Tag Archives: engine build

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 🙂

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!

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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 – Steam 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

Retirement Beckons!

A change of pace and circumstance

Well it seems I have not posted since November and the arrival of Befur’s trailer. Since then a lot has happened (so Happy Xmas, and Happy New Year)… I have had the fortune to be made redundant, and have (with Louise’s kind support) agreed to turn that into retirement – so from the end of February there will be no more working interruptions, and as I am only “on call” now, progress should be faster. So with the shingles finally subsiding, and hopefully the last of the winter colds and the left shoulder starting to free up,  there can be no more excuses – so 2015 looks bright indeed 🙂 Continue reading