Tag Archives: leak compound steam

Engine Meets Hull

Just a note to commemorate another milestone. Yesterday we (neighbour Mike and I) lifted the engine into the boat! Hurrah!

We had spent a deal of time debating how best to do this, with the hydraulic bucket on the tractor being the initial option – but in the end we both felt a bit “windy” about working under the engine held up by an ageing tractor, and instead opted for the “trusty” Chinese chain-hoist strapped to an RSJ in the roof of Mike’s barn. We then picked the engine up, and manoeuvred the boat under the engine. To make it more interesting, we really don’t know how heavy it is – but the two of us could not lift it by hand to get it to the engine crane to put on a trailer for the trip to the barn (200yd push in light snow!)

The decision as to installation was to epoxy four M10 studs into the engine bearers and then use nuts on the studs to secure the engine bed down.

Woodwork Meets Engineering

This was another point in the build where the “looks good to the eye” world of boat-building meets the “accurate to a fraction of a mm” world of engine and transmission.  The key was that the hold-down studs were in the middle of the bearers (for maximum strength) and the engine’s “cam-belt” pulley was truly in line with the pullet on the prop-shaft.

This inevitably leads to an hour or two of “eyeing it up”, followed by a couple of goes at “marking it out” followed by that moment where one “girds ones loins”, picks up the drill and “goes for it”!

With the holes in and the studs loosely in place we tried to wrestle the engine onto its bolts while it swung on the hoist. Eventually it was done, and checked that it would all line up.

Leaving it overnight, we came back this morning, re-slung the engine to get it to better hang level, then lifted it up, removed the studs, filled the holes with neat epoxy, let that soak in and then re-filled with thickened epoxy. Then filled the drip tray, engine spacers and lowered the engine back into place, fitting the studs from above this time – some amount of fishing was needed to get all the studs properly located into their holes, but it all went together, and is now “setting” overnight.


Just a few to provide the flavour of the process…(as usual, click for a bigger pic). Boiler next!

Befur in the Barn

Befur in the Barn

alles up!

alles up!

A bit of adjustment

A bit of adjustment

Engine Installed

Engine Installed


Engine installed - view from stern

Engine installed – view from stern



Three Months and Counting!

We are feeling like the end (of the first phase) of “project Befur” is in sight – we have set a goal of having her on the water in April – the remaining 90 days appear to be passing at some speed.

This time I wanted to document the final work to get the engine and boiler ready for installation in the boat, the electrical system and Louise’s work on fitting out.

Boiler & Engine

Having completed the bench test, I disassembled the plant, making sure we dried everything out to stop the boiler corroding while in storage and ensure any frost did not cause damage. We put the sensitive bits (gauges and lubricator) in-doors to keep warm. However, a week or so later it became obvious that there was some corrosion occurring in the engine as it became very stiff to turn. So pumped some oil into the inlet, and ran it on compressed air for a few minutes to free things up and ensure everything was covered. (need to keep an eye on this over the next few weeks).

The small ball races in the scotch crank could not cope with the strain!

Also, as we cleaned up, we discovered a collection of “bits” in the sump, which revealed themselves to be the remains of a set of small ball-bearings from the “business end” of the scotch crank driving the pumps – I had worried about their small size, and testing proved this concern to be correct! (There were a lot of bits!)

I remade the crank pins in silver-steel and hardened the running part and fitted small needle-roller bearings which hopefully will survive the loads better – time will tell.

Boiler with cover, and engine ready to be lifted.

The remaining task was to make an outer housing for the boiler, to keep the hot bits at bay, and look a little nicer. So it was back to the woodwork!

In my hurry (and cheap-skate mindset) I decided to make the cover from ply with wooden cladding – and purchased a bundle of the cheapest battening from the local builder’s merchant. The first job was to get the ice and snow of this and then chop it into appropriate lengths, ready to plane to size – the planer didn’t like the ice! So the timber got put in the boiler house to dry out for a few days.

Then it was planed to size and epoxied into place on the ply, and varnished. Of course I was hurrying things too much, and the wood continued to dry out while it was in the house being varnished – so the end result has some rather “rustic” warping and splits, but given that this is not a structural component, it will have to do for now!

Following on from Lou burning herself on a hot funnel a few years back, I also decided to fit some handrails to the boiler to encourage people not to catch hold of the hot bits. I was quite pleased with these. I had purchased some bronze castings for the ends of the handrails (at and SBA auction), and nickel plated these (along with some of the valve-gear components on the engine) in the same way as previously done for other engine parts. These matched the A4 (316) stainless tube for the rails and make the finished job look quite nice. (click pic for larger version)


So while some members of the SBA are firmly of the opinion that electrics and steam boats should not ever be seen together, Befur is having a complete set for the following reasons:

  • The boiler is fired by a standard commercial pressure-jet burner which needs 240VAC to drive it.
  • The composting loo requires a small fan operating continuously to keep it running cleanly (i.e. not smelling, no flies etc.).
  • As Befur is going to spend her life in the water  (as opposed to on a trailer), we need automatic bilge pumps and navigating lights.
  • As (in the end as a sailing yacht) we aim to do some coastal sailing we are fitting her with VHF radio.
  • As we are aiming to “camp” on the boat we also need cabin lights and the ubiquitous USB charging points!

Electrical Panel

So the plan is to have batteries to drive a 240v inverter for the burner (which also provides the USB sockets), and drive the other ancillaries. When running the batteries are recharged via the alternator on the engine, but when moored solar panels on the cabin roof are designed to keep the batteries topped-up and replenish power used for anchor lights, bilge pumps and loo.

After a lot of thinking and head scratching, we eventually concluded that a 100amp-hour AGM leisure battery should provide enough capacity (remember the inverter draws about 25amps to run the burner, and it might take about 10 to 15 minutes to get steam to run the engine and steam pumps before the alternator can take over).

The burner only consumes about 300watts when running, but as the fan/pump motor is an induction one the start up currents are much higher. After trying several inverters I eventually settled on one rated at 1,500watts which seems to do the job.

As to the solar panels, it is quite hard to guess the size needed. The only continuous loads are the loo fan (which is v small ~150mA) and overnight LED anchor-light (5w). So in the end I opted for a pair of 10W semi-flexible panels.

These will be wired in parallel (to help overcome the loss of power resulting from one being shaded by a mast or rope), and we have fitted a PWM power controller. This prevents overcharging, and also has a function which provides switched power for navigation lights which automatically turns on/off at sunset and sunrise.

Testing Electrical System, although Cumbria December sun didn’t appear to be bright enough to generate a measurable charge!

These controllers are not the most efficient – MPPT controllers do a better job of extracting power from the solar panels, but cost ~£100+.  The Chinese  controller I purchased is called “MPPT T40” in an attempt to fool the purchaser, as it is actually a PWM one! – come-on eBay!

I built a control panel to hold all the switches, inverter, controller and fuses (the controller is not fitted in this pic.)

Testing 100+AMP thermal breakers is a challange – even the welder would not make the largest ones trip out before the breakers in the house decided the workshop looked like it had shorted out!!!


Lastly, we should include some pictures of Louise’s efforts in producing the first cushions for the cockpit – she has quite a lot of work ahead of her, as we also need cushions for the beds in the cabin – a cover for the boat and eventually sails when we fit the mast and sailing rig next year – they look very posh!

Louise and Cockpit Cushions



A final video: Everything running on the bench

First Fix the Bugs!

Following on from the Boiler test, and a quick trial we identified just over 20 items that needed some attention. So a week later, with all these items fixed (from leaking valves to painting and plating valve gear components), we are ready to try again.

The Fire-up Plan

We enlist the support of neighbour Micheal Slack (who is also housing the hull) and embark upon a frantic half hour of trying to put the water and steam where we need it and get the plant running properly.

This involves:

  1. Lighting the burner, and raising some steam.
  2. Getting the blue steam pump pumping cooling water thru the condenser to condense the exhaust steam from pump (and engine).
  3. Warming the engine thru with steam to get it ready to start.
  4. Getting the engine to run so that the air pump removes the condensed water from the condenser to create a vacuum.
  5. Getting the boiler feed pumps on the engine running (so Mike can stop with the hand pump).
  6. And get the alternator running to prove that we can provide electrical power for the burner, lights, radio etc.

Getting that lot to happen at the same time took some time and several attempts (and a lot of water on the floor)! It will me much easier when there is a lake providing the cooling feed water, rather than a hosepipe and bucket! But it all worked even the real McCoy lubricator and the whistle!

I was also pleased that the engine does not appear too noisy or knocking, just a bit of noise from the chains. So a good day!

A video of the day

Enjoy the video of edited highlights – with enthusiastic commentary from our “cameraman” Louise!


“Final” Notes on other potential issues

Having “finished” and tested my engine there were a final set of issues that I suggest you keep an eye on:

  • Piston Rod Lubrication Fitting Clash: The drawings show the small-end and cross head lubrication is achieved via drillings at the  top of the piston rods. There is no indication of how oil is delivered to these drillings. I have arranged this using small-bore flexible nylon tube and push fittings. I installed a small elbow into the feed hole to allow the push fittings to point between the bores. However, space is very limited here, being close under the lower cylinder covers and stuffing box glands. When I packed the glands I found that as these sat slightly lower they clashed with the oil feeds at TDC. I can see no way to move the oil feeds. So I resorted to machining away some of the bolting flange of the stuffing-box glands next to the columns. This has worked, but clearances here are tight.
  • Air Pump Drain Modification: the drawings show a simple drain plug screwed into the bottom of the air pump body. In my design of pump drives this is hard to reach, and having a circulating pump exhausting into the condenser, you can get into the situation where the condenser becomes full of condensate if the main engine/air pump is not running. So I have brought this drain out to a simple taper cock. This just makes things a bit easier.
  • Pinning the Drop Arms: During early testing I found the drop arms had a tendency to slip on the weighshaft. So I installed small taper pins to secure them.
  • Reversing Lever Clash: This was just me not spotting a problem earlier. I fitted the weighshaft at the top of the column position. On final installation I discovered the level collides with the exhaust pipe in full-ahead. Just keep an eye open. 🙂

A Boiler Full of Steam

Well the 10th November 2017 marks a major milestone – the boiler passed its initial inspection and steam test, and is now certified for use. (big smiles all round).

Picture of Engine, Boiler Etc. ready for test

Sadly, everything was too frenetic to take pictures during the steam test – but here it is just before we pressed go!

John, our inspector from SBAS Ltd (the SBA’s Boiler Inspecting Company) had been booked to arrive at 3:00pm – at 9:00am I set about final sealing of the try-cocks on the sight gauge – at 1:30pm I nearly called to cancel the appointment as no amount of fiddling and fitting would make them seal, with a constant drip from each of them at anything above 50psi 😦

Finally I made them seal with a combination of shredded graphite string and a binding of PTFE tape to seal the valve stems – dry as a bone at test pressure of 375spi, big sigh of relief. A final tightening of some of the 60+ joints in the steam circuit and we wound up with a boiler that held over 350psi for over one and a half hours without a single pump being needed. (This is a hydraulic test so the boiler is filled to the top (to exclude all the air and thereby minimise any “bangs” resulting from a failure.)

So the pressure test is complete. Next the steam and accumulation tests. So we wheel the complete set of machinery (engine, boiler, steam pumps, battery and regulator) outside (with a lot of puffing and blowing), drained the water in the boiler down to operating level, and we light the burner.

The burner needed some adjusting to get it to light and burn fairly cleanly (a little more tweaking needed) and we quickly had 10psi on the gauge (5-6 mins)  – so we turned off the burner and checked round for leaks or other problems and to let the boiler “adjust” to its new state of hotness.

All looked good so we brought it up to 50psi to check the water gauge (sight glass) was reading correctly and all the various blowdows operated correctly – they did! (more smiles).

The next step is to make sure the safety valve opens at the correct pressure and is able to control the pressure within 10% of safe working pressure with the burner full on.

So, burner on and another 10mins to come to working pressure of 250psi (17Bar) – whereupon I got an impromptu (but complete) hot shower. The safety valve did open OK, but as the water was quite high in the boiler. and had been dosed with washing soda to bring the PH up to 11 (and probably because of all the crud left in the boiler) we got a lot of water carried over into the exhaust steam (what is known as priming) which provided the aforementioned hot shower. There was enough showering down on the 240v wiring of the burner that I decided to kill the power while we dried things off….

So with a little less than a litre of diesel left for the burner we lit it once more and went for the accumulation test. By now it’s getting a little cold and dark, so reading the gauge within the billowing clouds of steam was quite hard for John, but after a few minutes he was happy that all was good – we were passed.

Not wanting to waste all this nice steam we tried the Worthington Simpson steam pump (A post on the restoration of this is on the way) in anger, and it performed quite well – supplying feed water at over 200psi….. and then we tried the engine!  after some warming thru this ran too and even the generator seemed to be making 7.5amps at a modest speed – but we highlighted the next (somewhat expected) list of jobs:

  • Two of the relief-drain valves seemed not to want to close (more clouds of steam and investigation needed)
  • The circulating pumps (engine driven) did not deliver enough cold water to the condenser to condense the exhaust steam and create the vacuum. So we are going to revert to the original design of the engine-driven pumps acting boiler feed pumps and the steam pump as a circulating pump.
  • I think I saw a couple pin-hole leaks in the feed pump plumbing which need checking
  • We need to finalise the plumbing from the cylinder drains
  • On the next run we need to get the displacement lubricator running.
  • We need to check the alternator performance to make sure we can generate the 20+amps we need to drive the inverter for the burner.

….then we can think about attempting to install the whole she-bang in the hull!!!! (Spring ’18 Launch – yes,  I think we might make it!)


Finishing the Superheaters & Boiler Casing

Work on the Boiler continues with the finishing and installing of the Economiser (pre-heats the incoming water to the boiler using waste heat from just before the flue) and the Superheater (adds energy to the steam on the way to the engine, again using waste heat from the flue gasses.

Milling and Drilling the Econo/Superheater Headers

As noted in the last post, I decided to mill the recesses in the two halves of the headers, as there is a lot of metal to shift, and with the “ripping” milling cutters this was by far quicker. (some pics)….

Milling Recesses in Headers

Milling Recesses

O-ring milling set up

O-ring milling set up

Some finished headers

Some finished headers





Tapping Machine 😦

As there were such a lot of M8 holes to tap (about 48 per boiler) I thought I would “invest” in a tapping head for the mill, and went for a cheap Chinese one – and you certainly get what you pay for… I was worried when it arrived as it appeared to not have a load-sensitive clutch, so decided to try it gently on a test piece… the pictures show how that worked out…

The £^*kin Tapping Head

The £^*kin Tapping Head

Machine Tapping in Action

Machine Tapping in Action

I can imagine it would have been OK with tapping thru holes, but even being as careful and slow as I could, it was useless on a blind hole -sheering the tap instantly. I was just very happy that I snapped the tap in a test piece, and did not scrap a header that I had spent some time (and money) on making… So it’s back to standard/hand mode… and we have a full set…

Back to the old method

Back to the old method

Some finished headers

Some finished headers

Cutting the O-ring Grooves

The final job on the headers is to cut the 4.5mm wide groves for the o-rings that seal the joint between the two halves. I was a little nervous about cutting these in the lathe, as you need to produce a narrow tool with additional clearance to avoid the outer edge of the groove as it is cut.

O-ring milling set up

O-ring milling set up

So, again I decided to mill these, using a small slot drill and the rotary table. This did work, but was slow and tool wear was a problem – I might revert to lathe cutting these for the drum ends.  The setup for milling the grooves was to fit new clamps in the recess before removing the clamps on the rotary table that were holding the header while recess milling (see pic). This meant we knew that the part was still centred on the rotary table, ensuring the recess and o-ring groove were concentric.

With all this complete we just needed to fit the tubes with the same expanding process as used on the main drums.

Boiler Casing

You will recall I drew the parts for the inner casing of the boiler in ViaCAD and then had them plasma cut directly from the drawing; this meant assembly was quite simple. I used M5 rivnuts and screws to make the assembly, spotting through from the plasma cut holes to locate the rivnuts. This went well. I also purchased an American design of tool for fitting the rivnuts, this is based on a pair of wedges which produce the compression to expand the rivnuts. The more normal “pop-rivet” style of tool requires bigger hands and forearm muscles that I currently own!

Completed Inner Casing

Completed Inner Casing

Starting the casing

Starting the casing

Pressure test

The last job is to pressure test the assembly, as the boiler is rated to 250psi, the hydraulic test (with the assembly full of water to avoid any large bangs!) is 500psi. Once we located the one tube we failed to expand (light shower ensues) the assembly proved pressure-tight – which is more than could be said for the plugs and pump, which took several hours of work to fettle to a point where they would stand the pressure. (In the process I became a complete fan of Dowty Seals, which rendered the plugs in the headers pressure-tight with little more than finger pressure inserting the plugs. Here is a video of one of the completed assemblies under pressure (before I cured the leaking pump!!).

Not a bad months work in total…


Tube Expanding and Economiser Headers

Just an update on progress with the boiler and other (interrupting) activities.

Tube Expanding

Nigel was good enough to make the trip north and assist with the tubing of the first boiler.

This was actually a simple, if repetitive, job.

Fitting the tubes

We firstly supported the three drums in the casing end plates, which were temporarily joined with lengths of timber. When fitting the tubes the game plan is to first locate the “centre” row of straight tubes, then fit the outer rows.

In practice there is not enough clearance to insert the first end of the tube with the drums in their correct orientation, so one firstly turns one of the drums in the casing to allow one end of each of the first row of tubes to be slid into this drum, and then the drum can be rotated back to its correct orientation and the free end of the tube inserted into the other drum.   (Hint: Insert them into the mud drum first, we actually started by inserting them into the steam drum first, but they fall out as you rotate this drum).

Once the straight tubes are in place then the outer rows can be inserted by inserting the tube into one drum and pushing it in as far as the first bend, this then provides the clearance to allow the  tub to be swung into place and then you can slide the free end back into the other drum.

Once the tubes are in place you can commence expanding (in fact we expanded the straight tubes into place before inserting the bent ones. Drilling all the holes with a 12.1mm drill actually worked well and provided just enough clearance to allow assembly – any tighter and it would have been a real struggle.

How much expansion?

Before expanding we did the maths on how much expansion was needed. The idea is that firstly you expand the tube to take up the slack between the tube and the hole (12mm OD, 12.15mm hole) so this was 0.15mm on diameter, then you expand the tube by 5% of its wall thickness. So given a wall thickness of 0.7mm this meant expanding the tubes a further 0.07mm. So the resulting ID of the tube was 10.82mm.  We did this by test expanding one tube in stages and checking the diameter, and when it was right we measured the free-length of the mandrel still showing. This proved to be about 20mm, so we then made a 20mm collar for the mandrel which stopped the expanding at the right point.

This worked very well, the load on the drill driving the expander could be heard to change as the expander reached the collar, thus making it simple to know when each tube was tight, without a lot of squinting down the drums. It’s really a two man job, as one needs to hold the tube so that the required 3mm+ of the tube is extended into the drum, while the other drives the expander and “contraption”. A video of the process in action:

We actually fitted about three-quarters of the tubes that we could reach from one end and then turned the boiler around and did the tubes at the other end. It might have been better to work from both ends, as by the time we had finished the mud drums had been pushed out sideways in the casing by about 1mm – no big issue, but information we will use when expanding the other boilers.

One other issue was that the “contraption” and expander proved too long to be assembled inside the smaller mud drums. We solved this by shortening the “chuck” on the “contraption” and by shortening and regrinding the square drive on the expander.

Here are some pictures showing the process. About 14hrs work to expand the tubes for one boiler.


The next part of the job was to turn up the ends for the drum, and also the economiser and superheater ends.

I decided to start with the economiser and superheater ends. Having first drilled another 12.1mm hole in the centre of the blanks for the inner headers (to take one of the super heater tubes), this was initially a simple turning job with the blanks held on a mandrel pre-turned in a 3-jaw chuck – this lead to Interruption 1, the clutch on the Harrison started slipping when confronted with the loads of highspeed turning with the insert tooling I was using. So an hour of so cleaning and refilling the parts washer followed by getting all the oil off  the clutch plates solved the problem.

Then we needed to cut 70mm diameter 12mm deep recesses in the centre of each part – I started by boring one of these, but it was slow work, so I decided to change over to milling these – here two more interruptions intervened in progress. Firstly the Mill started a rather worrying clicking noise from the gearbox – trying to ignore it didn’t seem to work, so I concluded I needed to strip it and investigate, as any major failure would be catastrophic as there very few parts available if anything broke.

Rambaudi Mill Gearbox Servicing

Rambaudi Mill Gearbox Servicing

This was simple to do, but hard on the nerves  – more parts washing, lots of inspecting and new grease restored the machine to full (quiet) operation. I think small bits of dirt and swarf had migrated into the gears and spindle bearings, and the cleaning sorted things.


Lastly, I spent a while trying to resharpen a bunch of broken and worn milling cutters with pretty limited success – so I bit-the-bullet and purchased some new cutters, including a 16mm “ripping” cutter designed to rough out at higher speed – a good choice.

Recess Milling and PCD drilling

I decided to mount the header blanks on a rotary table and then mill the 70mm recesses with the ripping cutter, then remount the blanks on the table with a stud through the centre hole, located between a set of stops to drill the 12 M8 tapping holes using the DRO’s PCD program – nice and simple and accurate. More pics.