The Polson 1 thread got me thinking about what we do when we've bored out to the counterbores and need to replace the meat inside the cylinders. I've had the good fortune to see (but not the bad fortune to do a job of installing) a new sleeve placed into the cleaned up bore, with rings shrunk onto the ends of the cylinder, and bronze plugs screwed through both walls to hold it all in alignment before final boring to dimension. The rings on the OD of the cylinder make me presume a bit of pressure must be present, as if the sleeve was made large and pressed in, or was shrunk with liquid nitrogen and then allowed to expand in place.

Has anybody here done this job in recent history, and how did you do it and to what specifications for expansion, etc? I'm pretty sure it is something many of us will eventually need to think about.

dave

Dear Dave,

It is my understanding that GCR installed a sleeve to 4960 prior to my arrival. Mr. Robert Franzen may be able to answer your question.

Robby Peartree

Thanks robby - i got a PM from another resder who mentioned a recipe in a set of books from the American Technical Society published in the '40s that sounded a bit scary to me....included overboring half the stroke to .250 larger than the sleeve to reduce pressing pressure. That's a LOT of clearance!

dave

I seem to recall that IRM put a new cylinder liner in UP 428, back when Ed Beard, now of C&TS was still active at Union. Too bad Ed doesn't post here.

1/4" oversize? That doesn't sound right to me either. Maybe .025?

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Thanks Kelly, got a PM from the first guy again who cleared this up. I had visions of the back half of the liner flopping around as the piston jumped around inside it......

What book was your drawing from?

Back to my second question: who is doing this work now? Is there an industrial compressor rebuilding or other process that is very like this off the shelf?

Other other question: about banding the cylinder ends from the outside......specs for that work?

dave

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Me neither - i figure maybe a lot like sweating on a tire.....

dave

From an interested person on SteamTech:

The Canadian Pacific maintenance regulations (revised 1927) states that
cylinder bushings (sleeves) applied to reclaim worn cylinders or
bushings applied to all new locomotives will preferably be 3/4" in
thickness, turned smooth and have the same outside diameter as the
inside diameter of the cylinder and should be step bored, the back half
of the length of th bush and th ebore of the cylinder to be 1/8" less
than the particular locomotive drawing dimension.

Application of Bushings: Cylinder bushings will be the full length of
the cylinder and will be held in place by two cast iron or bronze plugs
threaded 1 1/2" pipe thread (dimensions of plug to drawing) and located
6" from each end of the cylinder, in the outer bottom corner, 30 degrees
from the vertical centre line. Step bushings will be pulled in cold.

Accompanying the above text is also a chart giving variations allowed in
bushing thickness depending on cylinder diameter (ranging from 18" - 23
1/2") and cylinder wall thickness. (I can scan and send to you if you
would like).

Of interest with the above is the bushings not being an interference fit
but held in place with plugs and the end cover (and presumably corrosion
after having been in service?). Perhaps a little along similar lines is
during the construction of the South Australian Railways 500, 600 and
700 class locomotives at Sir W.G. Armstrong Whitworth & Co. in the mid
1920's trouble was had in installing the cylinder liners, Using gas
burners to heat the cylinders (long before liquid nitrogen to cool the
liners) the liners would become stuck under the max specified 10 ton
installation pressure or the cylinder casting would crack during cool
down. Steam was then used to heat the cylinders as this was more even
and did not subject the cylinder to any more heat than when in service.
Changes were also made to the outside diameter of the liner (-0.002") so
when pressed in using steam to heat the cylinders an installation
pressure of less than 10 tons could be achieved and the bursting
pressure of the cylinders not exceeded. To make things even easier both
the cylinders and liners were stepped slightly in the middle (dimension
of this step unknown to me). And one last item of interest is that the
port openings were machined in the liner after being pressed in.

(The above information on the 500, 600 and 700 class cylinders and
liners was found in "A History of the South Australian Railways. Volume
6: Mountains, Mikados and Pacifics" Ron Stewien 2010)

Also, practical and experienced steam guy Alan from down under tells me "just like changing valve liners only bigger." Verrrrry helpful. He also sent an interesting link to how to remove liners:

http://www.heritageexpress.com.au/pages ... -10-31.htm

3801 doesn't have the fabricated saddle, but a cast steel saddle made for original lining with a cast iron sleeve - not done after wearing out a new bore. I think the photo comparing the drivers and firemans liners shows the difference between one fit correctly down its length and one with a bit of wiggle room.

So, it seems stepping the iners into a stepped bore is SOP in the English speaking world. I'm wondering if the use of liquid nitrogen would allow us to completely machine the liner before installation since heavy pressure would no longer be required for installation? if so, would the specs for the liner's OD need to be altered?

dave

I have an old VHS video somewhere where Gary Bensman is performing a cylinder reline. I don't recall seeing any heat applied to the cylinder but the sleeve was obviously cooled and was frosty in appearance. The ports were already machined in the sleeve. Gary made it look easy and it slid completely in in one movement then a quick twist with a bar to line up the ports. Piece of cake ;o)

I'm guessing it was on the 261.

Way Cool (literally). I thought that ight be an easier technique. Now if only he would share his methods with the rest of us.

dave

Kelly,

The 475 was originally built by baldwin, did the N&W replace the cylinders at some point? Otherwise, that would be evidence of poor baldwin castings..... Something which is to me much more digestible.

Details? Jason

I would suspect those engines were built as compounds, no? That would mean the cylinders were replaced at some time.

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