thanks in advance...

[johngriffiths]

If you look up "Mudlark" owned by the late David Harding you will see that he used a fairly large single cylinder engine mounted starboard driving, via a 3" toothed belt, the central prop shaft. He never had to change the belt over many years, thousands of hours, use. Having spent lots of hours boating with him, its effectiveness can be vouched for. The layout enabled the boiler with its central firedoor to be readily accessed and it utilised space fore and aft very well.

[malcolmd]

Yes, I had one trip out with David when I first joined the SBA, and I also thought it made a very good layout - thanks John, good to have a second opinion.

[fredrosse]

The Margaret S has the engine moved 2 inches to starboard side, the VFT boiler 1 inch to port. While just small changes, it makes for better access all around, and better machinery arrangement too. While a better arrangement, I still wanted to keep the center of gravity on the centerline of the boat. I think this balance should be maintained, but there are other bits that could be positioned to maintain an even balance of (zero) list if need be.

[malcolmd]

thanks Fred...

[Mike Cole]

I am fitting my new boiler a couple of inches off centre to improve the clearance with a side mounted steering wheel.

[Dhutch]

I think it depends on your needs, the boat, etc.

Our engine is dead in line, with an almost direct drive to the prop , but the boiler which is large is of-set to allow a walkway past it. This works for us, and as the plant is in an engine room and we need enough ballast like yourself anyway, all is fine. The effect of filling/empting the boiler is not overly significant to boat trim and the level remains very constant through out the season. The coal (1.5ton) is also slightly to one side, and we do have the manually trim-correct for this.

Other boats have the engine of, with a belt of a pair of UJs or CVs so as it takes you.

Obviously if the engine is on show, aesthetics come into it, but with work this doesnt need to be an issue depending on the aim.


Daniel