Tag Archives: engine build

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!

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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 ūüė¶

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!)

A Plumber’s Nightmare & a Real McCoy

Over the last few days we have encountered the two items mentioned in the title in real life, in a slightly stressful way.

The Real McCoy

One of Elijah McCoy's displacement lubricators - actually this one was made by the Detroit Lubricator Company.

One of Elijah McCoy’s displacement lubricators – actually this one was made by the Detroit Lubricator Company.

While Wikipedia suggests two origins for the phrase “The Real McCoy”, the most well documented version relates to one of the brass beauties shown here.

It is a displacement lubricator patented by one of Elijah McCoy’ in the 1870s in America. ¬†These devices perform a simple, but vital, role of providing internal lubrication for steam engine cylinders and valve gear, but they do it using an apparently impossible process.

Basically they are attached to a ‘T’ in the steam line supplying the engine. You fill the lubricator with oil, and then via a mechanism which is not at all intuitive, the steam in the steam line to the engine decides it would prefer to be in the lubricator and, as it migrates that way and condenses as it cools, displaces the oil which is forced back into the steam line. So the connection to the engine sees steam heading one way and oil heading the other with nothing obvious causing that to happen!! The lubricator has a number of valves to control the rate that this happens and allow the machine to be shut off and refilled while underway.

Apparently¬†Elijah McCoy’s ¬†lubricators were so good and reliable that companies wishing to purchase steam locomotives were given to checking that it was fitted with a “Real McCoy Lubricator” – hence the phrase ūüôā

In my case I purchased this at an auction a few years ago, and prior to fitting it I needed to pressure test this (as with all other pressurised components). As I did this, it revealed a number of leaks and failed seals on the two sight glasses.

Taking it apart revealed seals that may once have been rubber, but in the intervening years (100+?) had turned into something more like wood. I managed to find some replacement ones that just needed shortening, but fitting these is a tense process as cracking the glass would be just too easy.

Anyway, we managed it, and with a little TLC and returning some of the needle valves, we had the Real McCoy: a leak-less displacement lubricator.

The Plumber’s Nightmare

The fwd boiler fittings almost complete.

The fwd boiler fittings almost complete.

The rest of the week has been consumed by attempting to fit the fittings to the forward end of the boiler.

This seemed as though it would be a simple process, but pushed me to the edge of serious depression.

Due to the temperature and pressure of this assembly (250psi and 200+ degrees Centigrade) all of this needs to be in steel pipe with screwed fittings.

The problem is that while one can imagine how it all goes together, the reality is more complex, principally because you can’t actually screw all the parts together as the end points are fixed and so you can’t tighten everything.

Moreover it appears to need a certain sort of brain/thinking to figure this out – my respect for plumbers has been raised considerably! This was born out by half an hour in Penrith at the sales desk of a pipeline and hydraulic supplier while the staff demonstrated considerable fortitude (and difficulty) in “rummaging” through their stock to find the combination of bits we needed. (Actually I found this quite encouraging – if they couldn’t sort it out, perhaps I was not being a complete klutz.)

The net of this story is that what you need are “cone unions” – and I think the ones provided by Bessegers (like these)¬†are by far the best design. These allow you to assemble the screwed bits, and then attach the assembly to the component you are plumbing without needing to move the joints you have made.

The second take away, is that sometimes you need to opt for an indirect path for the piping to allow you to accommodate the offsets in all three dimensions.

Onwards!

Mid 2017 Update

Progress since April

Well, it seems like high time I provided an update, as the last one was in April!

At some level it feels like not much has been achieved, but that’s because a lot of the work has been “bitty”, finishing up jobs and tidying up items that had been hanging around for a while – and then there was the distraction of needing to design/build a new garden shed (the last one literally blew down – the joys of living 900ft up in the Pennines!).

So here is a list of the items I can recall completing….

  • Finishing the inner Boiler casing – next job is to “lag” the inside with ceramic board insulation
  • Making a manifold for the feed clacks – basically milling and turning off about 80% of a steel block.
  • Remaking the battery pack for the VHF transceiver – no replacements available.
  • Testing the antique Sailor VHF radio – (using the aforementioned transceiver)
  • Rebuilding and modifying the lubricator pump and plumbing to fix leaks – (correction; most leaks!)
  • Making a sump/oil tray for the engine – expensively made from spare 3mm brass sheet!!!
  • Repainting the condenser – maximum Nitromors, but looks better.
  • Finishing steam re-heater ¬†– making unions, and lagging in “broken bone” plaster bandage.
  • Plumbing in the condenser steam and cooling water circuits¬†– lots of cursing, custom unions and silver soldering.
  • Fixing the pump/alternator assembly to sump – decided the floating design was no good.
  • Craning the engine and boiler around ready for testing.
  • Spent a fine day on Grayling on Windermere – we all need a break sometimes!

Next Steps

  • I think the engine is now effectively ready to install into the boat, but we are going to bench test the whole shbang before we do this.
  • Strip the boiler casing and fit the insulation.
  • Mount inner and outer funnel onto boiler.
  • Screw cut the M20 and M16 stays for the boiler (thanks John for loan of larger lathe).
  • Make water gauge – modified castings arrived (thanks to Ian Cross for the pattern making).
  • Assemble and pressure test the boiler!!!!!!

I have assembled a slideshow of photos to record some of the above items, rather than post them all individually – enjoy!

 

Shiny Things

While we await the 600+ cut and bent boiler tubes from the other members of the “Boiler Collective” beavering away in Sussex, we went back to the engine to try and close off the final list of “to do” jobs….

Cleading/Lagging/Cladding

I think Cleading is the official word for this, even though WordPress objects!

This is installed around the cylinder block to try to keep the heat in, raise the temperature of the block and reduce power-sapping condensation in the cylinders. (A thin film of condensate on the cylinder walls can apparently eat up to about 50% of the input steam in small (2″) cylinders according to this paper).

While on the face of it the Leak’s cleading can be quite simple, it still took two days of paper templates and careful nibbling of the 40thou stainless sheet I chose to use. This is thicker than often used, but I had discovered in using the same material on the 5″ Nigel Gresley I built, that is produces a far more robust job, and is much less prone to kinks and dents.

This was layed over a sheet of Kaowool blanket (with extra layers stuffed into the spaces) and secured with 2BA screws (temp ones shown in pictures) and I was quite pleased with the overall job.

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Condenser Mounting

The mounting of the ancillaries onto the engine always seems to entail many hours of contemplation and procrastination (see next bit). On the Leak the condenser was not discussed in the original Model Engineer articles, and while the drawings are available the mounting is left to the builder’s discretion.

I opted not to undertake the building of the condenser. and instead managed to purchase a second-hand item (probably for a Stuart Turner 6A) from Simpson’s in Coniston at a very fair price. I eventually decided to build some large “shelf brackets” from some 3mm brass plate in the “stores”, and attached these to the flat faces on the rear of the bed and columns that were originally meant to hold the air/feed pump assemblies and cross-head guide. Having polished them with those fantastic York abrasive¬†rubber blocks that Cromwell stock they looked quite posh!

The Condenser Shelf Brackets

The Condenser Shelf Brackets

Clearly the condenser itself still needs a coat of nice paint!

Displacement Activity

The next task is to find a place to mount the lubricator pump, and this engendered a lot of head scratching and eventually got diverted into some classic “displacement activity” (things you do to avoid doing the thing you need to do!).

So I polished the gauges I plan to use… more abrasive-block work and a nice result…

Shiny Gauge Set

Shiny Gauge Set

Onwards…..

Relief Vales and Drain Cocks

An experiment РSteam Operated Combined Drains & Relief

Much earlier in the process I baulked at drilling the cylinder castings for the cylinder drain cocks because they looked hard to drill with out risking damage to some rather expensive castings. Moreover, previous experience with manual cylinder drain cocks on the loco had been poor (leaky, difficult linkages etc.) and on the steam launch most people seem to opt for 4 manually operated cocks which involves a deal of “faffing” in use. Continue reading

Drivetrain and Spline cutting

We have turned one eye to the business of the drive train and prop-shaft for Befur.

I have concluded that I am putting a CV joint in the drive train, to allow the engine to be mounted horizontally, and also going to use a toothed belt drive from the engine to the prop-shaft, so allow me to install the engine off-centre, and improve internal layout.

The “Drivetrain”

Continue reading