Birthdays come and go and mine has just been and went. Anne-Marie received this beautiful clock and barometer set which I will mount on a piece of mahogany to go into the cabin. I received quite a number of cards and comments from friends thank you, some of them kind.
I have been doing quite a lot of things off-line although most of my time has been spent refurbishing our new office. I have muscles now I had forgotten.
I do have some conundrums to.
How do I plumb in the calorifier from the engine? Do I take a link from the thermostat housing back to the return after the heat exchanger? Do I have to buy a new thermostat housing with a T piece fixed to it and where might I get such a thing?
Why is the gearbox so noisy on tick over or low revs?
I dropped over to check on Anne Marie this afternoon as the weather in UK has been stormy yesterday and today. I spent some time sealing down two of the five access hatch covers to the fuel tank – three to go.
I can only find one water leak at the moment (from above) and that is stubbornly refusing to disappear. Mind you I haven’t actually tried to cure it yet.
Anyway on my way home across The Marsh (The Romney Marsh on the Kent/Sussex border in UK), alongside the Royal Military Canal, I had to stop. It was 5.45 and getting low light towards dusk. There was a lovely barn owl flying along the ditches looking for supper. It ignored me and flew within 5m of where I was stopped in my car. Why don’t I carry a proper camera with me when I need one? I watched it for five minutes or so. Lovely – I have only seen a few in my 65 years and this was one of the best.
I wrote this some time ago but realised I hadn’t published it so here goes. This is about how I selected my new propeller (last year).
Having bought the reconditioned engine (Perkins 4.108) with a TMP12000 reduction gearbox (2.1) from John in Benderloch (Scotland) I have discovered that it is fitted with left-hand output shaft. This is a problem as the propeller originally fitted to Anne Marie was for a right hand gear box. If I don’t change it I will be going backwards to go forwards and go forwards to go backwards. Not very intuitive and definitely bad for the gear box thrust bearings as they are not designed to work that way for long periods.
This is not a good idea.
So I needed a new propeller and this requires me to know certain facts about the existing one.
The DIAMETER of the ‘swept’ area. This is the distance from the tip of the blade to the centre of the shaft x 2.
2. The NUMBER OF BLADES. In this case there are three.
3. Because the propeller fits on a tapered shaft I need the SHAFT DIAMETER at the boat side and the shaft diameter at the rudder side. In this case the larger one is 30 mm and the smaller one 20 mm.
4. The THICKNESS of the propeller at its centre (hub size) along the shaft. In our case this is 3 inches.
5. Finally we need the PITCH. This is a strange concept (for me anyway). Imagine screwing a nut along a bole. As you turn the nut it moves along the bolt and the propeller is no different. The Pitch of the nut & bolt is the distance the nut travels along the bolt in one complete revolution. The pitch of the propeller is the distance the propeller would travel on one revolution if it were moving through the water with no resistance or drag. To measure this on a big propeller you really need to have the propeller off the boat and on a flat surface.
Now fortunately I have taken the propeller off the boat and removed it from the prop shaft. I have attached a short video of how I calculated the pitch because it is easier to see than to explain but effectively you do this.
Firstly the three blades of the propller are identical so it doesn’t matter which blade you use to do the measurements as they each give the same answer.
Lay the propeller flat on a sheet of paper. Mark the centre point and the point either side of one of the blades at its widest point. This should be the same distance for each measurement from the centre point.
Measure the height of each blade at its top-most point and its lower-most point when lying flight flat on a tabletop. The tells you how far that blade will move when rotated the width of that specific blade.
You need to know how far the blade will move between these two points and that’s a simple measurement from one side to the other on the flat surface. This is because you need to calculate the angle that each blade moves from one side of blade to the other when it is rotating.
In Anne-Marie’s case the propeller angle is 53°. Now circle is 360° therefore it’s a simple matter to know if you divide Trevor and 60 x 53 you get a little over six times. On the basis that you know this you can multiply that figure (six) by the height of the front and back element of the blade (40 Or 1 1/2 inches). This gives a figure of 10.
Therefore the dimensions of the propeller 18 diameter with a 10 pitch.
I was given a little book by my daughter recently written by Ben Crawshaw entitled ‘Catalan Castaway’. It’s about a guy (Ben) who builds a small open boat and sails/rows it around the coast a few miles south of Barcelona in Spain. This is not about building a boat but using it and it makes good reading. He got me thinking about the stories I am telling about Anne Marie so I thought I’d do what my daughter told me to do sometime ago which is “to make the blog more interesting” (whatever that means) – well actually it means I have to make the blog more interesting – hence the title.
So today is February 17, 2019 and it is a lovely calm sunny morning with high tide about 0900 at Rye on the south coast of England. I shall go down shortly (10.30) and start Anne Marie‘s engine and see what happens.
I have been pottering away in the garage recently dealing with the engine control panel. I am adding an electronic push button solenoid to switch the engine off as at the moment we pull a piece of string. Over the past couple of weeks I have been manufacturing some brackets to support the engine control lines (Ultraflex gear change and the accelerator) and now I can start the engine, change gear and accelerate from the cockpit and all the instruments are there.
I got a ‘stop solenoid’ (E-bay, China) about four weeks ago .
A WHAT I hear you ask? “A ‘stop-solenoid’.” I respond. “It’s used to switch the engine off by pushing a button in the cockpit. When you press the button it activates a motor which pulls a wire about 40mm (1 1/2 inches) and this stops the engine. When you release the button the wire relaxes and the engine can be restarted. At the moment I pull a piece of string.
Anyway, I need a ‘pull wire when activated’ solenoid but unfortunately I was sent was the wrong one. This one pulls when switched off which means the engine would be ‘unstartable’. I am currently awaiting a replacement but it is being shipped by sea from China so I’m not holding my breath. The people selling it were very kind and very nice and did not quibble so I do have a spare solenoid if anybody needs one.
Having said that I have found a way (I think) of making this work but it means the solenoid will be powered up all the time and so if it fails I will not be able to run the engine – so on second thoughts I need the other one.
Apart from it being winter, the reason nothing much is happening on Anne Marie at the moment is because we are refurbishing an office for our business and I’m spending most of the week there. It is colder inside the office than it is outside so I’m not quite sure of the benefits. It is however putting Anne Marie on the back boiler for a few months.
So what have I been doing ….?
– I have been painting the steering pedestal which is getting better but still only has undercoat on it.
– My friend Alan is rebuilding all the cockpit seating, turning two planks of Iroko into slats and making a wonderful job of it. I have just received another batch of black Sika Flex 291i which Alan is going to use to create the black stripes beloved by boat owners. She will look lovely when done.
– The most recent thing I have been doing of note is salvaging some iron ingots. Because we have changed the layout of Anne Marie and put the galley on the port side we have a slight, very slight, list to port due to the extra weight and the boat is not quite in balance. We have removed an old goods lift from the office (it used to be a bank) and I have salvaged three very heavy cast-iron counter-weights from it. I shall place these in Anne Marie on the starboard side to counter the list. It certainly can’t do any harm. I am encasing them in resin to protect them against the vagaries of seawater. I will then place them in the boat and if it works I will resin them in place so they can’t move about when we are bobbing about on the waves.
– Lastly you may have read about my slight error with the engine sea-cock recently. This has resulted in a dirty old bilge and I have a job to do to clean it up. I have started but it will take a deal of time as it is very awkward working upside down in a tight spot. Fortunately the boat is not moving about much. I have got a job to do to prevent siphoning of raw water into the engine and this will require some thought and research on the Vetus web-site.
Anyway the little birds are tweeting and the sky is blue. The wind is calm and all seems good with the world apart from The B word which seems to be dominating every waking thought (or not depending on whose side you are on).
One last thought in the last couple of weeks we have seen a marked decline in our wild bird population. We normally have a large contingent of blue tits, great tits, coal tits, sparrows, dunnocks, robins, blackbirds, chaffinches and goldfinches. However yesterday I saw a pair of sparrowhawks so I suspect they’ve been helping themselves. We also have about 15 magpies zooming around so they are probably helping themselves as well. Not a good time to be a little bird I suspect.
I have been asked how I extracted the cutless bearing from Anne Marie and then put in a replacement. It was a long process of trial and error this is in summary how it worked.
The cutless bearing holds the propeller shaft in place when it spins in the hull. Without a cutless bearing the shaft would flap about and break. It is water-lubricated so water can get past the bearing so it is not a seal. Propeller shafts need an internal seal to prevent the boat filling with water. In Anne Marie’s case this is a Volvo Penta drip-less shaft seal.
Some boats with long propeller shafts have more than one cutless bearing and some have a bearing in the ‘skeg’. Anne Marie has a long traditional style keel so the cutless bearing fits inside the stern tube which carries the propeller shaft.
EXTRACTING THE OLD BEARING
Firstly I had not got the rudder fitted at this point. The arrangement I used would need to be tweaked if the rudder was present. I also withdrew the propeller shaft too so I had total access to the stern tube and the existing cutless bearing.
Importantly some bearings are secured in place with a grub screw so you need to grind away paint and filler to find out if one is fitted. Fortunately (or unfortunately) for me there was not one. Skegs often use grub screws because they are a ‘loose’ fit and the grub screw holds the bearing in place. With Anne Marie it is held in place by friction.
I made up a small disk of plate metal just the right diameter to fit inside the stern tube. This took some time because I wanted to make certain that it would not jam and that the plate was strong enough – I used 6mm plate steel. The disk had to be small enough to just slide freely into the empty shaft but not too small so as to move past the existing bearing. A cutless bearing shell is about 3 mm thick so there is not much room for error.
I drilled a 12 mm diameter hole in the centre of this disk to take a 12 mm diameter threaded steel rod about 1m long. I bolted the disk at one end of the rod using four bolts to lock it in place (two either side) so it would not undo when under strain – and there was a lot of that! I made up a U shaped wooden jig with 4″x 2″ (100×50) timber long enough to take the extracted bearing – it was about 6″ (150) long and 4″ (100) wide – and I drilled a 12 mm hole centrally through the bottom of the U. I then threaded the rod from the inside of the boat, through the stern tube, so that the disk was on the inside of the boat and the free end on the outside. I then pushed the U-shaped jig down the free end of the rod so that the two ends of the jig pressed against the hull either side of the bearing. In that way I was able to pull the rod through the shaft by turning the nut on the outer (free) end. I had to place a large washer on the outer end to spread the load because the pressure created tended to pull the nut into the wood rather than the nut pulling the rod through the shaft.
It was then a case of using a 12mm ring spanner and just winding and winding – and winding. Every now and then I gave the bearing a light tap of encouragement with a hammer and it slowly pulled out. After about 30 minutes it was out.
PUTTING A NEW ONE IN
This was a different story and took a while.
I read up about this but most videos and blogs were pretty unhelpful which just told me it was going to be difficult. None showed a cutless bearing on a long-keeled boat, they were all skeg type.
You are supposed to install the bearing in a specific orientation too but when writing this I can’t remember what that is so look it up.
I started by freezing the new bearing overnight and keeping it in a cool box until needed. I persuaded myself that this would shrink the bearing’s diameter so that it would be easily inserted. I’m not convinced.
I also cleaned out the stern tube to remove scratches, burrs or dirt/dust to reduce any friction. I also wetted the inside surface. Don’t be too fastidious here as you need to maintain the size of the stern tube as you want the bearing to sit tight once in.
Then I used the reverse principle to wind the bearing into place but this proved almost impossible. I got the bearing about one-third in and then it just locked solid. I had it aligned correctly but the friction was just too great. I took it out, cooled it down and tried again, probably half-a-dozen times.
Eventually I succumbed to the little devil on my shoulder which kept on saying “Hit it hard and if it doesn’t work use a bigger hammer”. My bigger hammer was a 7lb (3kg) sledge hammer and a colleague. You know the saying “When I nod my head, hit it”, well that was pretty much what we did.
We used a variety of ‘dollies’ to protect the shaft such as the 4×2 timber but the best proved to be a 3×2 piece of heavy duty, hard rubber which was lying around. I never found out whose it was and it’s probably still where I left it.
Putting the new bearing in was a significantly difficult job and I hated that I had to resort to brute force but there really was no other way for a simple soul like me to get it in. Good luck with yours!
Now I have done a video of the removal. I was too knackered to video the installation but there are some photos.
I have been advised that to make my blog more interesting I should sex it up. We’ll see.
I discovered lots of water in the bilges last week and my electric bilge pump pant took about five minutes to empty it. I had known there were leaks coming through in a small way but we haven’t had much rain over the summer and so I hadn’t really bothered. Now I’m really wet I thought I better do something about it.
I have therefore installed the hatch surround in the hope that that will enable the water leaks around the hatch to stay outside the boat and drain out through the hatch drains.
I have also fitted a new lock to the door so that we have a semblance of security on the boat.
I have now received a pull-off solenoid system to use as an engine cut-off. Written in Chinese I hope I can wire it up properly. That will be the last part of the engine wiring I think and so I can install the Control Panel in the cockpit.
I have also manufactured the Perspex cover for the Control Panel and bought some nice new hinges. All I need now is to buy a latch to keep it closed and it’ll be fully ready.
With winter on the way (not here yet Met Office), and time available to work on Anne-Marie short, I should be dabbling here and there on jobs. Mostly I will do work at home but I shall also try to get there as much as possible although I do have other things to do.