Entries by Nigel Bennett

I can now write about a huge development in the last few days.

To support the Turntable Fund, follow this link!

A turntable has been a key element of the museum plan for many years.  This will be the center of the long term plan to house and present our steam collection in a roundhouse setting.  More than that it will present a fascinating visitor attraction, photographic opportunities and the ability to turn all types of equipment to present in different orientations to those with which we are familiar.

We have had on site for a number of years the C&NW table from Harvard.  However, this is not of a length that would accommodate larger pieces of the collection.  So various opportunities have been explored over the years to obtain a larger table, ideally thru donation.  A couple of weeks ago we became aware that Union Pacific had included the table of the Burnham (Denver) repair facility, that we had hoped to obtain by donation, in an auction of all assets of this, now closed, facility.

This table was a target in many ways.

·         It is one of the largest at 130ft. and capable of turning any equipment at IRM;

·         It is an historic item, being a centerpiece of the Denver & Rio Grande works at Burnham;

·         Dating from 1941, it was installed to support Challengers coming to the Burnham facility;

·         In 2012 it was subject to a total refurbishment, believed to have cost at least $500,000, so is in virtually as new condition

·         Despite its length it is of very shallow depth.  This is a critical consideration at Union due to the high water table.

In view of this the board approved funding to try to acquire it by purchase at the auction.

I am pleased to say that we were successful and actually obtained the table at what was basically a scrap price of $10,000.  This is our new acquisition giving some idea of its excellent condition.

Our new acquisition in its current home

View along the table

Clearly this is just a beginning.  We must now move it from Denver to Union, which is no small exercise and will cost several times the purchase price.  Once at Union we will have to construct the pit in which it can be installed.  This is a MAJOR construction project and will depend upon fundraising on a large scale.

However, as substantially the largest turntable in preservation, the expectation is that this will provide IRM with a major attraction in years to come.

Another month of steady progress in the steam shop.  There is rather less detail this month as I was away for three weekends visiting family in the UK.

Obviously the central focus is on getting #1630 complete in time for the start of operations in May.  The regular work for the annual inspection continues in parallel with the major project of the valve overhaul.

The boiler and other work for the annual inspection is now largely done.  A couple of weeks back, Phil cleaned and checked the arch tubes.  After that the last of the wash out plugs were re-installed.  Yesterday the testing of the pressure gauges was carried out so these can now be re-installed.  The boiler will then have everything in place for the hydro-test.

We will now schedule this test with the FRA inspector.  Once this is done we can conduct the internal inspection and, subject to any issues detected in testing, plan on steaming.

Obviously one essential part of the annual inspection is correcting those items that are considered out of or close to allowable tolerance.    In this context, the spring loaded buffer on the front of the tender is was overhauled and the upper cross head bearing on the fireman’s side is being re-metaled.

The buffer has been cleaned, spacers made to take up the slack in the springs and painted.  Yesterday it was re-installed onto the tender. 

Tender buffer back in place

The tender is now complete and all that remains is to re-couple it to the locomotive by refitting the main drawbar.  This has been removed, thoroughly cleaned and inspected for any cracks as required for the annual.  Recoupling will be done as we prepare for steaming as this is best done by pulling the tender out of the shop and lifting the drawbar into place outside, where we have space to use the fork-lift.

A big job completed recently was casting the new Babbitt bearing for the crosshead.  What does this mean?.  Babbitt (alloys of tin or lead with copper and antimony) has been used for nearly 200 years to create a bearing surface against steel or iron.  A favorable combination of relative softness, compression resistance and porosity, which facilitates the distribution of lubrication, mean that it is widely used for bearing surfaces to this day. 

However, while modern usage is usually as a thin layer in a backing shell of a harder material, the more traditional usage made use of another property, low melting point.  The metal melts around 400-500 degrees and casts well at 800-900 degrees.  It will adhere well to iron or steel that is treated with a flux but not to a dirty surface.  The principle is then simple.  One iron or steel surface, normally a casting, does not need to be machined and is over-size versus the shaft or rod that moves against it.  Molten Babbitt is then poured into the over-sized space in which it solidifies to form the bearing surface.

In the most basic form, the bearing is cast in situ.  A smoky flame is used to soot the surface against which the bearing will slide, any gaps thru which the molten metal could escape are blocked and the molten metal is poured in.  The contraction of the Babbitt as it cools provides a small clearance and the bearing should be ready to go with no machining necessary.

The bearing that we must replace is that in the top of the crosshead which bears on the slide bar.  In theory this could be cast in place.  However it was felt to be considerably safer and more accurate to cast the Babbitt in the crosshead shoe with some excess and then machine it to final size on the planer.

To do this the shoe, with a tray positioned in the center to make the “U” shaped channel, forms the mold. 

Jason adjusts the tray in the shoe

Shoe in furnace with mold in place

The whole assembly is heated in the furnace so that the Babbitt remains liquid when it is poured into the mold.  The shoe is tinned to help the Babbitt to adhere while the tray is soot coated to help it release after cooling.

Jason tins the shoe to make Babbitt adhere

Babbitt being melted in the second furnace

Pouring the Babbitt

Once the babbit had completely cooled, the tray was removed, the crosshead shoe was mounted onto the planer and Tom has started machining the babbit to its final dimensions.

Shoe in planer and bearing part machined

Meanwhile the valve overhaul has progressed well.

Both valve chambers are now bored to size and the boring rig has been removed.

Valve cylinder after re-boring

The valve rods were sent out to a specialist for surfacing to remove areas of wear that form over time as they run in the gland packing.  These are now back and ready to start the reassembly of the valves.

The four cast iron blanks to make the new bull rings have now been machined to final internal and outside diameters.  Needless to say, each of the spiders proved to be of slightly different diameters, so each of the blanks is now unique to one particular spider and therefore one of the four positions in the locomotive.  They have also been tested in the bores and proved to be the required fit on the external diameter. 

These are now off-site being machined to produce the finished bull rings.

Many happy hours have been spent in cleaning the spiders and valve bodies.  It is essential to remove the hard carbon built up on these but, each has a small lip that secures the spring ring.  So it is a long and careful process to carefully remove the carbon without causing wear to the lip.

Spider stripped and cleaned

In preparation for re-assembly the studs that hold the cylinder ends have been inspected and around 50%, that were excessively corroded, have been replaced.  This provided interesting confirmation of the history of #1630.  On the engineer’s side 15 of the total 20 required replacement but on the fireman’s side only 4 needed replacement.  This is explained but the fact that, in the late 1930’s, she was involved in a head on collision with a Mikado, suffered heavy front end damage, and the FS cylinder casting was replaced.  So the casting and studs on the ES are mostly 20 years older than those on the FS.

New studs in place and the hone in place in the cylinder

A minor set-back has been the conclusion that the bores need to be honed before the valves can be refitted.  As with many things in the steam shop, this needs unusual equipment.  Honing a 12inch cylinder requires a pretty slow turning motor.  While we have such a motor, it has not been used in many years and proved to need overhaul before it could be used.  That is nearly complete so the honing can hopefully be done soon.

Once this is done and the bull rings are completed, we should be able to start re-assembly of the valves.

Meanwhile work has progressed slowly but steadily on the Shay.

One major step is that the form #4, engineering assessment of the boiler has been completed and submitted for FRA review.

Most of the holes for rivets in the smokebox have now been reamed so we are getting close to being ready to rivet.

Phil has been working on fitting the grates.  This is a significant job as the grate assembly is new.  Prior to overhaul she ran with a less than satisfactory arrangement fitted when she was converted from oil burning.  This time she is being fitted with a new grate set up that should be more satisfactory ……………… once the new castings are carefully adjusted and fitted to newly installed bearers.  With a lot of work Phil has now got the grate bearers fitted and the grates themselves are now being test fitted.

Mike has been replacing some broken studs in the cylinder heads.

Jerry has been making good progress on lagging the boiler.

Jerry fits lagging to the boiler

Progress.  One complete section

Work has continued steadily on the cab for #428.  The riveting team have been making good a few final missing rivets.  Dennis has been filling holes and shaping the roof to remove a few non-standard curves that it had developed and John has been painting and fitting the window guides.

In the shop.

Collin has made considerable progress on the large compressor despite having to be away a couple of weeks on business.  (Two weeks at ore loading facility in Northern Canada in mid-winter.  Temperatures heading to -40.  He does get the nicest assignments!).  One damaged valve was replaced and he has made significant progress on lapping the other valves.  The compressor now runs much more smoothly, sucks intake air with considerable force and pumps the reservoir up to the 150psi operating pressure pretty quickly.

From testing yesterday, the reservoir safety valve operates correctly.  We were also able to identify two leaking gaskets that will need to be replaced.  Once these are replaced, the compressor should be serviceable.  Two other key steps were agreed.  Everything on the compressor is now installed enabling Dennis to finish and install the guards over the drive belts and the method for unloading air pressure to allow the compressor to start when the reservoir is under pressure was agreed.  Parts for this will now be ored3er and fitted while we wait for the replacement gaskets.  Hopefully we should be able to get to readiness for the system to be inspected in about three weeks.

There was sudden major movement on another long standing project.  The control cabinet for the wheel lather arrived.  John and Bob started to install this.  They have now identified exactly what parts are required for the low voltage control circuits so this is coming together at last.

We have also had donated an excellent large band saw that will be most useful in the shop.

New band saw is unloaded

So a lot of progress but still quite a lot to do for the start of the season.  Watch this space.

Nigel

A very busy month in the steam shop that can best be described as “so far so good”.

In the last blog I outlined the plan for work on #1630 this Winter.  Thru January we have worked steadily on this plan.  The discovery in December that the valve chambers were worn to the extent that both need to be re-bored turned the program for this Winter from one that looked relatively simple in comparison the last year into one that will be a challenge to complete for May.

However, we have now completed re-boring the first valve chamber (engineer’s side), which is a huge step.  In this entry, I will describe what has been involved in getting this far.  What we have found so far does suggest that, once this work is completed she will be substantially more capable than at any time since she arrived from Eagle Pitcher.

The detailed measurements of the two valve cylinders revealed a great deal of wear.  The valve moves over a relatively limited proportion of the overall cylinder length (over and either side of the port openings.  This means that the wear is very uneven over the length of the bore.  In our case the worst area of wear (on the fireman’s side) was approaching 1/8^th inch larger in diameter than the unworn areas of the same bore.  This is well beyond tolerances that would have been acceptable during overhaul in steam days.

Wear on the FS cylinder liners

Each valve is a quite complicated assembly.  This shows one complete valve just detached from its rod.

A complete valve assembly

The seal between the valve and the cylinder at each end is made by two pairs of spring loaded rings.  Each ring is made up of 4 equal segments.  Between each pair of rings is a solid iron bull ring.  It is the bull ring that forms the bearing between the valve and the liners of the valve chamber.  When new the clearance between the raised section of the bull ring and the liner should be 1/32 inch.  Not visible when the valve is assembled is the fact that the bull ring has extensions on either side of the visible bearing surface and about ½ inch below it.  These form the base of the channels in which the spring rings fit.

At each end of the valve is a cast “spider” which has a central hole thru which fits the valve rod.  The spider has a machined cylindrical body the end of which fits into the fabricated valve body.  The spring and bull rings are fitted around the cylindrical body of the spider.  When the components are fitted to the valve rod and the not tightened the bull rings set the spacing between the spider and the valve body and so set the critical width of the slots in which ride the spring rings.  This is a very significant dimension as the spring rings must be free to move to maintain the seal but, as they are prevented from coming out of the valve only by small lips, excessive play can lead to a ring segment coming free and damaging the cylinder.  The machining of new bull rings will be a careful and accurate exercise!.

The whole valve is assembled on the valve rod.  The back of the valve assembly sits against a ring firmly attached to the rod.  When the rods are separated from the valve, the retaining ring can be clearly seen

Both valve rods

When assembled as below the ring is hard against the spider at the back of the valve.

Valve retaining ring

The various parts of the valve are fitted moving from back to front and then the other end of the assembly is clamped into place by a nut threaded onto the front of the valve rod so holding the parts together as a single assembly.  Here you can see the large castellated nut and cotter that clamps the assembly from the front.

Valve clamping nut

Once the clamping nut is removed the front spider can be carefully driven away from the valve body.  The amount of force needed varies depending upon the extent to which carbon has built up around the parts.  Comparing this view to the previous one, the spider has moved far enough away from the valve body to open up the slot which traps the rear pair of spring rings sufficiently to allow the spring and rings to be removed.  At this point the front pair of rings are still trapped in their slot between the bull ring and the spider.

Spider partly removed

Considerably later, the bull ring has been pulled off the spider releasing the front pair of rings and the old bull ring is now shown on top of the cast iron that is being prepared for machining to make the replacement.

Bull ring and replacement

With all rings removed the spider sits on its own and is in process of thorough cleaning to remove all carbon and allow the new bull ring and spring rings to be assembled onto it.

Spider being cleaned

Similar cleaning is required on the valve body, here seen with both spiders removed.

Valve body completely stripped

Both valves have now been stripped to their components and cleaning of the valve bodies and spiders is well under way.  We have new spring rings of various sizes that were obtained with the locomotive in the 1970’s.  These were made in 1/16^th inch increments between the nominal bore size (12 inch) and the maximum allowable re-bored size (12 3/8 inch).  We do not have a complete range so the actual size to which we bore the cylinders will be determined by both what is required to remove the wear and reach a smooth, true bore and the rings we have available.  The likely size is 12 3/16 as this is both slightly above the worst measured areas of wear and a size for which we have adequate new rings.

So far the ES valve liners have been bored.  First the substantial mounts, that hold the bearing ion which the boring bar rotates, must be firmly bolted to to each end of the casting.

Mount for the boring bar

Once the mounts are in place, the boring bar itself must be carefully slide into the mounts.  This is a fun exercise!.  The bar must be very rigid as the objective is to hold the cutters so that they maintain accuracy of cut to within thousands of an inch along it whole length.  This requires a bar of about 3 inch diameter.  It took 6 guys to move it along the shop.  So gently positioning and sliding it into position is no small task!.  Just to make it more fun, the cutter head must be placed over the bar as it is fitted thru the rear bearing and before the bar can be pushed along the length of the cylinder.

Loading the boring bar

Success.  Here the end of the bar projects thru the bearing at the other end of the cylinder.

Boring bar in place

The boring itself is very difficult to capture.  The gears that allow the cutter to be manually advanced and retracted, then locked to the screw mechanism to make the cut, have been attached to the shaft at the front.

An air motor then turns the shaft, with the cutter head attached, while the gears slowly turn a geared shaft running the length of the boring bar to which the cutter head is geared.  In this way the cutter head is advanced a fraction of an inch at each rotation.  Each cut takes about 30 minutes but it takes at least that long to accurately adjust the cutter head to required depth for the next cut

Boring in progress

Once the actual re-bored size is determined, we can start to machine the new bull rings.  These are required to be 1/32 under the bore size on their flat surface.

The bull rings and cylinder liners are made of cast iron, the wear properties of which were found most suitable for this application.  This makes the first stage of producing replacements unusual.  I suspect that, in steam days, blanks, from which the bull rings would be machined, were specially cast for the purpose and requiring limited machining to complete. Nowadays that is not economic on a small scale.  Suitable rings are not available so we must start from a disk.  The first step is therefore to produce the ring, of a suitable size for final machining, by cutting probably 75% of the total weight of the disk out of the center to produce a ring.  This is a long and tedious process on the lathe, taking several hours for each ring.  Brian has worked at this for several days and has now produced the 4 rings needed.  All this was accomplished amid a deal of comments from the rest of the team around him going into the mass production of iron filings!.

Producing a bull ring blank

In other areas

Works continued on producing the bracing that will allow us to rivet the smokebox of the Shay.

Good progress has been made on completing the cab of #428 to the extent that it is now being fitted with windows.

The large compressor for the new air system is now wired and was recently run in test mode.  This was the first time that this compressor has run under load since it was salvaged from the Milwaukee Road shops many years ago.  Testing allowed a number of adjustments to be made but also indicated the need to replace one valve and install an unloading mechanism.  This will take a couple of week but then we should be ready for inspection and commissioning.

Nigel

Brian also provided an update on a locomotive that is rarely heard of.

In fact, we hope that this is a lead in to the sort of thing we hope to do more of in future.  As space becomes available in the new barns in the South Yards, we hope to move smaller equipment stored partially stripped for restoration out of barn 9 so that larger pieces can be moved into this barn for conservation and cosmetic restoration.

Chicago, Burlington & Quincy 2-8-2 #4963

Hello all,

Everyone needs a day off once in a while.  My trips up to IRM to work on the shay could, I suppose, be considered "vacation time".  But even while on a work vacation I still need a break from working on the shay.  But instead of doing what any normal person would do and take a day off away from the shop, I relax and unwind by working on little projects on other locomotives.

Chicago, Burlington & Quincy 4963 has become one such "little" project I have worked on for a few hours on each of my trips to IRM in 2015.  The locomotive currently sits at the far south end of track 94 in barn 9.  While the three other locomotives on display at the far south end of the barn--Milwaukee Road 265, the Pennsylvania Railroad GG1 electric, and DT&I 16--look quite nice cosmetically as viewed from the end of the building, the 4963 looked incomplete and out of place.

As was – the poor relation

Looking at the locomotive every time I was in that part of barn 9, I decided there are a few things I could do to improve the appearance of the front end of the locomotive.

The smokebox was already years ago painted a light grey, and much of the piping, handrails, and such were in primer.  The first step then was to paint the smokebox.  The smokebox received a couple of coats of what is called Slip Plate paint.  This is basically graphite in suspension in other chemicals that, when dries, looks very close in appearance to the graphite and valve oil mixture we use on 1630's smokebox, but unlike that paint it does not require heat to dry it.  This Slip Plate paint is used in general industry as a lubricant, and is used by some steam locomotive operators as a smokebox paint.  Following a couple of coats of this paint, all of the above mentioned parts on the front of the locomotive that were in primer received a couple of coats of black paint.  This in itself created a remarkable transformation in the appearance of the locomotive!

Now the locomotive needed a headlight.  While we do not have 4963's original headlight, fortunately for the locomotive there was one readily available.  The past several years Phil has been putting a headlight on Chicago, Rock Island & Pacific 938 during the summer season.  This headlight, while very nice looking on the 938, is not the proper headlight for the locomotive.  We do have the headlight that 938 was retired with, and Phil has been working on restoring it to put back on the locomotive.  The headlight that has been on 938 recently is, in fact, a headlight from another Burlington 2-8-2 from a class older than 4963.  This headlight was brought out to barn nine and lifted onto the locomotive with the help of several Steam Department volunteers.  So while not her own original headlight, 4963 now has a true Burlington headlight!  The headlight was wired into the electrical power in the building, and now comes on when the lights in that part of the building are turned on.

The headlight looks great on 4963.  However, there were no number glass plates in the headlight.  Before my most-recent trip to IRM in October, I made two new number plates for the headlight.  These were made by hand cutting individual numbers from heavy paper to use as stencils, then painting painting around these in black on plate glass, then covering the same side of the glass in white paint.  This technique allows light from a bulb inside the headlight to shine through the numbers at night.  There were several different techniques used to make number plates like these, such as using a metal or cardboard stencil between two pieces of glass, but my research shows this particular process was one of the techniques used on the Burlington.  An additional piece of glass was placed in the brackets with each of these painted pieces to protect them, and special thanks needs to go to Tim Peters of the Electric Car Department for not only giving me the glass to use for this, but also for offering to cut it.  Thank you, Tim!

At this point I thought it sure would look great if 4963 had a number plate on the front of the smokebox again.  Luckily for us, Tom Schneider, curator of the Steam Department, was able to have a replica number plate cast years ago for the locomotive.  The plate needed to have mounting holes drilled and tapped for bolts to secure it to the smokebox, then several coats of primer and black paint were applied, followed up by several coats of yellow lettering paint.  Once dry, JD and I brought it out to the 4963 and bolted it on.

The new plate

Now 4963 really looks like something to be proud of!  I still need to add another coat or two of Slip Plate paint on the smokebox on the front and on the side the public sees, as well as several coats on the side of the locomotive facing the side wall of the barn.  Over time I would like to add proper classification lamp holders and flag holders to the front of the smokebox.  We have metal on hand that was cut long ago to make new class lamp holders.  Eventually I hope to get these welded together and machined and painted.  We have the correct lamps on hand.  New flag holders would have to be cast.  We have ones on another locomotive that are correct and can be used as patterns to have the new ones cast.

One nice feature on this locomotive's smokebox is a set of hinges that allow workers to open up the whole smokebox face and swing it to the side without having to remove it from the locomotive.  Half of each of the two hinge assemblies are still bolted to the side of the smokebox.  While looking around in the smokebox we found one of the two parts that bolts on to the front of the locomotive. We appear to be missing the other piece.  If any readers out there know where we could acquire the other hinge piece, please let us know.

Looking much better

How much farther will we go on the cosmetic work on this locomotive?  I don't know.  Right now it is just being worked on as I have a few spare hours a few times a year, and that is how it will be for the foreseeable future.  However, money also talks, and if you would like to see a little more cosmetic work done on the locomotive over time, a few more dollars in her restricted fund couldn't hurt!

Oh, and to answer the question which I know will be asked:  Right now there is no plan to return the locomotive to operation.  However, the locomotive has many good things going for it towards any future rebuild.  The tender tank is in very good shape, as is the cab.  The running gear is far from new and is missing a few parts, but is generally not in horrible shape upon initial inspection.  The firebox also doesn't show any obvious problems upon initial inspection.  However, there are many parts from in the cab missing, as well as the bell, whistle, auxiliary steam dome lid, and a list of other items.  That being said, there is nothing I have seen to preclude its restoration sometime years down the road.  And with her appearance improving, it is easier and easier to imagine what 4963 must have looked like in revenue service on the Burlington.